all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
blob 51c9100d2c2969c9e11959bcaa3b078d61b0ca75 359326 bytes (raw)
name: lisp/simple.el 	 # note: path name is non-authoritative(*)

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
7459
7460
7461
7462
7463
7464
7465
7466
7467
7468
7469
7470
7471
7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
7488
7489
7490
7491
7492
7493
7494
7495
7496
7497
7498
7499
7500
7501
7502
7503
7504
7505
7506
7507
7508
7509
7510
7511
7512
7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
7533
7534
7535
7536
7537
7538
7539
7540
7541
7542
7543
7544
7545
7546
7547
7548
7549
7550
7551
7552
7553
7554
7555
7556
7557
7558
7559
7560
7561
7562
7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
7577
7578
7579
7580
7581
7582
7583
7584
7585
7586
7587
7588
7589
7590
7591
7592
7593
7594
7595
7596
7597
7598
7599
7600
7601
7602
7603
7604
7605
7606
7607
7608
7609
7610
7611
7612
7613
7614
7615
7616
7617
7618
7619
7620
7621
7622
7623
7624
7625
7626
7627
7628
7629
7630
7631
7632
7633
7634
7635
7636
7637
7638
7639
7640
7641
7642
7643
7644
7645
7646
7647
7648
7649
7650
7651
7652
7653
7654
7655
7656
7657
7658
7659
7660
7661
7662
7663
7664
7665
7666
7667
7668
7669
7670
7671
7672
7673
7674
7675
7676
7677
7678
7679
7680
7681
7682
7683
7684
7685
7686
7687
7688
7689
7690
7691
7692
7693
7694
7695
7696
7697
7698
7699
7700
7701
7702
7703
7704
7705
7706
7707
7708
7709
7710
7711
7712
7713
7714
7715
7716
7717
7718
7719
7720
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
7736
7737
7738
7739
7740
7741
7742
7743
7744
7745
7746
7747
7748
7749
7750
7751
7752
7753
7754
7755
7756
7757
7758
7759
7760
7761
7762
7763
7764
7765
7766
7767
7768
7769
7770
7771
7772
7773
7774
7775
7776
7777
7778
7779
7780
7781
7782
7783
7784
7785
7786
7787
7788
7789
7790
7791
7792
7793
7794
7795
7796
7797
7798
7799
7800
7801
7802
7803
7804
7805
7806
7807
7808
7809
7810
7811
7812
7813
7814
7815
7816
7817
7818
7819
7820
7821
7822
7823
7824
7825
7826
7827
7828
7829
7830
7831
7832
7833
7834
7835
7836
7837
7838
7839
7840
7841
7842
7843
7844
7845
7846
7847
7848
7849
7850
7851
7852
7853
7854
7855
7856
7857
7858
7859
7860
7861
7862
7863
7864
7865
7866
7867
7868
7869
7870
7871
7872
7873
7874
7875
7876
7877
7878
7879
7880
7881
7882
7883
7884
7885
7886
7887
7888
7889
7890
7891
7892
7893
7894
7895
7896
7897
7898
7899
7900
7901
7902
7903
7904
7905
7906
7907
7908
7909
7910
7911
7912
7913
7914
7915
7916
7917
7918
7919
7920
7921
7922
7923
7924
7925
7926
7927
7928
7929
7930
7931
7932
7933
7934
7935
7936
7937
7938
7939
7940
7941
7942
7943
7944
7945
7946
7947
7948
7949
7950
7951
7952
7953
7954
7955
7956
7957
7958
7959
7960
7961
7962
7963
7964
7965
7966
7967
7968
7969
7970
7971
7972
7973
7974
7975
7976
7977
7978
7979
7980
7981
7982
7983
7984
7985
7986
7987
7988
7989
7990
7991
7992
7993
7994
7995
7996
7997
7998
7999
8000
8001
8002
8003
8004
8005
8006
8007
8008
8009
8010
8011
8012
8013
8014
8015
8016
8017
8018
8019
8020
8021
8022
8023
8024
8025
8026
8027
8028
8029
8030
8031
8032
8033
8034
8035
8036
8037
8038
8039
8040
8041
8042
8043
8044
8045
8046
8047
8048
8049
8050
8051
8052
8053
8054
8055
8056
8057
8058
8059
8060
8061
8062
8063
8064
8065
8066
8067
8068
8069
8070
8071
8072
8073
8074
8075
8076
8077
8078
8079
8080
8081
8082
8083
8084
8085
8086
8087
8088
8089
8090
8091
8092
8093
8094
8095
8096
8097
8098
8099
8100
8101
8102
8103
8104
8105
8106
8107
8108
8109
8110
8111
8112
8113
8114
8115
8116
8117
8118
8119
8120
8121
8122
8123
8124
8125
8126
8127
8128
8129
8130
8131
8132
8133
8134
8135
8136
8137
8138
8139
8140
8141
8142
8143
8144
8145
8146
8147
8148
8149
8150
8151
8152
8153
8154
8155
8156
8157
8158
8159
8160
8161
8162
8163
8164
8165
8166
8167
8168
8169
8170
8171
8172
8173
8174
8175
8176
8177
8178
8179
8180
8181
8182
8183
8184
8185
8186
8187
8188
8189
8190
8191
8192
8193
8194
8195
8196
8197
8198
8199
8200
8201
8202
8203
8204
8205
8206
8207
8208
8209
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
8236
8237
8238
8239
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
8261
8262
8263
8264
8265
8266
8267
8268
8269
8270
8271
8272
8273
8274
8275
8276
8277
8278
8279
8280
8281
8282
8283
8284
8285
8286
8287
8288
8289
8290
8291
8292
8293
8294
8295
8296
8297
8298
8299
8300
8301
8302
8303
8304
8305
8306
8307
8308
8309
8310
8311
8312
8313
8314
8315
8316
8317
8318
8319
8320
8321
8322
8323
8324
8325
8326
8327
8328
8329
8330
8331
8332
8333
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
8354
8355
8356
8357
8358
8359
8360
8361
8362
8363
8364
8365
8366
8367
8368
8369
8370
8371
8372
8373
8374
8375
8376
8377
8378
8379
8380
8381
8382
8383
8384
8385
8386
8387
8388
8389
8390
8391
8392
8393
8394
8395
8396
8397
8398
8399
8400
8401
8402
8403
8404
8405
8406
8407
8408
8409
8410
8411
8412
8413
8414
8415
8416
8417
8418
8419
8420
8421
8422
8423
8424
8425
8426
8427
8428
8429
8430
8431
8432
8433
8434
8435
8436
8437
8438
8439
8440
8441
8442
8443
8444
8445
8446
8447
8448
8449
8450
8451
8452
8453
8454
8455
8456
8457
8458
8459
8460
8461
8462
8463
8464
8465
8466
8467
8468
8469
8470
8471
8472
8473
8474
8475
8476
8477
8478
8479
8480
8481
8482
8483
8484
8485
8486
8487
8488
8489
8490
8491
8492
8493
8494
8495
8496
8497
8498
8499
8500
8501
8502
8503
8504
8505
8506
8507
8508
8509
8510
8511
8512
8513
8514
8515
8516
8517
8518
8519
8520
8521
8522
8523
8524
8525
8526
8527
8528
8529
8530
8531
8532
8533
8534
8535
8536
8537
8538
8539
8540
8541
8542
8543
8544
8545
8546
8547
8548
8549
8550
8551
8552
8553
8554
8555
8556
8557
8558
8559
8560
8561
8562
8563
8564
8565
8566
8567
8568
8569
8570
8571
8572
8573
8574
8575
8576
8577
8578
8579
8580
8581
8582
8583
8584
8585
8586
8587
8588
8589
8590
8591
8592
8593
8594
8595
8596
8597
8598
8599
8600
8601
8602
8603
8604
8605
8606
8607
8608
8609
8610
8611
8612
8613
8614
8615
8616
8617
8618
8619
8620
8621
8622
8623
8624
8625
8626
8627
8628
8629
8630
8631
8632
8633
8634
8635
8636
8637
8638
8639
8640
8641
8642
8643
8644
8645
8646
8647
8648
8649
8650
8651
8652
8653
8654
8655
8656
8657
8658
8659
8660
8661
8662
8663
8664
8665
8666
8667
8668
8669
8670
8671
8672
8673
8674
8675
8676
8677
8678
8679
8680
8681
8682
8683
8684
8685
8686
8687
8688
8689
8690
8691
8692
8693
8694
8695
8696
8697
8698
8699
8700
8701
8702
8703
8704
8705
8706
8707
8708
8709
8710
8711
8712
8713
8714
8715
8716
8717
8718
8719
8720
8721
8722
8723
8724
8725
8726
8727
8728
8729
8730
8731
8732
8733
8734
8735
8736
8737
8738
8739
8740
8741
8742
8743
8744
8745
8746
8747
8748
8749
8750
8751
8752
8753
8754
8755
8756
8757
8758
8759
8760
 
;;; simple.el --- basic editing commands for Emacs  -*- lexical-binding: t -*-

;; Copyright (C) 1985-1987, 1993-2016 Free Software Foundation, Inc.

;; Maintainer: emacs-devel@gnu.org
;; Keywords: internal
;; Package: emacs

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; A grab-bag of basic Emacs commands not specifically related to some
;; major mode or to file-handling.

;;; Code:

(eval-when-compile (require 'cl-lib))

(declare-function widget-convert "wid-edit" (type &rest args))
(declare-function shell-mode "shell" ())

;;; From compile.el
(defvar compilation-current-error)
(defvar compilation-context-lines)

(defcustom idle-update-delay 0.5
  "Idle time delay before updating various things on the screen.
Various Emacs features that update auxiliary information when point moves
wait this many seconds after Emacs becomes idle before doing an update."
  :type 'number
  :group 'display
  :version "22.1")

(defgroup killing nil
  "Killing and yanking commands."
  :group 'editing)

(defgroup paren-matching nil
  "Highlight (un)matching of parens and expressions."
  :group 'matching)
\f
;;; next-error support framework

(defgroup next-error nil
  "`next-error' support framework."
  :group 'compilation
  :version "22.1")

(defface next-error
  '((t (:inherit region)))
  "Face used to highlight next error locus."
  :group 'next-error
  :version "22.1")

(defcustom next-error-highlight 0.5
  "Highlighting of locations in selected source buffers.
If a number, highlight the locus in `next-error' face for the given time
in seconds, or until the next command is executed.
If t, highlight the locus until the next command is executed, or until
some other locus replaces it.
If nil, don't highlight the locus in the source buffer.
If `fringe-arrow', indicate the locus by the fringe arrow
indefinitely until some other locus replaces it."
  :type '(choice (number :tag "Highlight for specified time")
                 (const :tag "Semipermanent highlighting" t)
                 (const :tag "No highlighting" nil)
                 (const :tag "Fringe arrow" fringe-arrow))
  :group 'next-error
  :version "22.1")

(defcustom next-error-highlight-no-select 0.5
  "Highlighting of locations in `next-error-no-select'.
If number, highlight the locus in `next-error' face for given time in seconds.
If t, highlight the locus indefinitely until some other locus replaces it.
If nil, don't highlight the locus in the source buffer.
If `fringe-arrow', indicate the locus by the fringe arrow
indefinitely until some other locus replaces it."
  :type '(choice (number :tag "Highlight for specified time")
                 (const :tag "Semipermanent highlighting" t)
                 (const :tag "No highlighting" nil)
                 (const :tag "Fringe arrow" fringe-arrow))
  :group 'next-error
  :version "22.1")

(defcustom next-error-recenter nil
  "Display the line in the visited source file recentered as specified.
If non-nil, the value is passed directly to `recenter'."
  :type '(choice (integer :tag "Line to recenter to")
                 (const :tag "Center of window" (4))
                 (const :tag "No recentering" nil))
  :group 'next-error
  :version "23.1")

(defcustom next-error-hook nil
  "List of hook functions run by `next-error' after visiting source file."
  :type 'hook
  :group 'next-error)

(defvar next-error-highlight-timer nil)

(defvar next-error-overlay-arrow-position nil)
(put 'next-error-overlay-arrow-position 'overlay-arrow-string (purecopy "=>"))
(add-to-list 'overlay-arrow-variable-list 'next-error-overlay-arrow-position)

(defvar next-error-last-buffer nil
  "The most recent `next-error' buffer.
A buffer becomes most recent when its compilation, grep, or
similar mode is started, or when it is used with \\[next-error]
or \\[compile-goto-error].")

(defvar next-error-function nil
  "Function to use to find the next error in the current buffer.
The function is called with 2 parameters:
ARG is an integer specifying by how many errors to move.
RESET is a boolean which, if non-nil, says to go back to the beginning
of the errors before moving.
Major modes providing compile-like functionality should set this variable
to indicate to `next-error' that this is a candidate buffer and how
to navigate in it.")
(make-variable-buffer-local 'next-error-function)

(defvar next-error-move-function nil
  "Function to use to move to an error locus.
It takes two arguments, a buffer position in the error buffer
and a buffer position in the error locus buffer.
The buffer for the error locus should already be current.
nil means use goto-char using the second argument position.")
(make-variable-buffer-local 'next-error-move-function)

(defsubst next-error-buffer-p (buffer
			       &optional avoid-current
			       extra-test-inclusive
			       extra-test-exclusive)
  "Return non-nil if BUFFER is a `next-error' capable buffer.
If AVOID-CURRENT is non-nil, and BUFFER is the current buffer,
return nil.

The function EXTRA-TEST-INCLUSIVE, if non-nil, is called if
BUFFER would not normally qualify.  If it returns non-nil, BUFFER
is considered `next-error' capable, anyway, and the function
returns non-nil.

The function EXTRA-TEST-EXCLUSIVE, if non-nil, is called if the
buffer would normally qualify.  If it returns nil, BUFFER is
rejected, and the function returns nil."
  (and (buffer-name buffer)		;First make sure it's live.
       (not (and avoid-current (eq buffer (current-buffer))))
       (with-current-buffer buffer
	 (if next-error-function   ; This is the normal test.
	     ;; Optionally reject some buffers.
	     (if extra-test-exclusive
		 (funcall extra-test-exclusive)
	       t)
	   ;; Optionally accept some other buffers.
	   (and extra-test-inclusive
		(funcall extra-test-inclusive))))))

(defun next-error-find-buffer (&optional avoid-current
					 extra-test-inclusive
					 extra-test-exclusive)
  "Return a `next-error' capable buffer.

If AVOID-CURRENT is non-nil, treat the current buffer
as an absolute last resort only.

The function EXTRA-TEST-INCLUSIVE, if non-nil, is called in each buffer
that normally would not qualify.  If it returns t, the buffer
in question is treated as usable.

The function EXTRA-TEST-EXCLUSIVE, if non-nil, is called in each buffer
that would normally be considered usable.  If it returns nil,
that buffer is rejected."
  (or
   ;; 1. If one window on the selected frame displays such buffer, return it.
   (let ((window-buffers
          (delete-dups
           (delq nil (mapcar (lambda (w)
                               (if (next-error-buffer-p
				    (window-buffer w)
                                    avoid-current
                                    extra-test-inclusive extra-test-exclusive)
                                   (window-buffer w)))
                             (window-list))))))
     (if (eq (length window-buffers) 1)
         (car window-buffers)))
   ;; 2. If next-error-last-buffer is an acceptable buffer, use that.
   (if (and next-error-last-buffer
            (next-error-buffer-p next-error-last-buffer avoid-current
                                 extra-test-inclusive extra-test-exclusive))
       next-error-last-buffer)
   ;; 3. If the current buffer is acceptable, choose it.
   (if (next-error-buffer-p (current-buffer) avoid-current
			    extra-test-inclusive extra-test-exclusive)
       (current-buffer))
   ;; 4. Look for any acceptable buffer.
   (let ((buffers (buffer-list)))
     (while (and buffers
                 (not (next-error-buffer-p
		       (car buffers) avoid-current
		       extra-test-inclusive extra-test-exclusive)))
       (setq buffers (cdr buffers)))
     (car buffers))
   ;; 5. Use the current buffer as a last resort if it qualifies,
   ;; even despite AVOID-CURRENT.
   (and avoid-current
	(next-error-buffer-p (current-buffer) nil
			     extra-test-inclusive extra-test-exclusive)
	(progn
	  (message "This is the only buffer with error message locations")
	  (current-buffer)))
   ;; 6. Give up.
   (error "No buffers contain error message locations")))

(defun next-error (&optional arg reset)
  "Visit next `next-error' message and corresponding source code.

If all the error messages parsed so far have been processed already,
the message buffer is checked for new ones.

A prefix ARG specifies how many error messages to move;
negative means move back to previous error messages.
Just \\[universal-argument] as a prefix means reparse the error message buffer
and start at the first error.

The RESET argument specifies that we should restart from the beginning.

\\[next-error] normally uses the most recently started
compilation, grep, or occur buffer.  It can also operate on any
buffer with output from the \\[compile], \\[grep] commands, or,
more generally, on any buffer in Compilation mode or with
Compilation Minor mode enabled, or any buffer in which
`next-error-function' is bound to an appropriate function.
To specify use of a particular buffer for error messages, type
\\[next-error] in that buffer when it is the only one displayed
in the current frame.

Once \\[next-error] has chosen the buffer for error messages, it
runs `next-error-hook' with `run-hooks', and stays with that buffer
until you use it in some other buffer which uses Compilation mode
or Compilation Minor mode.

To control which errors are matched, customize the variable
`compilation-error-regexp-alist'."
  (interactive "P")
  (if (consp arg) (setq reset t arg nil))
  (when (setq next-error-last-buffer (next-error-find-buffer))
    ;; we know here that next-error-function is a valid symbol we can funcall
    (with-current-buffer next-error-last-buffer
      (funcall next-error-function (prefix-numeric-value arg) reset)
      (when next-error-recenter
        (recenter next-error-recenter))
      (run-hooks 'next-error-hook))))

(defun next-error-internal ()
  "Visit the source code corresponding to the `next-error' message at point."
  (setq next-error-last-buffer (current-buffer))
  ;; we know here that next-error-function is a valid symbol we can funcall
  (with-current-buffer next-error-last-buffer
    (funcall next-error-function 0 nil)
    (when next-error-recenter
      (recenter next-error-recenter))
    (run-hooks 'next-error-hook)))

(defalias 'goto-next-locus 'next-error)
(defalias 'next-match 'next-error)

(defun previous-error (&optional n)
  "Visit previous `next-error' message and corresponding source code.

Prefix arg N says how many error messages to move backwards (or
forwards, if negative).

This operates on the output from the \\[compile] and \\[grep] commands."
  (interactive "p")
  (next-error (- (or n 1))))

(defun first-error (&optional n)
  "Restart at the first error.
Visit corresponding source code.
With prefix arg N, visit the source code of the Nth error.
This operates on the output from the \\[compile] command, for instance."
  (interactive "p")
  (next-error n t))

(defun next-error-no-select (&optional n)
  "Move point to the next error in the `next-error' buffer and highlight match.
Prefix arg N says how many error messages to move forwards (or
backwards, if negative).
Finds and highlights the source line like \\[next-error], but does not
select the source buffer."
  (interactive "p")
  (let ((next-error-highlight next-error-highlight-no-select))
    (next-error n))
  (pop-to-buffer next-error-last-buffer))

(defun previous-error-no-select (&optional n)
  "Move point to the previous error in the `next-error' buffer and highlight match.
Prefix arg N says how many error messages to move backwards (or
forwards, if negative).
Finds and highlights the source line like \\[previous-error], but does not
select the source buffer."
  (interactive "p")
  (next-error-no-select (- (or n 1))))

;; Internal variable for `next-error-follow-mode-post-command-hook'.
(defvar next-error-follow-last-line nil)

(define-minor-mode next-error-follow-minor-mode
  "Minor mode for compilation, occur and diff modes.
With a prefix argument ARG, enable mode if ARG is positive, and
disable it otherwise.  If called from Lisp, enable mode if ARG is
omitted or nil.
When turned on, cursor motion in the compilation, grep, occur or diff
buffer causes automatic display of the corresponding source code location."
  :group 'next-error :init-value nil :lighter " Fol"
  (if (not next-error-follow-minor-mode)
      (remove-hook 'post-command-hook 'next-error-follow-mode-post-command-hook t)
    (add-hook 'post-command-hook 'next-error-follow-mode-post-command-hook nil t)
    (make-local-variable 'next-error-follow-last-line)))

;; Used as a `post-command-hook' by `next-error-follow-mode'
;; for the *Compilation* *grep* and *Occur* buffers.
(defun next-error-follow-mode-post-command-hook ()
  (unless (equal next-error-follow-last-line (line-number-at-pos))
    (setq next-error-follow-last-line (line-number-at-pos))
    (condition-case nil
	(let ((compilation-context-lines nil))
	  (setq compilation-current-error (point))
	  (next-error-no-select 0))
      (error t))))

\f
;;;

(defun fundamental-mode ()
  "Major mode not specialized for anything in particular.
Other major modes are defined by comparison with this one."
  (interactive)
  (kill-all-local-variables)
  (run-mode-hooks))

;; Special major modes to view specially formatted data rather than files.

(defvar special-mode-map
  (let ((map (make-sparse-keymap)))
    (suppress-keymap map)
    (define-key map "q" 'quit-window)
    (define-key map " " 'scroll-up-command)
    (define-key map [?\S-\ ] 'scroll-down-command)
    (define-key map "\C-?" 'scroll-down-command)
    (define-key map "?" 'describe-mode)
    (define-key map "h" 'describe-mode)
    (define-key map ">" 'end-of-buffer)
    (define-key map "<" 'beginning-of-buffer)
    (define-key map "g" 'revert-buffer)
    map))

(put 'special-mode 'mode-class 'special)
(define-derived-mode special-mode nil "Special"
  "Parent major mode from which special major modes should inherit."
  (setq buffer-read-only t))

;; Making and deleting lines.

(defvar self-insert-uses-region-functions nil
  "Special hook to tell if `self-insert-command' will use the region.
It must be called via `run-hook-with-args-until-success' with no arguments.
Any `post-self-insert-command' which consumes the region should
register a function on this hook so that things like `delete-selection-mode'
can refrain from consuming the region.")

(defvar hard-newline (propertize "\n" 'hard t 'rear-nonsticky '(hard))
  "Propertized string representing a hard newline character.")

(defun newline (&optional arg interactive)
  "Insert a newline, and move to left margin of the new line if it's blank.
If option `use-hard-newlines' is non-nil, the newline is marked with the
text-property `hard'.
With ARG, insert that many newlines.

If `electric-indent-mode' is enabled, this indents the final new line
that it adds, and reindents the preceding line.  To just insert
a newline, use \\[electric-indent-just-newline].

Calls `auto-fill-function' if the current column number is greater
than the value of `fill-column' and ARG is nil.
A non-nil INTERACTIVE argument means to run the `post-self-insert-hook'."
  (interactive "*P\np")
  (barf-if-buffer-read-only)
  ;; Call self-insert so that auto-fill, abbrev expansion etc. happens.
  ;; Set last-command-event to tell self-insert what to insert.
  (let* ((was-page-start (and (bolp) (looking-at page-delimiter)))
         (beforepos (point))
         (last-command-event ?\n)
         ;; Don't auto-fill if we have a numeric argument.
         (auto-fill-function (if arg nil auto-fill-function))
         (arg (prefix-numeric-value arg))
         (postproc
          ;; Do the rest in post-self-insert-hook, because we want to do it
          ;; *before* other functions on that hook.
          (lambda ()
            ;; We are not going to insert any newlines if arg is
            ;; non-positive.
            (or (and (numberp arg) (<= arg 0))
                (cl-assert (eq ?\n (char-before))))
            ;; Mark the newline(s) `hard'.
            (if use-hard-newlines
                (set-hard-newline-properties
                 (- (point) arg) (point)))
            ;; If the newline leaves the previous line blank, and we
            ;; have a left margin, delete that from the blank line.
            (save-excursion
              (goto-char beforepos)
              (beginning-of-line)
              (and (looking-at "[ \t]$")
                   (> (current-left-margin) 0)
                   (delete-region (point)
                                  (line-end-position))))
            ;; Indent the line after the newline, except in one case:
            ;; when we added the newline at the beginning of a line which
            ;; starts a page.
            (or was-page-start
                (move-to-left-margin nil t)))))
    (unwind-protect
        (if (not interactive)
            ;; FIXME: For non-interactive uses, many calls actually
            ;; just want (insert "\n"), so maybe we should do just
            ;; that, so as to avoid the risk of filling or running
            ;; abbrevs unexpectedly.
            (let ((post-self-insert-hook (list postproc)))
              (self-insert-command arg))
          (unwind-protect
              (progn
                (add-hook 'post-self-insert-hook postproc nil t)
                (self-insert-command arg))
            ;; We first used let-binding to protect the hook, but that
            ;; was naive since add-hook affects the symbol-default
            ;; value of the variable, whereas the let-binding might
            ;; only protect the buffer-local value.
            (remove-hook 'post-self-insert-hook postproc t)))
      (cl-assert (not (member postproc post-self-insert-hook)))
      (cl-assert (not (member postproc (default-value 'post-self-insert-hook))))))
  nil)

(defun set-hard-newline-properties (from to)
  (let ((sticky (get-text-property from 'rear-nonsticky)))
    (put-text-property from to 'hard 't)
    ;; If rear-nonsticky is not "t", add 'hard to rear-nonsticky list
    (if (and (listp sticky) (not (memq 'hard sticky)))
	(put-text-property from (point) 'rear-nonsticky
			   (cons 'hard sticky)))))

(defun open-line (n)
  "Insert a newline and leave point before it.
If there is a fill prefix and/or a `left-margin', insert them on
the new line if the line would have been blank.
With arg N, insert N newlines."
  (interactive "*p")
  (let* ((do-fill-prefix (and fill-prefix (bolp)))
	 (do-left-margin (and (bolp) (> (current-left-margin) 0)))
	 (loc (point-marker))
         ;; Don't expand an abbrev before point.
	 (abbrev-mode nil))
    (newline n)
    (goto-char loc)
    (while (> n 0)
      (cond ((bolp)
	     (if do-left-margin (indent-to (current-left-margin)))
	     (if do-fill-prefix (insert-and-inherit fill-prefix))))
      (forward-line 1)
      (setq n (1- n)))
    (goto-char loc)
    ;; Necessary in case a margin or prefix was inserted.
    (end-of-line)))

(defun split-line (&optional arg)
  "Split current line, moving portion beyond point vertically down.
If the current line starts with `fill-prefix', insert it on the new
line as well.  With prefix ARG, don't insert `fill-prefix' on new line.

When called from Lisp code, ARG may be a prefix string to copy."
  (interactive "*P")
  (skip-chars-forward " \t")
  (let* ((col (current-column))
	 (pos (point))
	 ;; What prefix should we check for (nil means don't).
	 (prefix (cond ((stringp arg) arg)
		       (arg nil)
		       (t fill-prefix)))
	 ;; Does this line start with it?
	 (have-prfx (and prefix
			 (save-excursion
			   (beginning-of-line)
			   (looking-at (regexp-quote prefix))))))
    (newline 1)
    (if have-prfx (insert-and-inherit prefix))
    (indent-to col 0)
    (goto-char pos)))

(defun delete-indentation (&optional arg)
  "Join this line to previous and fix up whitespace at join.
If there is a fill prefix, delete it from the beginning of this line.
With argument, join this line to following line."
  (interactive "*P")
  (beginning-of-line)
  (if arg (forward-line 1))
  (if (eq (preceding-char) ?\n)
      (progn
	(delete-region (point) (1- (point)))
	;; If the second line started with the fill prefix,
	;; delete the prefix.
	(if (and fill-prefix
		 (<= (+ (point) (length fill-prefix)) (point-max))
		 (string= fill-prefix
			  (buffer-substring (point)
					    (+ (point) (length fill-prefix)))))
	    (delete-region (point) (+ (point) (length fill-prefix))))
	(fixup-whitespace))))

(defalias 'join-line #'delete-indentation) ; easier to find

(defun delete-blank-lines ()
  "On blank line, delete all surrounding blank lines, leaving just one.
On isolated blank line, delete that one.
On nonblank line, delete any immediately following blank lines."
  (interactive "*")
  (let (thisblank singleblank)
    (save-excursion
      (beginning-of-line)
      (setq thisblank (looking-at "[ \t]*$"))
      ;; Set singleblank if there is just one blank line here.
      (setq singleblank
	    (and thisblank
		 (not (looking-at "[ \t]*\n[ \t]*$"))
		 (or (bobp)
		     (progn (forward-line -1)
			    (not (looking-at "[ \t]*$")))))))
    ;; Delete preceding blank lines, and this one too if it's the only one.
    (if thisblank
	(progn
	  (beginning-of-line)
	  (if singleblank (forward-line 1))
	  (delete-region (point)
			 (if (re-search-backward "[^ \t\n]" nil t)
			     (progn (forward-line 1) (point))
			   (point-min)))))
    ;; Delete following blank lines, unless the current line is blank
    ;; and there are no following blank lines.
    (if (not (and thisblank singleblank))
	(save-excursion
	  (end-of-line)
	  (forward-line 1)
	  (delete-region (point)
			 (if (re-search-forward "[^ \t\n]" nil t)
			     (progn (beginning-of-line) (point))
			   (point-max)))))
    ;; Handle the special case where point is followed by newline and eob.
    ;; Delete the line, leaving point at eob.
    (if (looking-at "^[ \t]*\n\\'")
	(delete-region (point) (point-max)))))

(defcustom delete-trailing-lines t
  "If non-nil, \\[delete-trailing-whitespace] deletes trailing lines.
Trailing lines are deleted only if `delete-trailing-whitespace'
is called on the entire buffer (rather than an active region)."
  :type 'boolean
  :group 'editing
  :version "24.3")

(defun delete-trailing-whitespace (&optional start end)
  "Delete trailing whitespace between START and END.
If called interactively, START and END are the start/end of the
region if the mark is active, or of the buffer's accessible
portion if the mark is inactive.

This command deletes whitespace characters after the last
non-whitespace character in each line between START and END.  It
does not consider formfeed characters to be whitespace.

If this command acts on the entire buffer (i.e. if called
interactively with the mark inactive, or called from Lisp with
END nil), it also deletes all trailing lines at the end of the
buffer if the variable `delete-trailing-lines' is non-nil."
  (interactive (progn
                 (barf-if-buffer-read-only)
                 (if (use-region-p)
                     (list (region-beginning) (region-end))
                   (list nil nil))))
  (save-match-data
    (save-excursion
      (let ((end-marker (and end (copy-marker end))))
        (goto-char (or start (point-min)))
        (with-syntax-table (make-syntax-table (syntax-table))
          ;; Don't delete formfeeds, even if they are considered whitespace.
          (modify-syntax-entry ?\f "_")
          ;; Treating \n as non-whitespace makes things easier.
          (modify-syntax-entry ?\n "_")
          (while (re-search-forward "\\s-+$" end-marker t)
            (delete-region (match-beginning 0) (match-end 0))))
        (if end
            (set-marker end-marker nil)
          ;; Delete trailing empty lines.
          (and delete-trailing-lines
               ;; Really the end of buffer.
               (= (goto-char (point-max)) (1+ (buffer-size)))
               (<= (skip-chars-backward "\n") -2)
               (delete-region (1+ (point)) (point-max)))))))
  ;; Return nil for the benefit of `write-file-functions'.
  nil)

(defun newline-and-indent ()
  "Insert a newline, then indent according to major mode.
Indentation is done using the value of `indent-line-function'.
In programming language modes, this is the same as TAB.
In some text modes, where TAB inserts a tab, this command indents to the
column specified by the function `current-left-margin'."
  (interactive "*")
  (delete-horizontal-space t)
  (newline nil t)
  (indent-according-to-mode))

(defun reindent-then-newline-and-indent ()
  "Reindent current line, insert newline, then indent the new line.
Indentation of both lines is done according to the current major mode,
which means calling the current value of `indent-line-function'.
In programming language modes, this is the same as TAB.
In some text modes, where TAB inserts a tab, this indents to the
column specified by the function `current-left-margin'."
  (interactive "*")
  (let ((pos (point)))
    ;; Be careful to insert the newline before indenting the line.
    ;; Otherwise, the indentation might be wrong.
    (newline)
    (save-excursion
      (goto-char pos)
      ;; We are at EOL before the call to indent-according-to-mode, and
      ;; after it we usually are as well, but not always.  We tried to
      ;; address it with `save-excursion' but that uses a normal marker
      ;; whereas we need `move after insertion', so we do the save/restore
      ;; by hand.
      (setq pos (copy-marker pos t))
      (indent-according-to-mode)
      (goto-char pos)
      ;; Remove the trailing white-space after indentation because
      ;; indentation may introduce the whitespace.
      (delete-horizontal-space t))
    (indent-according-to-mode)))

(defcustom read-quoted-char-radix 8
  "Radix for \\[quoted-insert] and other uses of `read-quoted-char'.
Legitimate radix values are 8, 10 and 16."
 :type '(choice (const 8) (const 10) (const 16))
 :group 'editing-basics)

(defun read-quoted-char (&optional prompt)
  "Like `read-char', but do not allow quitting.
Also, if the first character read is an octal digit,
we read any number of octal digits and return the
specified character code.  Any nondigit terminates the sequence.
If the terminator is RET, it is discarded;
any other terminator is used itself as input.

The optional argument PROMPT specifies a string to use to prompt the user.
The variable `read-quoted-char-radix' controls which radix to use
for numeric input."
  (let ((message-log-max nil)
	(help-events (delq nil (mapcar (lambda (c) (unless (characterp c) c))
				       help-event-list)))
	done (first t) (code 0) translated)
    (while (not done)
      (let ((inhibit-quit first)
	    ;; Don't let C-h or other help chars get the help
	    ;; message--only help function keys.  See bug#16617.
	    (help-char nil)
	    (help-event-list help-events)
	    (help-form
	     "Type the special character you want to use,
or the octal character code.
RET terminates the character code and is discarded;
any other non-digit terminates the character code and is then used as input."))
	(setq translated (read-key (and prompt (format "%s-" prompt))))
	(if inhibit-quit (setq quit-flag nil)))
      (if (integerp translated)
	  (setq translated (char-resolve-modifiers translated)))
      (cond ((null translated))
	    ((not (integerp translated))
	     (setq unread-command-events
                   (nconc (listify-key-sequence (this-single-command-raw-keys))
                          unread-command-events)
		   done t))
	    ((/= (logand translated ?\M-\^@) 0)
	     ;; Turn a meta-character into a character with the 0200 bit set.
	     (setq code (logior (logand translated (lognot ?\M-\^@)) 128)
		   done t))
	    ((and (<= ?0 translated)
                  (< translated (+ ?0 (min 10 read-quoted-char-radix))))
	     (setq code (+ (* code read-quoted-char-radix) (- translated ?0)))
	     (and prompt (setq prompt (message "%s %c" prompt translated))))
	    ((and (<= ?a (downcase translated))
		  (< (downcase translated)
                     (+ ?a -10 (min 36 read-quoted-char-radix))))
	     (setq code (+ (* code read-quoted-char-radix)
			   (+ 10 (- (downcase translated) ?a))))
	     (and prompt (setq prompt (message "%s %c" prompt translated))))
	    ((and (not first) (eq translated ?\C-m))
	     (setq done t))
	    ((not first)
	     (setq unread-command-events
                   (nconc (listify-key-sequence (this-single-command-raw-keys))
                          unread-command-events)
		   done t))
	    (t (setq code translated
		     done t)))
      (setq first nil))
    code))

(defun quoted-insert (arg)
  "Read next input character and insert it.
This is useful for inserting control characters.
With argument, insert ARG copies of the character.

If the first character you type after this command is an octal digit,
you should type a sequence of octal digits which specify a character code.
Any nondigit terminates the sequence.  If the terminator is a RET,
it is discarded; any other terminator is used itself as input.
The variable `read-quoted-char-radix' specifies the radix for this feature;
set it to 10 or 16 to use decimal or hex instead of octal.

In overwrite mode, this function inserts the character anyway, and
does not handle octal digits specially.  This means that if you use
overwrite as your normal editing mode, you can use this function to
insert characters when necessary.

In binary overwrite mode, this function does overwrite, and octal
digits are interpreted as a character code.  This is intended to be
useful for editing binary files."
  (interactive "*p")
  (let* ((char
	  ;; Avoid "obsolete" warnings for translation-table-for-input.
	  (with-no-warnings
	    (let (translation-table-for-input input-method-function)
	      (if (or (not overwrite-mode)
		      (eq overwrite-mode 'overwrite-mode-binary))
		  (read-quoted-char)
		(read-char))))))
    ;; This used to assume character codes 0240 - 0377 stand for
    ;; characters in some single-byte character set, and converted them
    ;; to Emacs characters.  But in 23.1 this feature is deprecated
    ;; in favor of inserting the corresponding Unicode characters.
    ;; (if (and enable-multibyte-characters
    ;;          (>= char ?\240)
    ;;          (<= char ?\377))
    ;;     (setq char (unibyte-char-to-multibyte char)))
    (unless (characterp char)
      (user-error "%s is not a valid character"
		  (key-description (vector char))))
    (if (> arg 0)
	(if (eq overwrite-mode 'overwrite-mode-binary)
	    (delete-char arg)))
    (while (> arg 0)
      (insert-and-inherit char)
      (setq arg (1- arg)))))

(defun forward-to-indentation (&optional arg)
  "Move forward ARG lines and position at first nonblank character."
  (interactive "^p")
  (forward-line (or arg 1))
  (skip-chars-forward " \t"))

(defun backward-to-indentation (&optional arg)
  "Move backward ARG lines and position at first nonblank character."
  (interactive "^p")
  (forward-line (- (or arg 1)))
  (skip-chars-forward " \t"))

(defun back-to-indentation ()
  "Move point to the first non-whitespace character on this line."
  (interactive "^")
  (beginning-of-line 1)
  (skip-syntax-forward " " (line-end-position))
  ;; Move back over chars that have whitespace syntax but have the p flag.
  (backward-prefix-chars))

(defun fixup-whitespace ()
  "Fixup white space between objects around point.
Leave one space or none, according to the context."
  (interactive "*")
  (save-excursion
    (delete-horizontal-space)
    (if (or (looking-at "^\\|\\s)")
	    (save-excursion (forward-char -1)
			    (looking-at "$\\|\\s(\\|\\s'")))
	nil
      (insert ?\s))))

(defun delete-horizontal-space (&optional backward-only)
  "Delete all spaces and tabs around point.
If BACKWARD-ONLY is non-nil, only delete them before point."
  (interactive "*P")
  (let ((orig-pos (point)))
    (delete-region
     (if backward-only
	 orig-pos
       (progn
	 (skip-chars-forward " \t")
	 (constrain-to-field nil orig-pos t)))
     (progn
       (skip-chars-backward " \t")
       (constrain-to-field nil orig-pos)))))

(defun just-one-space (&optional n)
  "Delete all spaces and tabs around point, leaving one space (or N spaces).
If N is negative, delete newlines as well, leaving -N spaces.
See also `cycle-spacing'."
  (interactive "*p")
  (cycle-spacing n nil 'single-shot))

(defvar cycle-spacing--context nil
  "Store context used in consecutive calls to `cycle-spacing' command.
The first time `cycle-spacing' runs, it saves in this variable:
its N argument, the original point position, and the original spacing
around point.")

(defun cycle-spacing (&optional n preserve-nl-back mode)
  "Manipulate whitespace around point in a smart way.
In interactive use, this function behaves differently in successive
consecutive calls.

The first call in a sequence acts like `just-one-space'.
It deletes all spaces and tabs around point, leaving one space
\(or N spaces).  N is the prefix argument.  If N is negative,
it deletes newlines as well, leaving -N spaces.
\(If PRESERVE-NL-BACK is non-nil, it does not delete newlines before point.)

The second call in a sequence deletes all spaces.

The third call in a sequence restores the original whitespace (and point).

If MODE is `single-shot', it only performs the first step in the sequence.
If MODE is `fast' and the first step would not result in any change
\(i.e., there are exactly (abs N) spaces around point),
the function goes straight to the second step.

Repeatedly calling the function with different values of N starts a
new sequence each time."
  (interactive "*p")
  (let ((orig-pos	 (point))
	(skip-characters (if (and n (< n 0)) " \t\n\r" " \t"))
	(num		 (abs (or n 1))))
    (skip-chars-backward (if preserve-nl-back " \t" skip-characters))
    (constrain-to-field nil orig-pos)
    (cond
     ;; Command run for the first time, single-shot mode or different argument
     ((or (eq 'single-shot mode)
	  (not (equal last-command this-command))
	  (not cycle-spacing--context)
	  (not (eq (car cycle-spacing--context) n)))
      (let* ((start (point))
	     (num   (- num (skip-chars-forward " " (+ num (point)))))
	     (mid   (point))
	     (end   (progn
		      (skip-chars-forward skip-characters)
		      (constrain-to-field nil orig-pos t))))
	(setq cycle-spacing--context  ;; Save for later.
	      ;; Special handling for case where there was no space at all.
	      (unless (= start end)
                (cons n (cons orig-pos (buffer-substring start (point))))))
	;; If this run causes no change in buffer content, delete all spaces,
	;; otherwise delete all excess spaces.
	(delete-region (if (and (eq mode 'fast) (zerop num) (= mid end))
			   start mid) end)
        (insert (make-string num ?\s))))

     ;; Command run for the second time.
     ((not (equal orig-pos (point)))
      (delete-region (point) orig-pos))

     ;; Command run for the third time.
     (t
      (insert (cddr cycle-spacing--context))
      (goto-char (cadr cycle-spacing--context))
      (setq cycle-spacing--context nil)))))
\f
(defun beginning-of-buffer (&optional arg)
  "Move point to the beginning of the buffer.
With numeric arg N, put point N/10 of the way from the beginning.
If the buffer is narrowed, this command uses the beginning of the
accessible part of the buffer.

Push mark at previous position, unless either a \\[universal-argument] prefix
is supplied, or Transient Mark mode is enabled and the mark is active."
  (declare (interactive-only "use `(goto-char (point-min))' instead."))
  (interactive "^P")
  (or (consp arg)
      (region-active-p)
      (push-mark))
  (let ((size (- (point-max) (point-min))))
    (goto-char (if (and arg (not (consp arg)))
		   (+ (point-min)
		      (if (> size 10000)
			  ;; Avoid overflow for large buffer sizes!
			  (* (prefix-numeric-value arg)
			     (/ size 10))
			(/ (+ 10 (* size (prefix-numeric-value arg))) 10)))
		 (point-min))))
  (if (and arg (not (consp arg))) (forward-line 1)))

(defun end-of-buffer (&optional arg)
  "Move point to the end of the buffer.
With numeric arg N, put point N/10 of the way from the end.
If the buffer is narrowed, this command uses the end of the
accessible part of the buffer.

