unofficial mirror of emacs-devel@gnu.org 
 help / color / mirror / code / Atom feed
blob fdd24317c6ad870abe8ccfb9f2f01dd7e307ecd6 42182 bytes (raw)
name: lisp/emacs-lisp/rx.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
 
;;; rx.el --- sexp notation for regular expressions  -*- lexical-binding: t -*-

;; Copyright (C) 2001-2019 Free Software Foundation, Inc.

;; Author: Gerd Moellmann <gerd@gnu.org>
;; Maintainer: emacs-devel@gnu.org
;; Keywords: strings, regexps, extensions

;; 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 is another implementation of sexp-form regular expressions.
;; It was unfortunately written without being aware of the Sregex
;; package coming with Emacs, but as things stand, Rx completely
;; covers all regexp features, which Sregex doesn't, doesn't suffer
;; from the bugs mentioned in the commentary section of Sregex, and
;; uses a nicer syntax (IMHO, of course :-).

;; This significantly extended version of the original, is almost
;; compatible with Sregex.  The only incompatibility I (fx) know of is
;; that the `repeat' form can't have multiple regexp args.

;; Now alternative forms are provided for a degree of compatibility
;; with Olin Shivers' attempted definitive SRE notation.  SRE forms
;; not catered for include: dsm, uncase, w/case, w/nocase, ,@<exp>,
;; ,<exp>, (word ...), word+, posix-string, and character class forms.
;; Some forms are inconsistent with SRE, either for historical reasons
;; or because of the implementation -- simple translation into Emacs
;; regexp strings.  These include: any, word.  Also, case-sensitivity
;; and greediness are controlled by variables external to the regexp,
;; and you need to feed the forms to the `posix-' functions to get
;; SRE's POSIX semantics.  There are probably more difficulties.

;; Rx translates a sexp notation for regular expressions into the
;; usual string notation.  The translation can be done at compile-time
;; by using the `rx' macro.  It can be done at run-time by calling
;; function `rx-to-string'.  See the documentation of `rx' for a
;; complete description of the sexp notation.
;;
;; Some examples of string regexps and their sexp counterparts:
;;
;; "^[a-z]*"
;; (rx (and line-start (0+ (in "a-z"))))
;;
;; "\n[^ \t]"
;; (rx (and "\n" (not (any " \t"))))
;;
;; "\\*\\*\\* EOOH \\*\\*\\*\n"
;; (rx "*** EOOH ***\n")
;;
;; "\\<\\(catch\\|finally\\)\\>[^_]"
;; (rx (and word-start (submatch (or "catch" "finally")) word-end
;;          (not (any ?_))))
;;
;; "[ \t\n]*:\\([^:]+\\|$\\)"
;; (rx (and (zero-or-more (in " \t\n")) ":"
;;          (submatch (or line-end (one-or-more (not (any ?:)))))))
;;
;; "^content-transfer-encoding:\\(\n?[\t ]\\)*quoted-printable\\(\n?[\t ]\\)*"
;; (rx (and line-start
;;          "content-transfer-encoding:"
;;          (+ (? ?\n)) (any " \t")
;;	    "quoted-printable"
;;	    (+ (? ?\n)) (any " \t"))
;;
;; (concat "^\\(?:" something-else "\\)")
;; (rx (and line-start (eval something-else))), statically or
;; (rx-to-string '(and line-start ,something-else)), dynamically.
;;
;; (regexp-opt '(STRING1 STRING2 ...))
;; (rx (or STRING1 STRING2 ...)), or in other words, `or' automatically
;; calls `regexp-opt' as needed.
;;
;; "^;;\\s-*\n\\|^\n"
;; (rx (or (and line-start ";;" (0+ space) ?\n)
;;         (and line-start ?\n)))
;;
;; "\\$[I]d: [^ ]+ \\([^ ]+\\) "
;; (rx (and "$Id: "
;;          (1+ (not (in " ")))
;;          " "
;;          (submatch (1+ (not (in " "))))
;;          " "))
;;
;; "\\\\\\\\\\[\\w+"
;; (rx (and ?\\ ?\\ ?\[ (1+ word)))
;;
;; etc.

;;; History:
;;

;;; Code:

(require 'cl-lib)

;; FIXME: support macros.

