unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
blob de18796628944551bc5790f0c8a2678dcbe7cb06 97168 bytes (raw)
name: lisp/treesit.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
 
;;; treesit.el --- tree-sitter utilities -*- lexical-binding: t -*-

;; Copyright (C) 2021-2022 Free Software Foundation, Inc.

;; 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 <https://www.gnu.org/licenses/>.

;;; Commentary:

;; This file is the Lisp counterpart of treesit.c.  Together they
;; provide tree-sitter integration for Emacs.  This file contains
;; convenient functions that are more idiomatic and flexible than the
;; exposed C API of tree-sitter.  It also contains frameworks for
;; integrating tree-sitter with font-lock, indentation, activating and
;; deactivating tree-sitter, debugging tree-sitter, etc.

;;; Code:

(eval-when-compile (require 'cl-lib))
(eval-when-compile (require 'subr-x)) ; For `string-join'.
(require 'cl-seq)
(require 'font-lock)

;;; Function declarations

(declare-function treesit-language-available-p "treesit.c")
(declare-function treesit-language-version "treesit.c")

(declare-function treesit-parser-p "treesit.c")
(declare-function treesit-node-p "treesit.c")
(declare-function treesit-compiled-query-p "treesit.c")
(declare-function treesit-query-p "treesit.c")
(declare-function treesit-query-language "treesit.c")

(declare-function treesit-node-parser "treesit.c")

(declare-function treesit-parser-create "treesit.c")
(declare-function treesit-parser-delete "treesit.c")
(declare-function treesit-parser-list "treesit.c")
(declare-function treesit-parser-buffer "treesit.c")
(declare-function treesit-parser-language "treesit.c")

(declare-function treesit-parser-root-node "treesit.c")

(declare-function treesit-parser-set-included-ranges "treesit.c")
(declare-function treesit-parser-included-ranges "treesit.c")
(declare-function treesit-parser-add-notifier "treesit.c")

(declare-function treesit-node-type "treesit.c")
(declare-function treesit-node-start "treesit.c")
(declare-function treesit-node-end "treesit.c")
(declare-function treesit-node-string "treesit.c")
(declare-function treesit-node-parent "treesit.c")
(declare-function treesit-node-child "treesit.c")
(declare-function treesit-node-check "treesit.c")
(declare-function treesit-node-field-name-for-child "treesit.c")
(declare-function treesit-node-child-count "treesit.c")
(declare-function treesit-node-child-by-field-name "treesit.c")
(declare-function treesit-node-next-sibling "treesit.c")
(declare-function treesit-node-prev-sibling "treesit.c")
(declare-function treesit-node-first-child-for-pos "treesit.c")
(declare-function treesit-node-descendant-for-range "treesit.c")
(declare-function treesit-node-eq "treesit.c")

(declare-function treesit-pattern-expand "treesit.c")
(declare-function treesit-query-expand "treesit.c")
(declare-function treesit-query-compile "treesit.c")
(declare-function treesit-query-capture "treesit.c")

(declare-function treesit-search-subtree "treesit.c")
(declare-function treesit-search-forward "treesit.c")
(declare-function treesit-induce-sparse-tree "treesit.c")

(declare-function treesit-available-p "treesit.c")

;;; Custom options

;; Tree-sitter always appear as treesit in symbols.
(defgroup treesit nil
  "Incremental parser.
It is used to enhance major mode features like font-lock,
indent, imenu, etc."
  :group 'tools
  :version "29.1")

(defcustom treesit-max-buffer-size
  (let ((mb (* 1024 1024)))
    ;; 40MB for 64-bit systems, 15 for 32-bit.
    (if (or (< most-positive-fixnum (* 2.0 1024 mb))
            ;; 32-bit system with wide ints.
            (string-match-p "--with-wide-int" system-configuration-options))
        (* 15 mb)
      (* 40 mb)))
  "Maximum buffer size (in bytes) for enabling tree-sitter parsing.

A typical tree-sitter parser needs 10 times as much memory as the
buffer it parses.  Also, the tree-sitter library has a hard limit
of max unsigned 32-bit value for byte offsets into buffer text."
  :type 'integer
  :version "29.1")

;;; Parser API supplement

(defun treesit-parse-string (string language)
  "Parse STRING using a parser for LANGUAGE.
Return the root node of the syntax tree."
  (with-temp-buffer
    (insert string)
    (treesit-parser-root-node
     (treesit-parser-create language))))

(defvar-local treesit-language-at-point-function nil
  "A function that returns the language at point.
This is used by `treesit-language-at', which is used by various
functions to determine which parser to use at point.

The function is called with one argument, the position of point.")

(defun treesit-language-at (position)
  "Return the language at POSITION.
This function assumes that parser ranges are up-to-date.  It
returns the return value of `treesit-language-at-point-function'
if it's non-nil, otherwise it returns the language of the first
parser in `treesit-parser-list', or nil if there is no parser."
  (if treesit-language-at-point-function
      (funcall treesit-language-at-point-function position)
    (when-let ((parser (car (treesit-parser-list))))
      (treesit-parser-language parser))))

;;; Node API supplement

(defun treesit-node-buffer (node)
  "Return the buffer in which NODE belongs."
  (treesit-parser-buffer
   (treesit-node-parser node)))

(defun treesit-node-language (node)
  "Return the language symbol that NODE's parser uses."
  (treesit-parser-language
   (treesit-node-parser node)))

(defun treesit-node-at (pos &optional parser-or-lang named)
  "Return the leaf node at position POS.

A leaf node is a node that doesn't have any child nodes.

The returned node's span covers POS: the node's beginning is before
or at POS, and the node's end is at or after POS.

If no leaf node's span covers POS (e.g., POS is on whitespace
between two leaf nodes), return the first leaf node after POS.

If there is no leaf node after POS, return the first leaf node
before POS.

Return nil if no leaf node can be returned.  If NAMED is non-nil,
only look for named nodes.

If PARSER-OR-LANG is nil, use the first parser in
`treesit-parser-list'; if PARSER-OR-LANG is a parser, use
that parser; if PARSER-OR-LANG is a language, find a parser using
that language in the current buffer, and use that."
  (let* ((root (if (treesit-parser-p parser-or-lang)
                   (treesit-parser-root-node parser-or-lang)
                 (treesit-buffer-root-node parser-or-lang)))
         (node root)
         (node-before root)
         (pos-1 (max (1- pos) (point-min)))
         next)
    (when node
      ;; This is very fast so no need for C implementation.
      (while (setq next (treesit-node-first-child-for-pos
                         node pos named))
        (setq node next))
      ;; If POS is at the end of buffer, after all the text, we will
      ;; end up with NODE = root node.  Instead of returning nil,
      ;; return the last leaf node in the tree for convenience.
      (if (treesit-node-eq node root)
          (progn
            (while (setq next (treesit-node-child node -1 named))
              (setq node next))
            node)
        ;; Normal case, where we found a node.
        (if (<= (treesit-node-start node) pos)
            node
          ;; So the node we found is completely after POS, try to find
          ;; a node whose end equals to POS.
          (while (setq next (treesit-node-first-child-for-pos
                             node-before pos-1 named))
            (setq node-before next))
          (if (eq (treesit-node-end node-before) pos)
              node-before
            node))))))

(defun treesit-node-on (beg end &optional parser-or-lang named)
  "Return the smallest node covering BEG to END.

BEWARE!  Calling this function on an empty line that is not
inside any top-level construct (function definition, etc.) most
probably will give you the root node, because the root node is
the smallest node that covers that empty line.  You probably want
to use `treesit-node-at' instead.

Return nil if none was found.  If NAMED is non-nil, only look for
named node.

If PARSER-OR-LANG is nil, use the first parser in
`treesit-parser-list'; if PARSER-OR-LANG is a parser, use
that parser; if PARSER-OR-LANG is a language, find a parser using
that language in the current buffer, and use that."
  (let ((root (if (treesit-parser-p parser-or-lang)
                  (treesit-parser-root-node parser-or-lang)
                (treesit-buffer-root-node parser-or-lang))))
    (treesit-node-descendant-for-range root beg (or end beg) named)))

(defun treesit-node-top-level (node &optional type)
  "Return the top-level equivalent of NODE.
Specifically, return the highest parent of NODE that has the same
type as it.  If no such parent exists, return nil.

If TYPE is non-nil, match each parent's type with TYPE as a
regexp, rather than using NODE's type."
  (let ((type (or type (treesit-node-type node)))
        (result nil))
    (cl-loop for cursor = (treesit-node-parent node)
             then (treesit-node-parent cursor)
             while cursor
             if (string-match-p type (treesit-node-type cursor))
             do (setq result cursor))
    result))

(defun treesit-buffer-root-node (&optional language)
  "Return the root node of the current buffer.
Use the first parser in `treesit-parser-list'.

If optional argument LANGUAGE is non-nil, use the first parser
for LANGUAGE."
  (if-let ((parser
            (or (if language
                    (treesit-parser-create language)
                  (or (car (treesit-parser-list))
                      (signal 'treesit-error
                              '("Buffer has no parser")))))))
      (treesit-parser-root-node parser)))

(defun treesit-filter-child (node pred &optional named)
  "Return children of NODE that satisfies predicate PRED.
PRED is a function that takes one argument, the child node.
If optional argument NAMED is non-nil, only search for named
node."
  (let ((child (treesit-node-child node 0 named))
        result)
    (while child
      (when (funcall pred child)
        (push child result))
      (setq child (treesit-node-next-sibling child named)))
    (reverse result)))

(defun treesit-node-text (node &optional no-property)
  "Return the buffer (or string) content corresponding to NODE.
If optional argument NO-PROPERTY is non-nil, remove text
properties."
  (when node
    (with-current-buffer (treesit-node-buffer node)
      (if no-property
          (buffer-substring-no-properties
           (treesit-node-start node)
           (treesit-node-end node))
        (buffer-substring
         (treesit-node-start node)
         (treesit-node-end node))))))

(defun treesit-parent-until (node pred)
  "Return the closest parent of NODE that satisfies PRED.
Return nil if none was found.  PRED should be a function that
takes one argument, the parent node."
  (let ((node (treesit-node-parent node)))
    (while (and node (not (funcall pred node)))
      (setq node (treesit-node-parent node)))
    node))

(defun treesit-parent-while (node pred)
  "Return the furthest parent of NODE that satisfies PRED.
Return nil if none was found.  PRED should be a function that
takes one argument, the parent node."
  (let ((last nil))
    (while (and node (funcall pred node))
      (setq last node
            node (treesit-node-parent node)))
    last))

(defalias 'treesit-traverse-parent #'treesit-parent-until)

(defun treesit-node-children (node &optional named)
  "Return a list of NODE's children.
If NAMED is non-nil, collect named child only."
  (mapcar (lambda (idx)
            (treesit-node-child node idx named))
          (number-sequence
           0 (1- (treesit-node-child-count node named)))))

(defun treesit-node-index (node &optional named)
  "Return the index of NODE in its parent.
If NAMED is non-nil, count named child only."
  (let ((count 0))
    (while (setq node (treesit-node-prev-sibling node named))
      (cl-incf count))
    count))

(defun treesit-node-field-name (node)
  "Return the field name of NODE as a child of its parent."
  (when-let ((parent (treesit-node-parent node))
             (idx (treesit-node-index node)))
    (treesit-node-field-name-for-child parent idx)))

;;; Query API supplement

(defun treesit-query-string (string query language)
  "Query STRING with QUERY in LANGUAGE.
See `treesit-query-capture' for QUERY."
  (with-temp-buffer
    (insert string)
    (let ((parser (treesit-parser-create language)))
      (treesit-query-capture
       (treesit-parser-root-node parser)
       query))))

(defun treesit-query-range (node query &optional beg end)
  "Query the current buffer and return ranges of captured nodes.