Push mark at previous position, unless either a \\[universal-argument] prefix
is supplied, or Transient Mark mode is enabled and the mark is active."
  (declare (interactive-only "use `(goto-char (point-max))' instead."))
  (interactive "^P")
  (or (consp arg) (region-active-p) (push-mark))
  (let ((size (- (point-max) (point-min))))
    (goto-char (if (and arg (not (consp arg)))
		   (- (point-max)
		      (if (> size 10000)
			  ;; Avoid overflow for large buffer sizes!
			  (* (prefix-numeric-value arg)
			     (/ size 10))
			(/ (* size (prefix-numeric-value arg)) 10)))
		 (point-max))))
  ;; If we went to a place in the middle of the buffer,
  ;; adjust it to the beginning of a line.
  (cond ((and arg (not (consp arg))) (forward-line 1))
	((and (eq (current-buffer) (window-buffer))
              (> (point) (window-end nil t)))
	 ;; If the end of the buffer is not already on the screen,
	 ;; then scroll specially to put it near, but not at, the bottom.
	 (overlay-recenter (point))
	 (recenter -3))))

(defcustom delete-active-region t
  "Whether single-char deletion commands delete an active region.
This has an effect only if Transient Mark mode is enabled, and
affects `delete-forward-char' and `delete-backward-char', though
not `delete-char'.

If the value is the symbol `kill', the active region is killed
instead of deleted."
  :type '(choice (const :tag "Delete active region" t)
                 (const :tag "Kill active region" kill)
                 (const :tag "Do ordinary deletion" nil))
  :group 'killing
  :version "24.1")

(defvar region-extract-function
  (lambda (delete)
    (when (region-beginning)
      (cond
       ((eq delete 'bounds)
        (list (cons (region-beginning) (region-end))))
       ((eq delete 'delete-only)
        (delete-region (region-beginning) (region-end)))
       (t
        (filter-buffer-substring (region-beginning) (region-end) delete)))))
  "Function to get the region's content.
Called with one argument DELETE.
If DELETE is `delete-only', then only delete the region and the return value
is undefined.  If DELETE is nil, just return the content as a string.
If DELETE is `bounds', then don't delete, but just return the
boundaries of the region as a list of (START . END) positions.
If anything else, delete the region and return its content as a string,
after filtering it with `filter-buffer-substring'.")

(defvar region-insert-function
  (lambda (lines)
    (let ((first t))
      (while lines
        (or first
            (insert ?\n))
        (insert-for-yank (car lines))
        (setq lines (cdr lines)
              first nil))))
  "Function to insert the region's content.
Called with one argument LINES.
Insert the region as a list of lines.")

(defun delete-backward-char (n &optional killflag)
  "Delete the previous N characters (following if N is negative).
If Transient Mark mode is enabled, the mark is active, and N is 1,
delete the text in the region and deactivate the mark instead.
To disable this, set option `delete-active-region' to nil.

Optional second arg KILLFLAG, if non-nil, means to kill (save in
kill ring) instead of delete.  Interactively, N is the prefix
arg, and KILLFLAG is set if N is explicitly specified.

When killing, the killed text is filtered by
`filter-buffer-substring' before it is saved in the kill ring, so
the actual saved text might be different from what was killed.

In Overwrite mode, single character backward deletion may replace
tabs with spaces so as to back over columns, unless point is at
the end of the line."
  (declare (interactive-only delete-char))
  (interactive "p\nP")
  (unless (integerp n)
    (signal 'wrong-type-argument (list 'integerp n)))
  (cond ((and (use-region-p)
	      delete-active-region
	      (= n 1))
	 ;; If a region is active, kill or delete it.
	 (if (eq delete-active-region 'kill)
	     (kill-region (region-beginning) (region-end) 'region)
           (funcall region-extract-function 'delete-only)))
	;; In Overwrite mode, maybe untabify while deleting
	((null (or (null overwrite-mode)
		   (<= n 0)
		   (memq (char-before) '(?\t ?\n))
		   (eobp)
		   (eq (char-after) ?\n)))
	 (let ((ocol (current-column)))
           (delete-char (- n) killflag)
	   (save-excursion
	     (insert-char ?\s (- ocol (current-column)) nil))))
	;; Otherwise, do simple deletion.
	(t (delete-char (- n) killflag))))

(defun delete-forward-char (n &optional killflag)
  "Delete the following N characters (previous if N is negative).
If Transient Mark mode is enabled, the mark is active, and N is 1,
delete the text in the region and deactivate the mark instead.
To disable this, set variable `delete-active-region' to nil.

Optional second arg KILLFLAG non-nil means to kill (save in kill
ring) instead of delete.  Interactively, N is the prefix arg, and
KILLFLAG is set if N was explicitly specified.

When killing, the killed text is filtered by
`filter-buffer-substring' before it is saved in the kill ring, so
the actual saved text might be different from what was killed."
  (declare (interactive-only delete-char))
  (interactive "p\nP")
  (unless (integerp n)
    (signal 'wrong-type-argument (list 'integerp n)))
  (cond ((and (use-region-p)
	      delete-active-region
	      (= n 1))
	 ;; If a region is active, kill or delete it.
	 (if (eq delete-active-region 'kill)
	     (kill-region (region-beginning) (region-end) 'region)
	   (funcall region-extract-function 'delete-only)))

	;; Otherwise, do simple deletion.
	(t (delete-char n killflag))))

(defun mark-whole-buffer ()
  "Put point at beginning and mark at end of buffer.
If narrowing is in effect, only uses the accessible part of the buffer.
You probably should not use this function in Lisp programs;
it is usually a mistake for a Lisp function to use any subroutine
that uses or sets the mark."
  (declare (interactive-only t))
  (interactive)
  (push-mark (point))
  (push-mark (point-max) nil t)
  ;; This is really `point-min' in most cases, but if we're in the
  ;; minibuffer, this is at the end of the prompt.
  (goto-char (minibuffer-prompt-end)))
\f

;; Counting lines, one way or another.

(defun goto-line (line &optional buffer)
  "Go to LINE, counting from line 1 at beginning of buffer.
If called interactively, a numeric prefix argument specifies
LINE; without a numeric prefix argument, read LINE from the
minibuffer.

If optional argument BUFFER is non-nil, switch to that buffer and
move to line LINE there.  If called interactively with \\[universal-argument]
as argument, BUFFER is the most recently selected other buffer.

Prior to moving point, this function sets the mark (without
activating it), unless Transient Mark mode is enabled and the
mark is already active.

This function is usually the wrong thing to use in a Lisp program.
What you probably want instead is something like:
  (goto-char (point-min))
  (forward-line (1- N))
If at all possible, an even better solution is to use char counts
rather than line counts."
  (declare (interactive-only forward-line))
  (interactive
   (if (and current-prefix-arg (not (consp current-prefix-arg)))
       (list (prefix-numeric-value current-prefix-arg))
     ;; Look for a default, a number in the buffer at point.
     (let* ((default
	      (save-excursion
		(skip-chars-backward "0-9")
		(if (looking-at "[0-9]")
		    (string-to-number
		     (buffer-substring-no-properties
		      (point)
		      (progn (skip-chars-forward "0-9")
			     (point)))))))
	    ;; Decide if we're switching buffers.
	    (buffer
	     (if (consp current-prefix-arg)
		 (other-buffer (current-buffer) t)))
	    (buffer-prompt
	     (if buffer
		 (concat " in " (buffer-name buffer))
	       "")))
       ;; Read the argument, offering that number (if any) as default.
       (list (read-number (format "Goto line%s: " buffer-prompt)
                          (list default (line-number-at-pos)))
	     buffer))))
  ;; Switch to the desired buffer, one way or another.
  (if buffer
      (let ((window (get-buffer-window buffer)))
	(if window (select-window window)
	  (switch-to-buffer-other-window buffer))))
  ;; Leave mark at previous position
  (or (region-active-p) (push-mark))
  ;; Move to the specified line number in that buffer.
  (save-restriction
    (widen)
    (goto-char (point-min))
    (if (eq selective-display t)
	(re-search-forward "[\n\C-m]" nil 'end (1- line))
      (forward-line (1- line)))))

(defun count-words-region (start end &optional arg)
  "Count the number of words in the region.
If called interactively, print a message reporting the number of
lines, words, and characters in the region (whether or not the
region is active); with prefix ARG, report for the entire buffer
rather than the region.

If called from Lisp, return the number of words between positions
START and END."
  (interactive (if current-prefix-arg
		   (list nil nil current-prefix-arg)
		 (list (region-beginning) (region-end) nil)))
  (cond ((not (called-interactively-p 'any))
	 (count-words start end))
	(arg
	 (count-words--buffer-message))
	(t
	 (count-words--message "Region" start end))))

(defun count-words (start end)
  "Count words between START and END.
If called interactively, START and END are normally the start and
end of the buffer; but if the region is active, START and END are
the start and end of the region.  Print a message reporting the
number of lines, words, and chars.

If called from Lisp, return the number of words between START and
END, without printing any message."
  (interactive (list nil nil))
  (cond ((not (called-interactively-p 'any))
	 (let ((words 0))
	   (save-excursion
	     (save-restriction
	       (narrow-to-region start end)
	       (goto-char (point-min))
	       (while (forward-word-strictly 1)
		 (setq words (1+ words)))))
	   words))
	((use-region-p)
	 (call-interactively 'count-words-region))
	(t
	 (count-words--buffer-message))))

(defun count-words--buffer-message ()
  (count-words--message
   (if (buffer-narrowed-p) "Narrowed part of buffer" "Buffer")
   (point-min) (point-max)))

(defun count-words--message (str start end)
  (let ((lines (count-lines start end))
	(words (count-words start end))
	(chars (- end start)))
    (message "%s has %d line%s, %d word%s, and %d character%s."
	     str
	     lines (if (= lines 1) "" "s")
	     words (if (= words 1) "" "s")
	     chars (if (= chars 1) "" "s"))))

(define-obsolete-function-alias 'count-lines-region 'count-words-region "24.1")

(defun what-line ()
  "Print the current buffer line number and narrowed line number of point."
  (interactive)
  (let ((start (point-min))
	(n (line-number-at-pos)))
    (if (= start 1)
	(message "Line %d" n)
      (save-excursion
	(save-restriction
	  (widen)
	  (message "line %d (narrowed line %d)"
		   (+ n (line-number-at-pos start) -1) n))))))

(defun count-lines (start end)
  "Return number of lines between START and END.
This is usually the number of newlines between them,
but can be one more if START is not equal to END
and the greater of them is not at the start of a line."
  (save-excursion
    (save-restriction
      (narrow-to-region start end)
      (goto-char (point-min))
      (if (eq selective-display t)
	  (save-match-data
	    (let ((done 0))
                     (while (re-search-forward "[\n\C-m]" nil t 40)
                       (setq done (+ 40 done)))
                     (while (re-search-forward "[\n\C-m]" nil t 1)
                       (setq done (+ 1 done)))
                     (goto-char (point-max))
                     (if (and (/= start end)
		       (not (bolp)))
		  (1+ done)
		done)))
	(- (buffer-size) (forward-line (buffer-size)))))))

(defun line-number-at-pos (&optional pos)
  "Return (narrowed) buffer line number at position POS.
If POS is nil, use current buffer location.
Counting starts at (point-min), so the value refers
to the contents of the accessible portion of the buffer."
  (let ((opoint (or pos (point))) start)
    (save-excursion
      (goto-char (point-min))
      (setq start (point))
      (goto-char opoint)
      (forward-line 0)
      (1+ (count-lines start (point))))))

(defun what-cursor-position (&optional detail)
  "Print info on cursor position (on screen and within buffer).
Also describe the character after point, and give its character code
in octal, decimal and hex.

For a non-ASCII multibyte character, also give its encoding in the
buffer's selected coding system if the coding system encodes the
character safely.  If the character is encoded into one byte, that
code is shown in hex.  If the character is encoded into more than one
byte, just \"...\" is shown.

In addition, with prefix argument, show details about that character
in *Help* buffer.  See also the command `describe-char'."
  (interactive "P")
  (let* ((char (following-char))
	 (bidi-fixer
	  ;; If the character is one of LRE, LRO, RLE, RLO, it will
	  ;; start a directional embedding, which could completely
	  ;; disrupt the rest of the line (e.g., RLO will display the
	  ;; rest of the line right-to-left).  So we put an invisible
	  ;; PDF character after these characters, to end the
	  ;; embedding, which eliminates any effects on the rest of
	  ;; the line.  For RLE and RLO we also append an invisible
	  ;; LRM, to avoid reordering the following numerical
	  ;; characters.  For LRI/RLI/FSI we append a PDI.
	  (cond ((memq char '(?\x202a ?\x202d))
		 (propertize (string ?\x202c) 'invisible t))
		((memq char '(?\x202b ?\x202e))
		 (propertize (string ?\x202c ?\x200e) 'invisible t))
		((memq char '(?\x2066 ?\x2067 ?\x2068))
		 (propertize (string ?\x2069) 'invisible t))
		;; Strong right-to-left characters cause reordering of
		;; the following numerical characters which show the
		;; codepoint, so append LRM to countermand that.
		((memq (get-char-code-property char 'bidi-class) '(R AL))
		 (propertize (string ?\x200e) 'invisible t))
		(t
		 "")))
	 (beg (point-min))
	 (end (point-max))
         (pos (point))
	 (total (buffer-size))
	 (percent (round (* 100.0 (1- pos)) (max 1 total)))
	 (hscroll (if (= (window-hscroll) 0)
		      ""
		    (format " Hscroll=%d" (window-hscroll))))
	 (col (current-column)))
    (if (= pos end)
	(if (or (/= beg 1) (/= end (1+ total)))
	    (message "point=%d of %d (%d%%) <%d-%d> column=%d%s"
		     pos total percent beg end col hscroll)
	  (message "point=%d of %d (EOB) column=%d%s"
		   pos total col hscroll))
      (let ((coding buffer-file-coding-system)
	    encoded encoding-msg display-prop under-display)
	(if (or (not coding)
		(eq (coding-system-type coding) t))
	    (setq coding (default-value 'buffer-file-coding-system)))
	(if (eq (char-charset char) 'eight-bit)
	    (setq encoding-msg
		  (format "(%d, #o%o, #x%x, raw-byte)" char char char))
	  ;; Check if the character is displayed with some `display'
	  ;; text property.  In that case, set under-display to the
	  ;; buffer substring covered by that property.
	  (setq display-prop (get-char-property pos 'display))
	  (if display-prop
	      (let ((to (or (next-single-char-property-change pos 'display)
			    (point-max))))
		(if (< to (+ pos 4))
		    (setq under-display "")
		  (setq under-display "..."
			to (+ pos 4)))
		(setq under-display
		      (concat (buffer-substring-no-properties pos to)
			      under-display)))
	    (setq encoded (and (>= char 128) (encode-coding-char char coding))))
	  (setq encoding-msg
		(if display-prop
		    (if (not (stringp display-prop))
			(format "(%d, #o%o, #x%x, part of display \"%s\")"
				char char char under-display)
		      (format "(%d, #o%o, #x%x, part of display \"%s\"->\"%s\")"
			      char char char under-display display-prop))
		  (if encoded
		      (format "(%d, #o%o, #x%x, file %s)"
			      char char char
			      (if (> (length encoded) 1)
				  "..."
				(encoded-string-description encoded coding)))
		    (format "(%d, #o%o, #x%x)" char char char)))))
	(if detail
	    ;; We show the detailed information about CHAR.
	    (describe-char (point)))
	(if (or (/= beg 1) (/= end (1+ total)))
	    (message "Char: %s%s %s point=%d of %d (%d%%) <%d-%d> column=%d%s"
		     (if (< char 256)
			 (single-key-description char)
		       (buffer-substring-no-properties (point) (1+ (point))))
		     bidi-fixer
		     encoding-msg pos total percent beg end col hscroll)
	  (message "Char: %s%s %s point=%d of %d (%d%%) column=%d%s"
		   (if enable-multibyte-characters
		       (if (< char 128)
			   (single-key-description char)
			 (buffer-substring-no-properties (point) (1+ (point))))
		     (single-key-description char))
		   bidi-fixer encoding-msg pos total percent col hscroll))))))
\f
;; Initialize read-expression-map.  It is defined at C level.
(defvar read-expression-map
  (let ((m (make-sparse-keymap)))
    (define-key m "\M-\t" 'completion-at-point)
    ;; Might as well bind TAB to completion, since inserting a TAB char is
    ;; much too rarely useful.
    (define-key m "\t" 'completion-at-point)
    (set-keymap-parent m minibuffer-local-map)
    m))

(defun read-minibuffer (prompt &optional initial-contents)
  "Return a Lisp object read using the minibuffer, unevaluated.
Prompt with PROMPT.  If non-nil, optional second arg INITIAL-CONTENTS
is a string to insert in the minibuffer before reading.
\(INITIAL-CONTENTS can also be a cons of a string and an integer.
Such arguments are used as in `read-from-minibuffer'.)"
  ;; Used for interactive spec `x'.
  (read-from-minibuffer prompt initial-contents minibuffer-local-map
                        t 'minibuffer-history))

(defun eval-minibuffer (prompt &optional initial-contents)
  "Return value of Lisp expression read using the minibuffer.
Prompt with PROMPT.  If non-nil, optional second arg INITIAL-CONTENTS
is a string to insert in the minibuffer before reading.
\(INITIAL-CONTENTS can also be a cons of a string and an integer.
Such arguments are used as in `read-from-minibuffer'.)"
  ;; Used for interactive spec `X'.
  (eval (read--expression prompt initial-contents)))

(defvar minibuffer-completing-symbol nil
  "Non-nil means completing a Lisp symbol in the minibuffer.")
(make-obsolete-variable 'minibuffer-completing-symbol nil "24.1" 'get)

(defvar minibuffer-default nil
  "The current default value or list of default values in the minibuffer.
The functions `read-from-minibuffer' and `completing-read' bind
this variable locally.")

(defcustom eval-expression-print-level 4
  "Value for `print-level' while printing value in `eval-expression'.
A value of nil means no limit."
  :group 'lisp
  :type '(choice (const :tag "No Limit" nil) integer)
  :version "21.1")

(defcustom eval-expression-print-length 12
  "Value for `print-length' while printing value in `eval-expression'.
A value of nil means no limit."
  :group 'lisp
  :type '(choice (const :tag "No Limit" nil) integer)
  :version "21.1")

(defcustom eval-expression-debug-on-error t
  "If non-nil set `debug-on-error' to t in `eval-expression'.
If nil, don't change the value of `debug-on-error'."
  :group 'lisp
  :type 'boolean
  :version "21.1")

(defun eval-expression-print-format (value)
  "If VALUE in an integer, return a specially formatted string.
This string will typically look like \" (#o1, #x1, ?\\C-a)\".
If VALUE is not an integer, nil is returned.
This function is used by functions like `prin1' that display the
result of expression evaluation."
  (if (and (integerp value)
	   (or (eq standard-output t)
	       (zerop (prefix-numeric-value current-prefix-arg))))
      (let ((char-string
	     (if (and (characterp value)
		      (char-displayable-p value))
		 (prin1-char value))))
        (if char-string
            (format " (#o%o, #x%x, %s)" value value char-string)
          (format " (#o%o, #x%x)" value value)))))

(defvar eval-expression-minibuffer-setup-hook nil
  "Hook run by `eval-expression' when entering the minibuffer.")

(defun read--expression (prompt &optional initial-contents)
  (let ((minibuffer-completing-symbol t))
    (minibuffer-with-setup-hook
        (lambda ()
          ;; FIXME: call emacs-lisp-mode?
          (add-function :before-until (local 'eldoc-documentation-function)
                        #'elisp-eldoc-documentation-function)
          (add-hook 'completion-at-point-functions
                    #'elisp-completion-at-point nil t)
          (run-hooks 'eval-expression-minibuffer-setup-hook))
      (read-from-minibuffer prompt initial-contents
                            read-expression-map t
                            'read-expression-history))))

;; We define this, rather than making `eval' interactive,
;; for the sake of completion of names like eval-region, eval-buffer.
(defun eval-expression (exp &optional insert-value)
  "Evaluate EXP and print value in the echo area.
When called interactively, read an Emacs Lisp expression and evaluate it.
Value is also consed on to front of the variable `values'.
Optional argument INSERT-VALUE non-nil (interactively, with prefix
argument) means insert the result into the current buffer instead of
printing it in the echo area.

Normally, this function truncates long output according to the value
of the variables `eval-expression-print-length' and
`eval-expression-print-level'.  With a prefix argument of zero,
however, there is no such truncation.  Such a prefix argument
also causes integers to be printed in several additional formats
\(octal, hexadecimal, and character).

Runs the hook `eval-expression-minibuffer-setup-hook' on entering the
minibuffer.

If `eval-expression-debug-on-error' is non-nil, which is the default,
this command arranges for all errors to enter the debugger."
  (interactive
   (list (read--expression "Eval: ")
	 current-prefix-arg))

  (if (null eval-expression-debug-on-error)
      (push (eval exp lexical-binding) values)
    (let ((old-value (make-symbol "t")) new-value)
      ;; Bind debug-on-error to something unique so that we can
      ;; detect when evalled code changes it.
      (let ((debug-on-error old-value))
	(push (eval (macroexpand-all exp) lexical-binding) values)
	(setq new-value debug-on-error))
      ;; If evalled code has changed the value of debug-on-error,
      ;; propagate that change to the global binding.
      (unless (eq old-value new-value)
	(setq debug-on-error new-value))))

  (let ((print-length (and (not (zerop (prefix-numeric-value insert-value)))
			   eval-expression-print-length))
	(print-level (and (not (zerop (prefix-numeric-value insert-value)))
			  eval-expression-print-level))
        (deactivate-mark))
    (if insert-value
	(with-no-warnings
	 (let ((standard-output (current-buffer)))
	   (prog1
	       (prin1 (car values))
	     (when (zerop (prefix-numeric-value insert-value))
	       (let ((str (eval-expression-print-format (car values))))
		 (if str (princ str)))))))
      (prog1
          (prin1 (car values) t)
        (let ((str (eval-expression-print-format (car values))))
          (if str (princ str t)))))))

(defun edit-and-eval-command (prompt command)
  "Prompting with PROMPT, let user edit COMMAND and eval result.
COMMAND is a Lisp expression.  Let user edit that expression in
the minibuffer, then read and evaluate the result."
  (let ((command
	 (let ((print-level nil)
	       (minibuffer-history-sexp-flag (1+ (minibuffer-depth))))
	   (unwind-protect
	       (read-from-minibuffer prompt
				     (prin1-to-string command)
				     read-expression-map t
				     'command-history)
	     ;; If command was added to command-history as a string,
	     ;; get rid of that.  We want only evaluable expressions there.
	     (if (stringp (car command-history))
		 (setq command-history (cdr command-history)))))))

    ;; If command to be redone does not match front of history,
    ;; add it to the history.
    (or (equal command (car command-history))
	(setq command-history (cons command command-history)))
    (eval command)))

(defun repeat-complex-command (arg)
  "Edit and re-evaluate last complex command, or ARGth from last.
A complex command is one which used the minibuffer.
The command is placed in the minibuffer as a Lisp form for editing.
The result is executed, repeating the command as changed.
If the command has been changed or is not the most recent previous
command it is added to the front of the command history.
You can use the minibuffer history commands \
\\<minibuffer-local-map>\\[next-history-element] and \\[previous-history-element]
to get different commands to edit and resubmit."
  (interactive "p")
  (let ((elt (nth (1- arg) command-history))
	newcmd)
    (if elt
	(progn
	  (setq newcmd
		(let ((print-level nil)
		      (minibuffer-history-position arg)
		      (minibuffer-history-sexp-flag (1+ (minibuffer-depth))))
		  (unwind-protect
		      (read-from-minibuffer
		       "Redo: " (prin1-to-string elt) read-expression-map t
		       (cons 'command-history arg))

		    ;; If command was added to command-history as a
		    ;; string, get rid of that.  We want only
		    ;; evaluable expressions there.
		    (if (stringp (car command-history))
			(setq command-history (cdr command-history))))))

	  ;; If command to be redone does not match front of history,
	  ;; add it to the history.
	  (or (equal newcmd (car command-history))
	      (setq command-history (cons newcmd command-history)))
          (apply #'funcall-interactively
		 (car newcmd)
		 (mapcar (lambda (e) (eval e t)) (cdr newcmd))))
      (if command-history
	  (error "Argument %d is beyond length of command history" arg)
	(error "There are no previous complex commands to repeat")))))


(defvar extended-command-history nil)
(defvar execute-extended-command--last-typed nil)

(defun read-extended-command ()
  "Read command name to invoke in `execute-extended-command'."
  (minibuffer-with-setup-hook
      (lambda ()
        (add-hook 'post-self-insert-hook
                  (lambda ()
                    (setq execute-extended-command--last-typed
                              (minibuffer-contents)))
                  nil 'local)
	(set (make-local-variable 'minibuffer-default-add-function)
	     (lambda ()
	       ;; Get a command name at point in the original buffer
	       ;; to propose it after M-n.
	       (with-current-buffer (window-buffer (minibuffer-selected-window))
		 (and (commandp (function-called-at-point))
		      (format "%S" (function-called-at-point)))))))
    ;; Read a string, completing from and restricting to the set of
    ;; all defined commands.  Don't provide any initial input.
    ;; Save the command read on the extended-command history list.
    (completing-read
     (concat (cond
	      ((eq current-prefix-arg '-) "- ")
	      ((and (consp current-prefix-arg)
		    (eq (car current-prefix-arg) 4)) "C-u ")
	      ((and (consp current-prefix-arg)
		    (integerp (car current-prefix-arg)))
	       (format "%d " (car current-prefix-arg)))
	      ((integerp current-prefix-arg)
	       (format "%d " current-prefix-arg)))
	     ;; This isn't strictly correct if `execute-extended-command'
	     ;; is bound to anything else (e.g. [menu]).
	     ;; It could use (key-description (this-single-command-keys)),
	     ;; but actually a prompt other than "M-x" would be confusing,
	     ;; because "M-x" is a well-known prompt to read a command
	     ;; and it serves as a shorthand for "Extended command: ".
	     "M-x ")
     (lambda (string pred action)
       (let ((pred
              (if (memq action '(nil t))
                  ;; Exclude obsolete commands from completions.
                  (lambda (sym)
                    (and (funcall pred sym)
                         (or (equal string (symbol-name sym))
                             (not (get sym 'byte-obsolete-info)))))
                pred)))
         (complete-with-action action obarray string pred)))
     #'commandp t nil 'extended-command-history)))

(defcustom suggest-key-bindings t
  "Non-nil means show the equivalent key-binding when M-x command has one.
The value can be a length of time to show the message for.
If the value is non-nil and not a number, we wait 2 seconds."
  :group 'keyboard
  :type '(choice (const :tag "off" nil)
                 (integer :tag "time" 2)
                 (other :tag "on")))

(defcustom extended-command-suggest-shorter t
  "If non-nil, show a shorter M-x invocation when there is one."
  :group 'keyboard
  :type 'boolean
  :version "25.2")

(defun execute-extended-command--shorter-1 (name length)
  (cond
   ((zerop length) (list ""))
   ((equal name "") nil)
   (t
    (nconc (mapcar (lambda (s) (concat (substring name 0 1) s))
                   (execute-extended-command--shorter-1
                    (substring name 1) (1- length)))
           (when (string-match "\\`\\(-\\)?[^-]*" name)
             (execute-extended-command--shorter-1
              (substring name (match-end 0)) length))))))

(defun execute-extended-command--shorter (name typed)
  (let ((candidates '())
        (max (length typed))
        (len 1)
        binding)
    (while (and (not binding)
                (progn
                  (unless candidates
                    (setq len (1+ len))
                    (setq candidates (execute-extended-command--shorter-1
                                      name len)))
                  ;; Don't show the help message if the binding isn't
                  ;; significantly shorter than the M-x command the user typed.
                  (< len (- max 5))))
      (let ((candidate (pop candidates)))
        (when (equal name
                       (car-safe (completion-try-completion
                                  candidate obarray 'commandp len)))
          (setq binding candidate))))
    binding))

(defun execute-extended-command (prefixarg &optional command-name typed)
  ;; Based on Fexecute_extended_command in keyboard.c of Emacs.
  ;; Aaron S. Hawley <aaron.s.hawley(at)gmail.com> 2009-08-24
  "Read a command name, then read the arguments and call the command.
To pass a prefix argument to the command you are
invoking, give a prefix argument to `execute-extended-command'."
  (declare (interactive-only command-execute))
  ;; FIXME: Remember the actual text typed by the user before completion,
  ;; so that we don't later on suggest the same shortening.
  (interactive
   (let ((execute-extended-command--last-typed nil))
     (list current-prefix-arg
           (read-extended-command)
           execute-extended-command--last-typed)))
  ;; Emacs<24 calling-convention was with a single `prefixarg' argument.
  (unless command-name
    (let ((current-prefix-arg prefixarg) ; for prompt
          (execute-extended-command--last-typed nil))
      (setq command-name (read-extended-command))
      (setq typed execute-extended-command--last-typed)))
  (let* ((function (and (stringp command-name) (intern-soft command-name)))
         (binding (and suggest-key-bindings
		       (not executing-kbd-macro)
		       (where-is-internal function overriding-local-map t))))
    (unless (commandp function)
      (error "`%s' is not a valid command name" command-name))
    (setq this-command function)
    ;; Normally `real-this-command' should never be changed, but here we really
    ;; want to pretend that M-x <cmd> RET is nothing more than a "key
    ;; binding" for <cmd>, so the command the user really wanted to run is
    ;; `function' and not `execute-extended-command'.  The difference is
    ;; visible in cases such as M-x <cmd> RET and then C-x z (bug#11506).
    (setq real-this-command function)
    (let ((prefix-arg prefixarg))
      (command-execute function 'record))
    ;; If enabled, show which key runs this command.
    ;; But first wait, and skip the message if there is input.
    (let* ((waited
            ;; If this command displayed something in the echo area;
            ;; wait a few seconds, then display our suggestion message.
            ;; FIXME: Wait *after* running post-command-hook!
            ;; FIXME: Don't wait if execute-extended-command--shorter won't
            ;; find a better answer anyway!
            (when suggest-key-bindings
              (sit-for (cond
                        ((zerop (length (current-message))) 0)
                        ((numberp suggest-key-bindings) suggest-key-bindings)
                        (t 2))))))
      (when (and waited (not (consp unread-command-events)))
        (unless (or (not extended-command-suggest-shorter)
                    binding executing-kbd-macro (not (symbolp function))
                    (<= (length (symbol-name function)) 2))
          ;; There's no binding for CMD.  Let's try and find the shortest
          ;; string to use in M-x.
          ;; FIXME: Can be slow.  Cache it maybe?
          (while-no-input
            (setq binding (execute-extended-command--shorter
                           (symbol-name function) typed))))
        (when binding
          (with-temp-message
              (format-message "You can run the command `%s' with %s"
                              function
                              (if (stringp binding)
                                  (concat "M-x " binding " RET")
                                (key-description binding)))
            (sit-for (if (numberp suggest-key-bindings)
                         suggest-key-bindings
                       2))))))))

(defun command-execute (cmd &optional record-flag keys special)
  ;; BEWARE: Called directly from the C code.
  "Execute CMD as an editor command.
CMD must be a symbol that satisfies the `commandp' predicate.
Optional second arg RECORD-FLAG non-nil
means unconditionally put this command in the variable `command-history'.
Otherwise, that is done only if an arg is read using the minibuffer.
The argument KEYS specifies the value to use instead of (this-command-keys)
when reading the arguments; if it is nil, (this-command-keys) is used.
The argument SPECIAL, if non-nil, means that this command is executing
a special event, so ignore the prefix argument and don't clear it."
  (setq debug-on-next-call nil)
  (let ((prefixarg (unless special
                     ;; FIXME: This should probably be done around
                     ;; pre-command-hook rather than here!
                     (prog1 prefix-arg
                       (setq current-prefix-arg prefix-arg)
                       (setq prefix-arg nil)
                       (when current-prefix-arg
                         (prefix-command-update))))))
    (if (and (symbolp cmd)
             (get cmd 'disabled)
             disabled-command-function)
        ;; FIXME: Weird calling convention!
        (run-hooks 'disabled-command-function)
      (let ((final cmd))
        (while
            (progn
              (setq final (indirect-function final))
              (if (autoloadp final)
                  (setq final (autoload-do-load final cmd)))))
        (cond
         ((arrayp final)
          ;; If requested, place the macro in the command history.  For
          ;; other sorts of commands, call-interactively takes care of this.
          (when record-flag
            (push `(execute-kbd-macro ,final ,prefixarg) command-history)
            ;; Don't keep command history around forever.
            (when (and (numberp history-length) (> history-length 0))
              (let ((cell (nthcdr history-length command-history)))
                (if (consp cell) (setcdr cell nil)))))
          (execute-kbd-macro final prefixarg))
         (t
          ;; Pass `cmd' rather than `final', for the backtrace's sake.
          (prog1 (call-interactively cmd record-flag keys)
            (when (and (symbolp cmd)
                       (get cmd 'byte-obsolete-info)
                       (not (get cmd 'command-execute-obsolete-warned)))
              (put cmd 'command-execute-obsolete-warned t)
              (message "%s" (macroexp--obsolete-warning
                             cmd (get cmd 'byte-obsolete-info) "command"))))))))))
\f
(defvar minibuffer-history nil
  "Default minibuffer history list.
This is used for all minibuffer input
except when an alternate history list is specified.

Maximum length of the history list is determined by the value
of `history-length', which see.")
(defvar minibuffer-history-sexp-flag nil
  "Control whether history list elements are expressions or strings.
If the value of this variable equals current minibuffer depth,
they are expressions; otherwise they are strings.
\(That convention is designed to do the right thing for
recursive uses of the minibuffer.)")
(setq minibuffer-history-variable 'minibuffer-history)
(setq minibuffer-history-position nil)  ;; Defvar is in C code.
(defvar minibuffer-history-search-history nil)

(defvar minibuffer-text-before-history nil
  "Text that was in this minibuffer before any history commands.
This is nil if there have not yet been any history commands
in this use of the minibuffer.")

(add-hook 'minibuffer-setup-hook 'minibuffer-history-initialize)

(defun minibuffer-history-initialize ()
  (setq minibuffer-text-before-history nil))

(defun minibuffer-avoid-prompt (_new _old)
  "A point-motion hook for the minibuffer, that moves point out of the prompt."
  (declare (obsolete cursor-intangible-mode "25.1"))
  (constrain-to-field nil (point-max)))

(defcustom minibuffer-history-case-insensitive-variables nil
  "Minibuffer history variables for which matching should ignore case.
If a history variable is a member of this list, then the
\\[previous-matching-history-element] and \\[next-matching-history-element]\
 commands ignore case when searching it, regardless of `case-fold-search'."
  :type '(repeat variable)
  :group 'minibuffer)

(defun previous-matching-history-element (regexp n)
  "Find the previous history element that matches REGEXP.
\(Previous history elements refer to earlier actions.)
With prefix argument N, search for Nth previous match.
If N is negative, find the next or Nth next match.
Normally, history elements are matched case-insensitively if
`case-fold-search' is non-nil, but an uppercase letter in REGEXP
makes the search case-sensitive.
See also `minibuffer-history-case-insensitive-variables'."
  (interactive
   (let* ((enable-recursive-minibuffers t)
	  (regexp (read-from-minibuffer "Previous element matching (regexp): "
					nil
					minibuffer-local-map
					nil
					'minibuffer-history-search-history
					(car minibuffer-history-search-history))))
     ;; Use the last regexp specified, by default, if input is empty.
     (list (if (string= regexp "")
	       (if minibuffer-history-search-history
		   (car minibuffer-history-search-history)
		 (user-error "No previous history search regexp"))
	     regexp)
	   (prefix-numeric-value current-prefix-arg))))
  (unless (zerop n)
    (if (and (zerop minibuffer-history-position)
	     (null minibuffer-text-before-history))
	(setq minibuffer-text-before-history
	      (minibuffer-contents-no-properties)))
    (let ((history (symbol-value minibuffer-history-variable))
	  (case-fold-search
	   (if (isearch-no-upper-case-p regexp t) ; assume isearch.el is dumped
	       ;; On some systems, ignore case for file names.
	       (if (memq minibuffer-history-variable
			 minibuffer-history-case-insensitive-variables)
		   t
		 ;; Respect the user's setting for case-fold-search:
		 case-fold-search)
	     nil))
	  prevpos
	  match-string
	  match-offset
	  (pos minibuffer-history-position))
      (while (/= n 0)
	(setq prevpos pos)
	(setq pos (min (max 1 (+ pos (if (< n 0) -1 1))) (length history)))
	(when (= pos prevpos)
	  (user-error (if (= pos 1)
                          "No later matching history item"
                        "No earlier matching history item")))
	(setq match-string
	      (if (eq minibuffer-history-sexp-flag (minibuffer-depth))
		  (let ((print-level nil))
		    (prin1-to-string (nth (1- pos) history)))
		(nth (1- pos) history)))
	(setq match-offset
	      (if (< n 0)
		  (and (string-match regexp match-string)
		       (match-end 0))
		(and (string-match (concat ".*\\(" regexp "\\)") match-string)
		     (match-beginning 1))))
	(when match-offset
	  (setq n (+ n (if (< n 0) 1 -1)))))
      (setq minibuffer-history-position pos)
      (goto-char (point-max))
      (delete-minibuffer-contents)
      (insert match-string)
      (goto-char (+ (minibuffer-prompt-end) match-offset))))
  (if (memq (car (car command-history)) '(previous-matching-history-element
					  next-matching-history-element))
      (setq command-history (cdr command-history))))

(defun next-matching-history-element (regexp n)
  "Find the next history element that matches REGEXP.
\(The next history element refers to a more recent action.)
With prefix argument N, search for Nth next match.
If N is negative, find the previous or Nth previous match.
Normally, history elements are matched case-insensitively if
`case-fold-search' is non-nil, but an uppercase letter in REGEXP
makes the search case-sensitive."
  (interactive
   (let* ((enable-recursive-minibuffers t)
	  (regexp (read-from-minibuffer "Next element matching (regexp): "
					nil
					minibuffer-local-map
					nil
					'minibuffer-history-search-history
 					(car minibuffer-history-search-history))))
     ;; Use the last regexp specified, by default, if input is empty.
     (list (if (string= regexp "")
	       (if minibuffer-history-search-history
		   (car minibuffer-history-search-history)
		 (user-error "No previous history search regexp"))
	     regexp)
	   (prefix-numeric-value current-prefix-arg))))
  (previous-matching-history-element regexp (- n)))

(defvar minibuffer-temporary-goal-position nil)

(defvar minibuffer-default-add-function 'minibuffer-default-add-completions
  "Function run by `goto-history-element' before consuming default values.
This is useful to dynamically add more elements to the list of default values
when `goto-history-element' reaches the end of this list.
Before calling this function `goto-history-element' sets the variable
`minibuffer-default-add-done' to t, so it will call this function only
once.  In special cases, when this function needs to be called more
than once, it can set `minibuffer-default-add-done' to nil explicitly,
overriding the setting of this variable to t in `goto-history-element'.")

(defvar minibuffer-default-add-done nil
  "When nil, add more elements to the end of the list of default values.
The value nil causes `goto-history-element' to add more elements to
the list of defaults when it reaches the end of this list.  It does
this by calling a function defined by `minibuffer-default-add-function'.")