(defvar rx-constituents              ;Not `const' because some modes extend it.
  '((and		. (rx-and 1 nil))
    (seq		. and)		; SRE
    (:			. and)		; SRE
    (sequence		. and)		; sregex
    (or			. (rx-or 1 nil))
    (|			. or)		; SRE
    (not-newline	. ".")
    (nonl		. not-newline)	; SRE
    (anything		. (rx-anything 0 nil))
    (any		. (rx-any 1 nil rx-check-any)) ; inconsistent with SRE
    (any		. ".")          ; sregex
    (in			. any)
    (char		. any)		; sregex
    (not-char		. (rx-not-char 1 nil rx-check-any)) ; sregex
    (not		. (rx-not 1 1 rx-check-not))
    (repeat		. (rx-repeat 2 nil))
    (=			. (rx-= 2 nil))	   ; SRE
    (>=			. (rx->= 2 nil))   ; SRE
    (**			. (rx-** 2 nil))   ; SRE
    (submatch		. (rx-submatch 1 nil)) ; SRE
    (group		. submatch)     ; sregex
    (submatch-n		. (rx-submatch-n 2 nil))
    (group-n		. submatch-n)
    (zero-or-more	. (rx-kleene 1 nil))
    (one-or-more	. (rx-kleene 1 nil))
    (zero-or-one	. (rx-kleene 1 nil))
    (\?			. zero-or-one)	; SRE
    (\??		. zero-or-one)
    (*			. zero-or-more)	; SRE
    (*?			. zero-or-more)
    (0+			. zero-or-more)
    (+			. one-or-more)	; SRE
    (+?			. one-or-more)
    (1+			. one-or-more)
    (optional		. zero-or-one)
    (opt		. zero-or-one)	; sregex
    (minimal-match	. (rx-greedy 1 1))
    (maximal-match	. (rx-greedy 1 1))
    (backref		. (rx-backref 1 1 rx-check-backref))
    (line-start		. "^")
    (bol		. line-start)	; SRE
    (line-end		. "$")
    (eol		. line-end)	; SRE
    (string-start	. "\\`")
    (bos		. string-start)	; SRE
    (bot		. string-start)	; sregex
    (string-end		. "\\'")
    (eos		. string-end)	; SRE
    (eot		. string-end)	; sregex
    (buffer-start	. "\\`")
    (buffer-end		. "\\'")
    (point		. "\\=")
    (word-start		. "\\<")
    (bow		. word-start)	; SRE
    (word-end		. "\\>")
    (eow		. word-end)	; SRE
    (word-boundary	. "\\b")
    (not-word-boundary	. "\\B")	; sregex
    (symbol-start       . "\\_<")
    (symbol-end         . "\\_>")
    (syntax		. (rx-syntax 1 1))
    (not-syntax		. (rx-not-syntax 1 1)) ; sregex
    (category		. (rx-category 1 1 rx-check-category))
    (eval		. (rx-eval 1 1))
    (regexp		. (rx-regexp 1 1 stringp))
    (regex		. regexp)       ; sregex
    (digit		. "[[:digit:]]")
    (numeric		. digit)	; SRE
    (num		. digit)	; SRE
    (control		. "[[:cntrl:]]") ; SRE
    (cntrl		. control)	 ; SRE
    (hex-digit		. "[[:xdigit:]]") ; SRE
    (hex		. hex-digit)	  ; SRE
    (xdigit		. hex-digit)	  ; SRE
    (blank		. "[[:blank:]]")  ; SRE
    (graphic		. "[[:graph:]]")  ; SRE
    (graph		. graphic)	  ; SRE
    (printing		. "[[:print:]]")  ; SRE
    (print		. printing)	  ; SRE
    (alphanumeric	. "[[:alnum:]]")  ; SRE
    (alnum		. alphanumeric)	  ; SRE
    (letter		. "[[:alpha:]]")
    (alphabetic		. letter)	; SRE
    (alpha		. letter)	; SRE
    (ascii		. "[[:ascii:]]") ; SRE
    (nonascii		. "[[:nonascii:]]")
    (lower		. "[[:lower:]]") ; SRE
    (lower-case		. lower)	 ; SRE
    (punctuation	. "[[:punct:]]") ; SRE
    (punct		. punctuation)	 ; SRE
    (space		. "[[:space:]]") ; SRE
    (whitespace		. space)	 ; SRE
    (white		. space)	 ; SRE
    (upper		. "[[:upper:]]") ; SRE
    (upper-case		. upper)	 ; SRE
    (word		. "[[:word:]]")	 ; inconsistent with SRE
    (wordchar		. word)		 ; sregex
    (not-wordchar	. "\\W"))
  "Alist of sexp form regexp constituents.
Each element of the alist has the form (SYMBOL . DEFN).
SYMBOL is a valid constituent of sexp regular expressions.
If DEFN is a string, SYMBOL is translated into DEFN.
If DEFN is a symbol, use the definition of DEFN, recursively.
Otherwise, DEFN must be a list (FUNCTION MIN-ARGS MAX-ARGS PREDICATE).
FUNCTION is used to produce code for SYMBOL.  MIN-ARGS and MAX-ARGS
are the minimum and maximum number of arguments the function-form
sexp constituent SYMBOL may have in sexp regular expressions.
MAX-ARGS nil means no limit.  PREDICATE, if specified, means that
all arguments must satisfy PREDICATE.")


(defconst rx-syntax
  '((whitespace		. ?-)
    (punctuation	. ?.)
    (word		. ?w)
    (symbol		. ?_)
    (open-parenthesis	. ?\()
    (close-parenthesis	. ?\))
    (expression-prefix	. ?\')
    (string-quote	. ?\")
    (paired-delimiter	. ?$)
    (escape		. ?\\)
    (character-quote	. ?/)
    (comment-start	. ?<)
    (comment-end	. ?>)
    (string-delimiter	. ?|)
    (comment-delimiter	. ?!))
  "Alist mapping Rx syntax symbols to syntax characters.
Each entry has the form (SYMBOL . CHAR), where SYMBOL is a valid
symbol in `(syntax SYMBOL)', and CHAR is the syntax character
corresponding to SYMBOL, as it would be used with \\s or \\S in
regular expressions.")


(defconst rx-categories
  '((space-for-indent           . ?\s)
    (base                       . ?.)
    (consonant			. ?0)
    (base-vowel			. ?1)
    (upper-diacritical-mark	. ?2)
    (lower-diacritical-mark	. ?3)
    (tone-mark			. ?4)
    (symbol			. ?5)
    (digit			. ?6)
    (vowel-modifying-diacritical-mark . ?7)
    (vowel-sign			. ?8)
    (semivowel-lower		. ?9)
    (not-at-end-of-line		. ?<)
    (not-at-beginning-of-line	. ?>)
    (alpha-numeric-two-byte	. ?A)
    (chinese-two-byte		. ?C)
    (chinse-two-byte		. ?C) ;; A typo in Emacs 21.1-24.3.
    (greek-two-byte		. ?G)
    (japanese-hiragana-two-byte . ?H)
    (indian-two-byte		. ?I)
    (japanese-katakana-two-byte . ?K)
    (strong-left-to-right       . ?L)
    (korean-hangul-two-byte	. ?N)
    (strong-right-to-left       . ?R)
    (cyrillic-two-byte		. ?Y)
    (combining-diacritic	. ?^)
    (ascii			. ?a)
    (arabic			. ?b)
    (chinese			. ?c)
    (ethiopic			. ?e)
    (greek			. ?g)
    (korean			. ?h)
    (indian			. ?i)
    (japanese			. ?j)
    (japanese-katakana		. ?k)
    (latin			. ?l)
    (lao			. ?o)
    (tibetan			. ?q)
    (japanese-roman		. ?r)
    (thai			. ?t)
    (vietnamese			. ?v)
    (hebrew			. ?w)
    (cyrillic			. ?y)
    (can-break			. ?|))
  "Alist mapping symbols to category characters.
Each entry has the form (SYMBOL . CHAR), where SYMBOL is a valid
symbol in `(category SYMBOL)', and CHAR is the category character
corresponding to SYMBOL, as it would be used with `\\c' or `\\C' in
regular expression strings.")