QUERY, NODE, BEG, END are the same as in
`treesit-query-capture'.  This function returns a list
of (START . END), where START and END specifics the range of each
captured node.  Capture names don't matter."
  (cl-loop for capture
           in (treesit-query-capture node query beg end)
           for node = (cdr capture)
           collect (cons (treesit-node-start node)
                         (treesit-node-end node))))

;;; Range API supplement

(defvar-local treesit-range-settings nil
  "A list of range settings.

Each element of the list is of the form (QUERY LANGUAGE).
When updating the range of each parser in the buffer,
`treesit-update-ranges' queries each QUERY, and sets LANGUAGE's
range to the range spanned by captured nodes.  QUERY must be a
compiled query.

QUERY can also be a function, in which case it is called with 2
arguments, START and END.  It should ensure parsers' ranges are
correct in the region between START and END.

The exact form of each setting is considered internal and subject
to change.  Use `treesit-range-rules' to set this variable.")

(defun treesit-range-rules (&rest query-specs)
  "Produce settings for `treesit-range-settings'.

QUERY-SPECS are a series of QUERY-SPECs, where each QUERY-SPEC is
a QUERY preceded by zero or more pairs of :KEYWORD and VALUE,
like this:

    :KEYWORD VALUE... QUERY

Each QUERY is a tree-sitter query in either the string,
s-expression or compiled form.

For each QUERY, :KEYWORD and VALUE pairs add meta information to
it.  For example,

    (treesit-range-rules
     :embed \\='javascript
     :host \\='html
     \\='((script_element (raw_text) @cap)))

The `:embed' keyword specifies the embedded language, and the
`:host' keyword specifies the host language.  They are used in
this way: Emacs queries QUERY in the host language's parser,
computes the ranges spanned by the captured nodes, and applies
these ranges to parsers for the embedded language.

QUERY can also be a function that takes two arguments, START and
END.  If QUERY is a function, it doesn't need the :KEYWORD VALUE
pair preceding it.  This function should set the ranges for
parsers in the current buffer in the region between START and
END.  It is OK for this function to set ranges in a larger region
that encompasses the region between START and END."
  (let (host embed result)
    (while query-specs
      (pcase (pop query-specs)
        (:host (let ((host-lang (pop query-specs)))
                 (unless (symbolp host-lang)
                   (signal 'treesit-error (list "Value of :host option should be a symbol" host-lang)))
                 (setq host host-lang)))
        (:embed (let ((embed-lang (pop query-specs)))
                  (unless (symbolp embed-lang)
                    (signal 'treesit-error (list "Value of :embed option should be a symbol" embed-lang)))
                  (setq embed embed-lang)))
        (query (if (functionp query)
                   (push (list query nil nil) result)
                 (when (null embed)
                   (signal 'treesit-error (list "Value of :embed option cannot be omitted")))
                 (when (null host)
                   (signal 'treesit-error (list "Value of :host option cannot be omitted")))
                 (push (list (treesit-query-compile host query)
                             embed host)
                       result))
               (setq host nil embed nil))))
    (nreverse result)))

(defun treesit--merge-ranges (old-ranges new-ranges start end)
  "Merge OLD-RANGES and NEW-RANGES, discarding ranges between START and END.
OLD-RANGES and NEW-RANGES are lists of cons of the form (BEG . END).
When merging the two ranges, if a range in OLD-RANGES intersects with
another range in NEW-RANGES, discard the one in OLD-RANGES and
keep the one in NEW-RANGES.  Also discard any range in OLD-RANGES
that intersects the region marked by START and END.

Return the merged list of ranges."
  (let ((result nil))
    (while (and old-ranges new-ranges)
      (let ((new-beg (caar new-ranges))
            (new-end (cdar new-ranges))
            (old-beg (caar old-ranges))
            (old-end (cdar old-ranges)))
        (cond
         ;; Old range intersects with START-END, discard.
         ((and (< start old-end)
               (< old-beg end))
          (setq old-ranges (cdr old-ranges)))
         ;; New range and old range don't intersect, new comes
         ;; before, push new.
         ((<= new-end old-beg)
          (push (car new-ranges) result)
          (setq new-ranges (cdr new-ranges)))
         ;; New range and old range don't intersect, old comes
         ;; before, push old.
         ((<= old-end new-beg)
          (push (car old-ranges) result)
          (setq old-ranges (cdr old-ranges)))
         (t ;; New and old range intersect, discard old.
          (setq old-ranges (cdr old-ranges))))))
    (let ((left-over (or new-ranges old-ranges)))
      (dolist (range left-over)
        (push range result)))
    (nreverse result)))

(defun treesit--clip-ranges (ranges start end)
  "Clip RANGES in between START and END.
RANGES is a list of ranges of the form (BEG . END).  Ranges
outside of the region between START and END are thrown away, and
those inside are kept."
  (cl-loop for range in ranges
           if (<= start (car range) (cdr range) end)
           collect range))

(defun treesit-update-ranges (&optional beg end)
  "Update the ranges for each language in the current buffer.
If BEG and END are non-nil, only update parser ranges in that
region."
  ;; When updating ranges, we want to avoid querying the whole buffer
  ;; which could be slow in very large buffers.  Instead, we only
  ;; query for nodes that intersect with the region between BEG and
  ;; END.  Also, we only update the ranges intersecting BEG and END;
  ;; outside of that region we inherit old ranges.
  (dolist (setting treesit-range-settings)
    (let ((query (nth 0 setting))
          (language (nth 1 setting))
          (beg (or beg (point-min)))
          (end (or end (point-max))))
      (if (functionp query) (funcall query beg end)
        (let* ((host-lang (treesit-query-language query))
               (parser (treesit-parser-create language))
               (old-ranges (treesit-parser-included-ranges parser))
               (new-ranges (treesit-query-range
                            host-lang query beg end))
               (set-ranges (treesit--clip-ranges
                            (treesit--merge-ranges
                             old-ranges new-ranges beg end)
                            (point-min) (point-max))))
          (dolist (parser (treesit-parser-list))
            (when (eq (treesit-parser-language parser)
                      language)
              (treesit-parser-set-included-ranges
               parser set-ranges))))))))

(defun treesit-parser-range-on (parser beg &optional end)
  "Check if PARSER's range covers the portion between BEG and END.

If it does, return the range covering that portion in the form
of (RANGE-BEG . RANGE-END), if not, return nil.  If nil or
omitted, default END to BEG."
  (let ((ranges (treesit-parser-included-ranges parser))
        (end (or end beg)))
    (if (null ranges)
        (cons (point-min) (point-max))
      (cl-loop for rng in ranges
               if (<= (car rng) beg end (cdr rng))
               return rng
               finally return nil))))

;;; Fontification

(define-error 'treesit-font-lock-error
              "Generic tree-sitter font-lock error"
              'treesit-error)

(defvar-local treesit-font-lock-level 3
  "Decoration level to be used by tree-sitter fontifications.

Major modes categorize their fontification features into levels,
from 1 which is the absolute minimum, to 4 that yields the maximum
fontifications.

Level 1 usually contains only comments and definitions.
Level 2 usually adds keywords, strings, constants, types, etc.
Level 3 usually represents a full-blown fontification, including
assignment, constants, numbers, properties, etc.
Level 4 adds everything else that can be fontified: delimiters,
operators, brackets, all functions and variables, etc.

In addition to the decoration level, individual features can be
turned on/off by calling `treesit-font-lock-recompute-features'.
Changing the decoration level requires calling
`treesit-font-lock-recompute-features' to have an effect.")

(defvar-local treesit--font-lock-query-expand-range (cons 0 0)
  "The amount to expand the start and end of the region when fontifying.
This should be a cons cell (START . END).  When fontifying a
buffer, Emacs will move the start of the query range backward by
START amount, and the end of the query range by END amount.  Both
START and END should be positive integers or 0.  This doesn't
affect the fontified range.")

(defvar-local treesit-font-lock-feature-list nil
  "A list of lists of feature symbols.

Use `treesit-font-lock-recompute-features' and
`treesit-font-lock-level' to configure enabled features.

Each sublist represents a decoration level.
`treesit-font-lock-level' controls which levels are activated.

Inside each sublist are feature symbols, which correspond to the
:feature value of a query defined in `treesit-font-lock-rules'.
Removing a feature symbol from this list disables the
corresponding query during font-lock.

Common feature names (for general programming languages) include
definition, type, assignment, builtin, constant, keyword,
string-interpolation, comment, doc, string, operator, property,
preprocessor, escape-sequence, key (in key-value pairs).  Major
modes are free to subdivide or extend on these common features.
See the manual for more explanations on some of the features.

For changes to this variable to take effect, run
`treesit-font-lock-recompute-features'.")

(defvar-local treesit-font-lock-settings nil
  "A list of SETTINGs for treesit-based fontification.

The exact format of each SETTING is considered internal.  Use
`treesit-font-lock-rules' to set this variable.

Each SETTING has the form:

    (QUERY ENABLE FEATURE OVERRIDE)

QUERY must be a compiled query.  See Info node `(elisp)Pattern
Matching' for how to write a query and compile it.

For SETTING to be activated for font-lock, ENABLE must be t.  To
disable this SETTING, set ENABLE to nil.

FEATURE is the \"feature name\" of the query.  Users can control
which features are enabled with `treesit-font-lock-level' and
`treesit-font-lock-feature-list'.

OVERRIDE is the override flag for this query.  Its value can be
t, nil, append, prepend, keep.  See more in
`treesit-font-lock-rules'.")

(defun treesit-font-lock-rules (&rest query-specs)
  "Return a value suitable for `treesit-font-lock-settings'.

QUERY-SPECS is a series of QUERY-SPECs.  Each QUERY-SPEC is a
QUERY preceded by multiple pairs of :KEYWORD and VALUE:

   :KEYWORD VALUE... QUERY

QUERY is a tree-sitter query in either the string, s-expression
or compiled form.  For each query, captured nodes are highlighted
with the capture name as its face.