(make-variable-buffer-local 'minibuffer-default-add-done)

(defun minibuffer-default-add-completions ()
  "Return a list of all completions without the default value.
This function is used to add all elements of the completion table to
the end of the list of defaults just after the default value."
  (let ((def minibuffer-default)
	(all (all-completions ""
			      minibuffer-completion-table
			      minibuffer-completion-predicate)))
    (if (listp def)
	(append def all)
      (cons def (delete def all)))))

(defun goto-history-element (nabs)
  "Puts element of the minibuffer history in the minibuffer.
The argument NABS specifies the absolute history position."
  (interactive "p")
  (when (and (not minibuffer-default-add-done)
	     (functionp minibuffer-default-add-function)
	     (< nabs (- (if (listp minibuffer-default)
			    (length minibuffer-default)
			  1))))
    (setq minibuffer-default-add-done t
	  minibuffer-default (funcall minibuffer-default-add-function)))
  (let ((minimum (if minibuffer-default
		     (- (if (listp minibuffer-default)
			    (length minibuffer-default)
			  1))
		   0))
	elt minibuffer-returned-to-present)
    (if (and (zerop minibuffer-history-position)
	     (null minibuffer-text-before-history))
	(setq minibuffer-text-before-history
	      (minibuffer-contents-no-properties)))
    (if (< nabs minimum)
	(user-error (if minibuffer-default
                        "End of defaults; no next item"
                      "End of history; no default available")))
    (if (> nabs (if (listp (symbol-value minibuffer-history-variable))
                    (length (symbol-value minibuffer-history-variable))
                  0))
	(user-error "Beginning of history; no preceding item"))
    (unless (memq last-command '(next-history-element
				 previous-history-element))
      (let ((prompt-end (minibuffer-prompt-end)))
	(set (make-local-variable 'minibuffer-temporary-goal-position)
	     (cond ((<= (point) prompt-end) prompt-end)
		   ((eobp) nil)
		   (t (point))))))
    (goto-char (point-max))
    (delete-minibuffer-contents)
    (setq minibuffer-history-position nabs)
    (cond ((< nabs 0)
	   (setq elt (if (listp minibuffer-default)
			 (nth (1- (abs nabs)) minibuffer-default)
		       minibuffer-default)))
	  ((= nabs 0)
	   (setq elt (or minibuffer-text-before-history ""))
	   (setq minibuffer-returned-to-present t)
	   (setq minibuffer-text-before-history nil))
	  (t (setq elt (nth (1- minibuffer-history-position)
			    (symbol-value minibuffer-history-variable)))))
    (insert
     (if (and (eq minibuffer-history-sexp-flag (minibuffer-depth))
	      (not minibuffer-returned-to-present))
	 (let ((print-level nil))
	   (prin1-to-string elt))
       elt))
    (goto-char (or minibuffer-temporary-goal-position (point-max)))))

(defun next-history-element (n)
  "Puts next element of the minibuffer history in the minibuffer.
With argument N, it uses the Nth following element."
  (interactive "p")
  (or (zerop n)
      (goto-history-element (- minibuffer-history-position n))))

(defun previous-history-element (n)
  "Puts previous element of the minibuffer history in the minibuffer.
With argument N, it uses the Nth previous element."
  (interactive "p")
  (or (zerop n)
      (goto-history-element (+ minibuffer-history-position n))))

(defun next-line-or-history-element (&optional arg)
  "Move cursor vertically down ARG lines, or to the next history element.
When point moves over the bottom line of multi-line minibuffer, puts ARGth
next element of the minibuffer history in the minibuffer."
  (interactive "^p")
  (or arg (setq arg 1))
  (let* ((old-point (point))
	 ;; Remember the original goal column of possibly multi-line input
	 ;; excluding the length of the prompt on the first line.
	 (prompt-end (minibuffer-prompt-end))
	 (old-column (unless (and (eolp) (> (point) prompt-end))
		       (if (= (line-number-at-pos) 1)
			   (max (- (current-column) (1- prompt-end)) 0)
			 (current-column)))))
    (condition-case nil
	(with-no-warnings
	  (next-line arg))
      (end-of-buffer
       ;; Restore old position since `line-move-visual' moves point to
       ;; the end of the line when it fails to go to the next line.
       (goto-char old-point)
       (next-history-element arg)
       ;; Reset `temporary-goal-column' because a correct value is not
       ;; calculated when `next-line' above fails by bumping against
       ;; the bottom of the minibuffer (bug#22544).
       (setq temporary-goal-column 0)
       ;; Restore the original goal column on the last line
       ;; of possibly multi-line input.
       (goto-char (point-max))
       (when old-column
	 (if (= (line-number-at-pos) 1)
	     (move-to-column (+ old-column (1- (minibuffer-prompt-end))))
	   (move-to-column old-column)))))))

(defun previous-line-or-history-element (&optional arg)
  "Move cursor vertically up ARG lines, or to the previous history element.
When point moves over the top line of multi-line minibuffer, puts ARGth
previous element of the minibuffer history in the minibuffer."
  (interactive "^p")
  (or arg (setq arg 1))
  (let* ((old-point (point))
	 ;; Remember the original goal column of possibly multi-line input
	 ;; excluding the length of the prompt on the first line.
	 (prompt-end (minibuffer-prompt-end))
	 (old-column (unless (and (eolp) (> (point) prompt-end))
		       (if (= (line-number-at-pos) 1)
			   (max (- (current-column) (1- prompt-end)) 0)
			 (current-column)))))
    (condition-case nil
	(with-no-warnings
	  (previous-line arg))
      (beginning-of-buffer
       ;; Restore old position since `line-move-visual' moves point to
       ;; the beginning of the line when it fails to go to the previous line.
       (goto-char old-point)
       (previous-history-element arg)
       ;; Reset `temporary-goal-column' because a correct value is not
       ;; calculated when `previous-line' above fails by bumping against
       ;; the top of the minibuffer (bug#22544).
       (setq temporary-goal-column 0)
       ;; Restore the original goal column on the first line
       ;; of possibly multi-line input.
       (goto-char (minibuffer-prompt-end))
       (if old-column
	   (if (= (line-number-at-pos) 1)
	       (move-to-column (+ old-column (1- (minibuffer-prompt-end))))
	     (move-to-column old-column))
	 ;; Put the cursor at the end of the visual line instead of the
	 ;; logical line, so the next `previous-line-or-history-element'
	 ;; would move to the previous history element, not to a possible upper
	 ;; visual line from the end of logical line in `line-move-visual' mode.
	 (end-of-visual-line)
	 ;; Since `end-of-visual-line' puts the cursor at the beginning
	 ;; of the next visual line, move it one char back to the end
	 ;; of the first visual line (bug#22544).
	 (unless (eolp) (backward-char 1)))))))

(defun next-complete-history-element (n)
  "Get next history element which completes the minibuffer before the point.
The contents of the minibuffer after the point are deleted, and replaced
by the new completion."
  (interactive "p")
  (let ((point-at-start (point)))
    (next-matching-history-element
     (concat
      "^" (regexp-quote (buffer-substring (minibuffer-prompt-end) (point))))
     n)
    ;; next-matching-history-element always puts us at (point-min).
    ;; Move to the position we were at before changing the buffer contents.
    ;; This is still sensible, because the text before point has not changed.
    (goto-char point-at-start)))

(defun previous-complete-history-element (n)
  "\
Get previous history element which completes the minibuffer before the point.
The contents of the minibuffer after the point are deleted, and replaced
by the new completion."
  (interactive "p")
  (next-complete-history-element (- n)))

;; For compatibility with the old subr of the same name.
(defun minibuffer-prompt-width ()
  "Return the display width of the minibuffer prompt.
Return 0 if current buffer is not a minibuffer."
  ;; Return the width of everything before the field at the end of
  ;; the buffer; this should be 0 for normal buffers.
  (1- (minibuffer-prompt-end)))
\f
;; isearch minibuffer history
(add-hook 'minibuffer-setup-hook 'minibuffer-history-isearch-setup)

(defvar minibuffer-history-isearch-message-overlay)
(make-variable-buffer-local 'minibuffer-history-isearch-message-overlay)

(defun minibuffer-history-isearch-setup ()
  "Set up a minibuffer for using isearch to search the minibuffer history.
Intended to be added to `minibuffer-setup-hook'."
  (set (make-local-variable 'isearch-search-fun-function)
       'minibuffer-history-isearch-search)
  (set (make-local-variable 'isearch-message-function)
       'minibuffer-history-isearch-message)
  (set (make-local-variable 'isearch-wrap-function)
       'minibuffer-history-isearch-wrap)
  (set (make-local-variable 'isearch-push-state-function)
       'minibuffer-history-isearch-push-state)
  (add-hook 'isearch-mode-end-hook 'minibuffer-history-isearch-end nil t))

(defun minibuffer-history-isearch-end ()
  "Clean up the minibuffer after terminating isearch in the minibuffer."
  (if minibuffer-history-isearch-message-overlay
      (delete-overlay minibuffer-history-isearch-message-overlay)))

(defun minibuffer-history-isearch-search ()
  "Return the proper search function, for isearch in minibuffer history."
  (lambda (string bound noerror)
    (let ((search-fun
	   ;; Use standard functions to search within minibuffer text
	   (isearch-search-fun-default))
	  found)
      ;; Avoid lazy-highlighting matches in the minibuffer prompt when
      ;; searching forward.  Lazy-highlight calls this lambda with the
      ;; bound arg, so skip the minibuffer prompt.
      (if (and bound isearch-forward (< (point) (minibuffer-prompt-end)))
	  (goto-char (minibuffer-prompt-end)))
      (or
       ;; 1. First try searching in the initial minibuffer text
       (funcall search-fun string
		(if isearch-forward bound (minibuffer-prompt-end))
		noerror)
       ;; 2. If the above search fails, start putting next/prev history
       ;; elements in the minibuffer successively, and search the string
       ;; in them.  Do this only when bound is nil (i.e. not while
       ;; lazy-highlighting search strings in the current minibuffer text).
       (unless bound
	 (condition-case nil
	     (progn
	       (while (not found)
		 (cond (isearch-forward
			(next-history-element 1)
			(goto-char (minibuffer-prompt-end)))
		       (t
			(previous-history-element 1)
			(goto-char (point-max))))
		 (setq isearch-barrier (point) isearch-opoint (point))
		 ;; After putting the next/prev history element, search
		 ;; the string in them again, until next-history-element
		 ;; or previous-history-element raises an error at the
		 ;; beginning/end of history.
		 (setq found (funcall search-fun string
				      (unless isearch-forward
					;; For backward search, don't search
					;; in the minibuffer prompt
					(minibuffer-prompt-end))
				      noerror)))
	       ;; Return point of the new search result
	       (point))
	   ;; Return nil when next(prev)-history-element fails
	   (error nil)))))))

(defun minibuffer-history-isearch-message (&optional c-q-hack ellipsis)
  "Display the minibuffer history search prompt.
If there are no search errors, this function displays an overlay with
the isearch prompt which replaces the original minibuffer prompt.
Otherwise, it displays the standard isearch message returned from
the function `isearch-message'."
  (if (not (and (minibufferp) isearch-success (not isearch-error)))
      ;; Use standard function `isearch-message' when not in the minibuffer,
      ;; or search fails, or has an error (like incomplete regexp).
      ;; This function overwrites minibuffer text with isearch message,
      ;; so it's possible to see what is wrong in the search string.
      (isearch-message c-q-hack ellipsis)
    ;; Otherwise, put the overlay with the standard isearch prompt over
    ;; the initial minibuffer prompt.
    (if (overlayp minibuffer-history-isearch-message-overlay)
	(move-overlay minibuffer-history-isearch-message-overlay
		      (point-min) (minibuffer-prompt-end))
      (setq minibuffer-history-isearch-message-overlay
	    (make-overlay (point-min) (minibuffer-prompt-end)))
      (overlay-put minibuffer-history-isearch-message-overlay 'evaporate t))
    (overlay-put minibuffer-history-isearch-message-overlay
		 'display (isearch-message-prefix c-q-hack ellipsis))
    ;; And clear any previous isearch message.
    (message "")))

(defun minibuffer-history-isearch-wrap ()
  "Wrap the minibuffer history search when search fails.
Move point to the first history element for a forward search,
or to the last history element for a backward search."
  ;; When `minibuffer-history-isearch-search' fails on reaching the
  ;; beginning/end of the history, wrap the search to the first/last
  ;; minibuffer history element.
  (if isearch-forward
      (goto-history-element (length (symbol-value minibuffer-history-variable)))
    (goto-history-element 0))
  (setq isearch-success t)
  (goto-char (if isearch-forward (minibuffer-prompt-end) (point-max))))

(defun minibuffer-history-isearch-push-state ()
  "Save a function restoring the state of minibuffer history search.
Save `minibuffer-history-position' to the additional state parameter
in the search status stack."
  (let ((pos minibuffer-history-position))
    (lambda (cmd)
      (minibuffer-history-isearch-pop-state cmd pos))))

(defun minibuffer-history-isearch-pop-state (_cmd hist-pos)
  "Restore the minibuffer history search state.
Go to the history element by the absolute history position HIST-POS."
  (goto-history-element hist-pos))

\f
;Put this on C-x u, so we can force that rather than C-_ into startup msg
(define-obsolete-function-alias 'advertised-undo 'undo "23.2")

(defconst undo-equiv-table (make-hash-table :test 'eq :weakness t)
  "Table mapping redo records to the corresponding undo one.
A redo record for undo-in-region maps to t.
A redo record for ordinary undo maps to the following (earlier) undo.")

(defvar undo-in-region nil
  "Non-nil if `pending-undo-list' is not just a tail of `buffer-undo-list'.")

(defvar undo-no-redo nil
  "If t, `undo' doesn't go through redo entries.")

(defvar pending-undo-list nil
  "Within a run of consecutive undo commands, list remaining to be undone.
If t, we undid all the way to the end of it.")

(defun undo (&optional arg)
  "Undo some previous changes.
Repeat this command to undo more changes.
A numeric ARG serves as a repeat count.

In Transient Mark mode when the mark is active, only undo changes within
the current region.  Similarly, when not in Transient Mark mode, just \\[universal-argument]
as an argument limits undo to changes within the current region."
  (interactive "*P")
  ;; Make last-command indicate for the next command that this was an undo.
  ;; That way, another undo will undo more.
  ;; If we get to the end of the undo history and get an error,
  ;; another undo command will find the undo history empty
  ;; and will get another error.  To begin undoing the undos,
  ;; you must type some other command.
  (let* ((modified (buffer-modified-p))
	 ;; For an indirect buffer, look in the base buffer for the
	 ;; auto-save data.
	 (base-buffer (or (buffer-base-buffer) (current-buffer)))
	 (recent-save (with-current-buffer base-buffer
			(recent-auto-save-p)))
	 message)
    ;; If we get an error in undo-start,
    ;; the next command should not be a "consecutive undo".
    ;; So set `this-command' to something other than `undo'.
    (setq this-command 'undo-start)

    (unless (and (eq last-command 'undo)
		 (or (eq pending-undo-list t)
		     ;; If something (a timer or filter?) changed the buffer
		     ;; since the previous command, don't continue the undo seq.
		     (let ((list buffer-undo-list))
		       (while (eq (car list) nil)
			 (setq list (cdr list)))
		       ;; If the last undo record made was made by undo
		       ;; it shows nothing else happened in between.
		       (gethash list undo-equiv-table))))
      (setq undo-in-region
	    (or (region-active-p) (and arg (not (numberp arg)))))
      (if undo-in-region
	  (undo-start (region-beginning) (region-end))
	(undo-start))
      ;; get rid of initial undo boundary
      (undo-more 1))
    ;; If we got this far, the next command should be a consecutive undo.
    (setq this-command 'undo)
    ;; Check to see whether we're hitting a redo record, and if
    ;; so, ask the user whether she wants to skip the redo/undo pair.
    (let ((equiv (gethash pending-undo-list undo-equiv-table)))
      (or (eq (selected-window) (minibuffer-window))
	  (setq message (format "%s%s!"
                                (if (or undo-no-redo (not equiv))
                                    "Undo" "Redo")
                                (if undo-in-region " in region" ""))))
      (when (and (consp equiv) undo-no-redo)
	;; The equiv entry might point to another redo record if we have done
	;; undo-redo-undo-redo-... so skip to the very last equiv.
	(while (let ((next (gethash equiv undo-equiv-table)))
		 (if next (setq equiv next))))
	(setq pending-undo-list equiv)))
    (undo-more
     (if (numberp arg)
	 (prefix-numeric-value arg)
       1))
    ;; Record the fact that the just-generated undo records come from an
    ;; undo operation--that is, they are redo records.
    ;; In the ordinary case (not within a region), map the redo
    ;; record to the following undos.
    ;; I don't know how to do that in the undo-in-region case.
    (let ((list buffer-undo-list))
      ;; Strip any leading undo boundaries there might be, like we do
      ;; above when checking.
      (while (eq (car list) nil)
	(setq list (cdr list)))
      (puthash list
               ;; Prevent identity mapping.  This can happen if
               ;; consecutive nils are erroneously in undo list.
               (if (or undo-in-region (eq list pending-undo-list))
                   t
                 pending-undo-list)
	       undo-equiv-table))
    ;; Don't specify a position in the undo record for the undo command.
    ;; Instead, undoing this should move point to where the change is.
    (let ((tail buffer-undo-list)
	  (prev nil))
      (while (car tail)
	(when (integerp (car tail))
	  (let ((pos (car tail)))
	    (if prev
		(setcdr prev (cdr tail))
	      (setq buffer-undo-list (cdr tail)))
	    (setq tail (cdr tail))
	    (while (car tail)
	      (if (eq pos (car tail))
		  (if prev
		      (setcdr prev (cdr tail))
		    (setq buffer-undo-list (cdr tail)))
		(setq prev tail))
	      (setq tail (cdr tail)))
	    (setq tail nil)))
	(setq prev tail tail (cdr tail))))
    ;; Record what the current undo list says,
    ;; so the next command can tell if the buffer was modified in between.
    (and modified (not (buffer-modified-p))
	 (with-current-buffer base-buffer
	   (delete-auto-save-file-if-necessary recent-save)))
    ;; Display a message announcing success.
    (if message
	(message "%s" message))))

(defun buffer-disable-undo (&optional buffer)
  "Make BUFFER stop keeping undo information.
No argument or nil as argument means do this for the current buffer."
  (interactive)
  (with-current-buffer (if buffer (get-buffer buffer) (current-buffer))
    (setq buffer-undo-list t)))

(defun undo-only (&optional arg)
  "Undo some previous changes.
Repeat this command to undo more changes.
A numeric ARG serves as a repeat count.
Contrary to `undo', this will not redo a previous undo."
  (interactive "*p")
  (let ((undo-no-redo t)) (undo arg)))

(defvar undo-in-progress nil
  "Non-nil while performing an undo.
Some change-hooks test this variable to do something different.")

(defun undo-more (n)
  "Undo back N undo-boundaries beyond what was already undone recently.
Call `undo-start' to get ready to undo recent changes,
then call `undo-more' one or more times to undo them."
  (or (listp pending-undo-list)
      (user-error (concat "No further undo information"
                          (and undo-in-region " for region"))))
  (let ((undo-in-progress t))
    ;; Note: The following, while pulling elements off
    ;; `pending-undo-list' will call primitive change functions which
    ;; will push more elements onto `buffer-undo-list'.
    (setq pending-undo-list (primitive-undo n pending-undo-list))
    (if (null pending-undo-list)
	(setq pending-undo-list t))))

(defun primitive-undo (n list)
  "Undo N records from the front of the list LIST.
Return what remains of the list."

  ;; This is a good feature, but would make undo-start
  ;; unable to do what is expected.
  ;;(when (null (car (list)))
  ;;  ;; If the head of the list is a boundary, it is the boundary
  ;;  ;; preceding this command.  Get rid of it and don't count it.
  ;;  (setq list (cdr list))))

  (let ((arg n)
        ;; In a writable buffer, enable undoing read-only text that is
        ;; so because of text properties.
        (inhibit-read-only t)
        ;; Don't let `intangible' properties interfere with undo.
        (inhibit-point-motion-hooks t)
        ;; We use oldlist only to check for EQ.  ++kfs
        (oldlist buffer-undo-list)
        (did-apply nil)
        (next nil))
    (while (> arg 0)
      (while (setq next (pop list))     ;Exit inner loop at undo boundary.
        ;; Handle an integer by setting point to that value.
        (pcase next
          ((pred integerp) (goto-char next))
          ;; Element (t . TIME) records previous modtime.
          ;; Preserve any flag of NONEXISTENT_MODTIME_NSECS or
          ;; UNKNOWN_MODTIME_NSECS.
          (`(t . ,time)
           ;; If this records an obsolete save
           ;; (not matching the actual disk file)
           ;; then don't mark unmodified.
           (when (or (equal time (visited-file-modtime))
                     (and (consp time)
                          (equal (list (car time) (cdr time))
                                 (visited-file-modtime))))
             (when (fboundp 'unlock-buffer)
               (unlock-buffer))
             (set-buffer-modified-p nil)))
          ;; Element (nil PROP VAL BEG . END) is property change.
          (`(nil . ,(or `(,prop ,val ,beg . ,end) pcase--dontcare))
           (when (or (> (point-min) beg) (< (point-max) end))
             (error "Changes to be undone are outside visible portion of buffer"))
           (put-text-property beg end prop val))
          ;; Element (BEG . END) means range was inserted.
          (`(,(and beg (pred integerp)) . ,(and end (pred integerp)))
           ;; (and `(,beg . ,end) `(,(pred integerp) . ,(pred integerp)))
           ;; Ideally: `(,(pred integerp beg) . ,(pred integerp end))
           (when (or (> (point-min) beg) (< (point-max) end))
             (error "Changes to be undone are outside visible portion of buffer"))
           ;; Set point first thing, so that undoing this undo
           ;; does not send point back to where it is now.
           (goto-char beg)
           (delete-region beg end))
          ;; Element (apply FUN . ARGS) means call FUN to undo.
          (`(apply . ,fun-args)
           (let ((currbuff (current-buffer)))
             (if (integerp (car fun-args))
                 ;; Long format: (apply DELTA START END FUN . ARGS).
                 (pcase-let* ((`(,delta ,start ,end ,fun . ,args) fun-args)
                              (start-mark (copy-marker start nil))
                              (end-mark (copy-marker end t)))
                   (when (or (> (point-min) start) (< (point-max) end))
                     (error "Changes to be undone are outside visible portion of buffer"))
                   (apply fun args) ;; Use `save-current-buffer'?
                   ;; Check that the function did what the entry
                   ;; said it would do.
                   (unless (and (= start start-mark)
                                (= (+ delta end) end-mark))
                     (error "Changes to be undone by function different than announced"))
                   (set-marker start-mark nil)
                   (set-marker end-mark nil))
               (apply fun-args))
             (unless (eq currbuff (current-buffer))
               (error "Undo function switched buffer"))
             (setq did-apply t)))
          ;; Element (STRING . POS) means STRING was deleted.
          (`(,(and string (pred stringp)) . ,(and pos (pred integerp)))
           (when (let ((apos (abs pos)))
                   (or (< apos (point-min)) (> apos (point-max))))
             (error "Changes to be undone are outside visible portion of buffer"))
           (let (valid-marker-adjustments)
             ;; Check that marker adjustments which were recorded
             ;; with the (STRING . POS) record are still valid, ie
             ;; the markers haven't moved.  We check their validity
             ;; before reinserting the string so as we don't need to
             ;; mind marker insertion-type.
             (while (and (markerp (car-safe (car list)))
                         (integerp (cdr-safe (car list))))
               (let* ((marker-adj (pop list))
                      (m (car marker-adj)))
                 (and (eq (marker-buffer m) (current-buffer))
                      (= pos m)
                      (push marker-adj valid-marker-adjustments))))
             ;; Insert string and adjust point
             (if (< pos 0)
                 (progn
                   (goto-char (- pos))
                   (insert string))
               (goto-char pos)
               (insert string)
               (goto-char pos))
             ;; Adjust the valid marker adjustments
             (dolist (adj valid-marker-adjustments)
               (set-marker (car adj)
                           (- (car adj) (cdr adj))))))
          ;; (MARKER . OFFSET) means a marker MARKER was adjusted by OFFSET.
          (`(,(and marker (pred markerp)) . ,(and offset (pred integerp)))
           (warn "Encountered %S entry in undo list with no matching (TEXT . POS) entry"
                 next)
           ;; Even though these elements are not expected in the undo
           ;; list, adjust them to be conservative for the 24.4
           ;; release.  (Bug#16818)
           (when (marker-buffer marker)
             (set-marker marker
                         (- marker offset)
                         (marker-buffer marker))))
          (_ (error "Unrecognized entry in undo list %S" next))))
      (setq arg (1- arg)))
    ;; Make sure an apply entry produces at least one undo entry,
    ;; so the test in `undo' for continuing an undo series
    ;; will work right.
    (if (and did-apply
             (eq oldlist buffer-undo-list))
        (setq buffer-undo-list
              (cons (list 'apply 'cdr nil) buffer-undo-list))))
  list)

;; Deep copy of a list
(defun undo-copy-list (list)
  "Make a copy of undo list LIST."
  (mapcar 'undo-copy-list-1 list))

(defun undo-copy-list-1 (elt)
  (if (consp elt)
      (cons (car elt) (undo-copy-list-1 (cdr elt)))
    elt))

(defun undo-start (&optional beg end)
  "Set `pending-undo-list' to the front of the undo list.
The next call to `undo-more' will undo the most recently made change.
If BEG and END are specified, then only undo elements
that apply to text between BEG and END are used; other undo elements
are ignored.  If BEG and END are nil, all undo elements are used."
  (if (eq buffer-undo-list t)
      (user-error "No undo information in this buffer"))
  (setq pending-undo-list
	(if (and beg end (not (= beg end)))
	    (undo-make-selective-list (min beg end) (max beg end))
	  buffer-undo-list)))

;; The positions given in elements of the undo list are the positions
;; as of the time that element was recorded to undo history.  In
;; general, subsequent buffer edits render those positions invalid in
;; the current buffer, unless adjusted according to the intervening
;; undo elements.
;;
;; Undo in region is a use case that requires adjustments to undo
;; elements.  It must adjust positions of elements in the region based
;; on newer elements not in the region so as they may be correctly
;; applied in the current buffer.  undo-make-selective-list
;; accomplishes this with its undo-deltas list of adjustments.  An
;; example undo history from oldest to newest:
;;
;; buf pos:
;; 123456789 buffer-undo-list undo-deltas
;; --------- ---------------- -----------
;; aaa       (1 . 4)          (1 . -3)
;; aaba      (3 . 4)          N/A (in region)
;; ccaaba    (1 . 3)          (1 . -2)
;; ccaabaddd (7 . 10)         (7 . -3)
;; ccaabdd   ("ad" . 6)       (6 . 2)
;; ccaabaddd (6 . 8)          (6 . -2)
;;  |   |<-- region: "caab", from 2 to 6
;;
;; When the user starts a run of undos in region,
;; undo-make-selective-list is called to create the full list of in
;; region elements.  Each element is adjusted forward chronologically
;; through undo-deltas to determine if it is in the region.
;;
;; In the above example, the insertion of "b" is (3 . 4) in the
;; buffer-undo-list.  The undo-delta (1 . -2) causes (3 . 4) to become
;; (5 . 6).  The next three undo-deltas cause no adjustment, so (5
;; . 6) is assessed as in the region and placed in the selective list.
;; Notably, the end of region itself adjusts from "2 to 6" to "2 to 5"
;; due to the selected element.  The "b" insertion is the only element
;; fully in the region, so in this example undo-make-selective-list
;; returns (nil (5 . 6)).
;;
;; The adjustment of the (7 . 10) insertion of "ddd" shows an edge
;; case.  It is adjusted through the undo-deltas: ((6 . 2) (6 . -2)).
;; Normally an undo-delta of (6 . 2) would cause positions after 6 to
;; adjust by 2.  However, they shouldn't adjust to less than 6, so (7
;; . 10) adjusts to (6 . 8) due to the first undo delta.
;;
;; More interesting is how to adjust the "ddd" insertion due to the
;; next undo-delta: (6 . -2), corresponding to reinsertion of "ad".
;; If the reinsertion was a manual retyping of "ad", then the total
;; adjustment should be (7 . 10) -> (6 . 8) -> (8 . 10).  However, if
;; the reinsertion was due to undo, one might expect the first "d"
;; character would again be a part of the "ddd" text, meaning its
;; total adjustment would be (7 . 10) -> (6 . 8) -> (7 . 10).
;;
;; undo-make-selective-list assumes in this situation that "ad" was a
;; new edit, even if it was inserted because of an undo.
;; Consequently, if the user undos in region "8 to 10" of the
;; "ccaabaddd" buffer, they could be surprised that it becomes
;; "ccaabad", as though the first "d" became detached from the
;; original "ddd" insertion.  This quirk is a FIXME.

(defun undo-make-selective-list (start end)
  "Return a list of undo elements for the region START to END.
The elements come from `buffer-undo-list', but we keep only the
elements inside this region, and discard those outside this
region.  The elements' positions are adjusted so as the returned
list can be applied to the current buffer."
  (let ((ulist buffer-undo-list)
        ;; A list of position adjusted undo elements in the region.
        (selective-list (list nil))
        ;; A list of undo-deltas for out of region undo elements.
        undo-deltas
        undo-elt)
    (while ulist
      (when undo-no-redo
        (while (gethash ulist undo-equiv-table)
          (setq ulist (gethash ulist undo-equiv-table))))
      (setq undo-elt (car ulist))
      (cond
       ((null undo-elt)
        ;; Don't put two nils together in the list
        (when (car selective-list)
          (push nil selective-list)))
       ((and (consp undo-elt) (eq (car undo-elt) t))
        ;; This is a "was unmodified" element.  Keep it
        ;; if we have kept everything thus far.
        (when (not undo-deltas)
          (push undo-elt selective-list)))
       ;; Skip over marker adjustments, instead relying
       ;; on finding them after (TEXT . POS) elements
       ((markerp (car-safe undo-elt))
        nil)
       (t
        (let ((adjusted-undo-elt (undo-adjust-elt undo-elt
                                                  undo-deltas)))
          (if (undo-elt-in-region adjusted-undo-elt start end)
              (progn
                (setq end (+ end (cdr (undo-delta adjusted-undo-elt))))
                (push adjusted-undo-elt selective-list)
                ;; Keep (MARKER . ADJUSTMENT) if their (TEXT . POS) was
                ;; kept.  primitive-undo may discard them later.
                (when (and (stringp (car-safe adjusted-undo-elt))
                           (integerp (cdr-safe adjusted-undo-elt)))
                  (let ((list-i (cdr ulist)))
                    (while (markerp (car-safe (car list-i)))
                      (push (pop list-i) selective-list)))))
            (let ((delta (undo-delta undo-elt)))
              (when (/= 0 (cdr delta))
                (push delta undo-deltas)))))))
      (pop ulist))
    (nreverse selective-list)))

(defun undo-elt-in-region (undo-elt start end)
  "Determine whether UNDO-ELT falls inside the region START ... END.
If it crosses the edge, we return nil.

Generally this function is not useful for determining
whether (MARKER . ADJUSTMENT) undo elements are in the region,
because markers can be arbitrarily relocated.  Instead, pass the
marker adjustment's corresponding (TEXT . POS) element."
  (cond ((integerp undo-elt)
	 (and (>= undo-elt start)
	      (<= undo-elt end)))
	((eq undo-elt nil)
	 t)
	((atom undo-elt)
	 nil)
	((stringp (car undo-elt))
	 ;; (TEXT . POSITION)
	 (and (>= (abs (cdr undo-elt)) start)
	      (<= (abs (cdr undo-elt)) end)))
	((and (consp undo-elt) (markerp (car undo-elt)))
	 ;; (MARKER . ADJUSTMENT)
         (<= start (car undo-elt) end))
	((null (car undo-elt))
	 ;; (nil PROPERTY VALUE BEG . END)
	 (let ((tail (nthcdr 3 undo-elt)))
	   (and (>= (car tail) start)
		(<= (cdr tail) end))))
	((integerp (car undo-elt))
	 ;; (BEGIN . END)
	 (and (>= (car undo-elt) start)
	      (<= (cdr undo-elt) end)))))

(defun undo-elt-crosses-region (undo-elt start end)
  "Test whether UNDO-ELT crosses one edge of that region START ... END.
This assumes we have already decided that UNDO-ELT
is not *inside* the region START...END."
  (declare (obsolete nil "25.1"))
  (cond ((atom undo-elt) nil)
	((null (car undo-elt))
	 ;; (nil PROPERTY VALUE BEG . END)
	 (let ((tail (nthcdr 3 undo-elt)))
	   (and (< (car tail) end)
		(> (cdr tail) start))))
	((integerp (car undo-elt))
	 ;; (BEGIN . END)
	 (and (< (car undo-elt) end)
	      (> (cdr undo-elt) start)))))

(defun undo-adjust-elt (elt deltas)
  "Return adjustment of undo element ELT by the undo DELTAS
list."
  (pcase elt
    ;; POSITION
    ((pred integerp)
     (undo-adjust-pos elt deltas))
    ;; (BEG . END)
    (`(,(and beg (pred integerp)) . ,(and end (pred integerp)))
     (undo-adjust-beg-end beg end deltas))
    ;; (TEXT . POSITION)
    (`(,(and text (pred stringp)) . ,(and pos (pred integerp)))
     (cons text (* (if (< pos 0) -1 1)
                   (undo-adjust-pos (abs pos) deltas))))
    ;; (nil PROPERTY VALUE BEG . END)
    (`(nil . ,(or `(,prop ,val ,beg . ,end) pcase--dontcare))
     `(nil ,prop ,val . ,(undo-adjust-beg-end beg end deltas)))
    ;; (apply DELTA START END FUN . ARGS)
    ;; FIXME
    ;; All others return same elt
    (_ elt)))

;; (BEG . END) can adjust to the same positions, commonly when an
;; insertion was undone and they are out of region, for example:
;;
;; buf pos:
;; 123456789 buffer-undo-list undo-deltas
;; --------- ---------------- -----------
;; [...]
;; abbaa     (2 . 4)          (2 . -2)
;; aaa       ("bb" . 2)       (2 . 2)
;; [...]
;;
;; "bb" insertion (2 . 4) adjusts to (2 . 2) because of the subsequent
;; undo.  Further adjustments to such an element should be the same as
;; for (TEXT . POSITION) elements.  The options are:
;;
;;   1: POSITION adjusts using <= (use-< nil), resulting in behavior
;;      analogous to marker insertion-type t.
;;
;;   2: POSITION adjusts using <, resulting in behavior analogous to
;;      marker insertion-type nil.
;;
;; There was no strong reason to prefer one or the other, except that
;; the first is more consistent with prior undo in region behavior.
(defun undo-adjust-beg-end (beg end deltas)
  "Return cons of adjustments to BEG and END by the undo DELTAS
list."
  (let ((adj-beg (undo-adjust-pos beg deltas)))
    ;; Note: option 2 above would be like (cons (min ...) adj-end)
    (cons adj-beg
          (max adj-beg (undo-adjust-pos end deltas t)))))

(defun undo-adjust-pos (pos deltas &optional use-<)
  "Return adjustment of POS by the undo DELTAS list, comparing
with < or <= based on USE-<."
  (dolist (d deltas pos)
    (when (if use-<
              (< (car d) pos)
            (<= (car d) pos))
      (setq pos
            ;; Don't allow pos to become less than the undo-delta
            ;; position.  This edge case is described in the overview
            ;; comments.
            (max (car d) (- pos (cdr d)))))))

;; Return the first affected buffer position and the delta for an undo element
;; delta is defined as the change in subsequent buffer positions if we *did*
;; the undo.
(defun undo-delta (undo-elt)
  (if (consp undo-elt)
      (cond ((stringp (car undo-elt))
	     ;; (TEXT . POSITION)
	     (cons (abs (cdr undo-elt)) (length (car undo-elt))))
	    ((integerp (car undo-elt))
	     ;; (BEGIN . END)
	     (cons (car undo-elt) (- (car undo-elt) (cdr undo-elt))))
	    (t
	     '(0 . 0)))
    '(0 . 0)))

;;; Default undo-boundary addition
;;
;; This section adds a new undo-boundary at either after a command is
;; called or in some cases on a timer called after a change is made in
;; any buffer.
(defvar-local undo-auto--last-boundary-cause nil
  "Describe the cause of the last undo-boundary.

If `explicit', the last boundary was caused by an explicit call to
`undo-boundary', that is one not called by the code in this
section.

If it is equal to `timer', then the last boundary was inserted
by `undo-auto--boundary-timer'.

If it is equal to `command', then the last boundary was inserted
automatically after a command, that is by the code defined in
this section.

If it is equal to a list, then the last boundary was inserted by
an amalgamating command.  The car of the list is the number of
times an amalgamating command has been called, and the cdr are the
buffers that were changed during the last command.")

(defvar undo-auto-current-boundary-timer nil
  "Current timer which will run `undo-auto--boundary-timer' or nil.

If set to non-nil, this will effectively disable the timer.")

(defvar undo-auto--this-command-amalgamating nil
  "Non-nil if `this-command' should be amalgamated.
This variable is set to nil by `undo-auto--boundaries' and is set
by `undo-auto-amalgamate'." )

(defun undo-auto--needs-boundary-p ()
  "Return non-nil if `buffer-undo-list' needs a boundary at the start."
  (car-safe buffer-undo-list))

(defun undo-auto--last-boundary-amalgamating-number ()
  "Return the number of amalgamating last commands or nil.
Amalgamating commands are, by default, either
`self-insert-command' and `delete-char', but can be any command
that calls `undo-auto-amalgamate'."
  (car-safe undo-auto--last-boundary-cause))

(defun undo-auto--ensure-boundary (cause)
  "Add an `undo-boundary' to the current buffer if needed.
REASON describes the reason that the boundary is being added; see
`undo-auto--last-boundary' for more information."
  (when (and
         (undo-auto--needs-boundary-p))
    (let ((last-amalgamating
           (undo-auto--last-boundary-amalgamating-number)))
      (undo-boundary)
      (setq undo-auto--last-boundary-cause
            (if (eq 'amalgamate cause)
                (cons
                 (if last-amalgamating (1+ last-amalgamating) 0)
                 undo-auto--undoably-changed-buffers)
              cause)))))

(defun undo-auto--boundaries (cause)
  "Check recently changed buffers and add a boundary if necessary.
REASON describes the reason that the boundary is being added; see
`undo-last-boundary' for more information."
  ;; (Bug #23785) All commands should ensure that there is an undo
  ;; boundary whether they have changed the current buffer or not.
  (when (eq cause 'command)
    (add-to-list 'undo-auto--undoably-changed-buffers (current-buffer)))
  (dolist (b undo-auto--undoably-changed-buffers)
          (when (buffer-live-p b)
            (with-current-buffer b
              (undo-auto--ensure-boundary cause))))
  (setq undo-auto--undoably-changed-buffers nil))

(defun undo-auto--boundary-timer ()
  "Timer which will run `undo--auto-boundary-timer'."
  (setq undo-auto-current-boundary-timer nil)
  (undo-auto--boundaries 'timer))

(defun undo-auto--boundary-ensure-timer ()
  "Ensure that the `undo-auto-boundary-timer' is set."
  (unless undo-auto-current-boundary-timer
    (setq undo-auto-current-boundary-timer
          (run-at-time 10 nil #'undo-auto--boundary-timer))))

(defvar undo-auto--undoably-changed-buffers nil
  "List of buffers that have changed recently.

This list is maintained by `undo-auto--undoable-change' and
`undo-auto--boundaries' and can be affected by changes to their
default values.")

(defun undo-auto--add-boundary ()
  "Add an `undo-boundary' in appropriate buffers."
  (undo-auto--boundaries
   (let ((amal undo-auto--this-command-amalgamating))
       (setq undo-auto--this-command-amalgamating nil)
       (if amal
           'amalgamate
         'command))))

(defun undo-auto-amalgamate ()
  "Amalgamate undo if necessary.
This function can be called before an amalgamating command.  It
removes the previous `undo-boundary' if a series of such calls
have been made.  By default `self-insert-command' and
`delete-char' are the only amalgamating commands, although this
function could be called by any command wishing to have this
behavior."
  (let ((last-amalgamating-count
         (undo-auto--last-boundary-amalgamating-number)))
    (setq undo-auto--this-command-amalgamating t)
    (when
        last-amalgamating-count
      (if
          (and
           (< last-amalgamating-count 20)
           (eq this-command last-command))
          ;; Amalgamate all buffers that have changed.
          (dolist (b (cdr undo-auto--last-boundary-cause))
            (when (buffer-live-p b)
              (with-current-buffer
                  b
                (when
                    ;; The head of `buffer-undo-list' is nil.
                    ;; `car-safe' doesn't work because
                    ;; `buffer-undo-list' need not be a list!
                    (and (listp buffer-undo-list)
                         (not (car buffer-undo-list)))
                  (setq buffer-undo-list
                        (cdr buffer-undo-list))))))
        (setq undo-auto--last-boundary-cause 0)))))

(defun undo-auto--undoable-change ()
  "Called after every undoable buffer change."
  (add-to-list 'undo-auto--undoably-changed-buffers (current-buffer))
  (undo-auto--boundary-ensure-timer))
;; End auto-boundary section

(defun undo-amalgamate-change-group (handle)
  "Amalgamate changes in change-group since HANDLE.
Remove all undo boundaries between the state of HANDLE and now.
HANDLE is as returned by `prepare-change-group'."
  (dolist (elt handle)
    (with-current-buffer (car elt)
      (setq elt (cdr elt))
      (when (consp buffer-undo-list)
        (let ((old-car (car-safe elt))
              (old-cdr (cdr-safe elt)))
          (unwind-protect
              (progn
                ;; Temporarily truncate the undo log at ELT.
                (when (consp elt)
                  (setcar elt t) (setcdr elt nil))
                (when
                    (or (null elt)        ;The undo-log was empty.
                        ;; `elt' is still in the log: normal case.
                        (eq elt (last buffer-undo-list))
                        ;; `elt' is not in the log any more, but that's because
                        ;; the log is "all new", so we should remove all
                        ;; boundaries from it.
                        (not (eq (last buffer-undo-list) (last old-cdr))))
                  (cl-callf (lambda (x) (delq nil x))
                      (if (car buffer-undo-list)
                          buffer-undo-list
                        ;; Preserve the undo-boundaries at either ends of the
                        ;; change-groups.
                        (cdr buffer-undo-list)))))
            ;; Reset the modified cons cell ELT to its original content.
            (when (consp elt)
              (setcar elt old-car)
              (setcdr elt old-cdr))))))))


(defcustom undo-ask-before-discard nil
  "If non-nil ask about discarding undo info for the current command.
Normally, Emacs discards the undo info for the current command if
it exceeds `undo-outer-limit'.  But if you set this option
non-nil, it asks in the echo area whether to discard the info.
If you answer no, there is a slight risk that Emacs might crash, so
only do it if you really want to undo the command.

This option is mainly intended for debugging.  You have to be
careful if you use it for other purposes.  Garbage collection is
inhibited while the question is asked, meaning that Emacs might
leak memory.  So you should make sure that you do not wait
excessively long before answering the question."
  :type 'boolean
  :group 'undo
  :version "22.1")

(defvar undo-extra-outer-limit nil
  "If non-nil, an extra level of size that's ok in an undo item.
We don't ask the user about truncating the undo list until the
current item gets bigger than this amount.

This variable only matters if `undo-ask-before-discard' is non-nil.")
(make-variable-buffer-local 'undo-extra-outer-limit)

;; When the first undo batch in an undo list is longer than
;; undo-outer-limit, this function gets called to warn the user that
;; the undo info for the current command was discarded.  Garbage
;; collection is inhibited around the call, so it had better not do a
;; lot of consing.
(setq undo-outer-limit-function 'undo-outer-limit-truncate)
(defun undo-outer-limit-truncate (size)
  (if undo-ask-before-discard
      (when (or (null undo-extra-outer-limit)
		(> size undo-extra-outer-limit))
	;; Don't ask the question again unless it gets even bigger.
	;; This applies, in particular, if the user quits from the question.
	;; Such a quit quits out of GC, but something else will call GC
	;; again momentarily.  It will call this function again,
	;; but we don't want to ask the question again.
	(setq undo-extra-outer-limit (+ size 50000))
	(if (let (use-dialog-box track-mouse executing-kbd-macro )
	      (yes-or-no-p (format-message
                            "Buffer `%s' undo info is %d bytes long; discard it? "
                            (buffer-name) size)))
	    (progn (setq buffer-undo-list nil)
		   (setq undo-extra-outer-limit nil)
		   t)
	  nil))
    (display-warning '(undo discard-info)
		     (concat
		      (format-message
                       "Buffer `%s' undo info was %d bytes long.\n"
                       (buffer-name) size)
		      "The undo info was discarded because it exceeded \
`undo-outer-limit'.

This is normal if you executed a command that made a huge change
to the buffer.  In that case, to prevent similar problems in the
future, set `undo-outer-limit' to a value that is large enough to
cover the maximum size of normal changes you expect a single
command to make, but not so large that it might exceed the
maximum memory allotted to Emacs.

If you did not execute any such command, the situation is
probably due to a bug and you should report it.

You can disable the popping up of this buffer by adding the entry
\(undo discard-info) to the user option `warning-suppress-types',
which is defined in the `warnings' library.\n")
		     :warning)
    (setq buffer-undo-list nil)
    t))
\f
(defcustom password-word-equivalents
  '("password" "passcode" "passphrase" "pass phrase"
    ; These are sorted according to the GNU en_US locale.
    "암호"		; ko
    "パスワード"	; ja
    "ପ୍ରବେଶ ସଙ୍କେତ"	; or
    "ពាក្យសម្ងាត់"		; km
    "adgangskode"	; da
    "contraseña"	; es
    "contrasenya"	; ca
    "geslo"		; sl
    "hasło"		; pl
    "heslo"		; cs, sk
    "iphasiwedi"	; zu
    "jelszó"		; hu
    "lösenord"		; sv
    "lozinka"		; hr, sr
    "mật khẩu"		; vi
    "mot de passe"	; fr
    "parola"		; tr
    "pasahitza"		; eu
    "passord"		; nb
    "passwort"		; de
    "pasvorto"		; eo
    "salasana"		; fi
    "senha"		; pt
    "slaptažodis"	; lt
    "wachtwoord"	; nl
    "كلمة السر"		; ar
    "ססמה"		; he
    "лозинка"		; sr
    "пароль"		; kk, ru, uk
    "गुप्तशब्द"		; mr
    "शब्दकूट"		; hi
    "પાસવર્ડ"		; gu
    "సంకేతపదము"		; te
    "ਪਾਸਵਰਡ"		; pa
    "ಗುಪ್ತಪದ"		; kn
    "கடவுச்சொல்"		; ta
    "അടയാളവാക്ക്"		; ml
    "গুপ্তশব্দ"		; as
    "পাসওয়ার্ড"		; bn_IN
    "රහස්පදය"		; si
    "密码"		; zh_CN
    "密碼"		; zh_TW
    )
  "List of words equivalent to \"password\".
This is used by Shell mode and other parts of Emacs to recognize
password prompts, including prompts in languages other than
English.  Different case choices should not be assumed to be
included; callers should bind `case-fold-search' to t."
  :type '(repeat string)
  :version "24.4"
  :group 'processes)

(defvar shell-command-history nil
  "History list for some commands that read shell commands.