(defvar rx-greedy-flag t
  "Non-nil means produce greedy regular expressions for `zero-or-one',
`zero-or-more', and `one-or-more'.  Dynamically bound.")


(defun rx-info (op head)
  "Return parsing/code generation info for OP.
If OP is the space character ASCII 32, return info for the symbol `?'.
If OP is the character `?', return info for the symbol `??'.
See also `rx-constituents'.
If HEAD is non-nil, then OP is the head of a sexp, otherwise it's
a standalone symbol."
  (cond ((eq op ? ) (setq op '\?))
	((eq op ??) (setq op '\??)))
  (let (old-op)
    (while (and (not (null op)) (symbolp op))
      (setq old-op op)
      (setq op (cdr (assq op rx-constituents)))
      (when (if head (stringp op) (consp op))
        ;; We found something but of the wrong kind.  Let's look for an
        ;; alternate definition for the other case.
        (let ((new-op
               (cdr (assq old-op (cdr (memq (assq old-op rx-constituents)
                                            rx-constituents))))))
          (if (and new-op (not (if head (stringp new-op) (consp new-op))))
              (setq op new-op))))))
  op)


(defun rx-check (form)
  "Check FORM according to its car's parsing info."
  (unless (listp form)
    (error "rx `%s' needs argument(s)" form))
  (let* ((rx (rx-info (car form) 'head))
	 (nargs (1- (length form)))
	 (min-args (nth 1 rx))
	 (max-args (nth 2 rx))
	 (type-pred (nth 3 rx)))
    (when (and (not (null min-args))
	       (< nargs min-args))
      (error "rx form `%s' requires at least %d args"
	     (car form) min-args))
    (when (and (not (null max-args))
	       (> nargs max-args))
      (error "rx form `%s' accepts at most %d args"
	     (car form) max-args))
    (when (not (null type-pred))
      (dolist (sub-form (cdr form))
	(unless (funcall type-pred sub-form)
	  (error "rx form `%s' requires args satisfying `%s'"
		 (car form) type-pred))))))


(defun rx-group-if (regexp group)
  "Put shy groups around REGEXP if seemingly necessary when GROUP
is non-nil."
  (cond
   ;; for some repetition
   ((eq group '*) (if (rx-atomic-p regexp) (setq group nil)))
   ;; for concatenation
   ((eq group ':)
    (if (rx-atomic-p
	 (if (string-match
	      "\\(?:[?*+]\\??\\|\\\\{[0-9]*,?[0-9]*\\\\}\\)\\'" regexp)
	     (substring regexp 0 (match-beginning 0))
	   regexp))
	(setq group nil)))
   ;; for OR
   ((eq group '|) (setq group nil))
   ;; do anyway
   ((eq group t))
   ((rx-atomic-p regexp t) (setq group nil)))
  (if group
      (concat "\\(?:" regexp "\\)")
    regexp))


(defvar rx-parent)
;; dynamically bound in some functions.


(defun rx-and (form)
  "Parse and produce code from FORM.
FORM is of the form `(and FORM1 ...)'."
  (rx-check form)
  (rx-group-if
   (mapconcat (lambda (x) (rx-form x ':)) (cdr form) nil)
   (and (memq rx-parent '(* t)) rx-parent)))


(defun rx-or (form)
  "Parse and produce code from FORM, which is `(or FORM1 ...)'."
  (rx-check form)
  (rx-group-if
   (if (memq nil (mapcar 'stringp (cdr form)))
       (mapconcat (lambda (x) (rx-form x '|)) (cdr form) "\\|")
     (regexp-opt (cdr form) nil t))
   (and (memq rx-parent '(: * t)) rx-parent)))


(defun rx-anything (form)
  "Match any character."
  (if (consp form)
      (error "rx `anything' syntax error: %s" form))
  (rx-or (list 'or 'not-newline ?\n)))


(defun rx-any-delete-from-range (char ranges)
  "Delete by side effect character CHAR from RANGES.
Only both edges of each range is checked."
  (let (m)
    (cond
     ((memq char ranges) (setq ranges (delq char ranges)))
     ((setq m (assq char ranges))
      (if (eq (1+ char) (cdr m))
	  (setcar (memq m ranges) (1+ char))
	(setcar m (1+ char))))
     ((setq m (rassq char ranges))
      (if (eq (1- char) (car m))
	  (setcar (memq m ranges) (1- char))
	(setcdr m (1- char)))))
    ranges))


(defun rx-any-condense-range (args)
  "Condense by side effect ARGS as range for Rx `any'."
  (let (str
	l)
    ;; set STR list of all strings
    ;; set L list of all ranges
    (mapc (lambda (e) (cond ((stringp e) (push e str))
			    ((numberp e) (push (cons e e) l))
                            ;; Ranges between ASCII and raw bytes are split,
                            ;; to prevent accidental inclusion of Unicode
                            ;; characters later on.
                            ((and (<= (car e) #x7f)
                                  (>= (cdr e) #x3fff80))
                             (push (cons (car e) #x7f) l)
                             (push (cons #x3fff80 (cdr e)) l))
			    (t (push e l))))
	  args)
    ;; condense overlapped ranges in L
    (let ((tail (setq l (sort l #'car-less-than-car)))
	  d)
      (while (setq d (cdr tail))
	(if (>= (cdar tail) (1- (caar d)))
	    (progn
	      (setcdr (car tail) (max (cdar tail) (cdar d)))
	      (setcdr tail (cdr d)))
	  (setq tail d))))
    ;; Separate small ranges to single number, and delete dups.
    (nconc
     (apply #'nconc
	    (mapcar (lambda (e)
		      (cond
		       ((= (car e) (cdr e)) (list (car e)))
		       ((= (1+ (car e)) (cdr e)) (list (car e) (cdr e)))
		       ((list e))))
		    l))
     (delete-dups str))))