:KEYWORD and VALUE pairs preceding a QUERY add meta information
to QUERY.  For example,

    (treesit-font-lock-rules
     :language \\='javascript
     :override t
     :feature\\='constant
     \\='((true) @font-lock-constant-face
       (false) @font-lock-constant-face)
     :language \\='html
     :feature \\='script
     \"(script_element) @font-lock-builtin-face\")

For each QUERY, a :language keyword and a :feature keyword are
required.  Each query's :feature is a symbol summarizing what the
query fontifies.  It is used to allow users to enable/disable
certain features.  See `treesit-font-lock-feature-list' for more.
Other keywords include:

  KEYWORD    VALUE      DESCRIPTION
  :override  nil        If the region already has a face,
                        discard the new face.
             t          Always apply the new face.
             `append'   Append the new face to existing ones.
             `prepend'  Prepend the new face to existing ones.
             `keep'     Fill-in regions without an existing face.

Capture names in QUERY should be face names like
`font-lock-keyword-face'.  The captured node will be fontified
with that face.

Capture names can also be function names, in which case the
function will be called with the following argument list:

    (NODE OVERRIDE START END &rest _)

where NODE is the tree-sitter node object, OVERRIDE is the
override option of that rule, and START and END specify the region
to be fontified.  This function should accept more arguments as
optional arguments for future extensibility, and it shouldn't
fontify text outside the region given by START and END.

If a capture name is both a face and a function, the face takes
priority.  If a capture name is not a face name nor a function
name, it is ignored."
  ;; Other tree-sitter function don't tend to be called unless
  ;; tree-sitter is enabled, which means tree-sitter must be compiled.
  ;; But this function is usually call in `defvar' which runs
  ;; regardless whether tree-sitter is enabled.  So we need this
  ;; guard.
  (when (treesit-available-p)
    (let (;; Tracks the current :language/:override/:toggle/:level value
          ;; that following queries will apply to.
          current-language current-override
          current-feature
          ;; The list this function returns.
          (result nil))
      (while query-specs
        (let ((token (pop query-specs)))
          (pcase token
            ;; (1) Process keywords.
            (:language
             (let ((lang (pop query-specs)))
               (when (or (not (symbolp lang)) (null lang))
                 (signal 'treesit-font-lock-error
                         `("Value of :language should be a symbol"
                           ,lang)))
               (setq current-language lang)))
            (:override
             (let ((flag (pop query-specs)))
               (when (not (memq flag '(t nil append prepend keep)))
                 (signal 'treesit-font-lock-error
                         `("Value of :override should be one of t, nil, append, prepend, keep"
                           ,flag))
                 (signal 'wrong-type-argument
                         `((or t nil append prepend keep)
                           ,flag)))
               (setq current-override flag)))
            (:feature
             (let ((var (pop query-specs)))
               (when (or (not (symbolp var))
                         (memq var '(t nil)))
                 (signal 'treesit-font-lock-error
                         `("Value of :feature should be a symbol"
                           ,var)))
               (setq current-feature var)))
            ;; (2) Process query.
            ((pred treesit-query-p)
             (when (null current-language)
               (signal 'treesit-font-lock-error
                       `("Language unspecified, use :language keyword to specify a language for this query" ,token)))
             (when (null current-feature)
               (signal 'treesit-font-lock-error
                       `("Feature unspecified, use :feature keyword to specify the feature name for this query" ,token)))
             (if (treesit-compiled-query-p token)
                 (push `(,current-language token) result)
               (push `(,(treesit-query-compile current-language token)
                       t
                       ,current-feature
                       ,current-override)
                     result))
             ;; Clears any configurations set for this query.
             (setq current-language nil
                   current-override nil
                   current-feature nil))
            (_ (signal 'treesit-font-lock-error
                       `("Unexpected value" ,token))))))
      (nreverse result))))

;; `font-lock-fontify-region-function' has the LOUDLY argument, but
;; `jit-lock-functions' doesn't pass that argument.  So even if we set
;; `font-lock-verbose' to t, if jit-lock is enabled (and it's almost
;; always is), we don't get debug messages.  So we add our own.
(defvar treesit--font-lock-verbose nil
  "If non-nil, print debug messages when fontifying.")

(defun treesit-font-lock-recompute-features (&optional add-list remove-list)
  "Enable/disable font-lock features.

Enable each feature in ADD-LIST, disable each feature in
REMOVE-LIST.

If both ADD-LIST and REMOVE-LIST are omitted, recompute each
feature according to `treesit-font-lock-feature-list' and
`treesit-font-lock-level'.  If the value of `treesit-font-lock-level',
is N, then the features in the first N sublists of
`treesit-font-lock-feature-list' are enabled, and the rest of
the features are disabled.

ADD-LIST and REMOVE-LIST are lists of feature symbols.  The
same feature symbol cannot appear in both lists; the function
signals the `treesit-font-lock-error' error if that happens."
  (when-let ((intersection (cl-intersection add-list remove-list)))
    (signal 'treesit-font-lock-error
            (list "ADD-LIST and REMOVE-LIST contain the same feature"
                  intersection)))
  (let* ((level treesit-font-lock-level)
         (base-features (cl-loop
                         for idx = 0 then (1+ idx)
                         for features in treesit-font-lock-feature-list
                         if (or (eq level t)
                                (>= level (1+ idx)))
                         append features))
         (features (cl-set-difference (cl-union base-features add-list)
                                      remove-list))
         ;; If additive non-nil, we are configuring on top of the
         ;; existing configuration, if nil, we are resetting
         ;; everything according to `treesit-font-lock-feature-list'.
         (additive (or add-list remove-list)))
    (cl-loop for idx = 0 then (1+ idx)
             for setting in treesit-font-lock-settings
             for feature = (nth 2 setting)
             for current-value = (nth 1 setting)
             ;; Set the ENABLE flag for the setting.
             do (setf (nth 1 (nth idx treesit-font-lock-settings))
                      (cond
                       ((not additive)
                        (if (memq feature features) t nil))
                       ((memq feature add-list) t)
                       ((memq feature remove-list) nil)
                       (t current-value))))))

(defun treesit-fontify-with-override
    (start end face override &optional bound-start bound-end)
  "Apply FACE to the region between START and END.
OVERRIDE can be nil, t, `append', `prepend', or `keep'.
See `treesit-font-lock-rules' for their semantic.

If BOUND-START and BOUND-END are non-nil, only fontify the region
in between them."
  (when (or (null bound-start) (null bound-end)
            (and bound-start bound-end
                 (<= bound-start end)
                 (>= bound-end start)))
    (when (and bound-start bound-end)
      (setq start (max bound-start start)
            end (min bound-end end)))
    (pcase override
      ('nil (unless (text-property-not-all start end 'face nil)
              (put-text-property start end 'face face)))
      ('t (put-text-property start end 'face face))
      ('append (font-lock-append-text-property
                start end 'face face))
      ('prepend (font-lock-prepend-text-property
                 start end 'face face))
      ('keep (font-lock-fillin-text-property
              start end 'face face))
      (_ (signal 'treesit-font-lock-error
                 (list
                  "Unrecognized value of :override option"
                  override))))))

(defun treesit--set-nonsticky (start end sym &optional remove)
  "Set `rear-nonsticky' property between START and END.
Set the property to a list containing SYM.  If there is already a
list, add SYM to that list.  If REMOVE is non-nil, remove SYM
instead."
  (let* ((prop (get-text-property start 'rear-nonsticky))
         (new-prop
          (pcase prop
            ((pred listp) ; PROP is a list or nil.
             (if remove
                 (remove sym prop)
               ;; We should make sure PORP doesn't contain SYM, but
               ;; whatever.
               (cons sym prop)))
            ;; PROP is t.
            (_ (if remove
                   nil
                 (list sym))))))
    (if (null new-prop)
        (remove-text-properties start end '(rear-nonsticky nil))
      (put-text-property start end 'rear-nonsticky new-prop))))

(defun treesit--children-covering-range (node start end)
  "Return a list of children of NODE covering a range.
The range is between START and END."
  (if-let* ((child (treesit-node-first-child-for-pos node start))
            (result (list child)))
      (progn
        (while (and child (< (treesit-node-end child) end)
                    (setq child (treesit-node-next-sibling child)))
          (push child result))
        (nreverse result))
    (list node)))

(defun treesit--children-covering-range-recurse
    (node start end threshold &optional limit)
  "Return a list of children of NODE covering a range.

Recursively go down the parse tree and collect children, until
all nodes in the returned list are smaller than THRESHOLD.  The
range is between START and END.

LIMIT is the recursion limit, which defaults to 100."
  (let* ((child (treesit-node-first-child-for-pos node start))
         (limit (or limit 100))
         result)
    ;; If LIMIT is exceeded, we are probably seeing the erroneously
    ;; tall tree, in that case, just give up.
    (while (and (> limit 0) child (<= (treesit-node-start child) end))
      ;; If child still too large, recurse down.  Otherwise collect
      ;; child.
      (if (> (- (treesit-node-end child)
                (treesit-node-start child))
             threshold)
          (dolist (r (treesit--children-covering-range-recurse
                      child start end threshold (1- limit)))
            (push r result))
        (push child result))
      (setq child (treesit-node-next-sibling child)))
    ;; If NODE has no child, keep NODE.
    (or result node)))

(defsubst treesit--node-length (node)
  "Return the length of the text of NODE."
  (- (treesit-node-end node) (treesit-node-start node)))

(defvar-local treesit--font-lock-fast-mode nil
  "If this variable is t, change the way we query so it's faster.
This is not a general optimization and should be RARELY needed!
See comments in `treesit-font-lock-fontify-region' for more
detail.")

;; Some details worth explaining:
;;
;; 1. When we apply face to a node, we clip the face into the
;; currently fontifying region, this way we don't overwrite faces
;; applied by regexp-based font-lock.  The clipped part will be
;; fontified fine when Emacs fontifies the region containing it.
;;
;; 2. If you insert an ending quote into a buffer, jit-lock only wants
;; to fontify that single quote, and (treesit-node-on start end) will
;; give you that quote node.  We want to capture the string and apply
;; string face to it, but querying on the quote node will not give us
;; the string node.  So we don't use treesit-node-on: using the root
;; node with a restricted range is very fast anyway (even in large
;; files of size ~10MB).  Plus, querying the result of
;; `treesit-node-on' could still miss patterns even if we use some
;; heuristic to enlarge the node (how much to enlarge? to which
;; extent?), it's much safer to just use the root node.
;;
;; Sometimes the source file has some errors that cause tree-sitter to
;; parse it into a enormously tall tree (10k levels tall).  In that
;; case querying the root node is very slow.  So we try to get
;; top-level nodes and query them.  This ensures that querying is fast
;; everywhere else, except for the problematic region.
;;
;; Some other time the source file has a top-level node that contains
;; a huge number of children (say, 10k children), querying that node
;; is also very slow, so instead of getting the top-level node, we
;; recursively go down the tree to find nodes that cover the region
;; but are reasonably small.
;;
;; 3. It is possible to capture a node that's completely outside the
;; region between START and END: as long as the whole pattern
;; intersects the region, all the captured nodes in that pattern are
;; returned.  If the node is outside of that region, (max node-start
;; start) and friends return bad values, so we filter them out.
;; However, we don't filter these nodes out if a function will process
;; the node, because could (and often do) fontify the relatives of the
;; captured node, not just the node itself.  If we took out those
;; nodes author of those functions would be very confused.
(defun treesit-font-lock-fontify-region (start end &optional loudly)
  "Fontify the region between START and END.
If LOUDLY is non-nil, display some debugging information."
  (when (or loudly treesit--font-lock-verbose)
    (message "Fontifying region: %s-%s" start end))
  (treesit-update-ranges start end)
  (font-lock-unfontify-region start end)
  (dolist (setting treesit-font-lock-settings)
    (let* ((query (nth 0 setting))
           (enable (nth 1 setting))
           (override (nth 3 setting))
           (language (treesit-query-language query)))
      (when-let ((nodes (list (treesit-buffer-root-node language)))
                 ;; Only activate if ENABLE flag is t.
                 (activate (eq t enable)))
        (ignore activate)