Maximum length of the history list is determined by the value
of `history-length', which see.")

(defvar shell-command-switch (purecopy "-c")
  "Switch used to have the shell execute its command line argument.")

(defvar shell-command-default-error-buffer nil
  "Buffer name for `shell-command' and `shell-command-on-region' error output.
This buffer is used when `shell-command' or `shell-command-on-region'
is run interactively.  A value of nil means that output to stderr and
stdout will be intermixed in the output stream.")

(declare-function mailcap-file-default-commands "mailcap" (files))
(declare-function dired-get-filename "dired" (&optional localp no-error-if-not-filep))

(defun minibuffer-default-add-shell-commands ()
  "Return a list of all commands associated with the current file.
This function is used to add all related commands retrieved by `mailcap'
to the end of the list of defaults just after the default value."
  (interactive)
  (let* ((filename (if (listp minibuffer-default)
		       (car minibuffer-default)
		     minibuffer-default))
	 (commands (and filename (require 'mailcap nil t)
			(mailcap-file-default-commands (list filename)))))
    (setq commands (mapcar (lambda (command)
			     (concat command " " filename))
			   commands))
    (if (listp minibuffer-default)
	(append minibuffer-default commands)
      (cons minibuffer-default commands))))

(declare-function shell-completion-vars "shell" ())

(defvar minibuffer-local-shell-command-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map minibuffer-local-map)
    (define-key map "\t" 'completion-at-point)
    map)
  "Keymap used for completing shell commands in minibuffer.")

(defun read-shell-command (prompt &optional initial-contents hist &rest args)
  "Read a shell command from the minibuffer.
The arguments are the same as the ones of `read-from-minibuffer',
except READ and KEYMAP are missing and HIST defaults
to `shell-command-history'."
  (require 'shell)
  (minibuffer-with-setup-hook
      (lambda ()
        (shell-completion-vars)
	(set (make-local-variable 'minibuffer-default-add-function)
	     'minibuffer-default-add-shell-commands))
    (apply 'read-from-minibuffer prompt initial-contents
	   minibuffer-local-shell-command-map
	   nil
	   (or hist 'shell-command-history)
	   args)))

(defcustom async-shell-command-buffer 'confirm-new-buffer
  "What to do when the output buffer is used by another shell command.
This option specifies how to resolve the conflict where a new command
wants to direct its output to the buffer `*Async Shell Command*',
but this buffer is already taken by another running shell command.

The value `confirm-kill-process' is used to ask for confirmation before
killing the already running process and running a new process
in the same buffer, `confirm-new-buffer' for confirmation before running
the command in a new buffer with a name other than the default buffer name,
`new-buffer' for doing the same without confirmation,
`confirm-rename-buffer' for confirmation before renaming the existing
output buffer and running a new command in the default buffer,
`rename-buffer' for doing the same without confirmation."
  :type '(choice (const :tag "Confirm killing of running command"
			confirm-kill-process)
		 (const :tag "Confirm creation of a new buffer"
			confirm-new-buffer)
		 (const :tag "Create a new buffer"
			new-buffer)
		 (const :tag "Confirm renaming of existing buffer"
			confirm-rename-buffer)
		 (const :tag "Rename the existing buffer"
			rename-buffer))
  :group 'shell
  :version "24.3")

(defun async-shell-command (command &optional output-buffer error-buffer)
  "Execute string COMMAND asynchronously in background.

Like `shell-command', but adds `&' at the end of COMMAND
to execute it asynchronously.

The output appears in the buffer `*Async Shell Command*'.
That buffer is in shell mode.

You can configure `async-shell-command-buffer' to specify what to do in
case when `*Async Shell Command*' buffer is already taken by another
running shell command.  To run COMMAND without displaying the output
in a window you can configure `display-buffer-alist' to use the action
`display-buffer-no-window' for the buffer `*Async Shell Command*'.

In Elisp, you will often be better served by calling `start-process'
directly, since it offers more control and does not impose the use of a
shell (with its need to quote arguments)."
  (interactive
   (list
    (read-shell-command "Async shell command: " nil nil
			(let ((filename
			       (cond
				(buffer-file-name)
				((eq major-mode 'dired-mode)
				 (dired-get-filename nil t)))))
			  (and filename (file-relative-name filename))))
    current-prefix-arg
    shell-command-default-error-buffer))
  (unless (string-match "&[ \t]*\\'" command)
    (setq command (concat command " &")))
  (shell-command command output-buffer error-buffer))

(defun shell-command (command &optional output-buffer error-buffer)
  "Execute string COMMAND in inferior shell; display output, if any.
With prefix argument, insert the COMMAND's output at point.

Interactively, prompt for COMMAND in the minibuffer.

If COMMAND ends in `&', execute it asynchronously.
The output appears in the buffer `*Async Shell Command*'.
That buffer is in shell mode.  You can also use
`async-shell-command' that automatically adds `&'.

Otherwise, COMMAND is executed synchronously.  The output appears in
the buffer `*Shell Command Output*'.  If the output is short enough to
display in the echo area (which is determined by the variables
`resize-mini-windows' and `max-mini-window-height'), it is shown
there, but it is nonetheless available in buffer `*Shell Command
Output*' even though that buffer is not automatically displayed.

To specify a coding system for converting non-ASCII characters
in the shell command output, use \\[universal-coding-system-argument] \
before this command.

Noninteractive callers can specify coding systems by binding
`coding-system-for-read' and `coding-system-for-write'.

The optional second argument OUTPUT-BUFFER, if non-nil,
says to put the output in some other buffer.
If OUTPUT-BUFFER is a buffer or buffer name, erase that buffer
and insert the output there.
If OUTPUT-BUFFER is not a buffer and not nil, insert the output
in current buffer after point leaving mark after it.
This cannot be done asynchronously.

If the command terminates without error, but generates output,
and you did not specify \"insert it in the current buffer\",
the output can be displayed in the echo area or in its buffer.
If the output is short enough to display in the echo area
\(determined by the variable `max-mini-window-height' if
`resize-mini-windows' is non-nil), it is shown there.
Otherwise,the buffer containing the output is displayed.

If there is output and an error, and you did not specify \"insert it
in the current buffer\", a message about the error goes at the end
of the output.

If there is no output, or if output is inserted in the current buffer,
then `*Shell Command Output*' is deleted.

If the optional third argument ERROR-BUFFER is non-nil, it is a buffer
or buffer name to which to direct the command's standard error output.
If it is nil, error output is mingled with regular output.
In an interactive call, the variable `shell-command-default-error-buffer'
specifies the value of ERROR-BUFFER.

In Elisp, you will often be better served by calling `call-process' or
`start-process' directly, since it offers more control and does not impose
the use of a shell (with its need to quote arguments)."

  (interactive
   (list
    (read-shell-command "Shell command: " nil nil
			(let ((filename
			       (cond
				(buffer-file-name)
				((eq major-mode 'dired-mode)
				 (dired-get-filename nil t)))))
			  (and filename (file-relative-name filename))))
    current-prefix-arg
    shell-command-default-error-buffer))
  ;; Look for a handler in case default-directory is a remote file name.
  (let ((handler
	 (find-file-name-handler (directory-file-name default-directory)
				 'shell-command)))
    (if handler
	(funcall handler 'shell-command command output-buffer error-buffer)
      (if (and output-buffer
	       (not (or (bufferp output-buffer)  (stringp output-buffer))))
	  ;; Output goes in current buffer.
	  (let ((error-file
		 (if error-buffer
		     (make-temp-file
		      (expand-file-name "scor"
					(or small-temporary-file-directory
					    temporary-file-directory)))
		   nil)))
	    (barf-if-buffer-read-only)
	    (push-mark nil t)
	    ;; We do not use -f for csh; we will not support broken use of
	    ;; .cshrcs.  Even the BSD csh manual says to use
	    ;; "if ($?prompt) exit" before things which are not useful
	    ;; non-interactively.  Besides, if someone wants their other
	    ;; aliases for shell commands then they can still have them.
	    (call-process shell-file-name nil
			  (if error-file
			      (list t error-file)
			    t)
			  nil shell-command-switch command)
	    (when (and error-file (file-exists-p error-file))
	      (if (< 0 (nth 7 (file-attributes error-file)))
		  (with-current-buffer (get-buffer-create error-buffer)
		    (let ((pos-from-end (- (point-max) (point))))
		      (or (bobp)
			  (insert "\f\n"))
		      ;; Do no formatting while reading error file,
		      ;; because that can run a shell command, and we
		      ;; don't want that to cause an infinite recursion.
		      (format-insert-file error-file nil)
		      ;; Put point after the inserted errors.
		      (goto-char (- (point-max) pos-from-end)))
		    (display-buffer (current-buffer))))
	      (delete-file error-file))
	    ;; This is like exchange-point-and-mark, but doesn't
	    ;; activate the mark.  It is cleaner to avoid activation,
	    ;; even though the command loop would deactivate the mark
	    ;; because we inserted text.
	    (goto-char (prog1 (mark t)
			 (set-marker (mark-marker) (point)
				     (current-buffer)))))
	;; Output goes in a separate buffer.
	;; Preserve the match data in case called from a program.
        ;; FIXME: It'd be ridiculous for an Elisp function to call
        ;; shell-command and assume that it won't mess the match-data!
	(save-match-data
	  (if (string-match "[ \t]*&[ \t]*\\'" command)
	      ;; Command ending with ampersand means asynchronous.
	      (let ((buffer (get-buffer-create
			     (or output-buffer "*Async Shell Command*")))
		    (directory default-directory)
		    proc)
		;; Remove the ampersand.
		(setq command (substring command 0 (match-beginning 0)))
		;; Ask the user what to do with already running process.
		(setq proc (get-buffer-process buffer))
		(when proc
		  (cond
		   ((eq async-shell-command-buffer 'confirm-kill-process)
		    ;; If will kill a process, query first.
		    (if (yes-or-no-p "A command is running in the default buffer.  Kill it? ")
			(kill-process proc)
		      (error "Shell command in progress")))
		   ((eq async-shell-command-buffer 'confirm-new-buffer)
		    ;; If will create a new buffer, query first.
		    (if (yes-or-no-p "A command is running in the default buffer.  Use a new buffer? ")
			(setq buffer (generate-new-buffer
				      (or (and (bufferp output-buffer) (buffer-name output-buffer))
					  output-buffer "*Async Shell Command*")))
		      (error "Shell command in progress")))
		   ((eq async-shell-command-buffer 'new-buffer)
		    ;; It will create a new buffer.
		    (setq buffer (generate-new-buffer
				  (or (and (bufferp output-buffer) (buffer-name output-buffer))
				      output-buffer "*Async Shell Command*"))))
		   ((eq async-shell-command-buffer 'confirm-rename-buffer)
		    ;; If will rename the buffer, query first.
		    (if (yes-or-no-p "A command is running in the default buffer.  Rename it? ")
			(progn
			  (with-current-buffer buffer
			    (rename-uniquely))
			  (setq buffer (get-buffer-create
					(or output-buffer "*Async Shell Command*"))))
		      (error "Shell command in progress")))
		   ((eq async-shell-command-buffer 'rename-buffer)
		    ;; It will rename the buffer.
		    (with-current-buffer buffer
		      (rename-uniquely))
		    (setq buffer (get-buffer-create
				  (or output-buffer "*Async Shell Command*"))))))
		(with-current-buffer buffer
		  (setq buffer-read-only nil)
		  ;; Setting buffer-read-only to nil doesn't suffice
		  ;; if some text has a non-nil read-only property,
		  ;; which comint sometimes adds for prompts.
		  (let ((inhibit-read-only t))
		    (erase-buffer))
		  (display-buffer buffer '(nil (allow-no-window . t)))
		  (setq default-directory directory)
		  (setq proc (start-process "Shell" buffer shell-file-name
					    shell-command-switch command))
		  (setq mode-line-process '(":%s"))
		  (require 'shell) (shell-mode)
		  (set-process-sentinel proc 'shell-command-sentinel)
		  ;; Use the comint filter for proper handling of carriage motion
		  ;; (see `comint-inhibit-carriage-motion'),.
		  (set-process-filter proc 'comint-output-filter)
		  ))
	    ;; Otherwise, command is executed synchronously.
	    (shell-command-on-region (point) (point) command
				     output-buffer nil error-buffer)))))))

(defun display-message-or-buffer (message &optional buffer-name action frame)
  "Display MESSAGE in the echo area if possible, otherwise in a pop-up buffer.
MESSAGE may be either a string or a buffer.

A pop-up buffer is displayed using `display-buffer' if MESSAGE is too long
for maximum height of the echo area, as defined by `max-mini-window-height'
if `resize-mini-windows' is non-nil.

Returns either the string shown in the echo area, or when a pop-up
buffer is used, the window used to display it.

If MESSAGE is a string, then the optional argument BUFFER-NAME is the
name of the buffer used to display it in the case where a pop-up buffer
is used, defaulting to `*Message*'.  In the case where MESSAGE is a
string and it is displayed in the echo area, it is not specified whether
the contents are inserted into the buffer anyway.

Optional arguments ACTION and FRAME are as for `display-buffer',
and are only used if a pop-up buffer is displayed."
  (cond ((and (stringp message) (not (string-match "\n" message)))
	 ;; Trivial case where we can use the echo area
	 (message "%s" message))
	((and (stringp message)
	      (= (string-match "\n" message) (1- (length message))))
	 ;; Trivial case where we can just remove single trailing newline
	 (message "%s" (substring message 0 (1- (length message)))))
	(t
	 ;; General case
	 (with-current-buffer
	     (if (bufferp message)
		 message
	       (get-buffer-create (or buffer-name "*Message*")))

	   (unless (bufferp message)
	     (erase-buffer)
	     (insert message))

	   (let ((lines
		  (if (= (buffer-size) 0)
		      0
		    (count-screen-lines nil nil nil (minibuffer-window)))))
	     (cond ((= lines 0))
		   ((and (or (<= lines 1)
			     (<= lines
				 (if resize-mini-windows
				     (cond ((floatp max-mini-window-height)
					    (* (frame-height)
					       max-mini-window-height))
					   ((integerp max-mini-window-height)
					    max-mini-window-height)
					   (t
					    1))
				   1)))
			 ;; Don't use the echo area if the output buffer is
			 ;; already displayed in the selected frame.
			 (not (get-buffer-window (current-buffer))))
		    ;; Echo area
		    (goto-char (point-max))
		    (when (bolp)
		      (backward-char 1))
		    (message "%s" (buffer-substring (point-min) (point))))
		   (t
		    ;; Buffer
		    (goto-char (point-min))
		    (display-buffer (current-buffer) action frame))))))))


;; We have a sentinel to prevent insertion of a termination message
;; in the buffer itself.
(defun shell-command-sentinel (process signal)
  (if (memq (process-status process) '(exit signal))
      (message "%s: %s."
	       (car (cdr (cdr (process-command process))))
	       (substring signal 0 -1))))

(defun shell-command-on-region (start end command
				      &optional output-buffer replace
				      error-buffer display-error-buffer
				      region-noncontiguous-p)
  "Execute string COMMAND in inferior shell with region as input.
Normally display output (if any) in temp buffer `*Shell Command Output*';
Prefix arg means replace the region with it.  Return the exit code of
COMMAND.

To specify a coding system for converting non-ASCII characters
in the input and output to the shell command, use \\[universal-coding-system-argument]
before this command.  By default, the input (from the current buffer)
is encoded using coding-system specified by `process-coding-system-alist',
falling back to `default-process-coding-system' if no match for COMMAND
is found in `process-coding-system-alist'.

Noninteractive callers can specify coding systems by binding
`coding-system-for-read' and `coding-system-for-write'.

If the command generates output, the output may be displayed
in the echo area or in a buffer.
If the output is short enough to display in the echo area
\(determined by the variable `max-mini-window-height' if
`resize-mini-windows' is non-nil), it is shown there.
Otherwise it is displayed in the buffer `*Shell Command Output*'.
The output is available in that buffer in both cases.

If there is output and an error, a message about the error
appears at the end of the output.  If there is no output, or if
output is inserted in the current buffer, the buffer `*Shell
Command Output*' is deleted.

Optional fourth arg OUTPUT-BUFFER specifies where to put the
command's output.  If the value is a buffer or buffer name,
erase that buffer and insert the output there.
If the value is nil, use the buffer `*Shell Command Output*'.
Any other non-nil value means to insert the output in the
current buffer after START.

Optional fifth arg REPLACE, if non-nil, means to insert the
output in place of text from START to END, putting point and mark
around it.

Optional sixth arg ERROR-BUFFER, if non-nil, specifies a buffer
or buffer name to which to direct the command's standard error
output.  If nil, error output is mingled with regular output.
When called interactively, `shell-command-default-error-buffer'
is used for ERROR-BUFFER.

Optional seventh arg DISPLAY-ERROR-BUFFER, if non-nil, means to
display the error buffer if there were any errors.  When called
interactively, this is t."
  (interactive (let (string)
		 (unless (mark)
		   (user-error "The mark is not set now, so there is no region"))
		 ;; Do this before calling region-beginning
		 ;; and region-end, in case subprocess output
		 ;; relocates them while we are in the minibuffer.
		 (setq string (read-shell-command "Shell command on region: "))
		 ;; call-interactively recognizes region-beginning and
		 ;; region-end specially, leaving them in the history.
		 (list (region-beginning) (region-end)
		       string
		       current-prefix-arg
		       current-prefix-arg
		       shell-command-default-error-buffer
		       t
		       (region-noncontiguous-p))))
  (let ((error-file
	 (if error-buffer
	     (make-temp-file
	      (expand-file-name "scor"
				(or small-temporary-file-directory
				    temporary-file-directory)))
	   nil))
	exit-status)
    ;; Unless a single contiguous chunk is selected, operate on multiple chunks.
    (if region-noncontiguous-p
        (let ((input (concat (funcall region-extract-function 'delete) "\n"))
              output)
          (with-temp-buffer
            (insert input)
            (call-process-region (point-min) (point-max)
                                 shell-file-name t t
                                 nil shell-command-switch
                                 command)
            (setq output (split-string (buffer-string) "\n")))
          (goto-char start)
          (funcall region-insert-function output))
      (if (or replace
              (and output-buffer
                   (not (or (bufferp output-buffer) (stringp output-buffer)))))
          ;; Replace specified region with output from command.
          (let ((swap (and replace (< start end))))
            ;; Don't muck with mark unless REPLACE says we should.
            (goto-char start)
            (and replace (push-mark (point) 'nomsg))
            (setq exit-status
                  (call-process-region start end shell-file-name replace
                                       (if error-file
                                           (list t error-file)
                                         t)
                                       nil shell-command-switch command))
            ;; It is rude to delete a buffer which the command is not using.
            ;; (let ((shell-buffer (get-buffer "*Shell Command Output*")))
            ;;   (and shell-buffer (not (eq shell-buffer (current-buffer)))
            ;; 	 (kill-buffer shell-buffer)))
            ;; Don't muck with mark unless REPLACE says we should.
            (and replace swap (exchange-point-and-mark)))
        ;; No prefix argument: put the output in a temp buffer,
        ;; replacing its entire contents.
        (let ((buffer (get-buffer-create
                       (or output-buffer "*Shell Command Output*"))))
          (unwind-protect
              (if (eq buffer (current-buffer))
                  ;; If the input is the same buffer as the output,
                  ;; delete everything but the specified region,
                  ;; then replace that region with the output.
                  (progn (setq buffer-read-only nil)
                         (delete-region (max start end) (point-max))
                         (delete-region (point-min) (min start end))
                         (setq exit-status
                               (call-process-region (point-min) (point-max)
                                                    shell-file-name t
                                                    (if error-file
                                                        (list t error-file)
                                                      t)
                                                    nil shell-command-switch
                                                    command)))
                ;; Clear the output buffer, then run the command with
                ;; output there.
                (let ((directory default-directory))
                  (with-current-buffer buffer
                    (setq buffer-read-only nil)
                    (if (not output-buffer)
                        (setq default-directory directory))
                    (erase-buffer)))
                (setq exit-status
                      (call-process-region start end shell-file-name nil
                                           (if error-file
                                               (list buffer error-file)
                                             buffer)
                                           nil shell-command-switch command)))
            ;; Report the output.
            (with-current-buffer buffer
              (setq mode-line-process
                    (cond ((null exit-status)
                           " - Error")
                          ((stringp exit-status)
                           (format " - Signal [%s]" exit-status))
                          ((not (equal 0 exit-status))
                           (format " - Exit [%d]" exit-status)))))
            (if (with-current-buffer buffer (> (point-max) (point-min)))
                ;; There's some output, display it
                (display-message-or-buffer buffer)
              ;; No output; error?
              (let ((output
                     (if (and error-file
                              (< 0 (nth 7 (file-attributes error-file))))
                         (format "some error output%s"
                                 (if shell-command-default-error-buffer
                                     (format " to the \"%s\" buffer"
                                             shell-command-default-error-buffer)
                                   ""))
                       "no output")))
                (cond ((null exit-status)
                       (message "(Shell command failed with error)"))
                      ((equal 0 exit-status)
                       (message "(Shell command succeeded with %s)"
                                output))
                      ((stringp exit-status)
                       (message "(Shell command killed by signal %s)"
                                exit-status))
                      (t
                       (message "(Shell command failed with code %d and %s)"
                                exit-status output))))
              ;; Don't kill: there might be useful info in the undo-log.
              ;; (kill-buffer buffer)
              )))))

    (when (and error-file (file-exists-p error-file))
      (if (< 0 (nth 7 (file-attributes error-file)))
	  (with-current-buffer (get-buffer-create error-buffer)
	    (let ((pos-from-end (- (point-max) (point))))
	      (or (bobp)
		  (insert "\f\n"))
	      ;; Do no formatting while reading error file,
	      ;; because that can run a shell command, and we
	      ;; don't want that to cause an infinite recursion.
	      (format-insert-file error-file nil)
	      ;; Put point after the inserted errors.
	      (goto-char (- (point-max) pos-from-end)))
	    (and display-error-buffer
		 (display-buffer (current-buffer)))))
      (delete-file error-file))
    exit-status))

(defun shell-command-to-string (command)
  "Execute shell command COMMAND and return its output as a string."
  (with-output-to-string
    (with-current-buffer
      standard-output
      (process-file shell-file-name nil t nil shell-command-switch command))))

(defun process-file (program &optional infile buffer display &rest args)
  "Process files synchronously in a separate process.
Similar to `call-process', but may invoke a file handler based on
`default-directory'.  The current working directory of the
subprocess is `default-directory'.

File names in INFILE and BUFFER are handled normally, but file
names in ARGS should be relative to `default-directory', as they
are passed to the process verbatim.  (This is a difference to
`call-process' which does not support file handlers for INFILE
and BUFFER.)

Some file handlers might not support all variants, for example
they might behave as if DISPLAY was nil, regardless of the actual
value passed."
  (let ((fh (find-file-name-handler default-directory 'process-file))
        lc stderr-file)
    (unwind-protect
        (if fh (apply fh 'process-file program infile buffer display args)
          (when infile (setq lc (file-local-copy infile)))
          (setq stderr-file (when (and (consp buffer) (stringp (cadr buffer)))
                              (make-temp-file "emacs")))
          (prog1
              (apply 'call-process program
                     (or lc infile)
                     (if stderr-file (list (car buffer) stderr-file) buffer)
                     display args)
            (when stderr-file (copy-file stderr-file (cadr buffer) t))))
      (when stderr-file (delete-file stderr-file))
      (when lc (delete-file lc)))))

(defvar process-file-side-effects t
  "Whether a call of `process-file' changes remote files.

By default, this variable is always set to t, meaning that a
call of `process-file' could potentially change any file on a
remote host.  When set to nil, a file handler could optimize
its behavior with respect to remote file attribute caching.

You should only ever change this variable with a let-binding;
never with `setq'.")

(defun start-file-process (name buffer program &rest program-args)
  "Start a program in a subprocess.  Return the process object for it.

Similar to `start-process', but may invoke a file handler based on
`default-directory'.  See Info node `(elisp)Magic File Names'.

This handler ought to run PROGRAM, perhaps on the local host,
perhaps on a remote host that corresponds to `default-directory'.
In the latter case, the local part of `default-directory' becomes
the working directory of the process.

PROGRAM and PROGRAM-ARGS might be file names.  They are not
objects of file handler invocation.  File handlers might not
support pty association, if PROGRAM is nil."
  (let ((fh (find-file-name-handler default-directory 'start-file-process)))
    (if fh (apply fh 'start-file-process name buffer program program-args)
      (apply 'start-process name buffer program program-args))))
\f
;;;; Process menu

(defvar tabulated-list-format)
(defvar tabulated-list-entries)
(defvar tabulated-list-sort-key)
(declare-function tabulated-list-init-header  "tabulated-list" ())
(declare-function tabulated-list-print "tabulated-list"
                  (&optional remember-pos update))

(defvar process-menu-query-only nil)

(defvar process-menu-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map [?d] 'process-menu-delete-process)
    map))

(define-derived-mode process-menu-mode tabulated-list-mode "Process Menu"
  "Major mode for listing the processes called by Emacs."
  (setq tabulated-list-format [("Process" 15 t)
			       ("PID"      7 t)
			       ("Status"   7 t)
			       ("Buffer"  15 t)
			       ("TTY"     12 t)
			       ("Command"  0 t)])
  (make-local-variable 'process-menu-query-only)
  (setq tabulated-list-sort-key (cons "Process" nil))
  (add-hook 'tabulated-list-revert-hook 'list-processes--refresh nil t)
  (tabulated-list-init-header))

(defun process-menu-delete-process ()
  "Kill process at point in a `list-processes' buffer."
  (interactive)
  (let ((pos (point)))
    (delete-process (tabulated-list-get-id))
    (revert-buffer)
    (goto-char (min pos (point-max)))
    (if (eobp)
        (forward-line -1)
      (beginning-of-line))))

(defun list-processes--refresh ()
  "Recompute the list of processes for the Process List buffer.
Also, delete any process that is exited or signaled."
  (setq tabulated-list-entries nil)
  (dolist (p (process-list))
    (cond ((memq (process-status p) '(exit signal closed))
	   (delete-process p))
	  ((or (not process-menu-query-only)
	       (process-query-on-exit-flag p))
	   (let* ((buf (process-buffer p))
		  (type (process-type p))
		  (pid  (if (process-id p) (format "%d" (process-id p)) "--"))
		  (name (process-name p))
		  (status (symbol-name (process-status p)))
		  (buf-label (if (buffer-live-p buf)
				 `(,(buffer-name buf)
				   face link
				   help-echo ,(format-message
					       "Visit buffer `%s'"
					       (buffer-name buf))
				   follow-link t
				   process-buffer ,buf
				   action process-menu-visit-buffer)
			       "--"))
		  (tty (or (process-tty-name p) "--"))
		  (cmd
		   (if (memq type '(network serial))
		       (let ((contact (process-contact p t)))
			 (if (eq type 'network)
			     (format "(%s %s)"
				     (if (plist-get contact :type)
					 "datagram"
				       "network")
				     (if (plist-get contact :server)
					 (format "server on %s"
						 (or
						  (plist-get contact :host)
						  (plist-get contact :local)))
				       (format "connection to %s"
					       (plist-get contact :host))))
			   (format "(serial port %s%s)"
				   (or (plist-get contact :port) "?")
				   (let ((speed (plist-get contact :speed)))
				     (if speed
					 (format " at %s b/s" speed)
				       "")))))
		     (mapconcat 'identity (process-command p) " "))))
	     (push (list p (vector name pid status buf-label tty cmd))
		   tabulated-list-entries))))))

(defun process-menu-visit-buffer (button)
  (display-buffer (button-get button 'process-buffer)))

(defun list-processes (&optional query-only buffer)
  "Display a list of all processes that are Emacs sub-processes.
If optional argument QUERY-ONLY is non-nil, only processes with
the query-on-exit flag set are listed.
Any process listed as exited or signaled is actually eliminated
after the listing is made.
Optional argument BUFFER specifies a buffer to use, instead of
\"*Process List*\".
The return value is always nil.

This function lists only processes that were launched by Emacs.  To
see other processes running on the system, use `list-system-processes'."
  (interactive)
  (or (fboundp 'process-list)
      (error "Asynchronous subprocesses are not supported on this system"))
  (unless (bufferp buffer)
    (setq buffer (get-buffer-create "*Process List*")))
  (with-current-buffer buffer
    (process-menu-mode)
    (setq process-menu-query-only query-only)
    (list-processes--refresh)
    (tabulated-list-print))
  (display-buffer buffer)
  nil)
\f
;;;; Prefix commands

(setq prefix-command--needs-update nil)
(setq prefix-command--last-echo nil)

(defun internal-echo-keystrokes-prefix ()
  ;; BEWARE: Called directly from C code.
  ;; If the return value is non-nil, it means we are in the middle of
  ;; a command with prefix, such as a command invoked with prefix-arg.
  (if (not prefix-command--needs-update)
      prefix-command--last-echo
    (setq prefix-command--last-echo
          (let ((strs nil))
            (run-hook-wrapped 'prefix-command-echo-keystrokes-functions
                              (lambda (fun) (push (funcall fun) strs)))
            (setq strs (delq nil strs))
            (when strs (mapconcat #'identity strs " "))))))

(defvar prefix-command-echo-keystrokes-functions nil
  "Abnormal hook which constructs the description of the current prefix state.
Each function is called with no argument, should return a string or nil.")

(defun prefix-command-update ()
  "Update state of prefix commands.
Call it whenever you change the \"prefix command state\"."
  (setq prefix-command--needs-update t))

(defvar prefix-command-preserve-state-hook nil
  "Normal hook run when a command needs to preserve the prefix.")

(defun prefix-command-preserve-state ()
  "Pass the current prefix command state to the next command.
Should be called by all prefix commands.
Runs `prefix-command-preserve-state-hook'."
  (run-hooks 'prefix-command-preserve-state-hook)
  ;; If the current command is a prefix command, we don't want the next (real)
  ;; command to have `last-command' set to, say, `universal-argument'.
  (setq this-command last-command)
  (setq real-this-command real-last-command)
  (prefix-command-update))

(defun reset-this-command-lengths ()
  (declare (obsolete prefix-command-preserve-state "25.1"))
  nil)

;;;;; The main prefix command.

;; FIXME: Declaration of `prefix-arg' should be moved here!?

(add-hook 'prefix-command-echo-keystrokes-functions
          #'universal-argument--description)
(defun universal-argument--description ()
  (when prefix-arg
    (concat "C-u"
            (pcase prefix-arg
              (`(-) " -")
              (`(,(and (pred integerp) n))
               (let ((str ""))
                 (while (and (> n 4) (= (mod n 4) 0))
                   (setq str (concat str " C-u"))
                   (setq n (/ n 4)))
                 (if (= n 4) str (format " %s" prefix-arg))))
              (_ (format " %s" prefix-arg))))))

(add-hook 'prefix-command-preserve-state-hook
          #'universal-argument--preserve)
(defun universal-argument--preserve ()
  (setq prefix-arg current-prefix-arg))

(defvar universal-argument-map
  (let ((map (make-sparse-keymap))
        (universal-argument-minus
         ;; For backward compatibility, minus with no modifiers is an ordinary
         ;; command if digits have already been entered.
         `(menu-item "" negative-argument
                     :filter ,(lambda (cmd)
                                (if (integerp prefix-arg) nil cmd)))))
    (define-key map [switch-frame]
      (lambda (e) (interactive "e")
        (handle-switch-frame e) (universal-argument--mode)))
    (define-key map [?\C-u] 'universal-argument-more)
    (define-key map [?-] universal-argument-minus)
    (define-key map [?0] 'digit-argument)
    (define-key map [?1] 'digit-argument)
    (define-key map [?2] 'digit-argument)
    (define-key map [?3] 'digit-argument)
    (define-key map [?4] 'digit-argument)
    (define-key map [?5] 'digit-argument)
    (define-key map [?6] 'digit-argument)
    (define-key map [?7] 'digit-argument)
    (define-key map [?8] 'digit-argument)
    (define-key map [?9] 'digit-argument)
    (define-key map [kp-0] 'digit-argument)
    (define-key map [kp-1] 'digit-argument)
    (define-key map [kp-2] 'digit-argument)
    (define-key map [kp-3] 'digit-argument)
    (define-key map [kp-4] 'digit-argument)
    (define-key map [kp-5] 'digit-argument)
    (define-key map [kp-6] 'digit-argument)
    (define-key map [kp-7] 'digit-argument)
    (define-key map [kp-8] 'digit-argument)
    (define-key map [kp-9] 'digit-argument)
    (define-key map [kp-subtract] universal-argument-minus)
    map)
  "Keymap used while processing \\[universal-argument].")

(defun universal-argument--mode ()
  (prefix-command-update)
  (set-transient-map universal-argument-map nil))

(defun universal-argument ()
  "Begin a numeric argument for the following command.
Digits or minus sign following \\[universal-argument] make up the numeric argument.
\\[universal-argument] following the digits or minus sign ends the argument.
\\[universal-argument] without digits or minus sign provides 4 as argument.
Repeating \\[universal-argument] without digits or minus sign
 multiplies the argument by 4 each time.
For some commands, just \\[universal-argument] by itself serves as a flag
which is different in effect from any particular numeric argument.
These commands include \\[set-mark-command] and \\[start-kbd-macro]."
  (interactive)
  (prefix-command-preserve-state)
  (setq prefix-arg (list 4))
  (universal-argument--mode))

(defun universal-argument-more (arg)
  ;; A subsequent C-u means to multiply the factor by 4 if we've typed
  ;; nothing but C-u's; otherwise it means to terminate the prefix arg.
  (interactive "P")
  (prefix-command-preserve-state)
  (setq prefix-arg (if (consp arg)
                       (list (* 4 (car arg)))
                     (if (eq arg '-)
                         (list -4)
                       arg)))
  (when (consp prefix-arg) (universal-argument--mode)))

(defun negative-argument (arg)
  "Begin a negative numeric argument for the next command.
\\[universal-argument] following digits or minus sign ends the argument."
  (interactive "P")
  (prefix-command-preserve-state)
  (setq prefix-arg (cond ((integerp arg) (- arg))
                         ((eq arg '-) nil)
                         (t '-)))
  (universal-argument--mode))

(defun digit-argument (arg)
  "Part of the numeric argument for the next command.
\\[universal-argument] following digits or minus sign ends the argument."
  (interactive "P")
  (prefix-command-preserve-state)
  (let* ((char (if (integerp last-command-event)
		   last-command-event
		 (get last-command-event 'ascii-character)))
	 (digit (- (logand char ?\177) ?0)))
    (setq prefix-arg (cond ((integerp arg)
                            (+ (* arg 10)
			       (if (< arg 0) (- digit) digit)))
                           ((eq arg '-)
                            ;; Treat -0 as just -, so that -01 will work.
                            (if (zerop digit) '- (- digit)))
                           (t
                            digit))))
  (universal-argument--mode))
\f

(defvar filter-buffer-substring-functions nil
  "This variable is a wrapper hook around `buffer-substring--filter'.")
(make-obsolete-variable 'filter-buffer-substring-functions
                        'filter-buffer-substring-function "24.4")

(defvar filter-buffer-substring-function #'buffer-substring--filter
  "Function to perform the filtering in `filter-buffer-substring'.
The function is called with the same 3 arguments (BEG END DELETE)
that `filter-buffer-substring' received.  It should return the
buffer substring between BEG and END, after filtering.  If DELETE is
non-nil, it should delete the text between BEG and END from the buffer.")

(defvar buffer-substring-filters nil
  "List of filter functions for `buffer-substring--filter'.
Each function must accept a single argument, a string, and return a string.
The buffer substring is passed to the first function in the list,
and the return value of each function is passed to the next.
As a special convention, point is set to the start of the buffer text
being operated on (i.e., the first argument of `buffer-substring--filter')
before these functions are called.")
(make-obsolete-variable 'buffer-substring-filters
                        'filter-buffer-substring-function "24.1")

(defun filter-buffer-substring (beg end &optional delete)
  "Return the buffer substring between BEG and END, after filtering.
If DELETE is non-nil, delete the text between BEG and END from the buffer.

This calls the function that `filter-buffer-substring-function' specifies
\(passing the same three arguments that it received) to do the work,
and returns whatever it does.  The default function does no filtering,
unless a hook has been set.

Use `filter-buffer-substring' instead of `buffer-substring',
`buffer-substring-no-properties', or `delete-and-extract-region' when
you want to allow filtering to take place.  For example, major or minor
modes can use `filter-buffer-substring-function' to extract characters
that are special to a buffer, and should not be copied into other buffers."
  (funcall filter-buffer-substring-function beg end delete))

(defun buffer-substring--filter (beg end &optional delete)
  "Default function to use for `filter-buffer-substring-function'.
Its arguments and return value are as specified for `filter-buffer-substring'.
This respects the wrapper hook `filter-buffer-substring-functions',
and the abnormal hook `buffer-substring-filters'.
No filtering is done unless a hook says to."
  (subr--with-wrapper-hook-no-warnings
    filter-buffer-substring-functions (beg end delete)
    (cond
     ((or delete buffer-substring-filters)
      (save-excursion
        (goto-char beg)
        (let ((string (if delete (delete-and-extract-region beg end)
                        (buffer-substring beg end))))
          (dolist (filter buffer-substring-filters)
            (setq string (funcall filter string)))
          string)))
     (t
      (buffer-substring beg end)))))


;;;; Window system cut and paste hooks.

(defvar interprogram-cut-function #'gui-select-text
  "Function to call to make a killed region available to other programs.
Most window systems provide a facility for cutting and pasting
text between different programs, such as the clipboard on X and
MS-Windows, or the pasteboard on Nextstep/Mac OS.

This variable holds a function that Emacs calls whenever text is
put in the kill ring, to make the new kill available to other
programs.  The function takes one argument, TEXT, which is a
string containing the text which should be made available.")

(defvar interprogram-paste-function #'gui-selection-value
  "Function to call to get text cut from other programs.
Most window systems provide a facility for cutting and pasting
text between different programs, such as the clipboard on X and
MS-Windows, or the pasteboard on Nextstep/Mac OS.

This variable holds a function that Emacs calls to obtain text
that other programs have provided for pasting.  The function is
called with no arguments.  If no other program has provided text
to paste, the function should return nil (in which case the
caller, usually `current-kill', should use the top of the Emacs
kill ring).  If another program has provided text to paste, the
function should return that text as a string (in which case the
caller should put this string in the kill ring as the latest
kill).

The function may also return a list of strings if the window
system supports multiple selections.  The first string will be
used as the pasted text, but the other will be placed in the kill
ring for easy access via `yank-pop'.

Note that the function should return a string only if a program
other than Emacs has provided a string for pasting; if Emacs
provided the most recent string, the function should return nil.
If it is difficult to tell whether Emacs or some other program
provided the current string, it is probably good enough to return
nil if the string is equal (according to `string=') to the last
text Emacs provided.")
\f


;;;; The kill ring data structure.

(defvar kill-ring nil
  "List of killed text sequences.
Since the kill ring is supposed to interact nicely with cut-and-paste
facilities offered by window systems, use of this variable should
interact nicely with `interprogram-cut-function' and
`interprogram-paste-function'.  The functions `kill-new',
`kill-append', and `current-kill' are supposed to implement this
interaction; you may want to use them instead of manipulating the kill
ring directly.")

(defcustom kill-ring-max 60
  "Maximum length of kill ring before oldest elements are thrown away."
  :type 'integer
  :group 'killing)

(defvar kill-ring-yank-pointer nil
  "The tail of the kill ring whose car is the last thing yanked.")

(defcustom save-interprogram-paste-before-kill nil
  "Save clipboard strings into kill ring before replacing them.
When one selects something in another program to paste it into Emacs,
but kills something in Emacs before actually pasting it,
this selection is gone unless this variable is non-nil,
in which case the other program's selection is saved in the `kill-ring'
before the Emacs kill and one can still paste it using \\[yank] \\[yank-pop]."
  :type 'boolean
  :group 'killing
  :version "23.2")

(defcustom kill-do-not-save-duplicates nil
  "Do not add a new string to `kill-ring' if it duplicates the last one.
The comparison is done using `equal-including-properties'."
  :type 'boolean
  :group 'killing
  :version "23.2")

(defun kill-new (string &optional replace)
  "Make STRING the latest kill in the kill ring.
Set `kill-ring-yank-pointer' to point to it.
If `interprogram-cut-function' is non-nil, apply it to STRING.
Optional second argument REPLACE non-nil means that STRING will replace
the front of the kill ring, rather than being added to the list.

When `save-interprogram-paste-before-kill' and `interprogram-paste-function'
are non-nil, saves the interprogram paste string(s) into `kill-ring' before
STRING.

When the yank handler has a non-nil PARAM element, the original STRING
argument is not used by `insert-for-yank'.  However, since Lisp code
may access and use elements from the kill ring directly, the STRING
argument should still be a \"useful\" string for such uses."
  (unless (and kill-do-not-save-duplicates
	       ;; Due to text properties such as 'yank-handler that
	       ;; can alter the contents to yank, comparison using
	       ;; `equal' is unsafe.
	       (equal-including-properties string (car kill-ring)))
    (if (fboundp 'menu-bar-update-yank-menu)
	(menu-bar-update-yank-menu string (and replace (car kill-ring)))))
  (when save-interprogram-paste-before-kill
    (let ((interprogram-paste (and interprogram-paste-function
                                   (funcall interprogram-paste-function))))
      (when interprogram-paste
        (dolist (s (if (listp interprogram-paste)
		       (nreverse interprogram-paste)
		     (list interprogram-paste)))
	  (unless (and kill-do-not-save-duplicates
		       (equal-including-properties s (car kill-ring)))
	    (push s kill-ring))))))
  (unless (and kill-do-not-save-duplicates
	       (equal-including-properties string (car kill-ring)))
    (if (and replace kill-ring)
	(setcar kill-ring string)
      (push string kill-ring)
      (if (> (length kill-ring) kill-ring-max)
	  (setcdr (nthcdr (1- kill-ring-max) kill-ring) nil))))
  (setq kill-ring-yank-pointer kill-ring)
  (if interprogram-cut-function
      (funcall interprogram-cut-function string)))

;; It has been argued that this should work similar to `self-insert-command'
;; which merges insertions in undo-list in groups of 20 (hard-coded in cmds.c).
(defcustom kill-append-merge-undo nil
  "Whether appending to kill ring also makes \\[undo] restore both pieces of text simultaneously."
  :type 'boolean
  :group 'killing
  :version "25.1")

(defun kill-append (string before-p)
  "Append STRING to the end of the latest kill in the kill ring.
If BEFORE-P is non-nil, prepend STRING to the kill.
Also removes the last undo boundary in the current buffer,
 depending on `kill-append-merge-undo'.
If `interprogram-cut-function' is set, pass the resulting kill to it."
  (let* ((cur (car kill-ring)))
    (kill-new (if before-p (concat string cur) (concat cur string))
	      (or (= (length cur) 0)
		  (equal nil (get-text-property 0 'yank-handler cur))))
    (when (and kill-append-merge-undo (not buffer-read-only))
      (let ((prev buffer-undo-list)
            (next (cdr buffer-undo-list)))
        ;; find the next undo boundary
        (while (car next)
          (pop next)
          (pop prev))
        ;; remove this undo boundary
        (when prev
          (setcdr prev (cdr next)))))))

(defcustom yank-pop-change-selection nil
  "Whether rotating the kill ring changes the window system selection.
If non-nil, whenever the kill ring is rotated (usually via the
`yank-pop' command), Emacs also calls `interprogram-cut-function'
to copy the new kill to the window system selection."
  :type 'boolean
  :group 'killing
  :version "23.1")

(defun current-kill (n &optional do-not-move)
  "Rotate the yanking point by N places, and then return that kill.
If N is zero and `interprogram-paste-function' is set to a
function that returns a string or a list of strings, and if that
function doesn't return nil, then that string (or list) is added
to the front of the kill ring and the string (or first string in
the list) is returned as the latest kill.