(defun rx-check-any-string (str)
  "Turn the `any' argument string STR into a list of characters.
The original order is not preserved.  Ranges, \"A-Z\", become pairs, (?A . ?Z)."
  (let ((decode-char
         ;; Make sure raw bytes are decoded as such, to avoid confusion with
         ;; U+0080..U+00FF.
         (if (multibyte-string-p str)
             #'identity
           (lambda (c) (if (<= #x80 c #xff)
                           (+ c #x3fff00)
                         c))))
        (len (length str))
        (i 0)
        (ret nil))
    (if (= 0 len)
        (error "String arg for Rx `any' must not be empty"))
    (while (< i len)
      (cond ((and (< i (- len 2))
                  (= (aref str (+ i 1)) ?-))
             ;; Range.
             (let ((start (funcall decode-char (aref str i)))
                   (end   (funcall decode-char (aref str (+ i 2)))))
               (cond ((< start end) (push (cons start end) ret))
                     ((= start end) (push start ret))
                     (t
                      (error "Rx character range `%c-%c' is reversed"
                             start end)))
               (setq i (+ i 3))))
            (t
             ;; Single character.
             (push (funcall decode-char (aref str i)) ret)
             (setq i (+ i 1)))))
    ret))


(defun rx-check-any (arg)
   "Check arg ARG for Rx `any'."
   (cond
    ((integerp arg) (list arg))
    ((symbolp arg)
     (let ((translation (condition-case nil
			    (rx-form arg)
			  (error nil))))
       (if (or (null translation)
	       (null (string-match "\\`\\[\\[:[-a-z]+:\\]\\]\\'" translation)))
	   (error "Invalid char class `%s' in Rx `any'" arg))
       (list (substring translation 1 -1)))) ; strip outer brackets
    ((and (characterp (car-safe arg)) (characterp (cdr-safe arg)))
     (unless (<= (car arg) (cdr arg))
       (error "Rx character range `%c-%c' is reversed"
              (car arg) (cdr arg)))
     (list arg))
    ((stringp arg) (rx-check-any-string arg))
    ((error
      "rx `any' requires string, character, char pair or char class args"))))


(defun rx-any (form)
  "Parse and produce code from FORM, which is `(any ARG ...)'.
ARG is optional."
  (rx-check form)
  (let* ((args (rx-any-condense-range
		(apply
		 #'nconc
		 (mapcar #'rx-check-any (cdr form)))))
	 m
	 s)
    (cond
     ;; single close bracket
     ;;	 => "[]...-]" or "[]...--.]"
     ((memq ?\] args)
      ;; set ] at the beginning
      (setq args (cons ?\] (delq ?\] args)))
      ;; set - at the end
      (if (or (memq ?- args) (assq ?- args))
	  (setq args (nconc (rx-any-delete-from-range ?- args)
			    (list ?-)))))
     ;; close bracket starts a range
     ;;  => "[]-....-]" or "[]-.--....]"
     ((setq m (assq ?\] args))
      ;; bring it to the beginning
      (setq args (cons m (delq m args)))
      (cond ((memq ?- args)
	     ;; to the end
	     (setq args (nconc (delq ?- args) (list ?-))))
	    ((setq m (assq ?- args))
	     ;; next to the bracket's range, make the second range
	     (setcdr args (cons m (delq m (cdr args)))))))
     ;; bracket in the end range
     ;;	 => "[]...-]"
     ((setq m (rassq ?\] args))
      ;; set ] at the beginning
      (setq args (cons ?\] (rx-any-delete-from-range ?\] args)))
      ;; set - at the end
      (if (or (memq ?- args) (assq ?- args))
	  (setq args (nconc (rx-any-delete-from-range ?- args)
			    (list ?-)))))
     ;; {no close bracket appears}
     ;;
     ;; bring single bar to the beginning
     ((memq ?- args)
      (setq args (cons ?- (delq ?- args))))
     ;; bar start a range, bring it to the beginning
     ((setq m (assq ?- args))
      (setq args (cons m (delq m args))))
     ;;
     ;; hat at the beginning?
     ((or (eq (car args) ?^) (eq (car-safe (car args)) ?^))
      (setq args (if (cdr args)
		     `(,(cadr args) ,(car args) ,@(cddr args))
		   (nconc (rx-any-delete-from-range ?^ args)
			  (list ?^))))))
    ;; some 1-char?
    (if (and (null (cdr args)) (numberp (car args))
	     (or (= 1 (length
		       (setq s (regexp-quote (string (car args))))))
		 (and (equal (car args) ?^) ;; unnecessary predicate?
		      (null (eq rx-parent '!)))))
	s
      (concat "["
	      (mapconcat
	       (lambda (e) (cond
			    ((numberp e) (string e))
			    ((consp e)
			     (if (and (= (1+ (car e)) (cdr e))
                                      ;; rx-any-condense-range should
                                      ;; prevent this case from happening.
				      (null (memq (car e) '(?\] ?-)))
                                      (null (memq (cdr e) '(?\] ?-))))
				 (string (car e) (cdr e))
			       (string (car e) ?- (cdr e))))
			    (e)))
	       args
	       nil)
	      "]"))))


(defun rx-check-not (arg)
  "Check arg ARG for Rx `not'."
  (unless (or (and (symbolp arg)
		   (string-match "\\`\\[\\[:[-a-z]+:\\]\\]\\'"
				 (condition-case nil
				     (rx-form arg)
				   (error ""))))
	      (eq arg 'word-boundary)
	      (and (consp arg)
		   (memq (car arg) '(not any in syntax category))))
    (error "rx `not' syntax error: %s" arg))
  t)