        ;; If we run into problematic files, use the "fast mode" to
        ;; try to recover.  See comment #2 above for more explanation.
        (when treesit--font-lock-fast-mode
          (setq nodes (treesit--children-covering-range-recurse
                       (car nodes) start end (* 4 jit-lock-chunk-size))))

        ;; Query each node.
        (dolist (sub-node nodes)
          (let* ((delta-start (car treesit--font-lock-query-expand-range))
                 (delta-end (cdr treesit--font-lock-query-expand-range))
                 (start-time (current-time))
                 (captures (treesit-query-capture
                            sub-node query
                            (max (- start delta-start) (point-min))
                            (min (+ end delta-end) (point-max))))
                 (end-time (current-time)))
            ;; If for any query the query time is strangely long,
            ;; switch to fast mode (see comments above).
            (when (> (time-to-seconds (time-subtract end-time start-time))
                     0.01)
              (setq-local treesit--font-lock-fast-mode t))

            ;; For each captured node, fontify that node.
            (with-silent-modifications
              (dolist (capture captures)
                (let* ((face (car capture))
                       (node (cdr capture))
                       (node-start (treesit-node-start node))
                       (node-end (treesit-node-end node)))
                  ;; If node is not in the region, take them out.  See
                  ;; comment #3 above for more detail.
                  (if (and (facep face)
                           (or (>= start node-end) (>= node-start end)))
                      (when (or loudly treesit--font-lock-verbose)
                        (message "Captured node %s(%s-%s) but it is outside of fontifing region" node node-start node-end))
                    (cond
                     ((facep face)
                      (treesit-fontify-with-override
                       (max node-start start) (min node-end end)
                       face override))
                     ((functionp face)
                      (funcall face node override start end)))
                    ;; Don't raise an error if FACE is neither a face nor
                    ;; a function.  This is to allow intermediate capture
                    ;; names used for #match and #eq.
                    (when (or loudly treesit--font-lock-verbose)
                      (message "Fontifying text from %d to %d, Face: %s, Node: %s"
                               (max node-start start) (min node-end end)
                               face (treesit-node-type node))))))))))))
  `(jit-lock-bounds ,start . ,end))

(defun treesit--font-lock-notifier (ranges parser)
  "Ensures updated parts of the parse-tree are refontified.
RANGES is a list of (BEG . END) ranges, PARSER is the tree-sitter
parser notifying of the change."
  (with-current-buffer (treesit-parser-buffer parser)
    (dolist (range ranges)
      (when treesit--font-lock-verbose
        (message "Notifier received range: %s-%s"
                 (car range) (cdr range)))
      (put-text-property (car range) (cdr range) 'fontified nil))))

;;; Indent

(define-error 'treesit-indent-error
              "Generic tree-sitter indentation error"
              'treesit-error)

(defvar treesit--indent-verbose nil
  "If non-nil, log progress when indenting.")

(defvar-local treesit-simple-indent-rules nil
  "A list of indent rule settings.
Each indent rule setting should be (LANGUAGE . RULES),
where LANGUAGE is a language symbol, and RULES is a list of

    (MATCHER ANCHOR OFFSET).

MATCHER determines whether this rule applies, ANCHOR and OFFSET
together determines which column to indent to.

A MATCHER is a function that takes three arguments (NODE PARENT
BOL).  BOL is the point where we are indenting: the beginning of
line content, the position of the first non-whitespace character.
NODE is the largest (highest-in-tree) node starting at that
point.  PARENT is the parent of NODE.

If MATCHER returns non-nil, meaning the rule matches, Emacs then
uses ANCHOR to find an anchor, it should be a function that takes
the same argument (NODE PARENT BOL) and returns a point.

Finally Emacs computes the column of that point returned by
ANCHOR and adds OFFSET to it, and indents to that column.  OFFSET
can be an integer or a variable whose value is an integer.

For MATCHER and ANCHOR, Emacs provides some convenient presets.
See `treesit-simple-indent-presets'.")

(defvar treesit-simple-indent-presets
  (list (cons 'match
              (lambda
                (&optional node-type parent-type node-field
                           node-index-min node-index-max)
                (lambda (node parent &rest _)
                  (and (or (null node-type)
                           (string-match-p
                            node-type (or (treesit-node-type node) "")))
                       (or (null parent-type)
                           (string-match-p
                            parent-type (treesit-node-type parent)))
                       (or (null node-field)
                           (string-match-p
                            node-field
                            (or (treesit-node-field-name node) "")))
                       (or (null node-index-min)
                           (>= (treesit-node-index node)
                               node-index-min))
                       (or (null node-index-max)
                           (<= (treesit-node-index node)
                               node-index-max))))))
        ;; TODO: Document if genuinely useful.
        (cons 'n-p-gp
              (lambda (node-t parent-t grand-parent-t)
                (lambda (node parent &rest _)
                  (and (or (null node-t)
                           (string-match-p
                            node-t (or (treesit-node-type node) "")))
                       (or (null parent-t)
                           (string-match-p
                            parent-t (treesit-node-type parent)))
                       (or (null grand-parent-t)
                           (string-match-p
                            grand-parent-t
                            (treesit-node-type
                             (treesit-node-parent parent))))))))
        (cons 'no-node (lambda (node &rest _) (null node)))
        (cons 'parent-is (lambda (type)
                           (lambda (_n parent &rest _)
                             (string-match-p
                              type (treesit-node-type parent)))))

        (cons 'node-is (lambda (type)
                         (lambda (node &rest _)
                           (string-match-p
                            type (or (treesit-node-type node) "")))))
        (cons 'field-is (lambda (name)
                          (lambda (node &rest _)
                            (string-match-p
                             name (or (treesit-node-field-name node) "")))))
        (cons 'comment-end (lambda (_node _parent bol &rest _)
                             (save-excursion
                               (goto-char bol)
                               (looking-at-p comment-end-skip))))
        ;; TODO: Document.
        (cons 'catch-all (lambda (&rest _) t))

        (cons 'query (lambda (pattern)
                       (lambda (node parent &rest _)
                         (cl-loop for capture
                                  in (treesit-query-capture
                                      parent pattern)
                                  if (treesit-node-eq node (cdr capture))
                                  return t
                                  finally return nil))))
        (cons 'first-sibling (lambda (_n parent &rest _)
                               (treesit-node-start
                                (treesit-node-child parent 0))))
        ;; TODO: Document.
        (cons 'nth-sibling (lambda (n &optional named)
                             (lambda (_n parent &rest _)
                               (treesit-node-start
                                (treesit-node-child parent n named)))))
        (cons 'parent (lambda (_n parent &rest _)
                        (treesit-node-start parent)))
        (cons 'comment-start
              (lambda (_n parent &rest _)
                (save-excursion
                  (goto-char (treesit-node-start parent))
                  (re-search-forward comment-start-skip)
                  (skip-syntax-backward "-")
                  (point))))
        (cons 'comment-start-skip
              (lambda (_n parent &rest _)
                (save-excursion
                  (goto-char (treesit-node-start parent))
                  (re-search-forward comment-start-skip)
                  (point))))
        ;; TODO: Document.
        (cons 'grand-parent
              (lambda (_n parent &rest _)
                (treesit-node-start (treesit-node-parent parent))))
        (cons 'parent-bol (lambda (_n parent &rest _)
                            (save-excursion
                              (goto-char (treesit-node-start parent))
                              (back-to-indentation)
                              (point))))
        (cons 'prev-sibling (lambda (node &rest _)
                              (treesit-node-start
                               (treesit-node-prev-sibling node))))
        (cons 'no-indent (lambda (_n _p bol &rest _) bol))
        (cons 'prev-line (lambda (_n _p bol &rest _)
                           (save-excursion
                             (goto-char bol)
                             (forward-line -1)
                             (skip-chars-forward " \t"))))
        (cons 'point-min (lambda (&rest _) (point-min)))
        ;; TODO: Document.
        (cons 'and (lambda (&rest fns)
                     (lambda (node parent bol &rest _)
                       (cl-reduce (lambda (a b) (and a b))
                                  (mapcar (lambda (fn)
                                            (funcall fn node parent bol))
                                          fns)))))
        (cons 'or (lambda (&rest fns)
                    (lambda (node parent bol &rest _)
                      (cl-reduce (lambda (a b) (or a b))
                                 (mapcar (lambda (fn)
                                           (funcall fn node parent bol))
                                         fns)))))
        (cons 'not (lambda (fn)
                     (lambda (node parent bol &rest _)
                       (debug)
                       (not (funcall fn node parent bol)))))
        (cons 'list (lambda (&rest fns)
                      (lambda (node parent bol &rest _)
                        (mapcar (lambda (fn)
                                  (funcall fn node parent bol))
                                fns)))))
  "A list of presets.
These presets that can be used as MATHER and ANCHOR in
`treesit-simple-indent-rules'.  MACHTERs and ANCHORs are
functions that take 3 arguments: NODE, PARENT and BOL.

MATCHER:

\(match NODE-TYPE PARENT-TYPE NODE-FIELD NODE-INDEX-MIN NODE-INDEX-MAX)

    NODE-TYPE checks for NODE's type, PARENT-TYPE checks for
    PARENT's type, NODE-FIELD checks for the field name of NODE
    in PARENT, NODE-INDEX-MIN and NODE-INDEX-MAX check for
    NODE's index in PARENT.  Therefore, to match the first child
    where PARENT is \"argument_list\", use

        (match nil \"argument_list\" nil nil 0 0).

    NODE-TYPE, PARENT-TYPE, and NODE-FIELD are regexps.

no-node

    Matches the case where NODE is nil, i.e., there is no node
    that starts at point.  This is the case when indenting an
    empty line.

\(parent-is TYPE)

    Check that PARENT's type matches regexp TYPE.

\(node-is TYPE)

    Checks that NODE's type matches regexp TYPE.

\(query QUERY)

    Queries PARENT with QUERY, and checks if NODE is
    captured (by any capture name).

comment-end

    Matches if text after point matches `treesit-comment-end'.