If N is not zero, and if `yank-pop-change-selection' is
non-nil, use `interprogram-cut-function' to transfer the
kill at the new yank point into the window system selection.

If optional arg DO-NOT-MOVE is non-nil, then don't actually
move the yanking point; just return the Nth kill forward."

  (let ((interprogram-paste (and (= n 0)
				 interprogram-paste-function
				 (funcall interprogram-paste-function))))
    (if interprogram-paste
	(progn
	  ;; Disable the interprogram cut function when we add the new
	  ;; text to the kill ring, so Emacs doesn't try to own the
	  ;; selection, with identical text.
	  (let ((interprogram-cut-function nil))
	    (if (listp interprogram-paste)
	      (mapc 'kill-new (nreverse interprogram-paste))
	      (kill-new interprogram-paste)))
	  (car kill-ring))
      (or kill-ring (error "Kill ring is empty"))
      (let ((ARGth-kill-element
	     (nthcdr (mod (- n (length kill-ring-yank-pointer))
			  (length kill-ring))
		     kill-ring)))
	(unless do-not-move
	  (setq kill-ring-yank-pointer ARGth-kill-element)
	  (when (and yank-pop-change-selection
		     (> n 0)
		     interprogram-cut-function)
	    (funcall interprogram-cut-function (car ARGth-kill-element))))
	(car ARGth-kill-element)))))



;;;; Commands for manipulating the kill ring.

(defcustom kill-read-only-ok nil
  "Non-nil means don't signal an error for killing read-only text."
  :type 'boolean
  :group 'killing)

(defun kill-region (beg end &optional region)
  "Kill (\"cut\") text between point and mark.
This deletes the text from the buffer and saves it in the kill ring.
The command \\[yank] can retrieve it from there.
\(If you want to save the region without killing it, use \\[kill-ring-save].)

If you want to append the killed region to the last killed text,
use \\[append-next-kill] before \\[kill-region].

Any command that calls this function is a \"kill command\".
If the previous command was also a kill command,
the text killed this time appends to the text killed last time
to make one entry in the kill ring.

The killed text is filtered by `filter-buffer-substring' before it is
saved in the kill ring, so the actual saved text might be different
from what was killed.

If the buffer is read-only, Emacs will beep and refrain from deleting
the text, but put the text in the kill ring anyway.  This means that
you can use the killing commands to copy text from a read-only buffer.

Lisp programs should use this function for killing text.
 (To delete text, use `delete-region'.)
Supply two arguments, character positions BEG and END indicating the
 stretch of text to be killed.  If the optional argument REGION is
 non-nil, the function ignores BEG and END, and kills the current
 region instead."
  ;; Pass mark first, then point, because the order matters when
  ;; calling `kill-append'.
  (interactive (list (mark) (point) 'region))
  (unless (and beg end)
    (user-error "The mark is not set now, so there is no region"))
  (condition-case nil
      (let ((string (if region
                        (funcall region-extract-function 'delete)
                      (filter-buffer-substring beg end 'delete))))
	(when string			;STRING is nil if BEG = END
	  ;; Add that string to the kill ring, one way or another.
	  (if (eq last-command 'kill-region)
	      (kill-append string (< end beg))
	    (kill-new string)))
	(when (or string (eq last-command 'kill-region))
	  (setq this-command 'kill-region))
	(setq deactivate-mark t)
	nil)
    ((buffer-read-only text-read-only)
     ;; The code above failed because the buffer, or some of the characters
     ;; in the region, are read-only.
     ;; We should beep, in case the user just isn't aware of this.
     ;; However, there's no harm in putting
     ;; the region's text in the kill ring, anyway.
     (copy-region-as-kill beg end region)
     ;; Set this-command now, so it will be set even if we get an error.
     (setq this-command 'kill-region)
     ;; This should barf, if appropriate, and give us the correct error.
     (if kill-read-only-ok
	 (progn (message "Read only text copied to kill ring") nil)
       ;; Signal an error if the buffer is read-only.
       (barf-if-buffer-read-only)
       ;; If the buffer isn't read-only, the text is.
       (signal 'text-read-only (list (current-buffer)))))))

;; copy-region-as-kill no longer sets this-command, because it's confusing
;; to get two copies of the text when the user accidentally types M-w and
;; then corrects it with the intended C-w.
(defun copy-region-as-kill (beg end &optional region)
  "Save the region as if killed, but don't kill it.
In Transient Mark mode, deactivate the mark.
If `interprogram-cut-function' is non-nil, also save the text for a window
system cut and paste.

The copied text is filtered by `filter-buffer-substring' before it is
saved in the kill ring, so the actual saved text might be different
from what was in the buffer.

When called from Lisp, save in the kill ring the stretch of text
between BEG and END, unless the optional argument REGION is
non-nil, in which case ignore BEG and END, and save the current
region instead.

This command's old key binding has been given to `kill-ring-save'."
  ;; Pass mark first, then point, because the order matters when
  ;; calling `kill-append'.
  (interactive (list (mark) (point)
		     (prefix-numeric-value current-prefix-arg)))
  (let ((str (if region
                 (funcall region-extract-function nil)
               (filter-buffer-substring beg end))))
  (if (eq last-command 'kill-region)
        (kill-append str (< end beg))
      (kill-new str)))
  (setq deactivate-mark t)
  nil)

(defun kill-ring-save (beg end &optional region)
  "Save the region as if killed, but don't kill it.
In Transient Mark mode, deactivate the mark.
If `interprogram-cut-function' is non-nil, also save the text for a window
system cut and paste.

If you want to append the killed line to the last killed text,
use \\[append-next-kill] before \\[kill-ring-save].

The copied text is filtered by `filter-buffer-substring' before it is
saved in the kill ring, so the actual saved text might be different
from what was in the buffer.

When called from Lisp, save in the kill ring the stretch of text
between BEG and END, unless the optional argument REGION is
non-nil, in which case ignore BEG and END, and save the current
region instead.

This command is similar to `copy-region-as-kill', except that it gives
visual feedback indicating the extent of the region being copied."
  ;; Pass mark first, then point, because the order matters when
  ;; calling `kill-append'.
  (interactive (list (mark) (point)
		     (prefix-numeric-value current-prefix-arg)))
  (copy-region-as-kill beg end region)
  ;; This use of called-interactively-p is correct because the code it
  ;; controls just gives the user visual feedback.
  (if (called-interactively-p 'interactive)
      (indicate-copied-region)))

(defun indicate-copied-region (&optional message-len)
  "Indicate that the region text has been copied interactively.
If the mark is visible in the selected window, blink the cursor
between point and mark if there is currently no active region
highlighting.

If the mark lies outside the selected window, display an
informative message containing a sample of the copied text.  The
optional argument MESSAGE-LEN, if non-nil, specifies the length
of this sample text; it defaults to 40."
  (let ((mark (mark t))
	(point (point))
	;; Inhibit quitting so we can make a quit here
	;; look like a C-g typed as a command.
	(inhibit-quit t))
    (if (pos-visible-in-window-p mark (selected-window))
	;; Swap point-and-mark quickly so as to show the region that
	;; was selected.  Don't do it if the region is highlighted.
	(unless (and (region-active-p)
		     (face-background 'region))
	  ;; Swap point and mark.
	  (set-marker (mark-marker) (point) (current-buffer))
	  (goto-char mark)
	  (sit-for blink-matching-delay)
	  ;; Swap back.
	  (set-marker (mark-marker) mark (current-buffer))
	  (goto-char point)
	  ;; If user quit, deactivate the mark
	  ;; as C-g would as a command.
	  (and quit-flag (region-active-p)
	       (deactivate-mark)))
      (let ((len (min (abs (- mark point))
		      (or message-len 40))))
	(if (< point mark)
	    ;; Don't say "killed"; that is misleading.
	    (message "Saved text until \"%s\""
		     (buffer-substring-no-properties (- mark len) mark))
	  (message "Saved text from \"%s\""
		   (buffer-substring-no-properties mark (+ mark len))))))))

(defun append-next-kill (&optional interactive)
  "Cause following command, if it kills, to add to previous kill.
If the next command kills forward from point, the kill is
appended to the previous killed text.  If the command kills
backward, the kill is prepended.  Kill commands that act on the
region, such as `kill-region', are regarded as killing forward if
point is after mark, and killing backward if point is before
mark.

If the next command is not a kill command, `append-next-kill' has
no effect.

The argument is used for internal purposes; do not supply one."
  (interactive "p")
  ;; We don't use (interactive-p), since that breaks kbd macros.
  (if interactive
      (progn
	(setq this-command 'kill-region)
	(message "If the next command is a kill, it will append"))
    (setq last-command 'kill-region)))

(defvar bidi-directional-controls-chars "\x202a-\x202e\x2066-\x2069"
  "Character set that matches bidirectional formatting control characters.")

(defvar bidi-directional-non-controls-chars "^\x202a-\x202e\x2066-\x2069"
  "Character set that matches any character except bidirectional controls.")

(defun squeeze-bidi-context-1 (from to category replacement)
  "A subroutine of `squeeze-bidi-context'.
FROM and TO should be markers, CATEGORY and REPLACEMENT should be strings."
  (let ((pt (copy-marker from))
	(limit (copy-marker to))
	(old-pt 0)
	lim1)
    (setq lim1 limit)
    (goto-char pt)
    (while (< pt limit)
      (if (> pt old-pt)
	  (move-marker lim1
		       (save-excursion
			 ;; L and R categories include embedding and
			 ;; override controls, but we don't want to
			 ;; replace them, because that might change
			 ;; the visual order.  Likewise with PDF and
			 ;; isolate controls.
			 (+ pt (skip-chars-forward
				bidi-directional-non-controls-chars
				limit)))))
      ;; Replace any run of non-RTL characters by a single LRM.
      (if (null (re-search-forward category lim1 t))
	  ;; No more characters of CATEGORY, we are done.
	  (setq pt limit)
	(replace-match replacement nil t)
	(move-marker pt (point)))
      (setq old-pt pt)
      ;; Skip directional controls, if any.
      (move-marker
       pt (+ pt (skip-chars-forward bidi-directional-controls-chars limit))))))

(defun squeeze-bidi-context (from to)
  "Replace characters between FROM and TO while keeping bidi context.

This function replaces the region of text with as few characters
as possible, while preserving the effect that region will have on
bidirectional display before and after the region."
  (let ((start (set-marker (make-marker)
			   (if (> from 0) from (+ (point-max) from))))
	(end (set-marker (make-marker) to))
	;; This is for when they copy text with read-only text
	;; properties.
	(inhibit-read-only t))
    (if (null (marker-position end))
	(setq end (point-max-marker)))
    ;; Replace each run of non-RTL characters with a single LRM.
    (squeeze-bidi-context-1 start end "\\CR+" "\x200e")
    ;; Replace each run of non-LTR characters with a single RLM.  Note
    ;; that the \cR category includes both the Arabic Letter (AL) and
    ;; R characters; here we ignore the distinction between them,
    ;; because that distinction only affects Arabic Number (AN)
    ;; characters, which are weak and don't affect the reordering.
    (squeeze-bidi-context-1 start end "\\CL+" "\x200f")))

(defun line-substring-with-bidi-context (start end &optional no-properties)
  "Return buffer text between START and END with its bidi context.

START and END are assumed to belong to the same physical line
of buffer text.  This function prepends and appends to the text
between START and END bidi control characters that preserve the
visual order of that text when it is inserted at some other place."
  (if (or (< start (point-min))
	  (> end (point-max)))
      (signal 'args-out-of-range (list (current-buffer) start end)))
  (let ((buf (current-buffer))
	substr para-dir from to)
    (save-excursion
      (goto-char start)
      (setq para-dir (current-bidi-paragraph-direction))
      (setq from (line-beginning-position)
	    to (line-end-position))
      (goto-char from)
      ;; If we don't have any mixed directional characters in the
      ;; entire line, we can just copy the substring without adding
      ;; any context.
      (if (or (looking-at-p "\\CR*$")
	      (looking-at-p "\\CL*$"))
	  (setq substr (if no-properties
			   (buffer-substring-no-properties start end)
			 (buffer-substring start end)))
	(setq substr
	      (with-temp-buffer
		(if no-properties
		    (insert-buffer-substring-no-properties buf from to)
		  (insert-buffer-substring buf from to))
		(squeeze-bidi-context 1 (1+ (- start from)))
		(squeeze-bidi-context (- end to) nil)
		(buffer-substring 1 (point-max)))))

      ;; Wrap the string in LRI/RLI..PDI pair to achieve 2 effects:
      ;; (1) force the string to have the same base embedding
      ;; direction as the paragraph direction at the source, no matter
      ;; what is the paragraph direction at destination; and (2) avoid
      ;; affecting the visual order of the surrounding text at
      ;; destination if there are characters of different
      ;; directionality there.
      (concat (if (eq para-dir 'left-to-right) "\x2066" "\x2067")
	      substr "\x2069"))))

(defun buffer-substring-with-bidi-context (start end &optional no-properties)
  "Return portion of current buffer between START and END with bidi context.

This function works similar to `buffer-substring', but it prepends and
appends to the text bidi directional control characters necessary to
preserve the visual appearance of the text if it is inserted at another
place.  This is useful when the buffer substring includes bidirectional
text and control characters that cause non-trivial reordering on display.
If copied verbatim, such text can have a very different visual appearance,
and can also change the visual appearance of the surrounding text at the
destination of the copy.

Optional argument NO-PROPERTIES, if non-nil, means copy the text without
the text properties."
  (let (line-end substr)
    (if (or (< start (point-min))
	    (> end (point-max)))
	(signal 'args-out-of-range (list (current-buffer) start end)))
    (save-excursion
      (goto-char start)
      (setq line-end (min end (line-end-position)))
      (while (< start end)
	(setq substr
	      (concat substr
		      (if substr "\n" "")
		      (line-substring-with-bidi-context start line-end
							no-properties)))
	(forward-line 1)
	(setq start (point))
	(setq line-end (min end (line-end-position))))
      substr)))
\f
;; Yanking.

(defcustom yank-handled-properties
  '((font-lock-face . yank-handle-font-lock-face-property)
    (category . yank-handle-category-property))
  "List of special text property handling conditions for yanking.
Each element should have the form (PROP . FUN), where PROP is a
property symbol and FUN is a function.  When the `yank' command
inserts text into the buffer, it scans the inserted text for
stretches of text that have `eq' values of the text property
PROP; for each such stretch of text, FUN is called with three
arguments: the property's value in that text, and the start and
end positions of the text.

This is done prior to removing the properties specified by
`yank-excluded-properties'."
  :group 'killing
  :type '(repeat (cons (symbol :tag "property symbol")
                       function))
  :version "24.3")

;; This is actually used in subr.el but defcustom does not work there.
(defcustom yank-excluded-properties
  '(category field follow-link fontified font-lock-face help-echo
    intangible invisible keymap local-map mouse-face read-only
    yank-handler)
  "Text properties to discard when yanking.
The value should be a list of text properties to discard or t,
which means to discard all text properties.

See also `yank-handled-properties'."
  :type '(choice (const :tag "All" t) (repeat symbol))
  :group 'killing
  :version "24.3")

(defvar yank-window-start nil)
(defvar yank-undo-function nil
  "If non-nil, function used by `yank-pop' to delete last stretch of yanked text.
Function is called with two parameters, START and END corresponding to
the value of the mark and point; it is guaranteed that START <= END.
Normally set from the UNDO element of a yank-handler; see `insert-for-yank'.")

(defun yank-pop (&optional arg)
  "Replace just-yanked stretch of killed text with a different stretch.
This command is allowed only immediately after a `yank' or a `yank-pop'.
At such a time, the region contains a stretch of reinserted
previously-killed text.  `yank-pop' deletes that text and inserts in its
place a different stretch of killed text.

With no argument, the previous kill is inserted.
With argument N, insert the Nth previous kill.
If N is negative, this is a more recent kill.

The sequence of kills wraps around, so that after the oldest one
comes the newest one.

When this command inserts killed text into the buffer, it honors
`yank-excluded-properties' and `yank-handler' as described in the
doc string for `insert-for-yank-1', which see."
  (interactive "*p")
  (if (not (eq last-command 'yank))
      (user-error "Previous command was not a yank"))
  (setq this-command 'yank)
  (unless arg (setq arg 1))
  (let ((inhibit-read-only t)
	(before (< (point) (mark t))))
    (if before
	(funcall (or yank-undo-function 'delete-region) (point) (mark t))
      (funcall (or yank-undo-function 'delete-region) (mark t) (point)))
    (setq yank-undo-function nil)
    (set-marker (mark-marker) (point) (current-buffer))
    (insert-for-yank (current-kill arg))
    ;; Set the window start back where it was in the yank command,
    ;; if possible.
    (set-window-start (selected-window) yank-window-start t)
    (if before
	;; This is like exchange-point-and-mark, but doesn't activate the mark.
	;; It is cleaner to avoid activation, even though the command
	;; loop would deactivate the mark because we inserted text.
	(goto-char (prog1 (mark t)
		     (set-marker (mark-marker) (point) (current-buffer))))))
  nil)

(defun yank (&optional arg)
  "Reinsert (\"paste\") the last stretch of killed text.
More precisely, reinsert the most recent kill, which is the
stretch of killed text most recently killed OR yanked.  Put point
at the end, and set mark at the beginning without activating it.
With just \\[universal-argument] as argument, put point at beginning, and mark at end.
With argument N, reinsert the Nth most recent kill.

When this command inserts text into the buffer, it honors the
`yank-handled-properties' and `yank-excluded-properties'
variables, and the `yank-handler' text property.  See
`insert-for-yank-1' for details.

See also the command `yank-pop' (\\[yank-pop])."
  (interactive "*P")
  (setq yank-window-start (window-start))
  ;; If we don't get all the way thru, make last-command indicate that
  ;; for the following command.
  (setq this-command t)
  (push-mark (point))
  (insert-for-yank (current-kill (cond
				  ((listp arg) 0)
				  ((eq arg '-) -2)
				  (t (1- arg)))))
  (if (consp arg)
      ;; This is like exchange-point-and-mark, but doesn't activate the mark.
      ;; It is cleaner to avoid activation, even though the command
      ;; loop would deactivate the mark because we inserted text.
      (goto-char (prog1 (mark t)
		   (set-marker (mark-marker) (point) (current-buffer)))))
  ;; If we do get all the way thru, make this-command indicate that.
  (if (eq this-command t)
      (setq this-command 'yank))
  nil)

(defun rotate-yank-pointer (arg)
  "Rotate the yanking point in the kill ring.
With ARG, rotate that many kills forward (or backward, if negative)."
  (interactive "p")
  (current-kill arg))
\f
;; Some kill commands.

;; Internal subroutine of delete-char
(defun kill-forward-chars (arg)
  (if (listp arg) (setq arg (car arg)))
  (if (eq arg '-) (setq arg -1))
  (kill-region (point) (+ (point) arg)))

;; Internal subroutine of backward-delete-char
(defun kill-backward-chars (arg)
  (if (listp arg) (setq arg (car arg)))
  (if (eq arg '-) (setq arg -1))
  (kill-region (point) (- (point) arg)))

(defcustom backward-delete-char-untabify-method 'untabify
  "The method for untabifying when deleting backward.
Can be `untabify' -- turn a tab to many spaces, then delete one space;
       `hungry' -- delete all whitespace, both tabs and spaces;
       `all' -- delete all whitespace, including tabs, spaces and newlines;
       nil -- just delete one character."
  :type '(choice (const untabify) (const hungry) (const all) (const nil))
  :version "20.3"
  :group 'killing)

(defun backward-delete-char-untabify (arg &optional killp)
  "Delete characters backward, changing tabs into spaces.
The exact behavior depends on `backward-delete-char-untabify-method'.
Delete ARG chars, and kill (save in kill ring) if KILLP is non-nil.
Interactively, ARG is the prefix arg (default 1)
and KILLP is t if a prefix arg was specified."
  (interactive "*p\nP")
  (when (eq backward-delete-char-untabify-method 'untabify)
    (let ((count arg))
      (save-excursion
	(while (and (> count 0) (not (bobp)))
	  (if (= (preceding-char) ?\t)
	      (let ((col (current-column)))
		(forward-char -1)
		(setq col (- col (current-column)))
		(insert-char ?\s col)
		(delete-char 1)))
	  (forward-char -1)
	  (setq count (1- count))))))
  (let* ((skip (cond ((eq backward-delete-char-untabify-method 'hungry) " \t")
                     ((eq backward-delete-char-untabify-method 'all)
                      " \t\n\r")))
         (n (if skip
                (let* ((oldpt (point))
                       (wh (- oldpt (save-excursion
                                      (skip-chars-backward skip)
                                      (constrain-to-field nil oldpt)))))
                  (+ arg (if (zerop wh) 0 (1- wh))))
              arg)))
    ;; Avoid warning about delete-backward-char
    (with-no-warnings (delete-backward-char n killp))))

(defun zap-to-char (arg char)
  "Kill up to and including ARGth occurrence of CHAR.
Case is ignored if `case-fold-search' is non-nil in the current buffer.
Goes backward if ARG is negative; error if CHAR not found."
  (interactive (list (prefix-numeric-value current-prefix-arg)
		     (read-char "Zap to char: " t)))
  ;; Avoid "obsolete" warnings for translation-table-for-input.
  (with-no-warnings
    (if (char-table-p translation-table-for-input)
	(setq char (or (aref translation-table-for-input char) char))))
  (kill-region (point) (progn
			 (search-forward (char-to-string char) nil nil arg)
			 (point))))

;; kill-line and its subroutines.

(defcustom kill-whole-line nil
  "If non-nil, `kill-line' with no arg at start of line kills the whole line."
  :type 'boolean
  :group 'killing)

(defun kill-line (&optional arg)
  "Kill the rest of the current line; if no nonblanks there, kill thru newline.
With prefix argument ARG, kill that many lines from point.
Negative arguments kill lines backward.
With zero argument, kills the text before point on the current line.

When calling from a program, nil means \"no arg\",
a number counts as a prefix arg.

To kill a whole line, when point is not at the beginning, type \
\\[move-beginning-of-line] \\[kill-line] \\[kill-line].

If `show-trailing-whitespace' is non-nil, this command will just
kill the rest of the current line, even if there are only
nonblanks there.

If option `kill-whole-line' is non-nil, then this command kills the whole line
including its terminating newline, when used at the beginning of a line
with no argument.  As a consequence, you can always kill a whole line
by typing \\[move-beginning-of-line] \\[kill-line].

If you want to append the killed line to the last killed text,
use \\[append-next-kill] before \\[kill-line].

If the buffer is read-only, Emacs will beep and refrain from deleting
the line, but put the line in the kill ring anyway.  This means that
you can use this command to copy text from a read-only buffer.
\(If the variable `kill-read-only-ok' is non-nil, then this won't
even beep.)"
  (interactive "P")
  (kill-region (point)
	       ;; It is better to move point to the other end of the kill
	       ;; before killing.  That way, in a read-only buffer, point
	       ;; moves across the text that is copied to the kill ring.
	       ;; The choice has no effect on undo now that undo records
	       ;; the value of point from before the command was run.
	       (progn
		 (if arg
		     (forward-visible-line (prefix-numeric-value arg))
		   (if (eobp)
		       (signal 'end-of-buffer nil))
		   (let ((end
			  (save-excursion
			    (end-of-visible-line) (point))))
		     (if (or (save-excursion
			       ;; If trailing whitespace is visible,
			       ;; don't treat it as nothing.
			       (unless show-trailing-whitespace
				 (skip-chars-forward " \t" end))
			       (= (point) end))
			     (and kill-whole-line (bolp)))
			 (forward-visible-line 1)
		       (goto-char end))))
		 (point))))

(defun kill-whole-line (&optional arg)
  "Kill current line.
With prefix ARG, kill that many lines starting from the current line.
If ARG is negative, kill backward.  Also kill the preceding newline.
\(This is meant to make \\[repeat] work well with negative arguments.)
If ARG is zero, kill current line but exclude the trailing newline."
  (interactive "p")
  (or arg (setq arg 1))
  (if (and (> arg 0) (eobp) (save-excursion (forward-visible-line 0) (eobp)))
      (signal 'end-of-buffer nil))
  (if (and (< arg 0) (bobp) (save-excursion (end-of-visible-line) (bobp)))
      (signal 'beginning-of-buffer nil))
  (unless (eq last-command 'kill-region)
    (kill-new "")
    (setq last-command 'kill-region))
  (cond ((zerop arg)
	 ;; We need to kill in two steps, because the previous command
	 ;; could have been a kill command, in which case the text
	 ;; before point needs to be prepended to the current kill
	 ;; ring entry and the text after point appended.  Also, we
	 ;; need to use save-excursion to avoid copying the same text
	 ;; twice to the kill ring in read-only buffers.
	 (save-excursion
	   (kill-region (point) (progn (forward-visible-line 0) (point))))
	 (kill-region (point) (progn (end-of-visible-line) (point))))
	((< arg 0)
	 (save-excursion
	   (kill-region (point) (progn (end-of-visible-line) (point))))
	 (kill-region (point)
		      (progn (forward-visible-line (1+ arg))
			     (unless (bobp) (backward-char))
			     (point))))
	(t
	 (save-excursion
	   (kill-region (point) (progn (forward-visible-line 0) (point))))
	 (kill-region (point)
		      (progn (forward-visible-line arg) (point))))))

(defun forward-visible-line (arg)
  "Move forward by ARG lines, ignoring currently invisible newlines only.
If ARG is negative, move backward -ARG lines.
If ARG is zero, move to the beginning of the current line."
  (condition-case nil
      (if (> arg 0)
	  (progn
	    (while (> arg 0)
	      (or (zerop (forward-line 1))
		  (signal 'end-of-buffer nil))
	      ;; If the newline we just skipped is invisible,
	      ;; don't count it.
	      (let ((prop
		     (get-char-property (1- (point)) 'invisible)))
		(if (if (eq buffer-invisibility-spec t)
			prop
		      (or (memq prop buffer-invisibility-spec)
			  (assq prop buffer-invisibility-spec)))
		    (setq arg (1+ arg))))
	      (setq arg (1- arg)))
	    ;; If invisible text follows, and it is a number of complete lines,
	    ;; skip it.
	    (let ((opoint (point)))
	      (while (and (not (eobp))
			  (let ((prop
				 (get-char-property (point) 'invisible)))
			    (if (eq buffer-invisibility-spec t)
				prop
			      (or (memq prop buffer-invisibility-spec)
				  (assq prop buffer-invisibility-spec)))))
		(goto-char
		 (if (get-text-property (point) 'invisible)
		     (or (next-single-property-change (point) 'invisible)
			 (point-max))
		   (next-overlay-change (point)))))
	      (unless (bolp)
		(goto-char opoint))))
	(let ((first t))
	  (while (or first (<= arg 0))
	    (if first
		(beginning-of-line)
	      (or (zerop (forward-line -1))
		  (signal 'beginning-of-buffer nil)))
	    ;; If the newline we just moved to is invisible,
	    ;; don't count it.
	    (unless (bobp)
	      (let ((prop
		     (get-char-property (1- (point)) 'invisible)))
		(unless (if (eq buffer-invisibility-spec t)
			    prop
			  (or (memq prop buffer-invisibility-spec)
			      (assq prop buffer-invisibility-spec)))
		  (setq arg (1+ arg)))))
	    (setq first nil))
	  ;; If invisible text follows, and it is a number of complete lines,
	  ;; skip it.
	  (let ((opoint (point)))
	    (while (and (not (bobp))
			(let ((prop
			       (get-char-property (1- (point)) 'invisible)))
			  (if (eq buffer-invisibility-spec t)
			      prop
			    (or (memq prop buffer-invisibility-spec)
				(assq prop buffer-invisibility-spec)))))
	      (goto-char
	       (if (get-text-property (1- (point)) 'invisible)
		   (or (previous-single-property-change (point) 'invisible)
		       (point-min))
		 (previous-overlay-change (point)))))
	    (unless (bolp)
	      (goto-char opoint)))))
    ((beginning-of-buffer end-of-buffer)
     nil)))

(defun end-of-visible-line ()
  "Move to end of current visible line."
  (end-of-line)
  ;; If the following character is currently invisible,
  ;; skip all characters with that same `invisible' property value,
  ;; then find the next newline.
  (while (and (not (eobp))
	      (save-excursion
		(skip-chars-forward "^\n")
		(let ((prop
		       (get-char-property (point) 'invisible)))
		  (if (eq buffer-invisibility-spec t)
		      prop
		    (or (memq prop buffer-invisibility-spec)
			(assq prop buffer-invisibility-spec))))))
    (skip-chars-forward "^\n")
    (if (get-text-property (point) 'invisible)
	(goto-char (or (next-single-property-change (point) 'invisible)
		       (point-max)))
      (goto-char (next-overlay-change (point))))
    (end-of-line)))
\f
(defun insert-buffer (buffer)
  "Insert after point the contents of BUFFER.
Puts mark after the inserted text.
BUFFER may be a buffer or a buffer name."
  (declare (interactive-only insert-buffer-substring))
  (interactive
   (list
    (progn
      (barf-if-buffer-read-only)
      (read-buffer "Insert buffer: "
		   (if (eq (selected-window) (next-window))
		       (other-buffer (current-buffer))
		     (window-buffer (next-window)))
		   t))))
  (push-mark
   (save-excursion
     (insert-buffer-substring (get-buffer buffer))
     (point)))
  nil)

(defun append-to-buffer (buffer start end)
  "Append to specified buffer the text of the region.
It is inserted into that buffer before its point.

When calling from a program, give three arguments:
BUFFER (or buffer name), START and END.
START and END specify the portion of the current buffer to be copied."
  (interactive
   (list (read-buffer "Append to buffer: " (other-buffer (current-buffer) t))
	 (region-beginning) (region-end)))
  (let* ((oldbuf (current-buffer))
         (append-to (get-buffer-create buffer))
         (windows (get-buffer-window-list append-to t t))
         point)
    (save-excursion
      (with-current-buffer append-to
        (setq point (point))
        (barf-if-buffer-read-only)
        (insert-buffer-substring oldbuf start end)
        (dolist (window windows)
          (when (= (window-point window) point)
            (set-window-point window (point))))))))

(defun prepend-to-buffer (buffer start end)
  "Prepend to specified buffer the text of the region.
It is inserted into that buffer after its point.

When calling from a program, give three arguments:
BUFFER (or buffer name), START and END.
START and END specify the portion of the current buffer to be copied."
  (interactive "BPrepend to buffer: \nr")
  (let ((oldbuf (current-buffer)))
    (with-current-buffer (get-buffer-create buffer)
      (barf-if-buffer-read-only)
      (save-excursion
	(insert-buffer-substring oldbuf start end)))))

(defun copy-to-buffer (buffer start end)
  "Copy to specified buffer the text of the region.
It is inserted into that buffer, replacing existing text there.

When calling from a program, give three arguments:
BUFFER (or buffer name), START and END.
START and END specify the portion of the current buffer to be copied."
  (interactive "BCopy to buffer: \nr")
  (let ((oldbuf (current-buffer)))
    (with-current-buffer (get-buffer-create buffer)
      (barf-if-buffer-read-only)
      (erase-buffer)
      (save-excursion
	(insert-buffer-substring oldbuf start end)))))
\f
(define-error 'mark-inactive (purecopy "The mark is not active now"))

(defvar activate-mark-hook nil
  "Hook run when the mark becomes active.
It is also run at the end of a command, if the mark is active and
it is possible that the region may have changed.")

(defvar deactivate-mark-hook nil
  "Hook run when the mark becomes inactive.")

(defun mark (&optional force)
  "Return this buffer's mark value as integer, or nil if never set.

In Transient Mark mode, this function signals an error if
the mark is not active.  However, if `mark-even-if-inactive' is non-nil,
or the argument FORCE is non-nil, it disregards whether the mark
is active, and returns an integer or nil in the usual way.

If you are using this in an editing command, you are most likely making
a mistake; see the documentation of `set-mark'."
  (if (or force (not transient-mark-mode) mark-active mark-even-if-inactive)
      (marker-position (mark-marker))
    (signal 'mark-inactive nil)))

;; Behind display-selections-p.

(defun deactivate-mark (&optional force)
  "Deactivate the mark.
If Transient Mark mode is disabled, this function normally does
nothing; but if FORCE is non-nil, it deactivates the mark anyway.

Deactivating the mark sets `mark-active' to nil, updates the
primary selection according to `select-active-regions', and runs
`deactivate-mark-hook'.

If Transient Mark mode was temporarily enabled, reset the value
of the variable `transient-mark-mode'; if this causes Transient
Mark mode to be disabled, don't change `mark-active' to nil or
run `deactivate-mark-hook'."
  (when (or (region-active-p) force)
    (when (and (if (eq select-active-regions 'only)
		   (eq (car-safe transient-mark-mode) 'only)
		 select-active-regions)
	       (region-active-p)
	       (display-selections-p))
      ;; The var `saved-region-selection', if non-nil, is the text in
      ;; the region prior to the last command modifying the buffer.
      ;; Set the selection to that, or to the current region.
      (cond (saved-region-selection
	     (if (gui-backend-selection-owner-p 'PRIMARY)
		 (gui-set-selection 'PRIMARY saved-region-selection))
	     (setq saved-region-selection nil))
	    ;; If another program has acquired the selection, region
	    ;; deactivation should not clobber it (Bug#11772).
	    ((and (/= (region-beginning) (region-end))
		  (or (gui-backend-selection-owner-p 'PRIMARY)
		      (null (gui-backend-selection-exists-p 'PRIMARY))))
	     (gui-set-selection 'PRIMARY
                                (funcall region-extract-function nil)))))
    (when mark-active (force-mode-line-update)) ;Refresh toolbar (bug#16382).
    (cond
     ((eq (car-safe transient-mark-mode) 'only)
      (setq transient-mark-mode (cdr transient-mark-mode))
      (if (eq transient-mark-mode (default-value 'transient-mark-mode))
          (kill-local-variable 'transient-mark-mode)))
     ((eq transient-mark-mode 'lambda)
      (kill-local-variable 'transient-mark-mode)))
    (setq mark-active nil)
    (run-hooks 'deactivate-mark-hook)
    (redisplay--update-region-highlight (selected-window))))

(defun activate-mark (&optional no-tmm)
  "Activate the mark.
If NO-TMM is non-nil, leave `transient-mark-mode' alone."
  (when (mark t)
    (unless (region-active-p)
      (force-mode-line-update) ;Refresh toolbar (bug#16382).
      (setq mark-active t)
      (unless (or transient-mark-mode no-tmm)
        (setq-local transient-mark-mode 'lambda))
      (run-hooks 'activate-mark-hook))))

(defun set-mark (pos)
  "Set this buffer's mark to POS.  Don't use this function!
That is to say, don't use this function unless you want
the user to see that the mark has moved, and you want the previous
mark position to be lost.

Normally, when a new mark is set, the old one should go on the stack.
This is why most applications should use `push-mark', not `set-mark'.

Novice Emacs Lisp programmers often try to use the mark for the wrong
purposes.  The mark saves a location for the user's convenience.
Most editing commands should not alter the mark.
To remember a location for internal use in the Lisp program,
store it in a Lisp variable.  Example:

   (let ((beg (point))) (forward-line 1) (delete-region beg (point)))."
  (if pos
      (progn
        (set-marker (mark-marker) pos (current-buffer))
        (activate-mark 'no-tmm))
    ;; Normally we never clear mark-active except in Transient Mark mode.
    ;; But when we actually clear out the mark value too, we must
    ;; clear mark-active in any mode.
    (deactivate-mark t)
    ;; `deactivate-mark' sometimes leaves mark-active non-nil, but
    ;; it should never be nil if the mark is nil.
    (setq mark-active nil)
    (set-marker (mark-marker) nil)))

(defun save-mark-and-excursion--save ()
  (cons
   (let ((mark (mark-marker)))
     (and (marker-position mark) (copy-marker mark)))
   mark-active))

(defun save-mark-and-excursion--restore (saved-mark-info)
  (let ((saved-mark (car saved-mark-info))
        (omark (marker-position (mark-marker)))
        (nmark nil)
        (saved-mark-active (cdr saved-mark-info)))
    ;; Mark marker
    (if (null saved-mark)
        (set-marker (mark-marker) nil)
      (setf nmark (marker-position saved-mark))
      (set-marker (mark-marker) nmark)
      (set-marker saved-mark nil))
    ;; Mark active
    (let ((cur-mark-active mark-active))
      (setq mark-active saved-mark-active)
      ;; If mark is active now, and either was not active or was at a
      ;; different place, run the activate hook.
      (if saved-mark-active
          (when (or (not cur-mark-active)
                    (not (eq omark nmark)))
            (run-hooks 'activate-mark-hook))
        ;; If mark has ceased to be active, run deactivate hook.
        (when cur-mark-active
          (run-hooks 'deactivate-mark-hook))))))

(defmacro save-mark-and-excursion (&rest body)
  "Like `save-excursion', but also save and restore the mark state.
This macro does what `save-excursion' did before Emacs 25.1."
  (declare (indent 0) (debug t))
  (let ((saved-marker-sym (make-symbol "saved-marker")))
    `(let ((,saved-marker-sym (save-mark-and-excursion--save)))
       (unwind-protect
            (save-excursion ,@body)
         (save-mark-and-excursion--restore ,saved-marker-sym)))))

(defcustom use-empty-active-region nil
  "Whether \"region-aware\" commands should act on empty regions.
If nil, region-aware commands treat the empty region as inactive.
If non-nil, region-aware commands treat the region as active as
long as the mark is active, even if the region is empty.

Region-aware commands are those that act on the region if it is
active and Transient Mark mode is enabled, and on the text near
point otherwise."
  :type 'boolean
  :version "23.1"
  :group 'editing-basics)

(defun use-region-p ()
  "Return t if the region is active and it is appropriate to act on it.
This is used by commands that act specially on the region under
Transient Mark mode.

The return value is t if Transient Mark mode is enabled and the
mark is active; furthermore, if `use-empty-active-region' is nil,
the region must not be empty.  Otherwise, the return value is nil.

For some commands, it may be appropriate to ignore the value of
`use-empty-active-region'; in that case, use `region-active-p'."
  (and (region-active-p)
       (or use-empty-active-region (> (region-end) (region-beginning)))))

(defun region-active-p ()
  "Return non-nil if Transient Mark mode is enabled and the mark is active.

Some commands act specially on the region when Transient Mark
mode is enabled.  Usually, such commands should use
`use-region-p' instead of this function, because `use-region-p'
also checks the value of `use-empty-active-region'."
  (and transient-mark-mode mark-active
       ;; FIXME: Somehow we sometimes end up with mark-active non-nil but
       ;; without the mark being set (e.g. bug#17324).  We really should fix
       ;; that problem, but in the mean time, let's make sure we don't say the
       ;; region is active when there's no mark.
       (progn (cl-assert (mark)) t)))

(defun region-noncontiguous-p ()
  "Return non-nil if the region contains several pieces.
An example is a rectangular region handled as a list of
separate contiguous regions for each line."
  (> (length (funcall region-extract-function 'bounds)) 1))

(defvar redisplay-unhighlight-region-function
  (lambda (rol) (when (overlayp rol) (delete-overlay rol))))

(defvar redisplay-highlight-region-function
  (lambda (start end window rol)
    (if (not (overlayp rol))
        (let ((nrol (make-overlay start end)))
          (funcall redisplay-unhighlight-region-function rol)
          (overlay-put nrol 'window window)
          (overlay-put nrol 'face 'region)
          ;; Normal priority so that a large region doesn't hide all the
          ;; overlays within it, but high secondary priority so that if it
          ;; ends/starts in the middle of a small overlay, that small overlay
          ;; won't hide the region's boundaries.
          (overlay-put nrol 'priority '(nil . 100))
          nrol)
      (unless (and (eq (overlay-buffer rol) (current-buffer))
                   (eq (overlay-start rol) start)
                   (eq (overlay-end rol) end))
        (move-overlay rol start end (current-buffer)))
      rol)))

(defun redisplay--update-region-highlight (window)
  (let ((rol (window-parameter window 'internal-region-overlay)))
    (if (not (and (region-active-p)
                  (or highlight-nonselected-windows
                      (eq window (selected-window))
                      (and (window-minibuffer-p)
                           (eq window (minibuffer-selected-window))))))
        (funcall redisplay-unhighlight-region-function rol)
      (let* ((pt (window-point window))
             (mark (mark))
             (start (min pt mark))
             (end   (max pt mark))
             (new
              (funcall redisplay-highlight-region-function
                       start end window rol)))
        (unless (equal new rol)
          (set-window-parameter window 'internal-region-overlay
                                new))))))

(defvar pre-redisplay-functions (list #'redisplay--update-region-highlight)
  "Hook run just before redisplay.
It is called in each window that is to be redisplayed.  It takes one argument,
which is the window that will be redisplayed.  When run, the `current-buffer'
is set to the buffer displayed in that window.")

(defun redisplay--pre-redisplay-functions (windows)
  (with-demoted-errors "redisplay--pre-redisplay-functions: %S"
    (if (null windows)
        (with-current-buffer (window-buffer (selected-window))
          (run-hook-with-args 'pre-redisplay-functions (selected-window)))
      (dolist (win (if (listp windows) windows (window-list-1 nil nil t)))
        (with-current-buffer (window-buffer win)
          (run-hook-with-args 'pre-redisplay-functions win))))))

(add-function :before pre-redisplay-function
              #'redisplay--pre-redisplay-functions)


(defvar-local mark-ring nil
  "The list of former marks of the current buffer, most recent first.")
(put 'mark-ring 'permanent-local t)

(defcustom mark-ring-max 16
  "Maximum size of mark ring.  Start discarding off end if gets this big."
  :type 'integer
  :group 'editing-basics)

(defvar global-mark-ring nil
  "The list of saved global marks, most recent first.")

(defcustom global-mark-ring-max 16
  "Maximum size of global mark ring.  \
Start discarding off end if gets this big."
  :type 'integer
  :group 'editing-basics)

(defun pop-to-mark-command ()
  "Jump to mark, and pop a new position for mark off the ring.
\(Does not affect global mark ring)."
  (interactive)
  (if (null (mark t))
      (user-error "No mark set in this buffer")
    (if (= (point) (mark t))
	(message "Mark popped"))
    (goto-char (mark t))
    (pop-mark)))

(defun push-mark-command (arg &optional nomsg)
  "Set mark at where point is.
If no prefix ARG and mark is already set there, just activate it.
Display `Mark set' unless the optional second arg NOMSG is non-nil."
  (interactive "P")
  (let ((mark (mark t)))
    (if (or arg (null mark) (/= mark (point)))
	(push-mark nil nomsg t)
      (activate-mark 'no-tmm)
      (unless nomsg
	(message "Mark activated")))))

(defcustom set-mark-command-repeat-pop nil
  "Non-nil means repeating \\[set-mark-command] after popping mark pops it again.
That means that C-u \\[set-mark-command] \\[set-mark-command]
will pop the mark twice, and
C-u \\[set-mark-command] \\[set-mark-command] \\[set-mark-command]
will pop the mark three times.