(defun rx-not (form)
  "Parse and produce code from FORM.  FORM is `(not ...)'."
  (rx-check form)
  (let ((result (rx-form (cadr form) '!))
	case-fold-search)
    (cond ((string-match "\\`\\[\\^" result)
	   (cond
	    ((equal result "[^]") "[^^]")
	    ((and (= (length result) 4) (null (eq rx-parent '!)))
	     (regexp-quote (substring result 2 3)))
	    ((concat "[" (substring result 2)))))
	  ((eq ?\[ (aref result 0))
	   (concat "[^" (substring result 1)))
	  ((string-match "\\`\\\\[scbw]" result)
	   (concat (upcase (substring result 0 2))
		   (substring result 2)))
	  ((string-match "\\`\\\\[SCBW]" result)
	   (concat (downcase (substring result 0 2))
		   (substring result 2)))
	  (t
	   (concat "[^" result "]")))))


(defun rx-not-char (form)
  "Parse and produce code from FORM.  FORM is `(not-char ...)'."
  (rx-check form)
  (rx-not `(not (in ,@(cdr form)))))


(defun rx-not-syntax (form)
  "Parse and produce code from FORM.  FORM is `(not-syntax SYNTAX)'."
  (rx-check form)
  (rx-not `(not (syntax ,@(cdr form)))))


(defun rx-trans-forms (form &optional skip)
  "If FORM's length is greater than two, transform it to length two.
A form (HEAD REST ...) becomes (HEAD (and REST ...)).
If SKIP is non-nil, allow that number of items after the head, i.e.
`(= N REST ...)' becomes `(= N (and REST ...))' if SKIP is 1."
  (unless skip (setq skip 0))
  (let ((tail (nthcdr (1+ skip) form)))
    (if (= (length tail) 1)
	form
      (let ((form (copy-sequence form)))
	(setcdr (nthcdr skip form) (list (cons 'and tail)))
	form))))


(defun rx-= (form)
  "Parse and produce code from FORM `(= N ...)'."
  (rx-check form)
  (setq form (rx-trans-forms form 1))
  (unless (and (integerp (nth 1 form))
	       (> (nth 1 form) 0))
    (error "rx `=' requires positive integer first arg"))
  (format "%s\\{%d\\}" (rx-form (nth 2 form) '*) (nth 1 form)))


(defun rx->= (form)
  "Parse and produce code from FORM `(>= N ...)'."
  (rx-check form)
  (setq form (rx-trans-forms form 1))
  (unless (and (integerp (nth 1 form))
	       (> (nth 1 form) 0))
    (error "rx `>=' requires positive integer first arg"))
  (format "%s\\{%d,\\}" (rx-form (nth 2 form) '*) (nth 1 form)))


(defun rx-** (form)
  "Parse and produce code from FORM `(** N M ...)'."
  (rx-check form)
  (rx-form (cons 'repeat (cdr (rx-trans-forms form 2))) '*))


(defun rx-repeat (form)
  "Parse and produce code from FORM.
FORM is either `(repeat N FORM1)' or `(repeat N M FORMS...)'."
  (rx-check form)
  (if (> (length form) 4)
      (setq form (rx-trans-forms form 2)))
  (if (null (nth 2 form))
      (setq form (cons (nth 0 form) (cons (nth 1 form) (nthcdr 3 form)))))
  (cond ((= (length form) 3)
	 (unless (and (integerp (nth 1 form))
		      (> (nth 1 form) 0))
	   (error "rx `repeat' requires positive integer first arg"))
	 (format "%s\\{%d\\}" (rx-form (nth 2 form) '*) (nth 1 form)))
	((or (not (integerp (nth 2 form)))
	     (< (nth 2 form) 0)
	     (not (integerp (nth 1 form)))
	     (< (nth 1 form) 0)
	     (< (nth 2 form) (nth 1 form)))
	 (error "rx `repeat' range error"))
	(t
	 (format "%s\\{%d,%d\\}" (rx-form (nth 3 form) '*)
		 (nth 1 form) (nth 2 form)))))


(defun rx-submatch (form)
  "Parse and produce code from FORM, which is `(submatch ...)'."
  (concat "\\("
          (if (= 2 (length form))
              ;; Only one sub-form.
              (rx-form (cadr form))
            ;; Several sub-forms implicitly concatenated.
            (mapconcat (lambda (re) (rx-form re ':)) (cdr form) nil))
          "\\)"))

(defun rx-submatch-n (form)
  "Parse and produce code from FORM, which is `(submatch-n N ...)'."
  (let ((n (nth 1 form)))
    (concat "\\(?" (number-to-string n) ":"
	    (if (= 3 (length form))
		;; Only one sub-form.
		(rx-form (nth 2 form))
	      ;; Several sub-forms implicitly concatenated.
	      (mapconcat (lambda (re) (rx-form re ':)) (cddr form) nil))
	    "\\)")))

(defun rx-backref (form)
  "Parse and produce code from FORM, which is `(backref N)'."
  (rx-check form)
  (format "\\%d" (nth 1 form)))

(defun rx-check-backref (arg)
  "Check arg ARG for Rx `backref'."
  (or (and (integerp arg) (>= arg 1) (<= arg 9))
      (error "rx `backref' requires numeric 1<=arg<=9: %s" arg)))

(defun rx-kleene (form)
  "Parse and produce code from FORM.
FORM is `(OP FORM1)', where OP is one of the `zero-or-one',
`zero-or-more' etc.  operators.
If OP is one of `*', `+', `?', produce a greedy regexp.
If OP is one of `*?', `+?', `??', produce a non-greedy regexp.
If OP is anything else, produce a greedy regexp if `rx-greedy-flag'
is non-nil."
  (rx-check form)
  (setq form (rx-trans-forms form))
  (let ((suffix (cond ((memq (car form) '(* + \? ?\s)) "")
		      ((memq (car form) '(*? +? \?? ??)) "?")
		      (rx-greedy-flag "")
		      (t "?")))
	(op (cond ((memq (car form) '(* *? 0+ zero-or-more)) "*")
		  ((memq (car form) '(+ +? 1+ one-or-more))  "+")
		  (t "?"))))
    (rx-group-if
     (concat (rx-form (cadr form) '*) op suffix)
     (and (memq rx-parent '(t *)) rx-parent))))


(defun rx-atomic-p (r &optional lax)
  "Return non-nil if regexp string R is atomic.
An atomic regexp R is one such that a suffix operator
appended to R will apply to all of R.  For example, \"a\"
\"[abc]\" and \"\\(ab\\|ab*c\\)\" are atomic and \"ab\",
\"[ab]c\", and \"ab\\|ab*c\" are not atomic.