ANCHOR:

first-sibling

    Returns the start of the first child of PARENT.

parent

    Returns the start of PARENT.

parent-bol

    Returns the beginning of non-space characters on the line where
    PARENT is on.

prev-sibling

    Returns the start of NODE's previous sibling.

no-indent

    Returns the start of NODE.

prev-line

    Returns the first non-whitespace character on the previous line.

point-min

    Returns the beginning of buffer, which is always at column 0.

comment-start

    Returns the position after a match for `treesit-comment-start'.
    Assumes PARENT is a comment node.

comment-start-skip

    Goes to the position that comment-start would return, skips
    whitespace after that, and returns the resulting position.
    Assumes PARENT is a comment node.")

(defun treesit--simple-indent-eval (exp)
  "Evaluate EXP.

If EXP is an application and the function is a key in
`treesit-simple-indent-presets', use the corresponding value as
the function."
  ;; We don't want to match uncompiled lambdas, so make sure this cons
  ;; is not a function.  We could move the condition functionp
  ;; forward, but better be explicit.
  (cond ((and (consp exp) (not (functionp exp)))
         (apply (treesit--simple-indent-eval (car exp))
                (mapcar #'treesit--simple-indent-eval
                        (cdr exp))))
        ;; Presets override functions, so this condition comes before
        ;; `functionp'.
        ((alist-get exp treesit-simple-indent-presets)
         (alist-get exp treesit-simple-indent-presets))
        ((functionp exp) exp)
        ((symbolp exp)
         (if (null exp)
             exp
           ;; Matchers only return lambdas, anchors only return
           ;; integer, so we should never see a variable.
           (signal 'treesit-indent-error
                   (list "Couldn't find the preset corresponding to expression"
                         exp))))
        (t exp)))

;; This variable might seem unnecessary: why split
;; `treesit-indent' and `treesit-simple-indent' into two
;; functions?  We add this variable in between because later we might
;; add more powerful indentation engines, and that new engine can
;; probably share `treesit-indent'.  It is also useful, suggested
;; by Stefan M, to have a function that figures out how much to indent
;; but doesn't actually performs the indentation, because we might
;; want to know where will a node indent to if we put it at some other
;; location, and use that information to calculate the actual
;; indentation.  And `treesit-simple-indent' is that function.  I
;; forgot the example Stefan gave, but it makes a lot of sense.
(defvar treesit-indent-function #'treesit-simple-indent
  "Function used by `treesit-indent' to do some of the work.

This function is called with

    (NODE PARENT BOL &rest _)

and returns

    (ANCHOR . OFFSET).

BOL is the position of the beginning of the line; NODE is the
\"largest\" node that starts at BOL; PARENT is its parent; ANCHOR
is a point (not a node), and OFFSET is a number.  Emacs finds the
column of ANCHOR and adds OFFSET to it as the final indentation
of the current line.")

(defun treesit--indent-1 ()
  "Indent the current line.
Return (ANCHOR . OFFSET).  This function is used by
`treesit-indent' and `treesit-indent-region'."
  ;; Basically holds the common part between the two indent function.
  (let* ((bol (save-excursion
                (forward-line 0)
                (skip-chars-forward " \t")
                (point)))
         (smallest-node
          (cond ((null (treesit-parser-list)) nil)
                ((eq 1 (length (treesit-parser-list)))
                 (treesit-node-at bol))
                ((treesit-language-at (point))
                 (treesit-node-at bol (treesit-language-at (point))))
                (t (treesit-node-at bol))))
         (node (treesit-parent-while
                smallest-node
                (lambda (node)
                  (eq bol (treesit-node-start node))))))
    (let*
        ((parser (if smallest-node
                     (treesit-node-parser smallest-node)
                   nil))
         ;; NODE would be nil if BOL is on a whitespace.  In that case
         ;; we set PARENT to the "node at point", which would
         ;; encompass the whitespace.
         (parent (cond ((and node parser)
                        (treesit-node-parent node))
                       (t (treesit-node-on bol bol)))))
      (funcall treesit-indent-function node parent bol))))

(defun treesit-indent ()
  "Indent according to the result of `treesit-indent-function'."
  (treesit-update-ranges (line-beginning-position)
                         (line-end-position))
  ;; We don't return 'noindent even if no rules match, because
  ;; `indent-for-tab-command' tries to indent itself when we return
  ;; 'noindent, which leads to wrong indentation at times.
  (pcase-let* ((`(,anchor . ,offset) (treesit--indent-1)))
    (when (and anchor offset)
      (let ((col (+ (save-excursion
                      (goto-char anchor)
                      (current-column))
                    offset))
            (delta (- (point-max) (point))))
        (indent-line-to col)
        ;; Now point is at the end of indentation.  If we started
        ;; from within the line, go back to where we started.
        (when (> (- (point-max) delta) (point))
          (goto-char (- (point-max) delta)))))))

;; Batch size can't be too large, because we put markers on each
;; ANCHOR, so a batch size of 400 lines means 400 markers.
(defvar treesit--indent-region-batch-size 400
  "How many lines of indent value do we precompute.
In `treesit-indent-region' we indent in batches: precompute
indent for each line, apply them in one go, let parser reparse,
and do it again.  This way the parser doesn't need to unnecessarily
reparse after indenting every single line.")

(defun treesit-indent-region (beg end)
  "Indent the region between BEG and END.
Similar to `treesit-indent', but indent a region instead."
  (treesit-update-ranges beg end)
  ;; We indent `treesit--indent-region-batch-size' lines at a time, to
  ;; reduce the number of times the parser needs to re-parse.  In each
  ;; batch, we go through each line and calculate the anchor and
  ;; offset as usual, but instead of modifying the buffer, we save
  ;; these information in a vector.  Once we've collected ANCHOR and
  ;; OFFSET for each line in the batch, we go through each line again
  ;; and apply the changes.  Now that buffer is modified, we need to
  ;; reparse the buffer before continuing to indent the next batch.
  (let* ((meta-len 2)
         (vector-len (* meta-len treesit--indent-region-batch-size))
         ;; This vector saves the indent meta for each line in the
         ;; batch.  It is a vector [ANCHOR OFFSET ANCHOR OFFSET...].
         ;; ANCHOR is a marker on the anchor position, and OFFSET is
         ;; an integer.  ANCHOR and OFFSET are either both nil, or
         ;; both valid.
         (meta-vec (make-vector vector-len 0))
         (lines-left-to-move 0)
         (end (copy-marker end t))
         (idx 0)
         (starting-pos 0)
         (announce-progress (> (- end beg) 80000)))
    (save-excursion
      (goto-char beg)
      ;; First pass.  Go through each line and compute the
      ;; indentation.
      (while (and (eq lines-left-to-move 0) (< (point) end))
        (setq idx 0
              starting-pos (point))
        (while (and (eq lines-left-to-move 0)
                    (< idx treesit--indent-region-batch-size)
                    (< (point) end))
          (if (looking-at (rx (* whitespace) eol) t)
              ;; Unlike in `indent-line' where we sometimes pre-indent
              ;; an empty line, We don't indent empty lines in
              ;; `indent-region'.  Set ANCHOR and OFFSET to nil.
              (setf (aref meta-vec (* idx meta-len)) nil
                    (aref meta-vec (+ 1 (* idx meta-len))) nil)
            (pcase-let* ((`(,anchor . ,offset) (treesit--indent-1))
                         (marker (aref meta-vec (* idx meta-len))))
              ;; Set ANCHOR.
              (when anchor
                (if (markerp marker)
                    (move-marker marker anchor)
                  (setf (aref meta-vec (* idx meta-len))
                        (copy-marker anchor t))))
              ;; SET OFFSET.
              (setf (aref meta-vec (+ 1 (* idx meta-len))) offset)))
          (cl-incf idx)
          (setq lines-left-to-move (forward-line 1)))
        ;; Now IDX = last valid IDX + 1.
        (goto-char starting-pos)
        ;; Second pass, go to each line and apply the indentation.
        (dotimes (jdx idx)
          (let ((anchor (aref meta-vec (* jdx meta-len)))
                (offset (aref meta-vec (+ 1 (* jdx meta-len)))))
            (when offset
              (let ((col (save-excursion
                           (goto-char anchor)
                           (+ offset (current-column)))))
                (indent-line-to col))))
          (forward-line 1))
        (when announce-progress
          (message "Indenting region...%s%%"
                   (/ (* (- (point) beg) 100) (- end beg)))))
      ;; Delete markers.
      (dotimes (idx treesit--indent-region-batch-size)
        (let ((marker (aref meta-vec (* idx meta-len))))
          (when (markerp marker)
            (move-marker marker nil))))
      (move-marker end nil))))

(defun treesit-simple-indent (node parent bol)
  "Calculate indentation according to `treesit-simple-indent-rules'.

BOL is the position of the first non-whitespace character on the
current line.  NODE is the largest node that starts at BOL,
PARENT is NODE's parent.

Return (ANCHOR . OFFSET) where ANCHOR is a node, OFFSET is the
indentation offset, meaning indent to align with ANCHOR and add
OFFSET."
  (if (null parent)
      (progn (when treesit--indent-verbose
               (message "PARENT is nil, not indenting"))
             (cons nil nil))
    (let* ((language (treesit-node-language parent))
           (rules (alist-get language
                             treesit-simple-indent-rules)))
      (cl-loop for rule in rules
               for pred = (nth 0 rule)
               for anchor = (nth 1 rule)
               for offset = (nth 2 rule)
               if (treesit--simple-indent-eval
                   (list pred node parent bol))
               do (when treesit--indent-verbose
                    (message "Matched rule: %S" rule))
               and
               return
               (let ((anchor-pos
                      (treesit--simple-indent-eval
                       (list anchor node parent bol))))
                 (cons anchor-pos (if (symbolp offset)
                                      (symbol-value offset)
                                    offset)))
               finally return
               (progn (when treesit--indent-verbose
                        (message "No matched rule"))
                      (cons nil nil))))))

(defun treesit--read-major-mode ()
  "Read a major mode using completion.
Helper function to use in the `interactive' spec of `treesit-check-indent'."
  (let* ((default (and (symbolp major-mode) (symbol-name major-mode)))
	 (mode
	  (completing-read
	   (format-prompt "Target major mode" default)
	   obarray
	   (lambda (sym)
	     (and (string-match-p "-mode\\'" (symbol-name sym))
		  (not (or (memq sym minor-mode-list)
                           (string-match-p "-minor-mode\\'"
                                           (symbol-name sym))))))
	   nil nil nil default nil)))
    (cond
     ((equal mode "nil") nil)
     ((and (stringp mode) (fboundp (intern mode))) (intern mode))
     (t mode))))

(defun treesit-check-indent (mode)
  "Compare the current buffer with how major mode MODE would indent it."
  (interactive (list (treesit--read-major-mode)))
  (let ((source-buf (current-buffer)))
    (with-temp-buffer
      (insert-buffer-substring source-buf)
      (funcall mode)
      (indent-region (point-min) (point-max))
      (diff-buffers source-buf (current-buffer)))))

(defun treesit--indent-rules-optimize (rules)
  "Optimize simple indent RULES.
RULES should be a value suitable for
`treesit-simple-indent-rules'.  Return the optimized version of
RULES."
  ;; Right now this function just compiles queries.  It doesn't
  ;; byte-compile matchers and anchors because it doesn't make much
  ;; difference.
  (cl-loop for setting in rules
           for lang = (car setting)
           for indent-rules = (cdr setting)
           collect
           (cl-labels
               ;; Optimize a matcher or anchor.
               ((optimize-func (func)
                  (pcase func
                    (`(query ,qry)
                     (list 'query (treesit-query-compile lang qry)))
                    (_ func)))
                ;; Optimize a rule (MATCHER ANCHOR OFFSET).
                (optimize-rule (rule)
                  (let ((matcher (nth 0 rule))
                        (anchor (nth 1 rule))
                        (offset (nth 2 rule)))
                    (list (optimize-func matcher)
                          (optimize-func anchor)
                          offset))))
             (cons lang (mapcar #'optimize-rule indent-rules)))))

;;; Search

(defun treesit-search-forward-goto
    (node predicate &optional start backward all)
  "Search forward for a node and move to its end position.