A value of nil means \\[set-mark-command]'s behavior does not change
after C-u \\[set-mark-command]."
  :type 'boolean
  :group 'editing-basics)

(defun set-mark-command (arg)
  "Set the mark where point is, or jump to the mark.
Setting the mark also alters the region, which is the text
between point and mark; this is the closest equivalent in
Emacs to what some editors call the \"selection\".

With no prefix argument, set the mark at point, and push the
old mark position on local mark ring.  Also push the old mark on
global mark ring, if the previous mark was set in another buffer.

When Transient Mark Mode is off, immediately repeating this
command activates `transient-mark-mode' temporarily.

With prefix argument (e.g., \\[universal-argument] \\[set-mark-command]), \
jump to the mark, and set the mark from
position popped off the local mark ring (this does not affect the global
mark ring).  Use \\[pop-global-mark] to jump to a mark popped off the global
mark ring (see `pop-global-mark').

If `set-mark-command-repeat-pop' is non-nil, repeating
the \\[set-mark-command] command with no prefix argument pops the next position
off the local (or global) mark ring and jumps there.

With \\[universal-argument] \\[universal-argument] as prefix
argument, unconditionally set mark where point is, even if
`set-mark-command-repeat-pop' is non-nil.

Novice Emacs Lisp programmers often try to use the mark for the wrong
purposes.  See the documentation of `set-mark' for more information."
  (interactive "P")
  (cond ((eq transient-mark-mode 'lambda)
	 (kill-local-variable 'transient-mark-mode))
	((eq (car-safe transient-mark-mode) 'only)
	 (deactivate-mark)))
  (cond
   ((and (consp arg) (> (prefix-numeric-value arg) 4))
    (push-mark-command nil))
   ((not (eq this-command 'set-mark-command))
    (if arg
	(pop-to-mark-command)
      (push-mark-command t)))
   ((and set-mark-command-repeat-pop
	 (eq last-command 'pop-global-mark)
	 (not arg))
    (setq this-command 'pop-global-mark)
    (pop-global-mark))
   ((or (and set-mark-command-repeat-pop
             (eq last-command 'pop-to-mark-command))
        arg)
    (setq this-command 'pop-to-mark-command)
    (pop-to-mark-command))
   ((eq last-command 'set-mark-command)
    (if (region-active-p)
        (progn
          (deactivate-mark)
          (message "Mark deactivated"))
      (activate-mark)
      (message "Mark activated")))
   (t
    (push-mark-command nil))))

(defun push-mark (&optional location nomsg activate)
  "Set mark at LOCATION (point, by default) and push old mark on mark ring.
If the last global mark pushed was not in the current buffer,
also push LOCATION on the global mark ring.
Display `Mark set' unless the optional second arg NOMSG is non-nil.

Novice Emacs Lisp programmers often try to use the mark for the wrong
purposes.  See the documentation of `set-mark' for more information.

In Transient Mark mode, activate mark if optional third arg ACTIVATE non-nil."
  (unless (null (mark t))
    (setq mark-ring (cons (copy-marker (mark-marker)) mark-ring))
    (when (> (length mark-ring) mark-ring-max)
      (move-marker (car (nthcdr mark-ring-max mark-ring)) nil)
      (setcdr (nthcdr (1- mark-ring-max) mark-ring) nil)))
  (set-marker (mark-marker) (or location (point)) (current-buffer))
  ;; Now push the mark on the global mark ring.
  (if (and global-mark-ring
	   (eq (marker-buffer (car global-mark-ring)) (current-buffer)))
      ;; The last global mark pushed was in this same buffer.
      ;; Don't push another one.
      nil
    (setq global-mark-ring (cons (copy-marker (mark-marker)) global-mark-ring))
    (when (> (length global-mark-ring) global-mark-ring-max)
      (move-marker (car (nthcdr global-mark-ring-max global-mark-ring)) nil)
      (setcdr (nthcdr (1- global-mark-ring-max) global-mark-ring) nil)))
  (or nomsg executing-kbd-macro (> (minibuffer-depth) 0)
      (message "Mark set"))
  (if (or activate (not transient-mark-mode))
      (set-mark (mark t)))
  nil)

(defun pop-mark ()
  "Pop off mark ring into the buffer's actual mark.
Does not set point.  Does nothing if mark ring is empty."
  (when mark-ring
    (setq mark-ring (nconc mark-ring (list (copy-marker (mark-marker)))))
    (set-marker (mark-marker) (+ 0 (car mark-ring)) (current-buffer))
    (move-marker (car mark-ring) nil)
    (if (null (mark t)) (ding))
    (setq mark-ring (cdr mark-ring)))
  (deactivate-mark))

(define-obsolete-function-alias
  'exchange-dot-and-mark 'exchange-point-and-mark "23.3")
(defun exchange-point-and-mark (&optional arg)
  "Put the mark where point is now, and point where the mark is now.
This command works even when the mark is not active,
and it reactivates the mark.

If Transient Mark mode is on, a prefix ARG deactivates the mark
if it is active, and otherwise avoids reactivating it.  If
Transient Mark mode is off, a prefix ARG enables Transient Mark
mode temporarily."
  (interactive "P")
  (let ((omark (mark t))
	(temp-highlight (eq (car-safe transient-mark-mode) 'only)))
    (if (null omark)
        (user-error "No mark set in this buffer"))
    (set-mark (point))
    (goto-char omark)
    (cond (temp-highlight
	   (setq-local transient-mark-mode (cons 'only transient-mark-mode)))
	  ((or (and arg (region-active-p)) ; (xor arg (not (region-active-p)))
	       (not (or arg (region-active-p))))
	   (deactivate-mark))
	  (t (activate-mark)))
    nil))

(defcustom shift-select-mode t
  "When non-nil, shifted motion keys activate the mark momentarily.

While the mark is activated in this way, any shift-translated point
motion key extends the region, and if Transient Mark mode was off, it
is temporarily turned on.  Furthermore, the mark will be deactivated
by any subsequent point motion key that was not shift-translated, or
by any action that normally deactivates the mark in Transient Mark mode.

See `this-command-keys-shift-translated' for the meaning of
shift-translation."
  :type 'boolean
  :group 'editing-basics)

(defun handle-shift-selection ()
  "Activate/deactivate mark depending on invocation thru shift translation.
This function is called by `call-interactively' when a command
with a `^' character in its `interactive' spec is invoked, before
running the command itself.

If `shift-select-mode' is enabled and the command was invoked
through shift translation, set the mark and activate the region
temporarily, unless it was already set in this way.  See
`this-command-keys-shift-translated' for the meaning of shift
translation.

Otherwise, if the region has been activated temporarily,
deactivate it, and restore the variable `transient-mark-mode' to
its earlier value."
  (cond ((and shift-select-mode this-command-keys-shift-translated)
         (unless (and mark-active
		      (eq (car-safe transient-mark-mode) 'only))
	   (setq-local transient-mark-mode
                       (cons 'only
                             (unless (eq transient-mark-mode 'lambda)
                               transient-mark-mode)))
           (push-mark nil nil t)))
        ((eq (car-safe transient-mark-mode) 'only)
         (setq transient-mark-mode (cdr transient-mark-mode))
         (if (eq transient-mark-mode (default-value 'transient-mark-mode))
             (kill-local-variable 'transient-mark-mode))
         (deactivate-mark))))

(define-minor-mode transient-mark-mode
  "Toggle Transient Mark mode.
With a prefix argument ARG, enable Transient Mark mode if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
Transient Mark mode if ARG is omitted or nil.

Transient Mark mode is a global minor mode.  When enabled, the
region is highlighted with the `region' face whenever the mark
is active.  The mark is \"deactivated\" by changing the buffer,
and after certain other operations that set the mark but whose
main purpose is something else--for example, incremental search,
\\[beginning-of-buffer], and \\[end-of-buffer].

You can also deactivate the mark by typing \\[keyboard-quit] or
\\[keyboard-escape-quit].

Many commands change their behavior when Transient Mark mode is
in effect and the mark is active, by acting on the region instead
of their usual default part of the buffer's text.  Examples of
such commands include \\[comment-dwim], \\[flush-lines], \\[keep-lines],
\\[query-replace], \\[query-replace-regexp], \\[ispell], and \\[undo].
To see the documentation of commands which are sensitive to the
Transient Mark mode, invoke \\[apropos-documentation] and type \"transient\"
or \"mark.*active\" at the prompt."
  :global t
  ;; It's defined in C/cus-start, this stops the d-m-m macro defining it again.
  :variable (default-value 'transient-mark-mode))

(defvar widen-automatically t
  "Non-nil means it is ok for commands to call `widen' when they want to.
Some commands will do this in order to go to positions outside
the current accessible part of the buffer.

If `widen-automatically' is nil, these commands will do something else
as a fallback, and won't change the buffer bounds.")

(defvar non-essential nil
  "Whether the currently executing code is performing an essential task.
This variable should be non-nil only when running code which should not
disturb the user.  E.g. it can be used to prevent Tramp from prompting the
user for a password when we are simply scanning a set of files in the
background or displaying possible completions before the user even asked
for it.")

(defun pop-global-mark ()
  "Pop off global mark ring and jump to the top location."
  (interactive)
  ;; Pop entries which refer to non-existent buffers.
  (while (and global-mark-ring (not (marker-buffer (car global-mark-ring))))
    (setq global-mark-ring (cdr global-mark-ring)))
  (or global-mark-ring
      (error "No global mark set"))
  (let* ((marker (car global-mark-ring))
	 (buffer (marker-buffer marker))
	 (position (marker-position marker)))
    (setq global-mark-ring (nconc (cdr global-mark-ring)
				  (list (car global-mark-ring))))
    (set-buffer buffer)
    (or (and (>= position (point-min))
	     (<= position (point-max)))
	(if widen-automatically
	    (widen)
	  (error "Global mark position is outside accessible part of buffer")))
    (goto-char position)
    (switch-to-buffer buffer)))
\f
(defcustom next-line-add-newlines nil
  "If non-nil, `next-line' inserts newline to avoid `end of buffer' error."
  :type 'boolean
  :version "21.1"
  :group 'editing-basics)

(defun next-line (&optional arg try-vscroll)
  "Move cursor vertically down ARG lines.
Interactively, vscroll tall lines if `auto-window-vscroll' is enabled.
Non-interactively, use TRY-VSCROLL to control whether to vscroll tall
lines: if either `auto-window-vscroll' or TRY-VSCROLL is nil, this
function will not vscroll.

ARG defaults to 1.

If there is no character in the target line exactly under the current column,
the cursor is positioned after the character in that line which spans this
column, or at the end of the line if it is not long enough.
If there is no line in the buffer after this one, behavior depends on the
value of `next-line-add-newlines'.  If non-nil, it inserts a newline character
to create a line, and moves the cursor to that line.  Otherwise it moves the
cursor to the end of the buffer.

If the variable `line-move-visual' is non-nil, this command moves
by display lines.  Otherwise, it moves by buffer lines, without
taking variable-width characters or continued lines into account.

The command \\[set-goal-column] can be used to create
a semipermanent goal column for this command.
Then instead of trying to move exactly vertically (or as close as possible),
this command moves to the specified goal column (or as close as possible).
The goal column is stored in the variable `goal-column', which is nil
when there is no goal column.  Note that setting `goal-column'
overrides `line-move-visual' and causes this command to move by buffer
lines rather than by display lines."
  (declare (interactive-only forward-line))
  (interactive "^p\np")
  (or arg (setq arg 1))
  (if (and next-line-add-newlines (= arg 1))
      (if (save-excursion (end-of-line) (eobp))
	  ;; When adding a newline, don't expand an abbrev.
	  (let ((abbrev-mode nil))
	    (end-of-line)
	    (insert (if use-hard-newlines hard-newline "\n")))
	(line-move arg nil nil try-vscroll))
    (if (called-interactively-p 'interactive)
	(condition-case err
	    (line-move arg nil nil try-vscroll)
	  ((beginning-of-buffer end-of-buffer)
	   (signal (car err) (cdr err))))
      (line-move arg nil nil try-vscroll)))
  nil)

(defun previous-line (&optional arg try-vscroll)
  "Move cursor vertically up ARG lines.
Interactively, vscroll tall lines if `auto-window-vscroll' is enabled.
Non-interactively, use TRY-VSCROLL to control whether to vscroll tall
lines: if either `auto-window-vscroll' or TRY-VSCROLL is nil, this
function will not vscroll.

ARG defaults to 1.

If there is no character in the target line exactly over the current column,
the cursor is positioned after the character in that line which spans this
column, or at the end of the line if it is not long enough.

If the variable `line-move-visual' is non-nil, this command moves
by display lines.  Otherwise, it moves by buffer lines, without
taking variable-width characters or continued lines into account.

The command \\[set-goal-column] can be used to create
a semipermanent goal column for this command.
Then instead of trying to move exactly vertically (or as close as possible),
this command moves to the specified goal column (or as close as possible).
The goal column is stored in the variable `goal-column', which is nil
when there is no goal column.  Note that setting `goal-column'
overrides `line-move-visual' and causes this command to move by buffer
lines rather than by display lines."
  (declare (interactive-only
            "use `forward-line' with negative argument instead."))
  (interactive "^p\np")
  (or arg (setq arg 1))
  (if (called-interactively-p 'interactive)
      (condition-case err
	  (line-move (- arg) nil nil try-vscroll)
	((beginning-of-buffer end-of-buffer)
	 (signal (car err) (cdr err))))
    (line-move (- arg) nil nil try-vscroll))
  nil)

(defcustom track-eol nil
  "Non-nil means vertical motion starting at end of line keeps to ends of lines.
This means moving to the end of each line moved onto.
The beginning of a blank line does not count as the end of a line.
This has no effect when the variable `line-move-visual' is non-nil."
  :type 'boolean
  :group 'editing-basics)

(defcustom goal-column nil
  "Semipermanent goal column for vertical motion, as set by \\[set-goal-column], or nil.
A non-nil setting overrides the variable `line-move-visual', which see."
  :type '(choice integer
		 (const :tag "None" nil))
  :group 'editing-basics)
(make-variable-buffer-local 'goal-column)

(defvar temporary-goal-column 0
  "Current goal column for vertical motion.
It is the column where point was at the start of the current run
of vertical motion commands.

When moving by visual lines via the function `line-move-visual', it is a cons
cell (COL . HSCROLL), where COL is the x-position, in pixels,
divided by the default column width, and HSCROLL is the number of
columns by which window is scrolled from left margin.

When the `track-eol' feature is doing its job, the value is
`most-positive-fixnum'.")

(defcustom line-move-ignore-invisible t
  "Non-nil means commands that move by lines ignore invisible newlines.
When this option is non-nil, \\[next-line], \\[previous-line], \\[move-end-of-line], and \\[move-beginning-of-line] behave
as if newlines that are invisible didn't exist, and count
only visible newlines.  Thus, moving across across 2 newlines
one of which is invisible will be counted as a one-line move.
Also, a non-nil value causes invisible text to be ignored when
counting columns for the purposes of keeping point in the same
column by \\[next-line] and \\[previous-line].

Outline mode sets this."
  :type 'boolean
  :group 'editing-basics)

(defcustom line-move-visual t
  "When non-nil, `line-move' moves point by visual lines.
This movement is based on where the cursor is displayed on the
screen, instead of relying on buffer contents alone.  It takes
into account variable-width characters and line continuation.
If nil, `line-move' moves point by logical lines.
A non-nil setting of `goal-column' overrides the value of this variable
and forces movement by logical lines.
A window that is  horizontally scrolled also forces movement by logical
lines."
  :type 'boolean
  :group 'editing-basics
  :version "23.1")

;; Only used if display-graphic-p.
(declare-function font-info "font.c" (name &optional frame))

(defun default-font-height ()
  "Return the height in pixels of the current buffer's default face font.

If the default font is remapped (see `face-remapping-alist'), the
function returns the height of the remapped face."
  (let ((default-font (face-font 'default)))
    (cond
     ((and (display-multi-font-p)
	   ;; Avoid calling font-info if the frame's default font was
	   ;; not changed since the frame was created.  That's because
	   ;; font-info is expensive for some fonts, see bug #14838.
	   (not (string= (frame-parameter nil 'font) default-font)))
      (aref (font-info default-font) 3))
     (t (frame-char-height)))))

(defun default-font-width ()
  "Return the width in pixels of the current buffer's default face font.

If the default font is remapped (see `face-remapping-alist'), the
function returns the width of the remapped face."
  (let ((default-font (face-font 'default)))
    (cond
     ((and (display-multi-font-p)
	   ;; Avoid calling font-info if the frame's default font was
	   ;; not changed since the frame was created.  That's because
	   ;; font-info is expensive for some fonts, see bug #14838.
	   (not (string= (frame-parameter nil 'font) default-font)))
      (let* ((info (font-info (face-font 'default)))
	     (width (aref info 11)))
	(if (> width 0)
	    width
	  (aref info 10))))
     (t (frame-char-width)))))

(defun default-line-height ()
  "Return the pixel height of current buffer's default-face text line.

The value includes `line-spacing', if any, defined for the buffer
or the frame."
  (let ((dfh (default-font-height))
	(lsp (if (display-graphic-p)
		 (or line-spacing
		     (default-value 'line-spacing)
		     (frame-parameter nil 'line-spacing)
		     0)
	       0)))
    (if (floatp lsp)
	(setq lsp (truncate (* (frame-char-height) lsp))))
    (+ dfh lsp)))

(defun window-screen-lines ()
  "Return the number of screen lines in the text area of the selected window.

This is different from `window-text-height' in that this function counts
lines in units of the height of the font used by the default face displayed
in the window, not in units of the frame's default font, and also accounts
for `line-spacing', if any, defined for the window's buffer or frame.

The value is a floating-point number."
  (let ((edges (window-inside-pixel-edges))
	(dlh (default-line-height)))
    (/ (float (- (nth 3 edges) (nth 1 edges))) dlh)))

;; Returns non-nil if partial move was done.
(defun line-move-partial (arg noerror &optional _to-end)
  (if (< arg 0)
      ;; Move backward (up).
      ;; If already vscrolled, reduce vscroll
      (let ((vs (window-vscroll nil t))
	    (dlh (default-line-height)))
	(when (> vs dlh)
	  (set-window-vscroll nil (- vs dlh) t)))

    ;; Move forward (down).
    (let* ((lh (window-line-height -1))
	   (rowh (car lh))
	   (vpos (nth 1 lh))
	   (ypos (nth 2 lh))
	   (rbot (nth 3 lh))
	   (this-lh (window-line-height))
	   (this-height (car this-lh))
	   (this-ypos (nth 2 this-lh))
	   (dlh (default-line-height))
	   (wslines (window-screen-lines))
	   (edges (window-inside-pixel-edges))
	   (winh (- (nth 3 edges) (nth 1 edges) 1))
	   py vs last-line)
      (if (> (mod wslines 1.0) 0.0)
	  (setq wslines (round (+ wslines 0.5))))
      (when (or (null lh)
		(>= rbot dlh)
		(<= ypos (- dlh))
		(null this-lh)
		(<= this-ypos (- dlh)))
	(unless lh
	  (let ((wend (pos-visible-in-window-p t nil t)))
	    (setq rbot (nth 3 wend)
		  rowh  (nth 4 wend)
		  vpos (nth 5 wend))))
	(unless this-lh
	  (let ((wstart (pos-visible-in-window-p nil nil t)))
	    (setq this-ypos (nth 2 wstart)
		  this-height (nth 4 wstart))))
	(setq py
	      (or (nth 1 this-lh)
		  (let ((ppos (posn-at-point))
			col-row)
		    (setq col-row (posn-actual-col-row ppos))
		    (if col-row
			(- (cdr col-row) (window-vscroll))
		      (cdr (posn-col-row ppos))))))
	;; VPOS > 0 means the last line is only partially visible.
	;; But if the part that is visible is at least as tall as the
	;; default font, that means the line is actually fully
	;; readable, and something like line-spacing is hidden.  So in
	;; that case we accept the last line in the window as still
	;; visible, and consider the margin as starting one line
	;; later.
	(if (and vpos (> vpos 0))
	    (if (and rowh
		     (>= rowh (default-font-height))
		     (< rowh dlh))
		(setq last-line (min (- wslines scroll-margin) vpos))
	      (setq last-line (min (- wslines scroll-margin 1) (1- vpos)))))
	(cond
	 ;; If last line of window is fully visible, and vscrolling
	 ;; more would make this line invisible, move forward.
	 ((and (or (< (setq vs (window-vscroll nil t)) dlh)
		   (null this-height)
		   (<= this-height dlh))
	       (or (null rbot) (= rbot 0)))
	  nil)
	 ;; If cursor is not in the bottom scroll margin, and the
	 ;; current line is is not too tall, move forward.
	 ((and (or (null this-height) (<= this-height winh))
	       vpos
	       (> vpos 0)
	       (< py last-line))
	  nil)
	 ;; When already vscrolled, we vscroll some more if we can,
	 ;; or clear vscroll and move forward at end of tall image.
	 ((> vs 0)
	  (when (or (and rbot (> rbot 0))
		    (and this-height (> this-height dlh)))
	    (set-window-vscroll nil (+ vs dlh) t)))
	 ;; If cursor just entered the bottom scroll margin, move forward,
	 ;; but also optionally vscroll one line so redisplay won't recenter.
	 ((and vpos
	       (> vpos 0)
	       (= py last-line))
	  ;; Don't vscroll if the partially-visible line at window
	  ;; bottom is not too tall (a.k.a. "just one more text
	  ;; line"): in that case, we do want redisplay to behave
	  ;; normally, i.e. recenter or whatever.
	  ;;
	  ;; Note: ROWH + RBOT from the value returned by
	  ;; pos-visible-in-window-p give the total height of the
	  ;; partially-visible glyph row at the end of the window.  As
	  ;; we are dealing with floats, we disregard sub-pixel
	  ;; discrepancies between that and DLH.
	  (if (and rowh rbot (>= (- (+ rowh rbot) winh) 1))
	      (set-window-vscroll nil dlh t))
	  (line-move-1 arg noerror)
	  t)
	 ;; If there are lines above the last line, scroll-up one line.
	 ((and vpos (> vpos 0))
	  (scroll-up 1)
	  t)
	 ;; Finally, start vscroll.
	 (t
	  (set-window-vscroll nil dlh t)))))))


;; This is like line-move-1 except that it also performs
;; vertical scrolling of tall images if appropriate.
;; That is not really a clean thing to do, since it mixes
;; scrolling with cursor motion.  But so far we don't have
;; a cleaner solution to the problem of making C-n do something
;; useful given a tall image.
(defun line-move (arg &optional noerror _to-end try-vscroll)
  "Move forward ARG lines.
If NOERROR, don't signal an error if we can't move ARG lines.
TO-END is unused.
TRY-VSCROLL controls whether to vscroll tall lines: if either
`auto-window-vscroll' or TRY-VSCROLL is nil, this function will
not vscroll."
  (if noninteractive
      (line-move-1 arg noerror)
    (unless (and auto-window-vscroll try-vscroll
		 ;; Only vscroll for single line moves
		 (= (abs arg) 1)
		 ;; Under scroll-conservatively, the display engine
		 ;; does this better.
		 (zerop scroll-conservatively)
		 ;; But don't vscroll in a keyboard macro.
		 (not defining-kbd-macro)
		 (not executing-kbd-macro)
		 (line-move-partial arg noerror))
      (set-window-vscroll nil 0 t)
      (if (and line-move-visual
	       ;; Display-based column are incompatible with goal-column.
	       (not goal-column)
	       ;; When the text in the window is scrolled to the left,
	       ;; display-based motion doesn't make sense (because each
	       ;; logical line occupies exactly one screen line).
	       (not (> (window-hscroll) 0))
	       ;; Likewise when the text _was_ scrolled to the left
	       ;; when the current run of vertical motion commands
	       ;; started.
	       (not (and (memq last-command
			       `(next-line previous-line ,this-command))
			 auto-hscroll-mode
			 (numberp temporary-goal-column)
			 (>= temporary-goal-column
			    (- (window-width) hscroll-margin)))))
	  (prog1 (line-move-visual arg noerror)
	    ;; If we moved into a tall line, set vscroll to make
	    ;; scrolling through tall images more smooth.
	    (let ((lh (line-pixel-height))
		  (edges (window-inside-pixel-edges))
		  (dlh (default-line-height))
		  winh)
	      (setq winh (- (nth 3 edges) (nth 1 edges) 1))
	      (if (and (< arg 0)
		       (< (point) (window-start))
		       (> lh winh))
		  (set-window-vscroll
		   nil
		   (- lh dlh) t))))
	(line-move-1 arg noerror)))))

;; Display-based alternative to line-move-1.
;; Arg says how many lines to move.  The value is t if we can move the
;; specified number of lines.
(defun line-move-visual (arg &optional noerror)
  "Move ARG lines forward.
If NOERROR, don't signal an error if we can't move that many lines."
  (let ((opoint (point))
	(hscroll (window-hscroll))
	target-hscroll)
    ;; Check if the previous command was a line-motion command, or if
    ;; we were called from some other command.
    (if (and (consp temporary-goal-column)
	     (memq last-command `(next-line previous-line ,this-command)))
	;; If so, there's no need to reset `temporary-goal-column',
	;; but we may need to hscroll.
	(if (or (/= (cdr temporary-goal-column) hscroll)
		(>  (cdr temporary-goal-column) 0))
	    (setq target-hscroll (cdr temporary-goal-column)))
      ;; Otherwise, we should reset `temporary-goal-column'.
      (let ((posn (posn-at-point))
	    x-pos)
	(cond
	 ;; Handle the `overflow-newline-into-fringe' case:
	 ((eq (nth 1 posn) 'right-fringe)
	  (setq temporary-goal-column (cons (- (window-width) 1) hscroll)))
	 ((car (posn-x-y posn))
	  (setq x-pos (car (posn-x-y posn)))
	  ;; In R2L lines, the X pixel coordinate is measured from the
	  ;; left edge of the window, but columns are still counted
	  ;; from the logical-order beginning of the line, i.e. from
	  ;; the right edge in this case.  We need to adjust for that.
	  (if (eq (current-bidi-paragraph-direction) 'right-to-left)
	      (setq x-pos (- (window-body-width nil t) 1 x-pos)))
	  (setq temporary-goal-column
		(cons (/ (float x-pos)
			 (frame-char-width))
                      hscroll)))
	 (executing-kbd-macro
	  ;; When we move beyond the first/last character visible in
	  ;; the window, posn-at-point will return nil, so we need to
	  ;; approximate the goal column as below.
	  (setq temporary-goal-column
		(mod (current-column) (window-text-width)))))))
    (if target-hscroll
	(set-window-hscroll (selected-window) target-hscroll))
    ;; vertical-motion can move more than it was asked to if it moves
    ;; across display strings with newlines.  We don't want to ring
    ;; the bell and announce beginning/end of buffer in that case.
    (or (and (or (and (>= arg 0)
		      (>= (vertical-motion
			   (cons (or goal-column
				     (if (consp temporary-goal-column)
					 (car temporary-goal-column)
				       temporary-goal-column))
				 arg))
			  arg))
		 (and (< arg 0)
		      (<= (vertical-motion
			   (cons (or goal-column
				     (if (consp temporary-goal-column)
					 (car temporary-goal-column)
				       temporary-goal-column))
				 arg))
			  arg)))
	     (or (>= arg 0)
		 (/= (point) opoint)
		 ;; If the goal column lies on a display string,
		 ;; `vertical-motion' advances the cursor to the end
		 ;; of the string.  For arg < 0, this can cause the
		 ;; cursor to get stuck.  (Bug#3020).
		 (= (vertical-motion arg) arg)))
	(unless noerror
	  (signal (if (< arg 0) 'beginning-of-buffer 'end-of-buffer)
		  nil)))))

;; This is the guts of next-line and previous-line.
;; Arg says how many lines to move.
;; The value is t if we can move the specified number of lines.
(defun line-move-1 (arg &optional noerror _to-end)
  ;; Don't run any point-motion hooks, and disregard intangibility,
  ;; for intermediate positions.
  (let ((inhibit-point-motion-hooks t)
	(opoint (point))
	(orig-arg arg))
    (if (consp temporary-goal-column)
	(setq temporary-goal-column (+ (car temporary-goal-column)
				       (cdr temporary-goal-column))))
    (unwind-protect
	(progn
	  (if (not (memq last-command '(next-line previous-line)))
	      (setq temporary-goal-column
		    (if (and track-eol (eolp)
			     ;; Don't count beg of empty line as end of line
			     ;; unless we just did explicit end-of-line.
			     (or (not (bolp)) (eq last-command 'move-end-of-line)))
			most-positive-fixnum
		      (current-column))))

	  (if (not (or (integerp selective-display)
                       line-move-ignore-invisible))
	      ;; Use just newline characters.
	      ;; Set ARG to 0 if we move as many lines as requested.
	      (or (if (> arg 0)
		      (progn (if (> arg 1) (forward-line (1- arg)))
			     ;; This way of moving forward ARG lines
			     ;; verifies that we have a newline after the last one.
			     ;; It doesn't get confused by intangible text.
			     (end-of-line)
			     (if (zerop (forward-line 1))
				 (setq arg 0)))
		    (and (zerop (forward-line arg))
			 (bolp)
			 (setq arg 0)))
		  (unless noerror
		    (signal (if (< arg 0)
				'beginning-of-buffer
			      'end-of-buffer)
			    nil)))
	    ;; Move by arg lines, but ignore invisible ones.
	    (let (done)
	      (while (and (> arg 0) (not done))
		;; If the following character is currently invisible,
		;; skip all characters with that same `invisible' property value.
		(while (and (not (eobp)) (invisible-p (point)))
		  (goto-char (next-char-property-change (point))))
		;; Move a line.
		;; We don't use `end-of-line', since we want to escape
		;; from field boundaries occurring exactly at point.
		(goto-char (constrain-to-field
			    (let ((inhibit-field-text-motion t))
			      (line-end-position))
			    (point) t t
			    'inhibit-line-move-field-capture))
		;; If there's no invisibility here, move over the newline.
		(cond
		 ((eobp)
		  (if (not noerror)
		      (signal 'end-of-buffer nil)
		    (setq done t)))
		 ((and (> arg 1)  ;; Use vertical-motion for last move
		       (not (integerp selective-display))
		       (not (invisible-p (point))))
		  ;; We avoid vertical-motion when possible
		  ;; because that has to fontify.
		  (forward-line 1))
		 ;; Otherwise move a more sophisticated way.
		 ((zerop (vertical-motion 1))
		  (if (not noerror)
		      (signal 'end-of-buffer nil)
		    (setq done t))))
		(unless done
		  (setq arg (1- arg))))
	      ;; The logic of this is the same as the loop above,
	      ;; it just goes in the other direction.
	      (while (and (< arg 0) (not done))
		;; For completely consistency with the forward-motion
		;; case, we should call beginning-of-line here.
		;; However, if point is inside a field and on a
		;; continued line, the call to (vertical-motion -1)
		;; below won't move us back far enough; then we return
		;; to the same column in line-move-finish, and point
		;; gets stuck -- cyd
		(forward-line 0)
		(cond
		 ((bobp)
		  (if (not noerror)
		      (signal 'beginning-of-buffer nil)
		    (setq done t)))
		 ((and (< arg -1) ;; Use vertical-motion for last move
		       (not (integerp selective-display))
		       (not (invisible-p (1- (point)))))
		  (forward-line -1))
		 ((zerop (vertical-motion -1))
		  (if (not noerror)
		      (signal 'beginning-of-buffer nil)
		    (setq done t))))
		(unless done
		  (setq arg (1+ arg))
		  (while (and ;; Don't move over previous invis lines
			  ;; if our target is the middle of this line.
			  (or (zerop (or goal-column temporary-goal-column))
			      (< arg 0))
			  (not (bobp)) (invisible-p (1- (point))))
		    (goto-char (previous-char-property-change (point))))))))
	  ;; This is the value the function returns.
	  (= arg 0))

      (cond ((> arg 0)
	     ;; If we did not move down as far as desired, at least go
	     ;; to end of line.  Be sure to call point-entered and
	     ;; point-left-hooks.
	     (let* ((npoint (prog1 (line-end-position)
			      (goto-char opoint)))
		    (inhibit-point-motion-hooks nil))
	       (goto-char npoint)))
	    ((< arg 0)
	     ;; If we did not move up as far as desired,
	     ;; at least go to beginning of line.
	     (let* ((npoint (prog1 (line-beginning-position)
			      (goto-char opoint)))
		    (inhibit-point-motion-hooks nil))
	       (goto-char npoint)))
	    (t
	     (line-move-finish (or goal-column temporary-goal-column)
			       opoint (> orig-arg 0)))))))

(defun line-move-finish (column opoint forward)
  (let ((repeat t))
    (while repeat
      ;; Set REPEAT to t to repeat the whole thing.
      (setq repeat nil)

      (let (new
	    (old (point))
	    (line-beg (line-beginning-position))
	    (line-end
	     ;; Compute the end of the line
	     ;; ignoring effectively invisible newlines.
	     (save-excursion
	       ;; Like end-of-line but ignores fields.
	       (skip-chars-forward "^\n")
	       (while (and (not (eobp)) (invisible-p (point)))
		 (goto-char (next-char-property-change (point)))
		 (skip-chars-forward "^\n"))
	       (point))))

	;; Move to the desired column.
	(line-move-to-column (truncate column))

	;; Corner case: suppose we start out in a field boundary in
	;; the middle of a continued line.  When we get to
	;; line-move-finish, point is at the start of a new *screen*
	;; line but the same text line; then line-move-to-column would
	;; move us backwards.  Test using C-n with point on the "x" in
	;;   (insert "a" (propertize "x" 'field t) (make-string 89 ?y))
	(and forward
	     (< (point) old)
	     (goto-char old))

	(setq new (point))

	;; Process intangibility within a line.
	;; With inhibit-point-motion-hooks bound to nil, a call to
	;; goto-char moves point past intangible text.

	;; However, inhibit-point-motion-hooks controls both the
	;; intangibility and the point-entered/point-left hooks.  The
	;; following hack avoids calling the point-* hooks
	;; unnecessarily.  Note that we move *forward* past intangible
	;; text when the initial and final points are the same.
	(goto-char new)
	(let ((inhibit-point-motion-hooks nil))
	  (goto-char new)

	  ;; If intangibility moves us to a different (later) place
	  ;; in the same line, use that as the destination.
	  (if (<= (point) line-end)
	      (setq new (point))
	    ;; If that position is "too late",
	    ;; try the previous allowable position.
	    ;; See if it is ok.
	    (backward-char)
	    (if (if forward
		    ;; If going forward, don't accept the previous
		    ;; allowable position if it is before the target line.
		    (< line-beg (point))
		  ;; If going backward, don't accept the previous
		  ;; allowable position if it is still after the target line.
		  (<= (point) line-end))
		(setq new (point))
	      ;; As a last resort, use the end of the line.
	      (setq new line-end))))

	;; Now move to the updated destination, processing fields
	;; as well as intangibility.
	(goto-char opoint)
	(let ((inhibit-point-motion-hooks nil))
	  (goto-char
	   ;; Ignore field boundaries if the initial and final
	   ;; positions have the same `field' property, even if the
	   ;; fields are non-contiguous.  This seems to be "nicer"
	   ;; behavior in many situations.
	   (if (eq (get-char-property new 'field)
	   	   (get-char-property opoint 'field))
	       new
	     (constrain-to-field new opoint t t
				 'inhibit-line-move-field-capture))))

	;; If all this moved us to a different line,
	;; retry everything within that new line.
	(when (or (< (point) line-beg) (> (point) line-end))
	  ;; Repeat the intangibility and field processing.
	  (setq repeat t))))))

(defun line-move-to-column (col)
  "Try to find column COL, considering invisibility.
This function works only in certain cases,
because what we really need is for `move-to-column'
and `current-column' to be able to ignore invisible text."
  (if (zerop col)
      (beginning-of-line)
    (move-to-column col))

  (when (and line-move-ignore-invisible
	     (not (bolp)) (invisible-p (1- (point))))
    (let ((normal-location (point))
	  (normal-column (current-column)))
      ;; If the following character is currently invisible,
      ;; skip all characters with that same `invisible' property value.
      (while (and (not (eobp))
		  (invisible-p (point)))
	(goto-char (next-char-property-change (point))))
      ;; Have we advanced to a larger column position?
      (if (> (current-column) normal-column)
	  ;; We have made some progress towards the desired column.
	  ;; See if we can make any further progress.
	  (line-move-to-column (+ (current-column) (- col normal-column)))
	;; Otherwise, go to the place we originally found
	;; and move back over invisible text.
	;; that will get us to the same place on the screen
	;; but with a more reasonable buffer position.
	(goto-char normal-location)
	(let ((line-beg
               ;; We want the real line beginning, so it's consistent
               ;; with bolp below, otherwise we might infloop.
               (let ((inhibit-field-text-motion t))
                 (line-beginning-position))))
	  (while (and (not (bolp)) (invisible-p (1- (point))))
	    (goto-char (previous-char-property-change (point) line-beg))))))))

(defun move-end-of-line (arg)
  "Move point to end of current line as displayed.
With argument ARG not nil or 1, move forward ARG - 1 lines first.
If point reaches the beginning or end of buffer, it stops there.

To ignore the effects of the `intangible' text or overlay
property, bind `inhibit-point-motion-hooks' to t.
If there is an image in the current line, this function
disregards newlines that are part of the text on which the image
rests."
  (interactive "^p")
  (or arg (setq arg 1))
  (let (done)
    (while (not done)
      (let ((newpos
	     (save-excursion
	       (let ((goal-column 0)
		     (line-move-visual nil))
		 (and (line-move arg t)
		      ;; With bidi reordering, we may not be at bol,
		      ;; so make sure we are.
		      (skip-chars-backward "^\n")
		      (not (bobp))
		      (progn
			(while (and (not (bobp)) (invisible-p (1- (point))))
			  (goto-char (previous-single-char-property-change
                                      (point) 'invisible)))
			(backward-char 1)))
		 (point)))))
	(goto-char newpos)
	(if (and (> (point) newpos)
		 (eq (preceding-char) ?\n))
	    (backward-char 1)
	  (if (and (> (point) newpos) (not (eobp))
		   (not (eq (following-char) ?\n)))
	      ;; If we skipped something intangible and now we're not
	      ;; really at eol, keep going.
	      (setq arg 1)
	    (setq done t)))))))

(defun move-beginning-of-line (arg)
  "Move point to beginning of current line as displayed.
\(If there's an image in the line, this disregards newlines
which are part of the text that the image rests on.)

With argument ARG not nil or 1, move forward ARG - 1 lines first.
If point reaches the beginning or end of buffer, it stops there.
To ignore intangibility, bind `inhibit-point-motion-hooks' to t."
  (interactive "^p")
  (or arg (setq arg 1))

  (let ((orig (point))
	first-vis first-vis-field-value)

    ;; Move by lines, if ARG is not 1 (the default).
    (if (/= arg 1)
	(let ((line-move-visual nil))
	  (line-move (1- arg) t)))

    ;; Move to beginning-of-line, ignoring fields and invisible text.
    (skip-chars-backward "^\n")
    (while (and (not (bobp)) (invisible-p (1- (point))))
      (goto-char (previous-char-property-change (point)))
      (skip-chars-backward "^\n"))

    ;; Now find first visible char in the line.
    (while (and (< (point) orig) (invisible-p (point)))
      (goto-char (next-char-property-change (point) orig)))
    (setq first-vis (point))

    ;; See if fields would stop us from reaching FIRST-VIS.
    (setq first-vis-field-value
	  (constrain-to-field first-vis orig (/= arg 1) t nil))

    (goto-char (if (/= first-vis-field-value first-vis)
		   ;; If yes, obey them.
		   first-vis-field-value
		 ;; Otherwise, move to START with attention to fields.
		 ;; (It is possible that fields never matter in this case.)
		 (constrain-to-field (point) orig
				     (/= arg 1) t nil)))))


;; Many people have said they rarely use this feature, and often type
;; it by accident.  Maybe it shouldn't even be on a key.
(put 'set-goal-column 'disabled t)

(defun set-goal-column (arg)
  "Set the current horizontal position as a goal for \\[next-line] and \\[previous-line].
Those commands will move to this position in the line moved to
rather than trying to keep the same horizontal position.
With a non-nil argument ARG, clears out the goal column
so that \\[next-line] and \\[previous-line] resume vertical motion.
The goal column is stored in the variable `goal-column'.
This is a buffer-local setting."
  (interactive "P")
  (if arg
      (progn
        (setq goal-column nil)
        (message "No goal column"))
    (setq goal-column (current-column))
    ;; The older method below can be erroneous if `set-goal-column' is bound
    ;; to a sequence containing %
    ;;(message (substitute-command-keys
    ;;"Goal column %d (use \\[set-goal-column] with an arg to unset it)")
    ;;goal-column)
    (message "%s"
	     (concat
	      (format "Goal column %d " goal-column)
	      (substitute-command-keys
	       "(use \\[set-goal-column] with an arg to unset it)")))

    )
  nil)
\f
;;; Editing based on visual lines, as opposed to logical lines.

(defun end-of-visual-line (&optional n)
  "Move point to end of current visual line.
With argument N not nil or 1, move forward N - 1 visual lines first.
If point reaches the beginning or end of buffer, it stops there.
To ignore intangibility, bind `inhibit-point-motion-hooks' to t."
  (interactive "^p")
  (or n (setq n 1))
  (if (/= n 1)
      (let ((line-move-visual t))
	(line-move (1- n) t)))
  ;; Unlike `move-beginning-of-line', `move-end-of-line' doesn't
  ;; constrain to field boundaries, so we don't either.
  (vertical-motion (cons (window-width) 0)))

(defun beginning-of-visual-line (&optional n)
  "Move point to beginning of current visual line.
With argument N not nil or 1, move forward N - 1 visual lines first.
If point reaches the beginning or end of buffer, it stops there.
To ignore intangibility, bind `inhibit-point-motion-hooks' to t."
  (interactive "^p")
  (or n (setq n 1))
  (let ((opoint (point)))
    (if (/= n 1)
	(let ((line-move-visual t))
	  (line-move (1- n) t)))
    (vertical-motion 0)
    ;; Constrain to field boundaries, like `move-beginning-of-line'.
    (goto-char (constrain-to-field (point) opoint (/= n 1)))))

(defun kill-visual-line (&optional arg)
  "Kill the rest of the visual line.
With prefix argument ARG, kill that many visual lines from point.
If ARG is negative, kill visual lines backward.
If ARG is zero, kill the text before point on the current visual
line.

If you want to append the killed line to the last killed text,
use \\[append-next-kill] before \\[kill-line].