This function may return false negatives, but it will not
return false positives.  It is nevertheless useful in
situations where an efficiency shortcut can be taken only if a
regexp is atomic.  The function can be improved to detect
more cases of atomic regexps.  Presently, this function
detects the following categories of atomic regexp;

  a group or shy group:  \\(...\\)
  a character class:     [...]
  a single character:    a

On the other hand, false negatives will be returned for
regexps that are atomic but end in operators, such as
\"a+\".  I think these are rare.  Probably such cases could
be detected without much effort.  A guarantee of no false
negatives would require a theoretic specification of the set
of all atomic regexps."
  (let ((l (length r)))
    (cond
     ((<= l 1))
     ((= l 2) (= (aref r 0) ?\\))
     ((= l 3) (string-match "\\`\\(?:\\\\[cCsS_]\\|\\[[^^]\\]\\)" r))
     ((null lax)
      (cond
       ((string-match "\\`\\[\\^?]?\\(?:\\[:[a-z]+:]\\|[^]]\\)*]\\'" r))
       ((string-match "\\`\\\\(\\(?:[^\\]\\|\\\\[^)]\\)*\\\\)\\'" r)))))))


(defun rx-syntax (form)
  "Parse and produce code from FORM, which is `(syntax SYMBOL)'."
  (rx-check form)
  (let* ((sym (cadr form))
	 (syntax (cdr (assq sym rx-syntax))))
    (unless syntax
      ;; Try sregex compatibility.
      (cond
       ((characterp sym) (setq syntax sym))
       ((symbolp sym)
        (let ((name (symbol-name sym)))
          (if (= 1 (length name))
              (setq syntax (aref name 0))))))
      (unless syntax
	(error "Unknown rx syntax `%s'" sym)))
    (format "\\s%c" syntax)))


(defun rx-check-category (form)
  "Check the argument FORM of a `(category FORM)'."
  (unless (or (integerp form)
	      (cdr (assq form rx-categories)))
    (error "Unknown category `%s'" form))
  t)


(defun rx-category (form)
  "Parse and produce code from FORM, which is `(category SYMBOL)'."
  (rx-check form)
  (let ((char (if (integerp (cadr form))
		  (cadr form)
		(cdr (assq (cadr form) rx-categories)))))
    (format "\\c%c" char)))


(defun rx-eval (form)
  "Parse and produce code from FORM, which is `(eval FORM)'."
  (rx-check form)
  (rx-form (eval (cadr form)) rx-parent))


(defun rx-greedy (form)
  "Parse and produce code from FORM.
If FORM is `(minimal-match FORM1)', non-greedy versions of `*',
`+', and `?' operators will be used in FORM1.  If FORM is
`(maximal-match FORM1)', greedy operators will be used."
  (rx-check form)
  (let ((rx-greedy-flag (eq (car form) 'maximal-match)))
    (rx-form (cadr form) rx-parent)))


(defun rx-regexp (form)
  "Parse and produce code from FORM, which is `(regexp STRING)'."
  (rx-check form)
  (rx-group-if (cadr form) rx-parent))


(defun rx-form (form &optional parent)
  "Parse and produce code for regular expression FORM.
FORM is a regular expression in sexp form.
PARENT shows which type of expression calls and controls putting of
shy groups around the result and some more in other functions."
  (let ((rx-parent parent))
    (cond
     ((stringp form)
      (rx-group-if (regexp-quote form)
                   (if (and (eq parent '*) (< 1 (length form)))
                       parent)))
     ((integerp form)
      (regexp-quote (char-to-string form)))
     ((symbolp form)
      (let ((info (rx-info form nil)))
        (cond ((stringp info)
               info)
              ((null info)
               (error "Unknown rx form `%s'" form))
              (t
               (funcall (nth 0 info) form)))))
     ((consp form)
      (let ((info (rx-info (car form) 'head)))
        (unless (consp info)
          (error "Unknown rx form `%s'" (car form)))
        (funcall (nth 0 info) form)))
     (t
      (error "rx syntax error at `%s'" form)))))


;;;###autoload
(defun rx-to-string (form &optional no-group)
  "Parse and produce code for regular expression FORM.
FORM is a regular expression in sexp form.
NO-GROUP non-nil means don't put shy groups around the result."
  (rx-group-if (rx-form form) (null no-group)))


;;;###autoload
(defmacro rx (&rest regexps)
  "Translate regular expressions REGEXPS in sexp form to a regexp string.
REGEXPS is a non-empty sequence of forms of the sort listed below.

Note that `rx' is a Lisp macro; when used in a Lisp program being
compiled, the translation is performed by the compiler.
See `rx-to-string' for how to do such a translation at run-time.

The following are valid subforms of regular expressions in sexp
notation.

STRING
     matches string STRING literally.

CHAR
     matches character CHAR literally.

`not-newline', `nonl'
     matches any character except a newline.

`anything'
     matches any character

`(any SET ...)'
`(in SET ...)'
`(char SET ...)'
     matches any character in SET ....  SET may be a character or string.
     Ranges of characters can be specified as `A-Z' in strings.
     Ranges may also be specified as conses like `(?A . ?Z)'.
     Reversed ranges like `Z-A' and `(?Z . ?A)' are not permitted.