Stop at the first node after NODE that matches PREDICATE.
PREDICATE can be either a regexp that matches against each node's
type case-insensitively, or a function that takes a node and
returns nil/non-nil for match/no match.

If a node matches, move to that node and return the node,
otherwise return nil.  If START is non-nil, stop at the
beginning rather than the end of a node.

This function guarantees that the matched node it returns makes
progress in terms of buffer position: the start/end position of
the returned node is always STRICTLY greater/less than that of
NODE.

BACKWARD and ALL are the same as in `treesit-search-forward'."
  (when-let* ((start-pos (if start
                             (treesit-node-start node)
                           (treesit-node-end node)))
              (current-pos start-pos))
    ;; When searching forward and stopping at beginnings, or search
    ;; backward stopping at ends, it is possible to "roll back" in
    ;; position.  Take three nodes N1, N2, N3 as an example, if we
    ;; start at N3, search for forward for beginning, and N1 matches,
    ;; we would stop at beg of N1, which is backwards!  So we skip N1
    ;; and keep going.
    ;;
    ;;   |<--------N1------->|
    ;;   |<--N2-->| |<--N3-->|
    (while (and node (if backward
                         (>= current-pos start-pos)
                       (<= current-pos start-pos)))
      (setq node (treesit-search-forward
                  node predicate backward all))
      (setq current-pos (if start
                            (treesit-node-start node)
                          (treesit-node-end node))))
    (cond
     ;; When there is a match and match made progress, go to the
     ;; result position.
     ((and node
           (if backward
               (< current-pos (point))
             (> current-pos (point))))
      (goto-char current-pos)))
    node))

;;; Navigation

(defvar-local treesit-defun-type-regexp nil
  "A regexp that matches the node type of defun nodes.
For example, \"(function|class)_definition\".

This is used by `treesit-beginning-of-defun' and friends.")

(defvar-local treesit-defun-prefer-top-level nil
  "When non-nil, Emacs prefers top-level defun.

In some languages, a defun could be nested in another one.
Normally Emacs stops at the first defun it encounters.  If this
variable's value is t, Emacs tries to find the top-level defun,
and ignores nested ones.

This variable can also be a list of cons cells of the
form (FROM . TO), where FROM and TO are tree-sitter node type
regexps.  When Emacs finds a defun node whose type matches any of
the FROM regexps in the list, it then tries to find a
higher-level node matching the corresponding TO regexp.")

(defun treesit--defun-maybe-top-level (node)
  "Maybe return the top-level equivalent of NODE.
For the detailed semantic see `treesit-defun-prefer-top-level'."
  (pcase treesit-defun-prefer-top-level
    ('nil node)
    ('t (or (treesit-node-top-level
             node treesit-defun-type-regexp)
            node))
    ((pred consp)
     (cl-loop
      for con in treesit-defun-prefer-top-level
      for from = (car con)
      for to = (cdr con)
      if (string-match-p from (treesit-node-type node))
      return (or (treesit-node-top-level node to)
                 node)
      finally return node))))

(defun treesit-beginning-of-defun (&optional arg)
  "Tree-sitter `beginning-of-defun' function.
ARG is the same as in `beginning-of-defun'."
  (let ((arg (or arg 1))
        (node (treesit-node-at (point))))
    (if (> arg 0)
        ;; Go backward.
        (while (and (> arg 0)
                    (setq node (treesit-search-forward-goto
                                node treesit-defun-type-regexp t t)))
          (setq node (treesit--defun-maybe-top-level node))
          (setq arg (1- arg)))
      ;; Go forward.
      (while (and (< arg 0)
                  (setq node (treesit-search-forward-goto
                              node treesit-defun-type-regexp)))
        (setq node (treesit--defun-maybe-top-level node))
        (setq arg (1+ arg))))
    (when node
      (goto-char (treesit-node-start node))
      t)))

(defun treesit-end-of-defun ()
  "Tree-sitter `end-of-defun' function."
  ;; Why not simply get the largest node at point: when point is at
  ;; (point-min), that gives us the root node.
  (let* ((node (treesit-search-forward
                (treesit-node-at (point)) treesit-defun-type-regexp t t))
         (top (treesit--defun-maybe-top-level node)))
    ;; Technically `end-of-defun' should only call this function when
    ;; point is at the beginning of a defun, so TOP should always be
    ;; non-nil, but things happen, and we want to be safe, so check
    ;; for TOP anyway.
    (when top
      (goto-char (treesit-node-end top)))))

;;; Activating tree-sitter

(defun treesit-ready-p (language &optional quiet)
  "Check whether tree-sitter is ready to be used for MODE and LANGUAGE.

LANGUAGE is the language symbol to check for availability.
It can also be a list of language symbols.

If tree-sitter is not ready, emit a warning and return nil.  If
the user has chosen to activate tree-sitter for LANGUAGE and
tree-sitter is ready, return non-nil.  If QUIET is t, don't emit
a warning in either case; if quiet is `message', display a message
instead of emitting a warning."
  (let ((language-list (if (consp language)
                           language
                         (list language)))
        msg)
    ;; Check for each condition and set MSG.
    (catch 'term
      (when (not (treesit-available-p))
        (setq msg "tree-sitter library is not compiled with Emacs")
        (throw 'term nil))
      (when (> (position-bytes (max (point-min) (1- (point-max))))
               treesit-max-buffer-size)
        (setq msg "buffer larger than `treesit-max-buffer-size'")
        (throw 'term nil))
      (dolist (lang language-list)
        (pcase-let ((`(,available . ,err)
                     (treesit-language-available-p lang t)))
          (when (not available)
            (setq msg (format "language definition for %s is unavailable (%s): %s"
                              lang (nth 0 err)
                              (string-join
                               (mapcar (lambda (x) (format "%s" x))
                                       (cdr err))
                               " ")))
            (throw 'term nil)))))
    ;; Decide if all conditions met and whether emit a warning.
    (if (not msg)
        t
      (setq msg (concat "Cannot activate tree-sitter, because " msg))
      (pcase quiet
        ('nil (display-warning 'treesit msg))
        ('message (message "%s" msg)))
      nil)))

(defun treesit-major-mode-setup ()
  "Activate tree-sitter to power major-mode features.

If `treesit-font-lock-settings' is non-nil, setup fontification and
enable `font-lock-mode'.

If `treesit-simple-indent-rules' is non-nil, setup indentation.

If `treesit-defun-type-regexp' is non-nil, setup
`beginning/end-of-defun' functions.

Make sure necessary parsers are created for the current buffer
before calling this function."
  ;; Font-lock.
  (when treesit-font-lock-settings
    ;; `font-lock-mode' wouldn't setup properly if
    ;; `font-lock-defaults' is nil, see `font-lock-specified-p'.
    (setq-local font-lock-defaults
                '( nil nil nil nil
                   (font-lock-fontify-syntactically-function
                    . treesit-font-lock-fontify-region)))
    (font-lock-mode 1)
    (treesit-font-lock-recompute-features)
    (dolist (parser (treesit-parser-list))
      (treesit-parser-add-notifier
       parser #'treesit--font-lock-notifier)))
  ;; Indent.
  (when treesit-simple-indent-rules
    (setq-local treesit-simple-indent-rules
                (treesit--indent-rules-optimize
                 treesit-simple-indent-rules))
    (setq-local indent-line-function #'treesit-indent)
    (setq-local indent-region-function #'treesit-indent-region))
  ;; Navigation.
  (when treesit-defun-type-regexp
    (setq-local beginning-of-defun-function #'treesit-beginning-of-defun)
    (setq-local end-of-defun-function #'treesit-end-of-defun)))

;;; Debugging

(defvar-local treesit--inspect-name nil
  "Used by `treesit-inspect-mode' to show node name in mode-line.")

(defun treesit-inspect-node-at-point (&optional arg)
  "Show information of the node at point.
If called interactively, show in echo area, otherwise set
`treesit--inspect-name' (which will appear in the mode-line
if `treesit-inspect-mode' is enabled).  Uses the first parser
in `treesit-parser-list'."
  (interactive "p")
  ;; NODE-LIST contains all the node that starts at point.
  (let* ((node-list
          (cl-loop for node = (treesit-node-at (point))
                   then (treesit-node-parent node)
                   while node
                   if (eq (treesit-node-start node)
                          (point))
                   collect node))
         (largest-node (car (last node-list)))
         (parent (treesit-node-parent largest-node))
         ;; node-list-acending contains all the node bottom-up, then
         ;; the parent.
         (node-list-acending
          (if (null largest-node)
              ;; If there are no nodes that start at point, just show
              ;; the node at point and its parent.
              (list (treesit-node-at (point))
                    (treesit-node-parent
                     (treesit-node-at (point))))
            (append node-list (list parent))))
         (name ""))
    ;; We draw nodes like (parent field-name: (node)) recursively,
    ;; so it could be (node1 field-name: (node2 field-name: (node3))).
    (dolist (node node-list-acending)
      (setq
       name
       (concat
        (if (treesit-node-field-name node)
            (format " %s: " (treesit-node-field-name node))
          " ")
        (if (treesit-node-check node 'named) "(" "\"")
        (propertize (or (treesit-node-type node) "N/A")
                    'face
                    (if (treesit-node-eq node largest-node)
                        'bold nil))
        name
        (if (treesit-node-check node 'named) ")" "\""))))
    (setq treesit--inspect-name name)
    (force-mode-line-update)
    (when arg
      (if node-list
          (message "%s" treesit--inspect-name)
        (message "No node at point")))))

(define-minor-mode treesit-inspect-mode
  "Minor mode that displays in the mode-line the node which starts at point.

When this mode is enabled, the mode-line displays

    PARENT FIELD-NAME: (NODE FIELD-NAME: (CHILD (...)))

where NODE, CHILD, etc, are nodes which begin at point.  PARENT
is the parent of NODE.  NODE is displayed in bold typeface.
FIELD-NAMEs are field names of NODE and CHILD, etc (see Info
node `(elisp)Language Definitions', heading \"Field names\").

If no node starts at point, i.e., point is in the middle of a
node, then the mode line displays the earliest node that spans point,
and its immediate parent.