If the buffer is read-only, Emacs will beep and refrain from deleting
the line, but put the line in the kill ring anyway.  This means that
you can use this command to copy text from a read-only buffer.
\(If the variable `kill-read-only-ok' is non-nil, then this won't
even beep.)"
  (interactive "P")
  ;; Like in `kill-line', it's better to move point to the other end
  ;; of the kill before killing.
  (let ((opoint (point))
	(kill-whole-line (and kill-whole-line (bolp))))
    (if arg
	(vertical-motion (prefix-numeric-value arg))
      (end-of-visual-line 1)
      (if (= (point) opoint)
	  (vertical-motion 1)
	;; Skip any trailing whitespace at the end of the visual line.
	;; We used to do this only if `show-trailing-whitespace' is
	;; nil, but that's wrong; the correct thing would be to check
	;; whether the trailing whitespace is highlighted.  But, it's
	;; OK to just do this unconditionally.
	(skip-chars-forward " \t")))
    (kill-region opoint (if (and kill-whole-line (looking-at "\n"))
			    (1+ (point))
			  (point)))))

(defun next-logical-line (&optional arg try-vscroll)
  "Move cursor vertically down ARG lines.
This is identical to `next-line', except that it always moves
by logical lines instead of visual lines, ignoring the value of
the variable `line-move-visual'."
  (interactive "^p\np")
  (let ((line-move-visual nil))
    (with-no-warnings
      (next-line arg try-vscroll))))

(defun previous-logical-line (&optional arg try-vscroll)
  "Move cursor vertically up ARG lines.
This is identical to `previous-line', except that it always moves
by logical lines instead of visual lines, ignoring the value of
the variable `line-move-visual'."
  (interactive "^p\np")
  (let ((line-move-visual nil))
    (with-no-warnings
      (previous-line arg try-vscroll))))

(defgroup visual-line nil
  "Editing based on visual lines."
  :group 'convenience
  :version "23.1")

(defvar visual-line-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map [remap kill-line] 'kill-visual-line)
    (define-key map [remap move-beginning-of-line] 'beginning-of-visual-line)
    (define-key map [remap move-end-of-line]  'end-of-visual-line)
    ;; These keybindings interfere with xterm function keys.  Are
    ;; there any other suitable bindings?
    ;; (define-key map "\M-[" 'previous-logical-line)
    ;; (define-key map "\M-]" 'next-logical-line)
    map))

(defcustom visual-line-fringe-indicators '(nil nil)
  "How fringe indicators are shown for wrapped lines in `visual-line-mode'.
The value should be a list of the form (LEFT RIGHT), where LEFT
and RIGHT are symbols representing the bitmaps to display, to
indicate wrapped lines, in the left and right fringes respectively.
See also `fringe-indicator-alist'.
The default is not to display fringe indicators for wrapped lines.
This variable does not affect fringe indicators displayed for
other purposes."
  :type '(list (choice (const :tag "Hide left indicator" nil)
		       (const :tag "Left curly arrow" left-curly-arrow)
		       (symbol :tag "Other bitmap"))
	       (choice (const :tag "Hide right indicator" nil)
		       (const :tag "Right curly arrow" right-curly-arrow)
		       (symbol :tag "Other bitmap")))
  :set (lambda (symbol value)
	 (dolist (buf (buffer-list))
	   (with-current-buffer buf
	     (when (and (boundp 'visual-line-mode)
			(symbol-value 'visual-line-mode))
	       (setq fringe-indicator-alist
		     (cons (cons 'continuation value)
			   (assq-delete-all
			    'continuation
			    (copy-tree fringe-indicator-alist)))))))
	 (set-default symbol value)))

(defvar visual-line--saved-state nil)

(define-minor-mode visual-line-mode
  "Toggle visual line based editing (Visual Line mode).
With a prefix argument ARG, enable Visual Line mode if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
the mode if ARG is omitted or nil.

When Visual Line mode is enabled, `word-wrap' is turned on in
this buffer, and simple editing commands are redefined to act on
visual lines, not logical lines.  See Info node `Visual Line
Mode' for details."
  :keymap visual-line-mode-map
  :group 'visual-line
  :lighter " Wrap"
  (if visual-line-mode
      (progn
	(set (make-local-variable 'visual-line--saved-state) nil)
	;; Save the local values of some variables, to be restored if
	;; visual-line-mode is turned off.
	(dolist (var '(line-move-visual truncate-lines
		       truncate-partial-width-windows
		       word-wrap fringe-indicator-alist))
	  (if (local-variable-p var)
	      (push (cons var (symbol-value var))
		    visual-line--saved-state)))
	(set (make-local-variable 'line-move-visual) t)
	(set (make-local-variable 'truncate-partial-width-windows) nil)
	(setq truncate-lines nil
	      word-wrap t
	      fringe-indicator-alist
	      (cons (cons 'continuation visual-line-fringe-indicators)
		    fringe-indicator-alist)))
    (kill-local-variable 'line-move-visual)
    (kill-local-variable 'word-wrap)
    (kill-local-variable 'truncate-lines)
    (kill-local-variable 'truncate-partial-width-windows)
    (kill-local-variable 'fringe-indicator-alist)
    (dolist (saved visual-line--saved-state)
      (set (make-local-variable (car saved)) (cdr saved)))
    (kill-local-variable 'visual-line--saved-state)))

(defun turn-on-visual-line-mode ()
  (visual-line-mode 1))

(define-globalized-minor-mode global-visual-line-mode
  visual-line-mode turn-on-visual-line-mode)

\f
(defun transpose-chars (arg)
  "Interchange characters around point, moving forward one character.
With prefix arg ARG, effect is to take character before point
and drag it forward past ARG other characters (backward if ARG negative).
If no argument and at end of line, the previous two chars are exchanged."
  (interactive "*P")
  (when (and (null arg) (eolp) (not (bobp))
	     (not (get-text-property (1- (point)) 'read-only)))
    (forward-char -1))
  (transpose-subr 'forward-char (prefix-numeric-value arg)))

(defun transpose-words (arg)
  "Interchange words around point, leaving point at end of them.
With prefix arg ARG, effect is to take word before or around point
and drag it forward past ARG other words (backward if ARG negative).
If ARG is zero, the words around or after point and around or after mark
are interchanged."
  ;; FIXME: `foo a!nd bar' should transpose into `bar and foo'.
  (interactive "*p")
  (transpose-subr 'forward-word arg))

(defun transpose-sexps (arg)
  "Like \\[transpose-words] but applies to sexps.
Does not work on a sexp that point is in the middle of
if it is a list or string."
  (interactive "*p")
  (transpose-subr
   (lambda (arg)
     ;; Here we should try to simulate the behavior of
     ;; (cons (progn (forward-sexp x) (point))
     ;;       (progn (forward-sexp (- x)) (point)))
     ;; Except that we don't want to rely on the second forward-sexp
     ;; putting us back to where we want to be, since forward-sexp-function
     ;; might do funny things like infix-precedence.
     (if (if (> arg 0)
	     (looking-at "\\sw\\|\\s_")
	   (and (not (bobp))
		(save-excursion (forward-char -1) (looking-at "\\sw\\|\\s_"))))
	 ;; Jumping over a symbol.  We might be inside it, mind you.
	 (progn (funcall (if (> arg 0)
			     'skip-syntax-backward 'skip-syntax-forward)
			 "w_")
		(cons (save-excursion (forward-sexp arg) (point)) (point)))
       ;; Otherwise, we're between sexps.  Take a step back before jumping
       ;; to make sure we'll obey the same precedence no matter which direction
       ;; we're going.
       (funcall (if (> arg 0) 'skip-syntax-backward 'skip-syntax-forward) " .")
       (cons (save-excursion (forward-sexp arg) (point))
	     (progn (while (or (forward-comment (if (> arg 0) 1 -1))
			       (not (zerop (funcall (if (> arg 0)
							'skip-syntax-forward
						      'skip-syntax-backward)
						    ".")))))
		    (point)))))
   arg 'special))

(defun transpose-lines (arg)
  "Exchange current line and previous line, leaving point after both.
With argument ARG, takes previous line and moves it past ARG lines.
With argument 0, interchanges line point is in with line mark is in."
  (interactive "*p")
  (transpose-subr (function
		   (lambda (arg)
		     (if (> arg 0)
			 (progn
			   ;; Move forward over ARG lines,
			   ;; but create newlines if necessary.
			   (setq arg (forward-line arg))
			   (if (/= (preceding-char) ?\n)
			       (setq arg (1+ arg)))
			   (if (> arg 0)
			       (newline arg)))
		       (forward-line arg))))
		  arg))

;; FIXME seems to leave point BEFORE the current object when ARG = 0,
;; which seems inconsistent with the ARG /= 0 case.
;; FIXME document SPECIAL.
(defun transpose-subr (mover arg &optional special)
  "Subroutine to do the work of transposing objects.
Works for lines, sentences, paragraphs, etc.  MOVER is a function that
moves forward by units of the given object (e.g. forward-sentence,
forward-paragraph).  If ARG is zero, exchanges the current object
with the one containing mark.  If ARG is an integer, moves the
current object past ARG following (if ARG is positive) or
preceding (if ARG is negative) objects, leaving point after the
current object."
  (let ((aux (if special mover
	       (lambda (x)
		 (cons (progn (funcall mover x) (point))
		       (progn (funcall mover (- x)) (point))))))
	pos1 pos2)
    (cond
     ((= arg 0)
      (save-excursion
	(setq pos1 (funcall aux 1))
	(goto-char (or (mark) (error "No mark set in this buffer")))
	(setq pos2 (funcall aux 1))
	(transpose-subr-1 pos1 pos2))
      (exchange-point-and-mark))
     ((> arg 0)
      (setq pos1 (funcall aux -1))
      (setq pos2 (funcall aux arg))
      (transpose-subr-1 pos1 pos2)
      (goto-char (car pos2)))
     (t
      (setq pos1 (funcall aux -1))
      (goto-char (car pos1))
      (setq pos2 (funcall aux arg))
      (transpose-subr-1 pos1 pos2)
      (goto-char (+ (car pos2) (- (cdr pos1) (car pos1))))))))

(defun transpose-subr-1 (pos1 pos2)
  (when (> (car pos1) (cdr pos1)) (setq pos1 (cons (cdr pos1) (car pos1))))
  (when (> (car pos2) (cdr pos2)) (setq pos2 (cons (cdr pos2) (car pos2))))
  (when (> (car pos1) (car pos2))
    (let ((swap pos1))
      (setq pos1 pos2 pos2 swap)))
  (if (> (cdr pos1) (car pos2)) (error "Don't have two things to transpose"))
  (atomic-change-group
    ;; This sequence of insertions attempts to preserve marker
    ;; positions at the start and end of the transposed objects.
    (let* ((word (buffer-substring (car pos2) (cdr pos2)))
	   (len1 (- (cdr pos1) (car pos1)))
	   (len2 (length word))
	   (boundary (make-marker)))
      (set-marker boundary (car pos2))
      (goto-char (cdr pos1))
      (insert-before-markers word)
      (setq word (delete-and-extract-region (car pos1) (+ (car pos1) len1)))
      (goto-char boundary)
      (insert word)
      (goto-char (+ boundary len1))
      (delete-region (point) (+ (point) len2))
      (set-marker boundary nil))))
\f
(defun backward-word (&optional arg)
  "Move backward until encountering the beginning of a word.
With argument ARG, do this that many times.
If ARG is omitted or nil, move point backward one word.

The word boundaries are normally determined by the buffer's syntax
table, but `find-word-boundary-function-table', such as set up
by `subword-mode', can change that.  If a Lisp program needs to
move by words determined strictly by the syntax table, it should
use `backward-word-strictly' instead."
  (interactive "^p")
  (forward-word (- (or arg 1))))

(defun mark-word (&optional arg allow-extend)
  "Set mark ARG words away from point.
The place mark goes is the same place \\[forward-word] would
move to with the same argument.
Interactively, if this command is repeated
or (in Transient Mark mode) if the mark is active,
it marks the next ARG words after the ones already marked."
  (interactive "P\np")
  (cond ((and allow-extend
	      (or (and (eq last-command this-command) (mark t))
		  (region-active-p)))
	 (setq arg (if arg (prefix-numeric-value arg)
		     (if (< (mark) (point)) -1 1)))
	 (set-mark
	  (save-excursion
	    (goto-char (mark))
	    (forward-word arg)
	    (point))))
	(t
	 (push-mark
	  (save-excursion
	    (forward-word (prefix-numeric-value arg))
	    (point))
	  nil t))))

(defun kill-word (arg)
  "Kill characters forward until encountering the end of a word.
With argument ARG, do this that many times."
  (interactive "p")
  (kill-region (point) (progn (forward-word arg) (point))))

(defun backward-kill-word (arg)
  "Kill characters backward until encountering the beginning of a word.
With argument ARG, do this that many times."
  (interactive "p")
  (kill-word (- arg)))

(defun current-word (&optional strict really-word)
  "Return the symbol or word that point is on (or a nearby one) as a string.
The return value includes no text properties.
If optional arg STRICT is non-nil, return nil unless point is within
or adjacent to a symbol or word.  In all cases the value can be nil
if there is no word nearby.
The function, belying its name, normally finds a symbol.
If optional arg REALLY-WORD is non-nil, it finds just a word."
  (save-excursion
    (let* ((oldpoint (point)) (start (point)) (end (point))
	   (syntaxes (if really-word "w" "w_"))
	   (not-syntaxes (concat "^" syntaxes)))
      (skip-syntax-backward syntaxes) (setq start (point))
      (goto-char oldpoint)
      (skip-syntax-forward syntaxes) (setq end (point))
      (when (and (eq start oldpoint) (eq end oldpoint)
		 ;; Point is neither within nor adjacent to a word.
		 (not strict))
	;; Look for preceding word in same line.
	(skip-syntax-backward not-syntaxes (line-beginning-position))
	(if (bolp)
	    ;; No preceding word in same line.
	    ;; Look for following word in same line.
	    (progn
	      (skip-syntax-forward not-syntaxes (line-end-position))
	      (setq start (point))
	      (skip-syntax-forward syntaxes)
	      (setq end (point)))
	  (setq end (point))
	  (skip-syntax-backward syntaxes)
	  (setq start (point))))
      ;; If we found something nonempty, return it as a string.
      (unless (= start end)
	(buffer-substring-no-properties start end)))))
\f
(defcustom fill-prefix nil
  "String for filling to insert at front of new line, or nil for none."
  :type '(choice (const :tag "None" nil)
		 string)
  :group 'fill)
(make-variable-buffer-local 'fill-prefix)
(put 'fill-prefix 'safe-local-variable 'string-or-null-p)

(defcustom auto-fill-inhibit-regexp nil
  "Regexp to match lines which should not be auto-filled."
  :type '(choice (const :tag "None" nil)
		 regexp)
  :group 'fill)

(defun do-auto-fill ()
  "The default value for `normal-auto-fill-function'.
This is the default auto-fill function, some major modes use a different one.
Returns t if it really did any work."
  (let (fc justify give-up
	   (fill-prefix fill-prefix))
    (if (or (not (setq justify (current-justification)))
	    (null (setq fc (current-fill-column)))
	    (and (eq justify 'left)
		 (<= (current-column) fc))
	    (and auto-fill-inhibit-regexp
		 (save-excursion (beginning-of-line)
				 (looking-at auto-fill-inhibit-regexp))))
	nil ;; Auto-filling not required
      (if (memq justify '(full center right))
	  (save-excursion (unjustify-current-line)))

      ;; Choose a fill-prefix automatically.
      (when (and adaptive-fill-mode
		 (or (null fill-prefix) (string= fill-prefix "")))
	(let ((prefix
	       (fill-context-prefix
		(save-excursion (fill-forward-paragraph -1) (point))
		(save-excursion (fill-forward-paragraph 1) (point)))))
	  (and prefix (not (equal prefix ""))
	       ;; Use auto-indentation rather than a guessed empty prefix.
	       (not (and fill-indent-according-to-mode
			 (string-match "\\`[ \t]*\\'" prefix)))
	       (setq fill-prefix prefix))))

      (while (and (not give-up) (> (current-column) fc))
	;; Determine where to split the line.
	(let* (after-prefix
	       (fill-point
		(save-excursion
		  (beginning-of-line)
		  (setq after-prefix (point))
		  (and fill-prefix
		       (looking-at (regexp-quote fill-prefix))
		       (setq after-prefix (match-end 0)))
		  (move-to-column (1+ fc))
		  (fill-move-to-break-point after-prefix)
		  (point))))

	  ;; See whether the place we found is any good.
	  (if (save-excursion
		(goto-char fill-point)
		(or (bolp)
		    ;; There is no use breaking at end of line.
		    (save-excursion (skip-chars-forward " ") (eolp))
		    ;; It is futile to split at the end of the prefix
		    ;; since we would just insert the prefix again.
		    (and after-prefix (<= (point) after-prefix))
		    ;; Don't split right after a comment starter
		    ;; since we would just make another comment starter.
		    (and comment-start-skip
			 (let ((limit (point)))
			   (beginning-of-line)
			   (and (re-search-forward comment-start-skip
						   limit t)
				(eq (point) limit))))))
	      ;; No good place to break => stop trying.
	      (setq give-up t)
	    ;; Ok, we have a useful place to break the line.  Do it.
	    (let ((prev-column (current-column)))
	      ;; If point is at the fill-point, do not `save-excursion'.
	      ;; Otherwise, if a comment prefix or fill-prefix is inserted,
	      ;; point will end up before it rather than after it.
	      (if (save-excursion
		    (skip-chars-backward " \t")
		    (= (point) fill-point))
		  (default-indent-new-line t)
		(save-excursion
		  (goto-char fill-point)
		  (default-indent-new-line t)))
	      ;; Now do justification, if required
	      (if (not (eq justify 'left))
		  (save-excursion
		    (end-of-line 0)
		    (justify-current-line justify nil t)))
	      ;; If making the new line didn't reduce the hpos of
	      ;; the end of the line, then give up now;
	      ;; trying again will not help.
	      (if (>= (current-column) prev-column)
		  (setq give-up t))))))
      ;; Justify last line.
      (justify-current-line justify t t)
      t)))

(defvar comment-line-break-function 'comment-indent-new-line
  "Mode-specific function which line breaks and continues a comment.
This function is called during auto-filling when a comment syntax
is defined.
The function should take a single optional argument, which is a flag
indicating whether it should use soft newlines.")

(defun default-indent-new-line (&optional soft)
  "Break line at point and indent.
If a comment syntax is defined, call `comment-indent-new-line'.

The inserted newline is marked hard if variable `use-hard-newlines' is true,
unless optional argument SOFT is non-nil."
  (interactive)
  (if comment-start
      (funcall comment-line-break-function soft)
    ;; Insert the newline before removing empty space so that markers
    ;; get preserved better.
    (if soft (insert-and-inherit ?\n) (newline 1))
    (save-excursion (forward-char -1) (delete-horizontal-space))
    (delete-horizontal-space)

    (if (and fill-prefix (not adaptive-fill-mode))
	;; Blindly trust a non-adaptive fill-prefix.
	(progn
	  (indent-to-left-margin)
	  (insert-before-markers-and-inherit fill-prefix))

      (cond
       ;; If there's an adaptive prefix, use it unless we're inside
       ;; a comment and the prefix is not a comment starter.
       (fill-prefix
	(indent-to-left-margin)
	(insert-and-inherit fill-prefix))
       ;; If we're not inside a comment, just try to indent.
       (t (indent-according-to-mode))))))

(defvar normal-auto-fill-function 'do-auto-fill
  "The function to use for `auto-fill-function' if Auto Fill mode is turned on.
Some major modes set this.")

(put 'auto-fill-function :minor-mode-function 'auto-fill-mode)
;; `functions' and `hooks' are usually unsafe to set, but setting
;; auto-fill-function to nil in a file-local setting is safe and
;; can be useful to prevent auto-filling.
(put 'auto-fill-function 'safe-local-variable 'null)

(define-minor-mode auto-fill-mode
  "Toggle automatic line breaking (Auto Fill mode).
With a prefix argument ARG, enable Auto Fill mode if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
the mode if ARG is omitted or nil.

When Auto Fill mode is enabled, inserting a space at a column
beyond `current-fill-column' automatically breaks the line at a
previous space.

When `auto-fill-mode' is on, the `auto-fill-function' variable is
non-nil.

The value of `normal-auto-fill-function' specifies the function to use
for `auto-fill-function' when turning Auto Fill mode on."
  :variable (auto-fill-function
             . (lambda (v) (setq auto-fill-function
                            (if v normal-auto-fill-function)))))

;; This holds a document string used to document auto-fill-mode.
(defun auto-fill-function ()
  "Automatically break line at a previous space, in insertion of text."
  nil)

(defun turn-on-auto-fill ()
  "Unconditionally turn on Auto Fill mode."
  (auto-fill-mode 1))

(defun turn-off-auto-fill ()
  "Unconditionally turn off Auto Fill mode."
  (auto-fill-mode -1))

(custom-add-option 'text-mode-hook 'turn-on-auto-fill)

(defun set-fill-column (arg)
  "Set `fill-column' to specified argument.
Use \\[universal-argument] followed by a number to specify a column.
Just \\[universal-argument] as argument means to use the current column."
  (interactive
   (list (or current-prefix-arg
             ;; We used to use current-column silently, but C-x f is too easily
             ;; typed as a typo for C-x C-f, so we turned it into an error and
             ;; now an interactive prompt.
             (read-number "Set fill-column to: " (current-column)))))
  (if (consp arg)
      (setq arg (current-column)))
  (if (not (integerp arg))
      ;; Disallow missing argument; it's probably a typo for C-x C-f.
      (error "set-fill-column requires an explicit argument")
    (message "Fill column set to %d (was %d)" arg fill-column)
    (setq fill-column arg)))
\f
(defun set-selective-display (arg)
  "Set `selective-display' to ARG; clear it if no arg.
When the value of `selective-display' is a number > 0,
lines whose indentation is >= that value are not displayed.
The variable `selective-display' has a separate value for each buffer."
  (interactive "P")
  (if (eq selective-display t)
      (error "selective-display already in use for marked lines"))
  (let ((current-vpos
	 (save-restriction
	   (narrow-to-region (point-min) (point))
	   (goto-char (window-start))
	   (vertical-motion (window-height)))))
    (setq selective-display
	  (and arg (prefix-numeric-value arg)))
    (recenter current-vpos))
  (set-window-start (selected-window) (window-start))
  (princ "selective-display set to " t)
  (prin1 selective-display t)
  (princ "." t))

(defvaralias 'indicate-unused-lines 'indicate-empty-lines)

(defun toggle-truncate-lines (&optional arg)
  "Toggle truncating of long lines for the current buffer.
When truncating is off, long lines are folded.
With prefix argument ARG, truncate long lines if ARG is positive,
otherwise fold them.  Note that in side-by-side windows, this
command has no effect if `truncate-partial-width-windows' is
non-nil."
  (interactive "P")
  (setq truncate-lines
	(if (null arg)
	    (not truncate-lines)
	  (> (prefix-numeric-value arg) 0)))
  (force-mode-line-update)
  (unless truncate-lines
    (let ((buffer (current-buffer)))
      (walk-windows (lambda (window)
		      (if (eq buffer (window-buffer window))
			  (set-window-hscroll window 0)))
		    nil t)))
  (message "Truncate long lines %s"
	   (if truncate-lines "enabled" "disabled")))

(defun toggle-word-wrap (&optional arg)
  "Toggle whether to use word-wrapping for continuation lines.
With prefix argument ARG, wrap continuation lines at word boundaries
if ARG is positive, otherwise wrap them at the right screen edge.
This command toggles the value of `word-wrap'.  It has no effect
if long lines are truncated."
  (interactive "P")
  (setq word-wrap
	(if (null arg)
	    (not word-wrap)
	  (> (prefix-numeric-value arg) 0)))
  (force-mode-line-update)
  (message "Word wrapping %s"
	   (if word-wrap "enabled" "disabled")))

(defvar overwrite-mode-textual (purecopy " Ovwrt")
  "The string displayed in the mode line when in overwrite mode.")
(defvar overwrite-mode-binary (purecopy " Bin Ovwrt")
  "The string displayed in the mode line when in binary overwrite mode.")

(define-minor-mode overwrite-mode
  "Toggle Overwrite mode.
With a prefix argument ARG, enable Overwrite mode if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
the mode if ARG is omitted or nil.

When Overwrite mode is enabled, printing characters typed in
replace existing text on a one-for-one basis, rather than pushing
it to the right.  At the end of a line, such characters extend
the line.  Before a tab, such characters insert until the tab is
filled in.  \\[quoted-insert] still inserts characters in
overwrite mode; this is supposed to make it easier to insert
characters when necessary."
  :variable (overwrite-mode
             . (lambda (v) (setq overwrite-mode (if v 'overwrite-mode-textual)))))

(define-minor-mode binary-overwrite-mode
  "Toggle Binary Overwrite mode.
With a prefix argument ARG, enable Binary Overwrite mode if ARG
is positive, and disable it otherwise.  If called from Lisp,
enable the mode if ARG is omitted or nil.

When Binary Overwrite mode is enabled, printing characters typed
in replace existing text.  Newlines are not treated specially, so
typing at the end of a line joins the line to the next, with the
typed character between them.  Typing before a tab character
simply replaces the tab with the character typed.
\\[quoted-insert] replaces the text at the cursor, just as
ordinary typing characters do.

Note that Binary Overwrite mode is not its own minor mode; it is
a specialization of overwrite mode, entered by setting the
`overwrite-mode' variable to `overwrite-mode-binary'."
  :variable (overwrite-mode
             . (lambda (v) (setq overwrite-mode (if v 'overwrite-mode-binary)))))

(define-minor-mode line-number-mode
  "Toggle line number display in the mode line (Line Number mode).
With a prefix argument ARG, enable Line Number mode if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
the mode if ARG is omitted or nil.

Line numbers do not appear for very large buffers and buffers
with very long lines; see variables `line-number-display-limit'
and `line-number-display-limit-width'."
  :init-value t :global t :group 'mode-line)

(define-minor-mode column-number-mode
  "Toggle column number display in the mode line (Column Number mode).
With a prefix argument ARG, enable Column Number mode if ARG is
positive, and disable it otherwise.

If called from Lisp, enable the mode if ARG is omitted or nil."
  :global t :group 'mode-line)

(define-minor-mode size-indication-mode
  "Toggle buffer size display in the mode line (Size Indication mode).
With a prefix argument ARG, enable Size Indication mode if ARG is
positive, and disable it otherwise.

If called from Lisp, enable the mode if ARG is omitted or nil."
  :global t :group 'mode-line)

(define-minor-mode auto-save-mode
  "Toggle auto-saving in the current buffer (Auto Save mode).
With a prefix argument ARG, enable Auto Save mode if ARG is
positive, and disable it otherwise.

If called from Lisp, enable the mode if ARG is omitted or nil."
  :variable ((and buffer-auto-save-file-name
                  ;; If auto-save is off because buffer has shrunk,
                  ;; then toggling should turn it on.
                  (>= buffer-saved-size 0))
             . (lambda (val)
                 (setq buffer-auto-save-file-name
                       (cond
                        ((null val) nil)
                        ((and buffer-file-name auto-save-visited-file-name
                              (not buffer-read-only))
                         buffer-file-name)
                        (t (make-auto-save-file-name))))))
  ;; If -1 was stored here, to temporarily turn off saving,
  ;; turn it back on.
  (and (< buffer-saved-size 0)
       (setq buffer-saved-size 0)))
\f
(defgroup paren-blinking nil
  "Blinking matching of parens and expressions."
  :prefix "blink-matching-"
  :group 'paren-matching)

(defcustom blink-matching-paren t
  "Non-nil means show matching open-paren when close-paren is inserted.
If t, highlight the paren.  If `jump', briefly move cursor to its
position.  If `jump-offscreen', move cursor there even if the
position is off screen.  With any other non-nil value, the
off-screen position of the opening paren will be shown in the
echo area."
  :type '(choice
          (const :tag "Disable" nil)
          (const :tag "Highlight" t)
          (const :tag "Move cursor" jump)
          (const :tag "Move cursor, even if off screen" jump-offscreen))
  :group 'paren-blinking)

(defcustom blink-matching-paren-on-screen t
  "Non-nil means show matching open-paren when it is on screen.
If nil, don't show it (but the open-paren can still be shown
in the echo area when it is off screen).

This variable has no effect if `blink-matching-paren' is nil.
\(In that case, the open-paren is never shown.)
It is also ignored if `show-paren-mode' is enabled."
  :type 'boolean
  :group 'paren-blinking)

(defcustom blink-matching-paren-distance (* 100 1024)
  "If non-nil, maximum distance to search backwards for matching open-paren.
If nil, search stops at the beginning of the accessible portion of the buffer."
  :version "23.2"                       ; 25->100k
  :type '(choice (const nil) integer)
  :group 'paren-blinking)

(defcustom blink-matching-delay 1
  "Time in seconds to delay after showing a matching paren."
  :type 'number
  :group 'paren-blinking)

(defcustom blink-matching-paren-dont-ignore-comments nil
  "If nil, `blink-matching-paren' ignores comments.
More precisely, when looking for the matching parenthesis,
it skips the contents of comments that end before point."
  :type 'boolean
  :group 'paren-blinking)

(defun blink-matching-check-mismatch (start end)
  "Return whether or not START...END are matching parens.
END is the current point and START is the blink position.
START might be nil if no matching starter was found.
Returns non-nil if we find there is a mismatch."
  (let* ((end-syntax (syntax-after (1- end)))
         (matching-paren (and (consp end-syntax)
                              (eq (syntax-class end-syntax) 5)
                              (cdr end-syntax))))
    ;; For self-matched chars like " and $, we can't know when they're
    ;; mismatched or unmatched, so we can only do it for parens.
    (when matching-paren
      (not (and start
                (or
                 (eq (char-after start) matching-paren)
                 ;; The cdr might hold a new paren-class info rather than
                 ;; a matching-char info, in which case the two CDRs
                 ;; should match.
                 (eq matching-paren (cdr-safe (syntax-after start)))))))))

(defvar blink-matching-check-function #'blink-matching-check-mismatch
  "Function to check parentheses mismatches.
The function takes two arguments (START and END) where START is the
position just before the opening token and END is the position right after.
START can be nil, if it was not found.
The function should return non-nil if the two tokens do not match.")

(defvar blink-matching--overlay
  (let ((ol (make-overlay (point) (point) nil t)))
    (overlay-put ol 'face 'show-paren-match)
    (delete-overlay ol)
    ol)
  "Overlay used to highlight the matching paren.")

(defun blink-matching-open ()
  "Momentarily highlight the beginning of the sexp before point."
  (interactive)
  (when (and (not (bobp))
	     blink-matching-paren)
    (let* ((oldpos (point))
	   (message-log-max nil) ; Don't log messages about paren matching.
	   (blinkpos
            (save-excursion
              (save-restriction
                (if blink-matching-paren-distance
                    (narrow-to-region
                     (max (minibuffer-prompt-end) ;(point-min) unless minibuf.
                          (- (point) blink-matching-paren-distance))
                     oldpos))
                (let ((parse-sexp-ignore-comments
                       (and parse-sexp-ignore-comments
                            (not blink-matching-paren-dont-ignore-comments))))
                  (condition-case ()
                      (progn
			(syntax-propertize (point))
                        (forward-sexp -1)
                        ;; backward-sexp skips backward over prefix chars,
                        ;; so move back to the matching paren.
                        (while (and (< (point) (1- oldpos))
                                    (let ((code (syntax-after (point))))
                                      (or (eq (syntax-class code) 6)
                                          (eq (logand 1048576 (car code))
                                              1048576))))
                          (forward-char 1))
                        (point))
                    (error nil))))))
           (mismatch (funcall blink-matching-check-function blinkpos oldpos)))
      (cond
       (mismatch
        (if blinkpos
            (if (minibufferp)
                (minibuffer-message "Mismatched parentheses")
              (message "Mismatched parentheses"))
          (if (minibufferp)
              (minibuffer-message "No matching parenthesis found")
            (message "No matching parenthesis found"))))
       ((not blinkpos) nil)
       ((or
         (eq blink-matching-paren 'jump-offscreen)
         (pos-visible-in-window-p blinkpos))
        ;; Matching open within window, temporarily move to or highlight
        ;; char after blinkpos but only if `blink-matching-paren-on-screen'
        ;; is non-nil.
        (and blink-matching-paren-on-screen
             (not show-paren-mode)
             (if (memq blink-matching-paren '(jump jump-offscreen))
                 (save-excursion
                   (goto-char blinkpos)
                   (sit-for blink-matching-delay))
               (unwind-protect
                   (progn
                     (move-overlay blink-matching--overlay blinkpos (1+ blinkpos)
                                   (current-buffer))
                     (sit-for blink-matching-delay))
                 (delete-overlay blink-matching--overlay)))))
       (t
        (let ((open-paren-line-string
               (save-excursion
                 (goto-char blinkpos)
                 ;; Show what precedes the open in its line, if anything.
                 (cond
                  ((save-excursion (skip-chars-backward " \t") (not (bolp)))
                   (buffer-substring (line-beginning-position)
                                     (1+ blinkpos)))
                  ;; Show what follows the open in its line, if anything.
                  ((save-excursion
                     (forward-char 1)
                     (skip-chars-forward " \t")
                     (not (eolp)))
                   (buffer-substring blinkpos
                                     (line-end-position)))
                  ;; Otherwise show the previous nonblank line,
                  ;; if there is one.
                  ((save-excursion (skip-chars-backward "\n \t") (not (bobp)))
                   (concat
                    (buffer-substring (progn
                                        (skip-chars-backward "\n \t")
                                        (line-beginning-position))
                                      (progn (end-of-line)
                                             (skip-chars-backward " \t")
                                             (point)))
                    ;; Replace the newline and other whitespace with `...'.
                    "..."
                    (buffer-substring blinkpos (1+ blinkpos))))
                  ;; There is nothing to show except the char itself.
                  (t (buffer-substring blinkpos (1+ blinkpos)))))))
          (minibuffer-message
           "Matches %s"
           (substring-no-properties open-paren-line-string))))))))

(defvar blink-paren-function 'blink-matching-open
  "Function called, if non-nil, whenever a close parenthesis is inserted.
More precisely, a char with closeparen syntax is self-inserted.")

(defun blink-paren-post-self-insert-function ()
  (when (and (eq (char-before) last-command-event) ; Sanity check.
             (memq (char-syntax last-command-event) '(?\) ?\$))
             blink-paren-function
             (not executing-kbd-macro)
             (not noninteractive)
	     ;; Verify an even number of quoting characters precede the close.
             ;; FIXME: Also check if this parenthesis closes a comment as
             ;; can happen in Pascal and SML.
	     (= 1 (logand 1 (- (point)
			       (save-excursion
				 (forward-char -1)
				 (skip-syntax-backward "/\\")
				 (point))))))
    (funcall blink-paren-function)))

(put 'blink-paren-post-self-insert-function 'priority 100)

(add-hook 'post-self-insert-hook #'blink-paren-post-self-insert-function
          ;; Most likely, this hook is nil, so this arg doesn't matter,
          ;; but I use it as a reminder that this function usually
          ;; likes to be run after others since it does
          ;; `sit-for'. That's also the reason it get a `priority' prop
          ;; of 100.
          'append)
\f
;; This executes C-g typed while Emacs is waiting for a command.
;; Quitting out of a program does not go through here;
;; that happens in the QUIT macro at the C code level.
(defun keyboard-quit ()
  "Signal a `quit' condition.
During execution of Lisp code, this character causes a quit directly.
At top-level, as an editor command, this simply beeps."
  (interactive)
  ;; Avoid adding the region to the window selection.
  (setq saved-region-selection nil)
  (let (select-active-regions)
    (deactivate-mark))
  (if (fboundp 'kmacro-keyboard-quit)
      (kmacro-keyboard-quit))
  (when completion-in-region-mode
    (completion-in-region-mode -1))
  ;; Force the next redisplay cycle to remove the "Def" indicator from
  ;; all the mode lines.
  (if defining-kbd-macro
      (force-mode-line-update t))
  (setq defining-kbd-macro nil)
  (let ((debug-on-quit nil))
    (signal 'quit nil)))

(defvar buffer-quit-function nil
  "Function to call to \"quit\" the current buffer, or nil if none.
\\[keyboard-escape-quit] calls this function when its more local actions
\(such as canceling a prefix argument, minibuffer or region) do not apply.")

(defun keyboard-escape-quit ()
  "Exit the current \"mode\" (in a generalized sense of the word).
This command can exit an interactive command such as `query-replace',
can clear out a prefix argument or a region,
can get out of the minibuffer or other recursive edit,
cancel the use of the current buffer (for special-purpose buffers),
or go back to just one window (by deleting all but the selected window)."
  (interactive)
  (cond ((eq last-command 'mode-exited) nil)
	((region-active-p)
	 (deactivate-mark))
	((> (minibuffer-depth) 0)
	 (abort-recursive-edit))
	(current-prefix-arg
	 nil)
	((> (recursion-depth) 0)
	 (exit-recursive-edit))
	(buffer-quit-function
	 (funcall buffer-quit-function))
	((not (one-window-p t))
	 (delete-other-windows))
	((string-match "^ \\*" (buffer-name (current-buffer)))
	 (bury-buffer))))

(defun play-sound-file (file &optional volume device)
  "Play sound stored in FILE.
VOLUME and DEVICE correspond to the keywords of the sound
specification for `play-sound'."
  (interactive "fPlay sound file: ")
  (let ((sound (list :file file)))
    (if volume
	(plist-put sound :volume volume))
    (if device
	(plist-put sound :device device))
    (push 'sound sound)
    (play-sound sound)))

\f
(defcustom read-mail-command 'rmail
  "Your preference for a mail reading package.
This is used by some keybindings which support reading mail.
See also `mail-user-agent' concerning sending mail."
  :type '(radio (function-item :tag "Rmail" :format "%t\n" rmail)
                (function-item :tag "Gnus" :format "%t\n" gnus)
                (function-item :tag "Emacs interface to MH"
                               :format "%t\n" mh-rmail)
                (function :tag "Other"))
  :version "21.1"
  :group 'mail)

(defcustom mail-user-agent 'message-user-agent
  "Your preference for a mail composition package.
Various Emacs Lisp packages (e.g. Reporter) require you to compose an
outgoing email message.  This variable lets you specify which
mail-sending package you prefer.

Valid values include:

  `message-user-agent'  -- use the Message package.
                           See Info node `(message)'.
  `sendmail-user-agent' -- use the Mail package.
                           See Info node `(emacs)Sending Mail'.
  `mh-e-user-agent'     -- use the Emacs interface to the MH mail system.
                           See Info node `(mh-e)'.
  `gnus-user-agent'     -- like `message-user-agent', but with Gnus
                           paraphernalia if Gnus is running, particularly
                           the Gcc: header for archiving.

Additional valid symbols may be available; check with the author of
your package for details.  The function should return non-nil if it
succeeds.

See also `read-mail-command' concerning reading mail."
  :type '(radio (function-item :tag "Message package"
			       :format "%t\n"
			       message-user-agent)
		(function-item :tag "Mail package"
			       :format "%t\n"
			       sendmail-user-agent)
		(function-item :tag "Emacs interface to MH"
			       :format "%t\n"
			       mh-e-user-agent)
		(function-item :tag "Message with full Gnus features"
			       :format "%t\n"
			       gnus-user-agent)
		(function :tag "Other"))
  :version "23.2"                       ; sendmail->message
  :group 'mail)

(defcustom compose-mail-user-agent-warnings t
  "If non-nil, `compose-mail' warns about changes in `mail-user-agent'.
If the value of `mail-user-agent' is the default, and the user
appears to have customizations applying to the old default,
`compose-mail' issues a warning."
  :type 'boolean
  :version "23.2"
  :group 'mail)

(defun rfc822-goto-eoh ()
  "If the buffer starts with a mail header, move point to the header's end.
Otherwise, moves to `point-min'.
The end of the header is the start of the next line, if there is one,
else the end of the last line.  This function obeys RFC822."
  (goto-char (point-min))
  (when (re-search-forward
	 "^\\([:\n]\\|[^: \t\n]+[ \t\n]\\)" nil 'move)
    (goto-char (match-beginning 0))))

;; Used by Rmail (e.g., rmail-forward).
(defvar mail-encode-mml nil
  "If non-nil, mail-user-agent's `sendfunc' command should mml-encode
the outgoing message before sending it.")

(defun compose-mail (&optional to subject other-headers continue
		     switch-function yank-action send-actions
		     return-action)
  "Start composing a mail message to send.
This uses the user's chosen mail composition package
as selected with the variable `mail-user-agent'.
The optional arguments TO and SUBJECT specify recipients
and the initial Subject field, respectively.

OTHER-HEADERS is an alist specifying additional
header fields.  Elements look like (HEADER . VALUE) where both
HEADER and VALUE are strings.

CONTINUE, if non-nil, says to continue editing a message already
being composed.  Interactively, CONTINUE is the prefix argument.

SWITCH-FUNCTION, if non-nil, is a function to use to
switch to and display the buffer used for mail composition.

YANK-ACTION, if non-nil, is an action to perform, if and when necessary,
to insert the raw text of the message being replied to.
It has the form (FUNCTION . ARGS).  The user agent will apply
FUNCTION to ARGS, to insert the raw text of the original message.
\(The user agent will also run `mail-citation-hook', *after* the
original text has been inserted in this way.)

SEND-ACTIONS is a list of actions to call when the message is sent.
Each action has the form (FUNCTION . ARGS).

RETURN-ACTION, if non-nil, is an action for returning to the
caller.  It has the form (FUNCTION . ARGS).  The function is
called after the mail has been sent or put aside, and the mail
buffer buried."
  (interactive
   (list nil nil nil current-prefix-arg))

  ;; In Emacs 23.2, the default value of `mail-user-agent' changed
  ;; from sendmail-user-agent to message-user-agent.  Some users may
  ;; encounter incompatibilities.  This hack tries to detect problems
  ;; and warn about them.
  (and compose-mail-user-agent-warnings
       (eq mail-user-agent 'message-user-agent)
       (let (warn-vars)
	 (dolist (var '(mail-mode-hook mail-send-hook mail-setup-hook
			mail-yank-hooks mail-archive-file-name
			mail-default-reply-to mail-mailing-lists
			mail-self-blind))
	   (and (boundp var)
		(symbol-value var)
		(push var warn-vars)))
	 (when warn-vars
	   (display-warning 'mail
			    (format-message "\
The default mail mode is now Message mode.
You have the following Mail mode variable%s customized:
\n  %s\n\nTo use Mail mode, set `mail-user-agent' to sendmail-user-agent.
To disable this warning, set `compose-mail-user-agent-warnings' to nil."
				    (if (> (length warn-vars) 1) "s" "")
				    (mapconcat 'symbol-name
					       warn-vars " "))))))

  (let ((function (get mail-user-agent 'composefunc)))
    (funcall function to subject other-headers continue switch-function
	     yank-action send-actions return-action)))

(defun compose-mail-other-window (&optional to subject other-headers continue
					    yank-action send-actions
					    return-action)
  "Like \\[compose-mail], but edit the outgoing message in another window."
  (interactive (list nil nil nil current-prefix-arg))
  (compose-mail to subject other-headers continue
		'switch-to-buffer-other-window yank-action send-actions
		return-action))

(defun compose-mail-other-frame (&optional to subject other-headers continue
					    yank-action send-actions
					    return-action)
  "Like \\[compose-mail], but edit the outgoing message in another frame."
  (interactive (list nil nil nil current-prefix-arg))
  (compose-mail to subject other-headers continue
		'switch-to-buffer-other-frame yank-action send-actions
		return-action))

\f
(defvar set-variable-value-history nil
  "History of values entered with `set-variable'.