     SET may also be the name of a character class: `digit',
     `control', `hex-digit', `blank', `graph', `print', `alnum',
     `alpha', `ascii', `nonascii', `lower', `punct', `space', `upper',
     `word', or one of their synonyms.

`(not (any SET ...))'
     matches any character not in SET ...

`line-start', `bol'
     matches the empty string, but only at the beginning of a line
     in the text being matched

`line-end', `eol'
     is similar to `line-start' but matches only at the end of a line

`string-start', `bos', `bot'
     matches the empty string, but only at the beginning of the
     string being matched against.

`string-end', `eos', `eot'
     matches the empty string, but only at the end of the
     string being matched against.

`buffer-start'
     matches the empty string, but only at the beginning of the
     buffer being matched against.  Actually equivalent to `string-start'.

`buffer-end'
     matches the empty string, but only at the end of the
     buffer being matched against.  Actually equivalent to `string-end'.

`point'
     matches the empty string, but only at point.

`word-start', `bow'
     matches the empty string, but only at the beginning of a word.

`word-end', `eow'
     matches the empty string, but only at the end of a word.

`word-boundary'
     matches the empty string, but only at the beginning or end of a
     word.

`(not word-boundary)'
`not-word-boundary'
     matches the empty string, but not at the beginning or end of a
     word.

`symbol-start'
     matches the empty string, but only at the beginning of a symbol.

`symbol-end'
     matches the empty string, but only at the end of a symbol.

`digit', `numeric', `num'
     matches 0 through 9.

`control', `cntrl'
     matches any character whose code is in the range 0-31.

`hex-digit', `hex', `xdigit'
     matches 0 through 9, a through f and A through F.

`blank'
     matches horizontal whitespace, as defined by Annex C of the
     Unicode Technical Standard #18.  In particular, it matches
     spaces, tabs, and other characters whose Unicode
     `general-category' property indicates they are spacing
     separators.

`graphic', `graph'
     matches graphic characters--everything except whitespace, ASCII
     and non-ASCII control characters, surrogates, and codepoints
     unassigned by Unicode.

`printing', `print'
     matches whitespace and graphic characters.

`alphanumeric', `alnum'
     matches alphabetic characters and digits.  For multibyte characters,
     it matches characters whose Unicode `general-category' property
     indicates they are alphabetic or decimal number characters.

`letter', `alphabetic', `alpha'
     matches alphabetic characters.  For multibyte characters,
     it matches characters whose Unicode `general-category' property
     indicates they are alphabetic characters.

`ascii'
     matches ASCII (unibyte) characters.

`nonascii'
     matches non-ASCII (multibyte) characters.

`lower', `lower-case'
     matches anything lower-case, as determined by the current case
     table.  If `case-fold-search' is non-nil, this also matches any
     upper-case letter.

`upper', `upper-case'
     matches anything upper-case, as determined by the current case
     table.  If `case-fold-search' is non-nil, this also matches any
     lower-case letter.

`punctuation', `punct'
     matches punctuation.  (But at present, for multibyte characters,
     it matches anything that has non-word syntax.)

`space', `whitespace', `white'
     matches anything that has whitespace syntax.

`word', `wordchar'
     matches anything that has word syntax.

`not-wordchar'
     matches anything that has non-word syntax.

`(syntax SYNTAX)'
     matches a character with syntax SYNTAX.  SYNTAX must be one
     of the following symbols, or a symbol corresponding to the syntax
     character, e.g. `\\.' for `\\s.'.

     `whitespace'		(\\s- in string notation)
     `punctuation'		(\\s.)
     `word'			(\\sw)
     `symbol'			(\\s_)
     `open-parenthesis'		(\\s()
     `close-parenthesis'	(\\s))
     `expression-prefix'	(\\s')
     `string-quote'		(\\s\")
     `paired-delimiter'		(\\s$)
     `escape'			(\\s\\)
     `character-quote'		(\\s/)
     `comment-start'		(\\s<)
     `comment-end'		(\\s>)
     `string-delimiter'		(\\s|)
     `comment-delimiter'	(\\s!)

`(not (syntax SYNTAX))'
     matches a character that doesn't have syntax SYNTAX.

`(category CATEGORY)'
     matches a character with category CATEGORY.  CATEGORY must be
     either a character to use for C, or one of the following symbols.

     `space-for-indent'                 (\\c\\s in string notation)
     `base'                             (\\c.)
     `consonant'			(\\c0)
     `base-vowel'			(\\c1)
     `upper-diacritical-mark'		(\\c2)
     `lower-diacritical-mark'		(\\c3)
     `tone-mark'		        (\\c4)
     `symbol'			        (\\c5)
     `digit'			        (\\c6)
     `vowel-modifying-diacritical-mark'	(\\c7)
     `vowel-sign'			(\\c8)
     `semivowel-lower'			(\\c9)
     `not-at-end-of-line'		(\\c<)
     `not-at-beginning-of-line'		(\\c>)
     `alpha-numeric-two-byte'		(\\cA)
     `chinese-two-byte'			(\\cC)
     `greek-two-byte'			(\\cG)
     `japanese-hiragana-two-byte'	(\\cH)
     `indian-two-byte'			(\\cI)
     `japanese-katakana-two-byte'	(\\cK)
     `strong-left-to-right'             (\\cL)
     `korean-hangul-two-byte'		(\\cN)
     `strong-right-to-left'             (\\cR)
     `cyrillic-two-byte'		(\\cY)
     `combining-diacritic'		(\\c^)
     `ascii'				(\\ca)
     `arabic'				(\\cb)
     `chinese'				(\\cc)
     `ethiopic'				(\\ce)
     `greek'				(\\cg)
     `korean'				(\\ch)
     `indian'				(\\ci)
     `japanese'				(\\cj)
     `japanese-katakana'		(\\ck)
     `latin'				(\\cl)
     `lao'				(\\co)
     `tibetan'				(\\cq)
     `japanese-roman'			(\\cr)
     `thai'				(\\ct)
     `vietnamese'			(\\cv)
     `hebrew'				(\\cw)
     `cyrillic'				(\\cy)
     `can-break'			(\\c|)

`(not (category CATEGORY))'
     matches a character that doesn't have category CATEGORY.