This minor mode doesn't create parsers on its own.  It uses the first
parser in `treesit-parser-list'."
  :lighter nil
  (if treesit-inspect-mode
      (progn
        (add-hook 'post-command-hook
                  #'treesit-inspect-node-at-point 0 t)
        (add-to-list 'mode-line-misc-info
                     '(:eval treesit--inspect-name)))
    (remove-hook 'post-command-hook
                 #'treesit-inspect-node-at-point t)
    (setq mode-line-misc-info
          (remove '(:eval treesit--inspect-name)
                  mode-line-misc-info))))

(defun treesit-query-validate (language query)
  "Check if QUERY is valid for LANGUAGE.
If QUERY is invalid, display the query in a popup buffer, jump
to the offending pattern and highlight the pattern."
  (cl-assert (or (consp query) (stringp query)))
  (let ((buf (get-buffer-create "*tree-sitter check query*")))
    (with-temp-buffer
      (treesit-parser-create language)
      (condition-case err
          (progn (treesit-query-capture language query)
                 (message "QUERY is valid"))
        (treesit-query-error
         (with-current-buffer buf
           (let* ((data (cdr err))
                  (message (nth 0 data))
                  (start (nth 1 data)))
             (erase-buffer)
             (insert (treesit-query-expand query))
             (goto-char start)
             (search-forward " " nil t)
             (put-text-property start (point) 'face 'error)
             (message "%s" (buffer-substring start (point)))
             (goto-char (point-min))
             (insert (format "%s: %d\n" message start))
             (forward-char start)))
         (pop-to-buffer buf))))))

;;; Explorer

(defvar-local treesit--explorer-buffer nil
  "Buffer used to display the syntax tree.")

(defvar-local treesit--explorer-source-buffer nil
  "Source buffer corresponding to the playground buffer.")

(defvar-local treesit--explorer-language nil
  "The language used in the playground.")

(defvar-local treesit--explorer-refresh-timer nil
  "Timer for refreshing the syntax tree buffer.")

(defvar-local treesit--explorer-highlight-overlay nil
  "Overlay used to highlight in syntax tree and source buffer.")

(defvar-local treesit--explorer-last-node nil
  "Last top-level node used to generate syntax tree.")

(defvar treesit-explore-mode)

(defun treesit--explorer--nodes-to-highlight (language)
  "Return nodes for LANGUAGE covered in region.
This function tries to return the largest node possible.  If the
region covers exactly one node, that node is returned (in a
list).  If the region covers more than one node, two nodes are
returned: the very first one in the region and the very last one
in the region."
  (let* ((beg (region-beginning))
         (end (region-end))
         (node (treesit-node-on beg end language))
         (node (or (treesit-parent-while
                    node
                    (lambda (n)
                      (<= beg (treesit-node-start n)
                          (treesit-node-end n) end)))
                   node)))
    ;; If NODE is completely contained in the region, return NODE,
    ;; otherwise return its children that are in the region.
    (if (<= beg (treesit-node-start node)
            (treesit-node-end node) end)
        (list node)
      (list (treesit-node-at beg)
            (treesit-search-forward
             (treesit-node-at end)
             (lambda (n)
               (<= (treesit-node-end n) end))
             t t)))))

(defun treesit--explorer-refresh ()
  "Update the syntax tree buffer."
  (when (and treesit-explore-mode
             (buffer-live-p treesit--explorer-buffer))
    (let* ((root (treesit-node-on
                  (window-start) (window-end) treesit--explorer-language))
           ;; Only highlight the current top-level construct.
           ;; Highlighting the whole buffer is slow and unnecessary.
           (top-level (treesit-node-first-child-for-pos
                       root (if (eolp)
                                (max (point-min) (1- (point)))
                              (point))
                       t))
           ;; Only highlight node when region is active, if we
           ;; highlight node at point the syntax tree is too jumpy.
           (nodes-hl
            (when (region-active-p)
              (treesit--explorer--nodes-to-highlight
               treesit--explorer-language)))
           ;; If we didn't edit the buffer nor change the top-level
           ;; node, don't redraw the whole syntax tree.
           (highlight-only (treesit-node-eq
                            top-level treesit--explorer-last-node))
           (source-buffer (current-buffer)))
      (setq-local treesit--explorer-last-node top-level)
      (with-current-buffer treesit--explorer-buffer
        (let ((inhibit-read-only t))
          (setq-local treesit--explorer-source-buffer source-buffer)
          ;; Redraw the syntax tree or just rehighlight the focused
          ;; node.
          (when (and top-level (not highlight-only))
            (erase-buffer)
            (treesit--explorer-draw-node top-level))
          (when-let ((pos (treesit--explorer-highlight-node nodes-hl))
                     (window (get-buffer-window
                              treesit--explorer-buffer)))
            (if highlight-only
                (goto-char pos)
              ;; If HIGHLIGHT-ONLY is nil, we erased the buffer and
              ;; re-inserted text, scroll down from the very top until
              ;; we can see the highlighted node.
              (goto-char (point-min))
              (while (and (null (pos-visible-in-window-p pos window))
                          (= (forward-line 4) 0))
                (set-window-start window (point))))
            (set-window-point window pos)))))))

(defun treesit--explorer-post-command (&rest _)
  "Post-command function that runs in the source buffer."
  (when treesit-explore-mode
    (when treesit--explorer-highlight-overlay
      (delete-overlay treesit--explorer-highlight-overlay))
    (when treesit--explorer-refresh-timer
      (cancel-timer treesit--explorer-refresh-timer))
    (setq-local treesit--explorer-refresh-timer
                (run-with-timer 0.1 nil #'treesit--explorer-refresh))))

(defun treesit--explorer-jump (button)
  "Mark the original text corresponding to BUTTON."
  (interactive)
  (when (and (derived-mode-p 'treesit--explorer-tree-mode)
             (buffer-live-p treesit--explorer-source-buffer))
    (with-current-buffer treesit--explorer-source-buffer
      (let ((start (button-get button 'node-start))
            (end (button-get button 'node-end)))
        (when treesit--explorer-highlight-overlay
          (delete-overlay treesit--explorer-highlight-overlay))
        (setq-local treesit--explorer-highlight-overlay
                    (make-overlay start end nil t nil))
        (overlay-put treesit--explorer-highlight-overlay
                     'face 'highlight)))))

(defun treesit--explorer-highlight-node (nodes)
  "Highlight nodes in NODES in the syntax tree buffer.
Return the start of the syntax tree text corresponding to NODE."
  (when treesit--explorer-highlight-overlay
    (delete-overlay treesit--explorer-highlight-overlay))
  (let ((start-node (car nodes))
        (end-node (car (last nodes)))
        start end)
    (when (and start-node end-node)
      (cl-loop for ov in (overlays-in (point-min) (point-max))
               while (or (null start) (null end))
               if (treesit-node-eq start-node
                                   (overlay-get ov 'treesit-node))
               do (setq start (overlay-start ov))
               if (treesit-node-eq end-node (overlay-get ov 'treesit-node))
               do (setq end (overlay-end ov)))
      (when (and start end)
        (setq-local treesit--explorer-highlight-overlay
                    (make-overlay start end))
        (overlay-put treesit--explorer-highlight-overlay
                     'face 'highlight)
        start))))

(defun treesit--explorer-draw-node (node)
  "Draw the syntax tree of NODE.

When this function is called, point should be at the position
where the node should start.  When this function returns, it
leaves point at the end of the last line of NODE."
  (let* ((type (treesit-node-type node))
         (field-name (treesit-node-field-name node))
         (children (treesit-node-children node))
         (named (treesit-node-check node 'named))
         ;; Column number of the start of the field-name, aka start of
         ;; the whole node.
         (before-field-column (current-column))
         ;; Column number after the field-name.
         after-field-column
         ;; Column number after the type.
         after-type-column
         ;; Are all children suitable for inline?
         (all-children-inline
          (eq 0 (apply #'+ (mapcar #'treesit-node-child-count children))))
         ;; If the child is the first child, we can inline, if the
         ;; previous child is suitable for inline, this child can
         ;; inline, if the previous child is not suitable for inline,
         ;; this child cannot inline.
         (can-inline t)
         ;; The beg and end of this node.
         beg end)
    (when treesit--explorer-highlight-overlay
      (delete-overlay treesit--explorer-highlight-overlay))

    (setq beg (point))
    ;; Draw field name.  If all children are suitable for inline, we
    ;; draw everything in one line, other wise draw field name and the
    ;; rest of the node in two lines.
    (when field-name
      (insert field-name ": ")
      (when (and children (not all-children-inline))
        (insert "\n")
        (indent-to-column (1+ before-field-column))))
    (setq after-field-column (current-column))

    ;; Draw type.
    (if named
        (progn
          (insert "(")
          (insert-text-button
           type 'action #'treesit--explorer-jump
           'follow-link t
           'node-start (treesit-node-start node)
           'node-end (treesit-node-end node)))
      (pcase type
        ("\n" (insert "\\n"))
        ("\t" (insert "\\t"))
        (" " (insert "SPC"))
        (_ (insert type))))
    (setq after-type-column (current-column))

    ;; Draw children.
    (dolist (child children)
      ;; If a child doesn't have children, it is suitable for inline.
      (let ((draw-inline (eq 0 (treesit-node-child-count child)))
            (children-indent (1+ after-field-column)))
        (while
            ;; This form returns t if it wants to run another
            ;; iteration, returns nil if it wants to stop.
            (if (and draw-inline can-inline)
                ;; Draw children on the same line.
                (let ((inline-beg (point)))
                  (insert " ")
                  (treesit--explorer-draw-node child)
                  ;; If we exceeds window width, draw on the next line.
                  (if (< (current-column) (window-width))
                      nil
                    (delete-region inline-beg (point))
                    (setq draw-inline nil
                          children-indent (1+ after-type-column))
                    t))
              ;; Draw children on the new line.
              (insert "\n")
              (indent-to-column children-indent)
              (treesit--explorer-draw-node child)
              nil))
        (setq can-inline draw-inline)))

    ;; Done drawing children, draw the ending paren.
    (when named (insert ")"))
    (setq end (point))

    ;; Associate the text with NODE, so we can later find a piece of
    ;; text by a node.
    (let ((ov (make-overlay beg end)))
      (overlay-put ov 'treesit-node node)
      (overlay-put ov 'evaporate t)
      (when (not named)
        (overlay-put ov 'face 'shadow)))))

(define-derived-mode treesit--explorer-tree-mode special-mode
  "TS Explorer"
  "Mode for displaying syntax trees for `treesit-explore-mode'."
  nil)