Maximum length of the history list is determined by the value
of `history-length', which see.")

(defun set-variable (variable value &optional make-local)
  "Set VARIABLE to VALUE.  VALUE is a Lisp object.
VARIABLE should be a user option variable name, a Lisp variable
meant to be customized by users.  You should enter VALUE in Lisp syntax,
so if you want VALUE to be a string, you must surround it with doublequotes.
VALUE is used literally, not evaluated.

If VARIABLE has a `variable-interactive' property, that is used as if
it were the arg to `interactive' (which see) to interactively read VALUE.

If VARIABLE has been defined with `defcustom', then the type information
in the definition is used to check that VALUE is valid.

Note that this function is at heart equivalent to the basic `set' function.
For a variable defined with `defcustom', it does not pay attention to
any :set property that the variable might have (if you want that, use
\\[customize-set-variable] instead).

With a prefix argument, set VARIABLE to VALUE buffer-locally."
  (interactive
   (let* ((default-var (variable-at-point))
          (var (if (custom-variable-p default-var)
		   (read-variable (format "Set variable (default %s): " default-var)
				  default-var)
		 (read-variable "Set variable: ")))
	  (minibuffer-help-form '(describe-variable var))
	  (prop (get var 'variable-interactive))
          (obsolete (car (get var 'byte-obsolete-variable)))
	  (prompt (format "Set %s %s to value: " var
			  (cond ((local-variable-p var)
				 "(buffer-local)")
				((or current-prefix-arg
				     (local-variable-if-set-p var))
				 "buffer-locally")
				(t "globally"))))
	  (val (progn
                 (when obsolete
                   (message (concat "`%S' is obsolete; "
                                    (if (symbolp obsolete) "use `%S' instead" "%s"))
                            var obsolete)
                   (sit-for 3))
                 (if prop
                     ;; Use VAR's `variable-interactive' property
                     ;; as an interactive spec for prompting.
                     (call-interactively `(lambda (arg)
                                            (interactive ,prop)
                                            arg))
                   (read-from-minibuffer prompt nil
                                         read-expression-map t
                                         'set-variable-value-history
                                         (format "%S" (symbol-value var)))))))
     (list var val current-prefix-arg)))

  (and (custom-variable-p variable)
       (not (get variable 'custom-type))
       (custom-load-symbol variable))
  (let ((type (get variable 'custom-type)))
    (when type
      ;; Match with custom type.
      (require 'cus-edit)
      (setq type (widget-convert type))
      (unless (widget-apply type :match value)
	(user-error "Value `%S' does not match type %S of %S"
		    value (car type) variable))))

  (if make-local
      (make-local-variable variable))

  (set variable value)

  ;; Force a thorough redisplay for the case that the variable
  ;; has an effect on the display, like `tab-width' has.
  (force-mode-line-update))
\f
;; Define the major mode for lists of completions.

(defvar completion-list-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map [mouse-2] 'choose-completion)
    (define-key map [follow-link] 'mouse-face)
    (define-key map [down-mouse-2] nil)
    (define-key map "\C-m" 'choose-completion)
    (define-key map "\e\e\e" 'delete-completion-window)
    (define-key map [left] 'previous-completion)
    (define-key map [right] 'next-completion)
    (define-key map [?\t] 'next-completion)
    (define-key map [backtab] 'previous-completion)
    (define-key map "q" 'quit-window)
    (define-key map "z" 'kill-this-buffer)
    map)
  "Local map for completion list buffers.")

;; Completion mode is suitable only for specially formatted data.
(put 'completion-list-mode 'mode-class 'special)

(defvar completion-reference-buffer nil
  "Record the buffer that was current when the completion list was requested.
This is a local variable in the completion list buffer.
Initial value is nil to avoid some compiler warnings.")

(defvar completion-no-auto-exit nil
  "Non-nil means `choose-completion-string' should never exit the minibuffer.
This also applies to other functions such as `choose-completion'.")

(defvar completion-base-position nil
  "Position of the base of the text corresponding to the shown completions.
This variable is used in the *Completions* buffers.
Its value is a list of the form (START END) where START is the place
where the completion should be inserted and END (if non-nil) is the end
of the text to replace.  If END is nil, point is used instead.")

(defvar completion-list-insert-choice-function #'completion--replace
  "Function to use to insert the text chosen in *Completions*.
Called with three arguments (BEG END TEXT), it should replace the text
between BEG and END with TEXT.  Expected to be set buffer-locally
in the *Completions* buffer.")

(defvar completion-base-size nil
  "Number of chars before point not involved in completion.
This is a local variable in the completion list buffer.
It refers to the chars in the minibuffer if completing in the
minibuffer, or in `completion-reference-buffer' otherwise.
Only characters in the field at point are included.

If nil, Emacs determines which part of the tail end of the
buffer's text is involved in completion by comparing the text
directly.")
(make-obsolete-variable 'completion-base-size 'completion-base-position "23.2")

(defun delete-completion-window ()
  "Delete the completion list window.
Go to the window from which completion was requested."
  (interactive)
  (let ((buf completion-reference-buffer))
    (if (one-window-p t)
	(if (window-dedicated-p) (delete-frame))
      (delete-window (selected-window))
      (if (get-buffer-window buf)
	  (select-window (get-buffer-window buf))))))

(defun previous-completion (n)
  "Move to the previous item in the completion list."
  (interactive "p")
  (next-completion (- n)))

(defun next-completion (n)
  "Move to the next item in the completion list.
With prefix argument N, move N items (negative N means move backward)."
  (interactive "p")
  (let ((beg (point-min)) (end (point-max)))
    (while (and (> n 0) (not (eobp)))
      ;; If in a completion, move to the end of it.
      (when (get-text-property (point) 'mouse-face)
	(goto-char (next-single-property-change (point) 'mouse-face nil end)))
      ;; Move to start of next one.
      (unless (get-text-property (point) 'mouse-face)
	(goto-char (next-single-property-change (point) 'mouse-face nil end)))
      (setq n (1- n)))
    (while (and (< n 0) (not (bobp)))
      (let ((prop (get-text-property (1- (point)) 'mouse-face)))
	;; If in a completion, move to the start of it.
	(when (and prop (eq prop (get-text-property (point) 'mouse-face)))
	  (goto-char (previous-single-property-change
		      (point) 'mouse-face nil beg)))
	;; Move to end of the previous completion.
	(unless (or (bobp) (get-text-property (1- (point)) 'mouse-face))
	  (goto-char (previous-single-property-change
		      (point) 'mouse-face nil beg)))
	;; Move to the start of that one.
	(goto-char (previous-single-property-change
		    (point) 'mouse-face nil beg))
	(setq n (1+ n))))))

(defun choose-completion (&optional event)
  "Choose the completion at point.
If EVENT, use EVENT's position to determine the starting position."
  (interactive (list last-nonmenu-event))
  ;; In case this is run via the mouse, give temporary modes such as
  ;; isearch a chance to turn off.
  (run-hooks 'mouse-leave-buffer-hook)
  (with-current-buffer (window-buffer (posn-window (event-start event)))
    (let ((buffer completion-reference-buffer)
          (base-size completion-base-size)
          (base-position completion-base-position)
          (insert-function completion-list-insert-choice-function)
          (choice
           (save-excursion
             (goto-char (posn-point (event-start event)))
             (let (beg end)
               (cond
                ((and (not (eobp)) (get-text-property (point) 'mouse-face))
                 (setq end (point) beg (1+ (point))))
                ((and (not (bobp))
                      (get-text-property (1- (point)) 'mouse-face))
                 (setq end (1- (point)) beg (point)))
                (t (error "No completion here")))
               (setq beg (previous-single-property-change beg 'mouse-face))
               (setq end (or (next-single-property-change end 'mouse-face)
                             (point-max)))
               (buffer-substring-no-properties beg end)))))

      (unless (buffer-live-p buffer)
        (error "Destination buffer is dead"))
      (quit-window nil (posn-window (event-start event)))

      (with-current-buffer buffer
        (choose-completion-string
         choice buffer
         (or base-position
             (when base-size
               ;; Someone's using old completion code that doesn't know
               ;; about base-position yet.
               (list (+ base-size (field-beginning))))
             ;; If all else fails, just guess.
             (list (choose-completion-guess-base-position choice)))
         insert-function)))))

;; Delete the longest partial match for STRING
;; that can be found before POINT.
(defun choose-completion-guess-base-position (string)
  (save-excursion
    (let ((opoint (point))
          len)
      ;; Try moving back by the length of the string.
      (goto-char (max (- (point) (length string))
                      (minibuffer-prompt-end)))
      ;; See how far back we were actually able to move.  That is the
      ;; upper bound on how much we can match and delete.
      (setq len (- opoint (point)))
      (if completion-ignore-case
          (setq string (downcase string)))
      (while (and (> len 0)
                  (let ((tail (buffer-substring (point) opoint)))
                    (if completion-ignore-case
                        (setq tail (downcase tail)))
                    (not (string= tail (substring string 0 len)))))
        (setq len (1- len))
        (forward-char 1))
      (point))))

(defun choose-completion-delete-max-match (string)
  (declare (obsolete choose-completion-guess-base-position "23.2"))
  (delete-region (choose-completion-guess-base-position string) (point)))

(defvar choose-completion-string-functions nil
  "Functions that may override the normal insertion of a completion choice.
These functions are called in order with three arguments:
CHOICE - the string to insert in the buffer,
BUFFER - the buffer in which the choice should be inserted,
BASE-POSITION - where to insert the completion.

If a function in the list returns non-nil, that function is supposed
to have inserted the CHOICE in the BUFFER, and possibly exited
the minibuffer; no further functions will be called.

If all functions in the list return nil, that means to use
the default method of inserting the completion in BUFFER.")

(defun choose-completion-string (choice &optional
                                        buffer base-position insert-function)
  "Switch to BUFFER and insert the completion choice CHOICE.
BASE-POSITION says where to insert the completion.
INSERT-FUNCTION says how to insert the completion and falls
back on `completion-list-insert-choice-function' when nil."

  ;; If BUFFER is the minibuffer, exit the minibuffer
  ;; unless it is reading a file name and CHOICE is a directory,
  ;; or completion-no-auto-exit is non-nil.

  ;; Some older code may call us passing `base-size' instead of
  ;; `base-position'.  It's difficult to make any use of `base-size',
  ;; so we just ignore it.
  (unless (consp base-position)
    (message "Obsolete `base-size' passed to choose-completion-string")
    (setq base-position nil))

  (let* ((buffer (or buffer completion-reference-buffer))
	 (mini-p (minibufferp buffer)))
    ;; If BUFFER is a minibuffer, barf unless it's the currently
    ;; active minibuffer.
    (if (and mini-p
             (not (and (active-minibuffer-window)
                       (equal buffer
			     (window-buffer (active-minibuffer-window))))))
	(error "Minibuffer is not active for completion")
      ;; Set buffer so buffer-local choose-completion-string-functions works.
      (set-buffer buffer)
      (unless (run-hook-with-args-until-success
	       'choose-completion-string-functions
               ;; The fourth arg used to be `mini-p' but was useless
               ;; (since minibufferp can be used on the `buffer' arg)
               ;; and indeed unused.  The last used to be `base-size', so we
               ;; keep it to try and avoid breaking old code.
	       choice buffer base-position nil)
        ;; This remove-text-properties should be unnecessary since `choice'
        ;; comes from buffer-substring-no-properties.
        ;;(remove-text-properties 0 (length choice) '(mouse-face nil) choice)
	;; Insert the completion into the buffer where it was requested.
        (funcall (or insert-function completion-list-insert-choice-function)
                 (or (car base-position) (point))
                 (or (cadr base-position) (point))
                 choice)
        ;; Update point in the window that BUFFER is showing in.
	(let ((window (get-buffer-window buffer t)))
	  (set-window-point window (point)))
	;; If completing for the minibuffer, exit it with this choice.
	(and (not completion-no-auto-exit)
             (minibufferp buffer)
	     minibuffer-completion-table
	     ;; If this is reading a file name, and the file name chosen
	     ;; is a directory, don't exit the minibuffer.
             (let* ((result (buffer-substring (field-beginning) (point)))
                    (bounds
                     (completion-boundaries result minibuffer-completion-table
                                            minibuffer-completion-predicate
                                            "")))
               (if (eq (car bounds) (length result))
                   ;; The completion chosen leads to a new set of completions
                   ;; (e.g. it's a directory): don't exit the minibuffer yet.
                   (let ((mini (active-minibuffer-window)))
                     (select-window mini)
                     (when minibuffer-auto-raise
                       (raise-frame (window-frame mini))))
                 (exit-minibuffer))))))))

(define-derived-mode completion-list-mode nil "Completion List"
  "Major mode for buffers showing lists of possible completions.
Type \\<completion-list-mode-map>\\[choose-completion] in the completion list\
 to select the completion near point.
Or click to select one with the mouse.

\\{completion-list-mode-map}"
  (set (make-local-variable 'completion-base-size) nil))

(defun completion-list-mode-finish ()
  "Finish setup of the completions buffer.
Called from `temp-buffer-show-hook'."
  (when (eq major-mode 'completion-list-mode)
    (setq buffer-read-only t)))

(add-hook 'temp-buffer-show-hook 'completion-list-mode-finish)


;; Variables and faces used in `completion-setup-function'.

(defcustom completion-show-help t
  "Non-nil means show help message in *Completions* buffer."
  :type 'boolean
  :version "22.1"
  :group 'completion)

;; This function goes in completion-setup-hook, so that it is called
;; after the text of the completion list buffer is written.
(defun completion-setup-function ()
  (let* ((mainbuf (current-buffer))
         (base-dir
          ;; FIXME: This is a bad hack.  We try to set the default-directory
          ;; in the *Completions* buffer so that the relative file names
          ;; displayed there can be treated as valid file names, independently
          ;; from the completion context.  But this suffers from many problems:
          ;; - It's not clear when the completions are file names.  With some
          ;;   completion tables (e.g. bzr revision specs), the listed
          ;;   completions can mix file names and other things.
          ;; - It doesn't pay attention to possible quoting.
          ;; - With fancy completion styles, the code below will not always
          ;;   find the right base directory.
          (if minibuffer-completing-file-name
              (file-name-as-directory
               (expand-file-name
                (buffer-substring (minibuffer-prompt-end)
                                  (- (point) (or completion-base-size 0))))))))
    (with-current-buffer standard-output
      (let ((base-size completion-base-size) ;Read before killing localvars.
            (base-position completion-base-position)
            (insert-fun completion-list-insert-choice-function))
        (completion-list-mode)
        (set (make-local-variable 'completion-base-size) base-size)
        (set (make-local-variable 'completion-base-position) base-position)
        (set (make-local-variable 'completion-list-insert-choice-function)
	     insert-fun))
      (set (make-local-variable 'completion-reference-buffer) mainbuf)
      (if base-dir (setq default-directory base-dir))
      ;; Maybe insert help string.
      (when completion-show-help
	(goto-char (point-min))
	(if (display-mouse-p)
	    (insert "Click on a completion to select it.\n"))
	(insert (substitute-command-keys
		 "In this buffer, type \\[choose-completion] to \
select the completion near point.\n\n"))))))

(add-hook 'completion-setup-hook 'completion-setup-function)

(define-key minibuffer-local-completion-map [prior] 'switch-to-completions)
(define-key minibuffer-local-completion-map "\M-v"  'switch-to-completions)

(defun switch-to-completions ()
  "Select the completion list window."
  (interactive)
  (let ((window (or (get-buffer-window "*Completions*" 0)
		    ;; Make sure we have a completions window.
                    (progn (minibuffer-completion-help)
                           (get-buffer-window "*Completions*" 0)))))
    (when window
      (select-window window)
      ;; In the new buffer, go to the first completion.
      ;; FIXME: Perhaps this should be done in `minibuffer-completion-help'.
      (when (bobp)
	(next-completion 1)))))
\f
;;; Support keyboard commands to turn on various modifiers.

;; These functions -- which are not commands -- each add one modifier
;; to the following event.

(defun event-apply-alt-modifier (_ignore-prompt)
  "\\<function-key-map>Add the Alt modifier to the following event.
For example, type \\[event-apply-alt-modifier] & to enter Alt-&."
  (vector (event-apply-modifier (read-event) 'alt 22 "A-")))
(defun event-apply-super-modifier (_ignore-prompt)
  "\\<function-key-map>Add the Super modifier to the following event.
For example, type \\[event-apply-super-modifier] & to enter Super-&."
  (vector (event-apply-modifier (read-event) 'super 23 "s-")))
(defun event-apply-hyper-modifier (_ignore-prompt)
  "\\<function-key-map>Add the Hyper modifier to the following event.
For example, type \\[event-apply-hyper-modifier] & to enter Hyper-&."
  (vector (event-apply-modifier (read-event) 'hyper 24 "H-")))
(defun event-apply-shift-modifier (_ignore-prompt)
  "\\<function-key-map>Add the Shift modifier to the following event.
For example, type \\[event-apply-shift-modifier] & to enter Shift-&."
  (vector (event-apply-modifier (read-event) 'shift 25 "S-")))
(defun event-apply-control-modifier (_ignore-prompt)
  "\\<function-key-map>Add the Ctrl modifier to the following event.
For example, type \\[event-apply-control-modifier] & to enter Ctrl-&."
  (vector (event-apply-modifier (read-event) 'control 26 "C-")))
(defun event-apply-meta-modifier (_ignore-prompt)
  "\\<function-key-map>Add the Meta modifier to the following event.
For example, type \\[event-apply-meta-modifier] & to enter Meta-&."
  (vector (event-apply-modifier (read-event) 'meta 27 "M-")))

(defun event-apply-modifier (event symbol lshiftby prefix)
  "Apply a modifier flag to event EVENT.
SYMBOL is the name of this modifier, as a symbol.
LSHIFTBY is the numeric value of this modifier, in keyboard events.
PREFIX is the string that represents this modifier in an event type symbol."
  (if (numberp event)
      (cond ((eq symbol 'control)
	     (if (and (<= (downcase event) ?z)
		      (>= (downcase event) ?a))
		 (- (downcase event) ?a -1)
	       (if (and (<= (downcase event) ?Z)
			(>= (downcase event) ?A))
		   (- (downcase event) ?A -1)
		 (logior (lsh 1 lshiftby) event))))
	    ((eq symbol 'shift)
	     (if (and (<= (downcase event) ?z)
		      (>= (downcase event) ?a))
		 (upcase event)
	       (logior (lsh 1 lshiftby) event)))
	    (t
	     (logior (lsh 1 lshiftby) event)))
    (if (memq symbol (event-modifiers event))
	event
      (let ((event-type (if (symbolp event) event (car event))))
	(setq event-type (intern (concat prefix (symbol-name event-type))))
	(if (symbolp event)
	    event-type
	  (cons event-type (cdr event)))))))

(define-key function-key-map [?\C-x ?@ ?h] 'event-apply-hyper-modifier)
(define-key function-key-map [?\C-x ?@ ?s] 'event-apply-super-modifier)
(define-key function-key-map [?\C-x ?@ ?m] 'event-apply-meta-modifier)
(define-key function-key-map [?\C-x ?@ ?a] 'event-apply-alt-modifier)
(define-key function-key-map [?\C-x ?@ ?S] 'event-apply-shift-modifier)
(define-key function-key-map [?\C-x ?@ ?c] 'event-apply-control-modifier)
\f
;;;; Keypad support.

;; Make the keypad keys act like ordinary typing keys.  If people add
;; bindings for the function key symbols, then those bindings will
;; override these, so this shouldn't interfere with any existing
;; bindings.

;; Also tell read-char how to handle these keys.
(mapc
 (lambda (keypad-normal)
   (let ((keypad (nth 0 keypad-normal))
	 (normal (nth 1 keypad-normal)))
     (put keypad 'ascii-character normal)
     (define-key function-key-map (vector keypad) (vector normal))))
 ;; See also kp-keys bound in bindings.el.
 '((kp-space ?\s)
   (kp-tab ?\t)
   (kp-enter ?\r)
   (kp-separator ?,)
   (kp-equal ?=)
   ;; Do the same for various keys that are represented as symbols under
   ;; GUIs but naturally correspond to characters.
   (backspace 127)
   (delete 127)
   (tab ?\t)
   (linefeed ?\n)
   (clear ?\C-l)
   (return ?\C-m)
   (escape ?\e)
   ))
\f
;;;;
;;;; forking a twin copy of a buffer.
;;;;

(defvar clone-buffer-hook nil
  "Normal hook to run in the new buffer at the end of `clone-buffer'.")

(defvar clone-indirect-buffer-hook nil
  "Normal hook to run in the new buffer at the end of `clone-indirect-buffer'.")

(defun clone-process (process &optional newname)
  "Create a twin copy of PROCESS.
If NEWNAME is nil, it defaults to PROCESS' name;
NEWNAME is modified by adding or incrementing <N> at the end as necessary.
If PROCESS is associated with a buffer, the new process will be associated
  with the current buffer instead.
Returns nil if PROCESS has already terminated."
  (setq newname (or newname (process-name process)))
  (if (string-match "<[0-9]+>\\'" newname)
      (setq newname (substring newname 0 (match-beginning 0))))
  (when (memq (process-status process) '(run stop open))
    (let* ((process-connection-type (process-tty-name process))
	   (new-process
	    (if (memq (process-status process) '(open))
		(let ((args (process-contact process t)))
		  (setq args (plist-put args :name newname))
		  (setq args (plist-put args :buffer
					(if (process-buffer process)
					    (current-buffer))))
		  (apply 'make-network-process args))
	      (apply 'start-process newname
		     (if (process-buffer process) (current-buffer))
		     (process-command process)))))
      (set-process-query-on-exit-flag
       new-process (process-query-on-exit-flag process))
      (set-process-inherit-coding-system-flag
       new-process (process-inherit-coding-system-flag process))
      (set-process-filter new-process (process-filter process))
      (set-process-sentinel new-process (process-sentinel process))
      (set-process-plist new-process (copy-sequence (process-plist process)))
      new-process)))

;; things to maybe add (currently partly covered by `funcall mode'):
;; - syntax-table
;; - overlays
(defun clone-buffer (&optional newname display-flag)
  "Create and return a twin copy of the current buffer.
Unlike an indirect buffer, the new buffer can be edited
independently of the old one (if it is not read-only).
NEWNAME is the name of the new buffer.  It may be modified by
adding or incrementing <N> at the end as necessary to create a
unique buffer name.  If nil, it defaults to the name of the
current buffer, with the proper suffix.  If DISPLAY-FLAG is
non-nil, the new buffer is shown with `pop-to-buffer'.  Trying to
clone a file-visiting buffer, or a buffer whose major mode symbol
has a non-nil `no-clone' property, results in an error.

Interactively, DISPLAY-FLAG is t and NEWNAME is the name of the
current buffer with appropriate suffix.  However, if a prefix
argument is given, then the command prompts for NEWNAME in the
minibuffer.

This runs the normal hook `clone-buffer-hook' in the new buffer
after it has been set up properly in other respects."
  (interactive
   (progn
     (if buffer-file-name
	 (error "Cannot clone a file-visiting buffer"))
     (if (get major-mode 'no-clone)
	 (error "Cannot clone a buffer in %s mode" mode-name))
     (list (if current-prefix-arg
	       (read-buffer "Name of new cloned buffer: " (current-buffer)))
	   t)))
  (if buffer-file-name
      (error "Cannot clone a file-visiting buffer"))
  (if (get major-mode 'no-clone)
      (error "Cannot clone a buffer in %s mode" mode-name))
  (setq newname (or newname (buffer-name)))
  (if (string-match "<[0-9]+>\\'" newname)
      (setq newname (substring newname 0 (match-beginning 0))))
  (let ((buf (current-buffer))
	(ptmin (point-min))
	(ptmax (point-max))
	(pt (point))
	(mk (if mark-active (mark t)))
	(modified (buffer-modified-p))
	(mode major-mode)
	(lvars (buffer-local-variables))
	(process (get-buffer-process (current-buffer)))
	(new (generate-new-buffer (or newname (buffer-name)))))
    (save-restriction
      (widen)
      (with-current-buffer new
	(insert-buffer-substring buf)))
    (with-current-buffer new
      (narrow-to-region ptmin ptmax)
      (goto-char pt)
      (if mk (set-mark mk))
      (set-buffer-modified-p modified)

      ;; Clone the old buffer's process, if any.
      (when process (clone-process process))

      ;; Now set up the major mode.
      (funcall mode)

      ;; Set up other local variables.
      (mapc (lambda (v)
	      (condition-case ()	;in case var is read-only
		  (if (symbolp v)
		      (makunbound v)
		    (set (make-local-variable (car v)) (cdr v)))
		(error nil)))
	    lvars)

      ;; Run any hooks (typically set up by the major mode
      ;; for cloning to work properly).
      (run-hooks 'clone-buffer-hook))
    (if display-flag
        ;; Presumably the current buffer is shown in the selected frame, so
        ;; we want to display the clone elsewhere.
        (let ((same-window-regexps nil)
              (same-window-buffer-names))
          (pop-to-buffer new)))
    new))


(defun clone-indirect-buffer (newname display-flag &optional norecord)
  "Create an indirect buffer that is a twin copy of the current buffer.

Give the indirect buffer name NEWNAME.  Interactively, read NEWNAME
from the minibuffer when invoked with a prefix arg.  If NEWNAME is nil
or if not called with a prefix arg, NEWNAME defaults to the current
buffer's name.  The name is modified by adding a `<N>' suffix to it
or by incrementing the N in an existing suffix.  Trying to clone a
buffer whose major mode symbol has a non-nil `no-clone-indirect'
property results in an error.

DISPLAY-FLAG non-nil means show the new buffer with `pop-to-buffer'.
This is always done when called interactively.

Optional third arg NORECORD non-nil means do not put this buffer at the
front of the list of recently selected ones.

Returns the newly created indirect buffer."
  (interactive
   (progn
     (if (get major-mode 'no-clone-indirect)
	 (error "Cannot indirectly clone a buffer in %s mode" mode-name))
     (list (if current-prefix-arg
	       (read-buffer "Name of indirect buffer: " (current-buffer)))
	   t)))
  (if (get major-mode 'no-clone-indirect)
      (error "Cannot indirectly clone a buffer in %s mode" mode-name))
  (setq newname (or newname (buffer-name)))
  (if (string-match "<[0-9]+>\\'" newname)
      (setq newname (substring newname 0 (match-beginning 0))))
  (let* ((name (generate-new-buffer-name newname))
	 (buffer (make-indirect-buffer (current-buffer) name t)))
    (with-current-buffer buffer
      (run-hooks 'clone-indirect-buffer-hook))
    (when display-flag
      (pop-to-buffer buffer norecord))
    buffer))


(defun clone-indirect-buffer-other-window (newname display-flag &optional norecord)
  "Like `clone-indirect-buffer' but display in another window."
  (interactive
   (progn
     (if (get major-mode 'no-clone-indirect)
	 (error "Cannot indirectly clone a buffer in %s mode" mode-name))
     (list (if current-prefix-arg
	       (read-buffer "Name of indirect buffer: " (current-buffer)))
	   t)))
  (let ((pop-up-windows t))
    (clone-indirect-buffer newname display-flag norecord)))

\f
;;; Handling of Backspace and Delete keys.

(defcustom normal-erase-is-backspace 'maybe
  "Set the default behavior of the Delete and Backspace keys.

If set to t, Delete key deletes forward and Backspace key deletes
backward.

If set to nil, both Delete and Backspace keys delete backward.

If set to `maybe' (which is the default), Emacs automatically
selects a behavior.  On window systems, the behavior depends on
the keyboard used.  If the keyboard has both a Backspace key and
a Delete key, and both are mapped to their usual meanings, the
option's default value is set to t, so that Backspace can be used
to delete backward, and Delete can be used to delete forward.

If not running under a window system, customizing this option
accomplishes a similar effect by mapping C-h, which is usually
generated by the Backspace key, to DEL, and by mapping DEL to C-d
via `keyboard-translate'.  The former functionality of C-h is
available on the F1 key.  You should probably not use this
setting if you don't have both Backspace, Delete and F1 keys.

Setting this variable with setq doesn't take effect.  Programmatically,
call `normal-erase-is-backspace-mode' (which see) instead."
  :type '(choice (const :tag "Off" nil)
		 (const :tag "Maybe" maybe)
		 (other :tag "On" t))
  :group 'editing-basics
  :version "21.1"
  :set (lambda (symbol value)
	 ;; The fboundp is because of a problem with :set when
	 ;; dumping Emacs.  It doesn't really matter.
	 (if (fboundp 'normal-erase-is-backspace-mode)
	     (normal-erase-is-backspace-mode (or value 0))
	   (set-default symbol value))))

(defun normal-erase-is-backspace-setup-frame (&optional frame)
  "Set up `normal-erase-is-backspace-mode' on FRAME, if necessary."
  (unless frame (setq frame (selected-frame)))
  (with-selected-frame frame
    (unless (terminal-parameter nil 'normal-erase-is-backspace)
      (normal-erase-is-backspace-mode
       (if (if (eq normal-erase-is-backspace 'maybe)
               (and (not noninteractive)
                    (or (memq system-type '(ms-dos windows-nt))
			(memq window-system '(w32 ns))
                        (and (memq window-system '(x))
                             (fboundp 'x-backspace-delete-keys-p)
                             (x-backspace-delete-keys-p))
                        ;; If the terminal Emacs is running on has erase char
                        ;; set to ^H, use the Backspace key for deleting
                        ;; backward, and the Delete key for deleting forward.
                        (and (null window-system)
                             (eq tty-erase-char ?\^H))))
             normal-erase-is-backspace)
           1 0)))))

(define-minor-mode normal-erase-is-backspace-mode
  "Toggle the Erase and Delete mode of the Backspace and Delete keys.
With a prefix argument ARG, enable this feature if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
the mode if ARG is omitted or nil.

On window systems, when this mode is on, Delete is mapped to C-d
and Backspace is mapped to DEL; when this mode is off, both
Delete and Backspace are mapped to DEL.  (The remapping goes via
`local-function-key-map', so binding Delete or Backspace in the
global or local keymap will override that.)

In addition, on window systems, the bindings of C-Delete, M-Delete,
C-M-Delete, C-Backspace, M-Backspace, and C-M-Backspace are changed in
the global keymap in accordance with the functionality of Delete and
Backspace.  For example, if Delete is remapped to C-d, which deletes
forward, C-Delete is bound to `kill-word', but if Delete is remapped
to DEL, which deletes backward, C-Delete is bound to
`backward-kill-word'.

If not running on a window system, a similar effect is accomplished by
remapping C-h (normally produced by the Backspace key) and DEL via
`keyboard-translate': if this mode is on, C-h is mapped to DEL and DEL
to C-d; if it's off, the keys are not remapped.

When not running on a window system, and this mode is turned on, the
former functionality of C-h is available on the F1 key.  You should
probably not turn on this mode on a text-only terminal if you don't
have both Backspace, Delete and F1 keys.

See also `normal-erase-is-backspace'."
  :variable ((eq (terminal-parameter nil 'normal-erase-is-backspace) 1)
             . (lambda (v)
                 (setf (terminal-parameter nil 'normal-erase-is-backspace)
                       (if v 1 0))))
  (let ((enabled (eq 1 (terminal-parameter
                        nil 'normal-erase-is-backspace))))

    (cond ((or (memq window-system '(x w32 ns pc))
	       (memq system-type '(ms-dos windows-nt)))
	   (let ((bindings
		  `(([M-delete] [M-backspace])
		    ([C-M-delete] [C-M-backspace])
		    ([?\e C-delete] [?\e C-backspace]))))

	     (if enabled
		 (progn
		   (define-key local-function-key-map [delete] [deletechar])
		   (define-key local-function-key-map [kp-delete] [deletechar])
		   (define-key local-function-key-map [backspace] [?\C-?])
                   (dolist (b bindings)
                     ;; Not sure if input-decode-map is really right, but
                     ;; keyboard-translate-table (used below) only works
                     ;; for integer events, and key-translation-table is
                     ;; global (like the global-map, used earlier).
                     (define-key input-decode-map (car b) nil)
                     (define-key input-decode-map (cadr b) nil)))
	       (define-key local-function-key-map [delete] [?\C-?])
	       (define-key local-function-key-map [kp-delete] [?\C-?])
	       (define-key local-function-key-map [backspace] [?\C-?])
               (dolist (b bindings)
                 (define-key input-decode-map (car b) (cadr b))
                 (define-key input-decode-map (cadr b) (car b))))))
	  (t
	   (if enabled
	       (progn
		 (keyboard-translate ?\C-h ?\C-?)
		 (keyboard-translate ?\C-? ?\C-d))
	     (keyboard-translate ?\C-h ?\C-h)
	     (keyboard-translate ?\C-? ?\C-?))))

    (if (called-interactively-p 'interactive)
	(message "Delete key deletes %s"
		 (if (eq 1 (terminal-parameter nil 'normal-erase-is-backspace))
		     "forward" "backward")))))
\f
(defvar vis-mode-saved-buffer-invisibility-spec nil
  "Saved value of `buffer-invisibility-spec' when Visible mode is on.")

(define-minor-mode read-only-mode
  "Change whether the current buffer is read-only.
With prefix argument ARG, make the buffer read-only if ARG is
positive, otherwise make it writable.  If buffer is read-only
and `view-read-only' is non-nil, enter view mode.

Do not call this from a Lisp program unless you really intend to
do the same thing as the \\[read-only-mode] command, including
possibly enabling or disabling View mode.  Also, note that this
command works by setting the variable `buffer-read-only', which
does not affect read-only regions caused by text properties.  To
ignore read-only status in a Lisp program (whether due to text
properties or buffer state), bind `inhibit-read-only' temporarily
to a non-nil value."
  :variable buffer-read-only
  (cond
   ((and (not buffer-read-only) view-mode)
    (View-exit-and-edit)
    (make-local-variable 'view-read-only)
    (setq view-read-only t))		; Must leave view mode.
   ((and buffer-read-only view-read-only
         ;; If view-mode is already active, `view-mode-enter' is a nop.
         (not view-mode)
         (not (eq (get major-mode 'mode-class) 'special)))
    (view-mode-enter))))

(define-minor-mode visible-mode
  "Toggle making all invisible text temporarily visible (Visible mode).
With a prefix argument ARG, enable Visible mode if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
the mode if ARG is omitted or nil.

This mode works by saving the value of `buffer-invisibility-spec'
and setting it to nil."
  :lighter " Vis"
  :group 'editing-basics
  (when (local-variable-p 'vis-mode-saved-buffer-invisibility-spec)
    (setq buffer-invisibility-spec vis-mode-saved-buffer-invisibility-spec)
    (kill-local-variable 'vis-mode-saved-buffer-invisibility-spec))
  (when visible-mode
    (set (make-local-variable 'vis-mode-saved-buffer-invisibility-spec)
	 buffer-invisibility-spec)
    (setq buffer-invisibility-spec nil)))
\f
(defvar messages-buffer-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map special-mode-map)
    (define-key map "g" nil)            ; nothing to revert
    map))

(define-derived-mode messages-buffer-mode special-mode "Messages"
  "Major mode used in the \"*Messages*\" buffer.")

(defun messages-buffer ()
  "Return the \"*Messages*\" buffer.
If it does not exist, create and it switch it to `messages-buffer-mode'."
  (or (get-buffer "*Messages*")
      (with-current-buffer (get-buffer-create "*Messages*")
        (messages-buffer-mode)
        (current-buffer))))

\f
;; Minibuffer prompt stuff.

;;(defun minibuffer-prompt-modification (start end)
;;  (error "You cannot modify the prompt"))
;;
;;
;;(defun minibuffer-prompt-insertion (start end)
;;  (let ((inhibit-modification-hooks t))
;;    (delete-region start end)
;;    ;; Discard undo information for the text insertion itself
;;    ;; and for the text deletion.above.
;;    (when (consp buffer-undo-list)
;;      (setq buffer-undo-list (cddr buffer-undo-list)))
;;    (message "You cannot modify the prompt")))
;;
;;
;;(setq minibuffer-prompt-properties
;;  (list 'modification-hooks '(minibuffer-prompt-modification)
;;	'insert-in-front-hooks '(minibuffer-prompt-insertion)))

\f
;;;; Problematic external packages.

;; rms says this should be done by specifying symbols that define
;; versions together with bad values.  This is therefore not as
;; flexible as it could be.  See the thread:
;; http://lists.gnu.org/archive/html/emacs-devel/2007-08/msg00300.html
(defconst bad-packages-alist
  ;; Not sure exactly which semantic versions have problems.
  ;; Definitely 2.0pre3, probably all 2.0pre's before this.
  '((semantic semantic-version "\\`2\\.0pre[1-3]\\'"
              "The version of `semantic' loaded does not work in Emacs 22.
It can cause constant high CPU load.
Upgrade to at least Semantic 2.0pre4 (distributed with CEDET 1.0pre4).")
    ;; CUA-mode does not work with GNU Emacs version 22.1 and newer.
    ;; Except for version 1.2, all of the 1.x and 2.x version of cua-mode
    ;; provided the `CUA-mode' feature.  Since this is no longer true,
    ;; we can warn the user if the `CUA-mode' feature is ever provided.
    (CUA-mode t nil
"CUA-mode is now part of the standard GNU Emacs distribution,
so you can now enable CUA via the Options menu or by customizing `cua-mode'.

You have loaded an older version of CUA-mode which does not work
correctly with this version of Emacs.  You should remove the old
version and use the one distributed with Emacs."))
  "Alist of packages known to cause problems in this version of Emacs.
Each element has the form (PACKAGE SYMBOL REGEXP STRING).
PACKAGE is either a regular expression to match file names, or a
symbol (a feature name), like for `with-eval-after-load'.
SYMBOL is either the name of a string variable, or t.  Upon
loading PACKAGE, if SYMBOL is t or matches REGEXP, display a
warning using STRING as the message.")

(defun bad-package-check (package)
  "Run a check using the element from `bad-packages-alist' matching PACKAGE."
  (condition-case nil
      (let* ((list (assoc package bad-packages-alist))
             (symbol (nth 1 list)))
        (and list
             (boundp symbol)
             (or (eq symbol t)
                 (and (stringp (setq symbol (eval symbol)))
                      (string-match-p (nth 2 list) symbol)))
             (display-warning package (nth 3 list) :warning)))
    (error nil)))

(dolist (elem bad-packages-alist)
  (let ((pkg (car elem)))
    (with-eval-after-load pkg
      (bad-package-check pkg))))

\f
;;; Generic dispatcher commands

;; Macro `define-alternatives' is used to create generic commands.
;; Generic commands are these (like web, mail, news, encrypt, irc, etc.)
;; that can have different alternative implementations where choosing
;; among them is exclusively a matter of user preference.

;; (define-alternatives COMMAND) creates a new interactive command
;; M-x COMMAND and a customizable variable COMMAND-alternatives.
;; Typically, the user will not need to customize this variable; packages
;; wanting to add alternative implementations should use
;;
;; ;;;###autoload (push '("My impl name" . my-impl-symbol) COMMAND-alternatives

(defmacro define-alternatives (command &rest customizations)
  "Define the new command `COMMAND'.

The argument `COMMAND' should be a symbol.

Running `M-x COMMAND RET' for the first time prompts for which
alternative to use and records the selected command as a custom
variable.

Running `C-u M-x COMMAND RET' prompts again for an alternative
and overwrites the previous choice.

The variable `COMMAND-alternatives' contains an alist with
alternative implementations of COMMAND.  `define-alternatives'
does not have any effect until this variable is set.

CUSTOMIZATIONS, if non-nil, should be composed of alternating
`defcustom' keywords and values to add to the declaration of
`COMMAND-alternatives' (typically :group and :version)."
  (let* ((command-name (symbol-name command))
         (varalt-name (concat command-name "-alternatives"))
         (varalt-sym (intern varalt-name))
         (varimp-sym (intern (concat command-name "--implementation"))))
    `(progn

       (defcustom ,varalt-sym nil
         ,(format "Alist of alternative implementations for the `%s' command.

Each entry must be a pair (ALTNAME . ALTFUN), where:
ALTNAME - The name shown at user to describe the alternative implementation.
ALTFUN  - The function called to implement this alternative."
                  command-name)
         :type '(alist :key-type string :value-type function)
         ,@customizations)

       (put ',varalt-sym 'definition-name ',command)
       (defvar ,varimp-sym nil "Internal use only.")

       (defun ,command (&optional arg)
         ,(format "Run generic command `%s'.
If used for the first time, or with interactive ARG, ask the user which
implementation to use for `%s'.  The variable `%s'
contains the list of implementations currently supported for this command."
                  command-name command-name varalt-name)
         (interactive "P")
         (when (or arg (null ,varimp-sym))
           (let ((val (completing-read
		       ,(format-message
                         "Select implementation for command `%s': "
                         command-name)
		       ,varalt-sym nil t)))
             (unless (string-equal val "")
	       (when (null ,varimp-sym)
		 (message
		  "Use C-u M-x %s RET`to select another implementation"
		  ,command-name)
		 (sit-for 3))
	       (customize-save-variable ',varimp-sym
					(cdr (assoc-string val ,varalt-sym))))))
         (if ,varimp-sym
             (call-interactively ,varimp-sym)
           (message "%s" ,(format-message
                           "No implementation selected for command `%s'"
                           command-name)))))))

\f
;;; Functions for changing capitalization that Do What I Mean
(defun upcase-dwim (arg)
  "Upcase words in the region, if active; if not, upcase word at point.
If the region is active, this function calls `upcase-region'.
Otherwise, it calls `upcase-word', with prefix argument passed to it
to upcase ARG words."
  (interactive "*p")
  (if (use-region-p)
      (upcase-region (region-beginning) (region-end))
    (upcase-word arg)))

(defun downcase-dwim (arg)
    "Downcase words in the region, if active; if not, downcase word at point.
If the region is active, this function calls `downcase-region'.
Otherwise, it calls `downcase-word', with prefix argument passed to it
to downcase ARG words."
  (interactive "*p")
  (if (use-region-p)
      (downcase-region (region-beginning) (region-end))
    (downcase-word arg)))

(defun capitalize-dwim (arg)
  "Capitalize words in the region, if active; if not, capitalize word at point.
If the region is active, this function calls `capitalize-region'.
Otherwise, it calls `capitalize-word', with prefix argument passed to it
to capitalize ARG words."
  (interactive "*p")
  (if (use-region-p)
      (capitalize-region (region-beginning) (region-end))
    (capitalize-word arg)))

\f

(provide 'simple)

;;; simple.el ends here

debug log:

solving 51c9100 ...
found 51c9100 in https://git.savannah.gnu.org/cgit/emacs.git

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this external index

	https://git.savannah.gnu.org/cgit/emacs.git
	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.