`(and SEXP1 SEXP2 ...)'
`(: SEXP1 SEXP2 ...)'
`(seq SEXP1 SEXP2 ...)'
`(sequence SEXP1 SEXP2 ...)'
     matches what SEXP1 matches, followed by what SEXP2 matches, etc.

`(submatch SEXP1 SEXP2 ...)'
`(group SEXP1 SEXP2 ...)'
     like `and', but makes the match accessible with `match-end',
     `match-beginning', and `match-string'.

`(submatch-n N SEXP1 SEXP2 ...)'
`(group-n N SEXP1 SEXP2 ...)'
     like `group', but make it an explicitly-numbered group with
     group number N.

`(or SEXP1 SEXP2 ...)'
`(| SEXP1 SEXP2 ...)'
     matches anything that matches SEXP1 or SEXP2, etc.  If all
     args are strings, use `regexp-opt' to optimize the resulting
     regular expression.

`(minimal-match SEXP)'
     produce a non-greedy regexp for SEXP.  Normally, regexps matching
     zero or more occurrences of something are \"greedy\" in that they
     match as much as they can, as long as the overall regexp can
     still match.  A non-greedy regexp matches as little as possible.

`(maximal-match SEXP)'
     produce a greedy regexp for SEXP.  This is the default.

Below, `SEXP ...' represents a sequence of regexp forms, treated as if
enclosed in `(and ...)'.

`(zero-or-more SEXP ...)'
`(0+ SEXP ...)'
     matches zero or more occurrences of what SEXP ... matches.

`(* SEXP ...)'
     like `zero-or-more', but always produces a greedy regexp, independent
     of `rx-greedy-flag'.

`(*? SEXP ...)'
     like `zero-or-more', but always produces a non-greedy regexp,
     independent of `rx-greedy-flag'.

`(one-or-more SEXP ...)'
`(1+ SEXP ...)'
     matches one or more occurrences of SEXP ...

`(+ SEXP ...)'
     like `one-or-more', but always produces a greedy regexp.

`(+? SEXP ...)'
     like `one-or-more', but always produces a non-greedy regexp.

`(zero-or-one SEXP ...)'
`(optional SEXP ...)'
`(opt SEXP ...)'
     matches zero or one occurrences of A.

`(? SEXP ...)'
     like `zero-or-one', but always produces a greedy regexp.

`(?? SEXP ...)'
     like `zero-or-one', but always produces a non-greedy regexp.

`(repeat N SEXP)'
`(= N SEXP ...)'
     matches N occurrences.

`(>= N SEXP ...)'
     matches N or more occurrences.

`(repeat N M SEXP)'
`(** N M SEXP ...)'
     matches N to M occurrences.

`(backref N)'
     matches what was matched previously by submatch N.

`(eval FORM)'
     evaluate FORM and insert result.  If result is a string,
     `regexp-quote' it.

`(regexp REGEXP)'
     include REGEXP in string notation in the result."
  (cond ((null regexps)
	 (error "No regexp"))
	((cdr regexps)
	 (rx-to-string `(and ,@regexps) t))
	(t
	 (rx-to-string (car regexps) t))))


(pcase-defmacro rx (&rest regexps)
  "Build a `pcase' pattern matching `rx' REGEXPS in sexp form.
The REGEXPS are interpreted as in `rx'.  The pattern matches any
string that is a match for the regular expression so constructed,
as if by `string-match'.

In addition to the usual `rx' constructs, REGEXPS can contain the
following constructs:

  (let REF SEXP...)  creates a new explicitly named reference to
                     a submatch that matches regular expressions
                     SEXP, and binds the match to REF.
  (backref REF)      creates a backreference to the submatch
                     introduced by a previous (let REF ...)
                     construct.  REF can be the same symbol
                     in the first argument of the corresponding
                     (let REF ...) construct, or it can be a
                     submatch number.  It matches the referenced
                     submatch.

The REFs are associated with explicitly named submatches starting
from 1.  Multiple occurrences of the same REF refer to the same
submatch.

If a case matches, the match data is modified as usual so you can
use it in the case body, but you still have to pass the correct
string as argument to `match-string'."
  (let* ((vars ())
         (rx-constituents
          `((let
             ,(lambda (form)
                (rx-check form)
                (let ((var (cadr form)))
                  (cl-check-type var symbol)
                  (let ((i (or (cl-position var vars :test #'eq)
                               (prog1 (length vars)
                                 (setq vars `(,@vars ,var))))))
                    (rx-form `(submatch-n ,(1+ i) ,@(cddr form))))))
             1 nil)
            (backref
             ,(lambda (form)
                (rx-check form)
                (rx-backref
                 `(backref ,(let ((var (cadr form)))
                              (if (integerp var) var
                                (1+ (cl-position var vars :test #'eq)))))))
             1 1
             ,(lambda (var)
                (cond ((integerp var) (rx-check-backref var))
                      ((memq var vars) t)
                      (t (error "rx `backref' variable must be one of %s: %s"
                                vars var)))))
            ,@rx-constituents))
         (regexp (rx-to-string `(seq ,@regexps) :no-group)))
    `(and (pred (string-match ,regexp))
          ,@(cl-loop for i from 1
                     for var in vars
                     collect `(app (match-string ,i) ,var)))))
\f
;; ;; sregex.el replacement

;; ;;;###autoload (provide 'sregex)
;; ;;;###autoload (autoload 'sregex "rx")
;; (defalias 'sregex 'rx-to-string)
;; ;;;###autoload (autoload 'sregexq "rx" nil nil 'macro)
;; (defalias 'sregexq 'rx)
\f
(provide 'rx)

;;; rx.el ends here

debug log:

solving fdd24317c6 ...
found fdd24317c6 in https://git.savannah.gnu.org/cgit/emacs.git

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

Code repositories for project(s) associated with this 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).