(define-minor-mode treesit-explore-mode
  "Enable exploring the current buffer's syntax tree.
Pops up a window showing the syntax tree of the source in the
current buffer in real time.  The corresponding node enclosing
the text in the active region is highlighted in the explorer
window."
  :lighter " TSplay"
  (if treesit-explore-mode
      (progn
        (unless (buffer-live-p treesit--explorer-buffer)
          (setq-local treesit--explorer-buffer
                      (get-buffer-create
                       (format "*tree-sitter playground for %s*"
                               (buffer-name))))
          (setq-local treesit--explorer-language
                      (intern (completing-read
                               "Language: "
                               (mapcar #'treesit-parser-language
                                       (treesit-parser-list)))))
          (with-current-buffer treesit--explorer-buffer
            (treesit--explorer-tree-mode)))
        (display-buffer treesit--explorer-buffer
                        (cons nil '((inhibit-same-window . t))))
        (treesit--explorer-refresh)
        (add-hook 'post-command-hook
                  #'treesit--explorer-post-command 0 t)
        (setq-local treesit--explorer-last-node nil))
    (remove-hook 'post-command-hook
                 #'treesit--explorer-post-command t)
    (kill-buffer treesit--explorer-buffer)))

;;; Etc

(declare-function find-library-name "find-func.el")
(defun treesit--check-manual-coverage ()
  "Print tree-sitter functions missing from the manual in message buffer."
  (interactive)
  (require 'find-func)
  (let ((functions-in-source
         (with-temp-buffer
           (insert-file-contents (find-library-name "treesit"))
           (cl-remove-if
            (lambda (name) (string-match "treesit--" name))
            (cl-sort
             (save-excursion
               (goto-char (point-min))
               (cl-loop while (re-search-forward
                               "^(defun \\([^ ]+\\)" nil t)
                        collect (match-string-no-properties 1)))
             #'string<))))
        (functions-in-manual
         (with-temp-buffer
           (insert-file-contents (expand-file-name
                                  "doc/lispref/parsing.texi"
                                  source-directory))
           (insert-file-contents (expand-file-name
                                  "doc/lispref/modes.texi"
                                  source-directory))
           (cl-sort
            (save-excursion
              (goto-char (point-min))
              (cl-loop while (re-search-forward
                              "^@defun \\([^ ]+\\)" nil t)
                       collect (match-string-no-properties 1)))
            #'string<))))
    (message "Missing: %s"
             (string-join
              (cl-remove-if
               (lambda (name) (member name functions-in-manual))
               functions-in-source)
              "\n"))))

;;; Shortdocs

(defun treesit--generate-shortdoc-examples ()
  "Generate examples for shortdoc."
  (with-temp-buffer
    (let (node parent)
      (insert "int c = 0;")
      (print (treesit-parser-create 'c))
      (print (treesit-parser-list))
      (goto-char (point-min))
      (print (setq node (treesit-node-at (point))))
      (print (setq parent (treesit-node-parent node)))
      (print (treesit-node-children parent))
      (print (treesit-node-next-sibling node))
      (print (treesit-node-child-by-field-name parent "declarator"))
      nil)))

(define-short-documentation-group treesit


  "Parsers"
  (treesit-parser-create
   :no-eval (treesit-parser-create)
   :eg-result-string "#<treesit-parser for c>")
  (treesit-parser-delete
   :no-value (treesit-parser-delete parser))
  (treesit-parser-list
   :no-eval (treesit-parser-list)
   :eg-result-string "(#<treesit-parser for c>)")
  (treesit-parser-buffer
   :no-eval (treesit-parser-buffer parser)
   :eg-result-string "#<buffer xdisp.c>")
  (treesit-parser-language
   :no-eval (treesit-parser-language parser)
   :eg-result c)
  (treesit-parser-add-notifier)
  (treesit-parser-remove-notifier)
  (treesit-parser-notifiers
   :no-eval (treesit-parser-notifiers parser)
   :eg-result (function1 function2 function3))


  "Parser ranges"
  (treesit-parser-set-included-ranges
   :no-value (treesit-parser-set-included-ranges parser '((1 . 4) (5 . 8))))
  (treesit-parser-included-ranges
   :no-eval (treesit-parser-included-ranges parser)
   :eg-result '((1 . 4) (5 . 8)))
  (treesit-query-range
   :no-eval (treesit-query-range node '((script_element) @cap))
   :eg-result-string '((1 . 4) (5 . 8)))


  "Retrieving a node"
  (treesit-node-at
   :no-eval (treesit-node-at (point))
   :eg-result-string "#<treesit-node (identifier) in 179-180>")
  (treesit-node-on
   :no-eval (treesit-node-on 18 28)
   :eg-result-string "#<treesit-node (compound_statement) in 143-290>")
  (treesit-buffer-root-node
   :no-eval (treesit-buffer-root-node)
   :eg-result-string "#<treesit-node (translation_unit) in 1-4830>")
  (treesit-parser-root-node
   :no-eval (treesit-parser-root-node parser)
   :eg-result-string "#<treesit-node (translation_unit) in 1-4830>")


  "Retrieving a node from another node"
  (treesit-node-parent
   :no-eval (treesit-node-parent node)
   :eg-result-string "#<treesit-node (declaration) in 1-11>")
  (treesit-node-child
   :no-eval (treesit-node-child node 0)
   :eg-result-string "#<treesit-node (primitive_type) in 1-4>")
  (treesit-node-children
   :no-eval (treesit-node-children node)
   :eg-result-string "(#<treesit-node (primitive_type) in 1-4> #<treesit-node (init_declarator) in 5-10> #<treesit-node \";\" in 10-11>)")
  (treesit-node-next-sibling
   :no-eval (treesit-node-next-sibling node)
   :eg-result-string "#<treesit-node (init_declarator) in 5-10>")
  (treesit-node-prev-sibling
   :no-eval (treesit-node-prev-sibling node)
   :eg-result-string "#<treesit-node (primitive_type) in 1-4>")
  (treesit-node-child-by-field-name
   :no-eval (treesit-node-child-by-field-name node "declarator")
   :eg-result-string "#<treesit-node (init_declarator) in 5-10>")


  (treesit-first-child-for-pos
   :no-eval (treesit-first-child-for-pos node 1)
   :eg-result-string "#<treesit-node (primitive_type) in 1-4>")
  (treesit-node-descendant-for-range
   :no-eval (treesit-node-descendant-for-range node 2 3)
   :eg-result-string "#<treesit-node (primitive_type) in 1-4>")


  "Searching for node"
  (treesit-search-subtree
   :no-eval (treesit-search-subtree node "function_definition")
   :eg-result-string "#<treesit-node (function_definition) in 57-146>")
  (treesit-search-forward
   :no-eval (treesit-search-forward node "function_definition")
   :eg-result-string "#<treesit-node (function_definition) in 57-146>")
  (treesit-search-forward-goto
   :no-eval (treesit-search-forward-goto node "function_definition")
   :eg-result-string "#<treesit-node (function_definition) in 57-146>")
  (treesit-induce-sparse-tree
   :no-eval (treesit-induce-sparse-tree node "function_definition")
   :eg-result-string "(nil (#<treesit-node (function_definition) in 57-146>) (#<treesit-node (function_definition) in 259-296>) (#<treesit-node (function_definition) in 303-659>))")
  (treesit-filter-child
   :no-eval (treesit-filter-child node (lambda (n) (equal (treesit-node-type) "identifier")))
   :eg-result-string "(#<treesit-node (identifier) in 195-196>)")
  (treesit-parent-until
   :no-eval (treesit-parent-until node (lambda (p) (eq (treesit-node-start p) (point))))
   :eg-result-string "#<treesit-node (declaration) in 1-11>")
  (treesit-parent-while
   :no-eval (treesit-parent-while node (lambda (p) (eq (treesit-node-start p) (point))))
   :eg-result-string "#<treesit-node (declaration) in 1-11>")
  (treesit-node-top-level
   :no-eval (treesit-node-top-level node)
   :eg-result-string "#<treesit-node (declaration) in 1-11>")


  "Retrieving node information"
  (treesit-node-text
   :no-eval (treesit-node-text node)
   :eg-result "int")
  (treesit-node-start
   :no-eval (treesit-node-start node)
   :eg-result 1)
  (treesit-node-end
   :no-eval (treesit-node-end node)
   :eg-result 10)
  (treesit-node-type
   :no-eval (treesit-node-type node)
   :eg-result "function_definition")
  (treesit-node-field-name
   :no-eval (treesit-node-field-name node)
   :eg-result "body")


  (treesit-node-parser
   :no-eval (treesit-node-parser node)
   :eg-result-string "#<treesit-parser for c>")
  (treesit-node-language
   :no-eval (treesit-node-language node)
   :eg-result c)
  (treesit-node-buffer
   :no-eval (treesit-node-buffer node)
   :eg-result-string "#<buffer xdisp.c>")


  (treesit-node-index
   :no-eval (treesit-node-index node)
   :eg-result 0)
  (treesit-node-string
   :no-eval (treesit-node-string node)
   :eg-result-string "(init_declarator declarator: (identifier) value: (number_literal))")
  (treesit-node-check
   :no-eval (treesit-node-check node 'named)
   :eg-result t)


  (treesit-field-name-for-child
   :no-eval (treesit-field-name-for-child node)
   :eg-result "body")
  (treesit-child-count
   :no-eval (treesit-child-count node)
   :eg-result 3)


  "Pattern matching"
  (treesit-query-capture
   :no-eval (treesit-query-capture node '((identifier) @id "return" @ret))
   :eg-result-string "((id . #<treesit-node (identifier) in 195-196>) (ret . #<treesit-node "return" in 338-344>))")
  (treesit-query-compile
   :no-eval (treesit-query-compile 'c '((identifier) @id "return" @ret))
   :eg-result-string "#<treesit-compiled-query>")
  (treesit-query-language
   :no-eval (treesit-query-language compiled-query)
   :eg-result c)
  (treesit-query-expand
   :eval (treesit-query-expand '((identifier) @id "return" @ret)))
  (treesit-pattern-expand
   :eval (treesit-pattern-expand :anchor)
   :eval (treesit-pattern-expand '(identifier))
   :eval (treesit-pattern-expand :equal))


  "Parsing a string"
  (treesit-parse-string
   :no-eval (treesit-parse-string "int c = 0;" 'c)
   :eg-result-string "#<treesit-node (translation_unit) in 1-11>")
  (treesit-query-string
   :no-eval (treesit-query-string "int c = 0;" '((identifier) @id) 'c)
   :eg-result-string "((id . #<treesit-node (identifier) in 5-6>))"))

(provide 'treesit)

;;; treesit.el ends here

debug log:

solving de18796628 ...
found de18796628 in https://yhetil.org/emacs-bugs/m1wn6wj3lf.fsf@yahoo.es/
found 85154d0d1c in https://git.savannah.gnu.org/cgit/emacs.git
preparing index
index prepared:
100644 85154d0d1c7ece254cfb2912c29a8e1599118ace	lisp/treesit.el

applying [1/1] https://yhetil.org/emacs-bugs/m1wn6wj3lf.fsf@yahoo.es/
diff --git a/lisp/treesit.el b/lisp/treesit.el
index 85154d0d1c..de18796628 100644

Checking patch lisp/treesit.el...
Applied patch lisp/treesit.el cleanly.

index at:
100644 de18796628944551bc5790f0c8a2678dcbe7cb06	lisp/treesit.el

(*) 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 public inbox

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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).