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e8af40ee | 1 | ;;; ebnf-bnf.el --- parser for EBNF |
984ae001 | 2 | |
1475cbb3 | 3 | ;; Copyright (C) 1999, 2000, 2001 Free Sofware Foundation, Inc. |
984ae001 | 4 | |
1475cbb3 | 5 | ;; Author: Vinicius Jose Latorre <vinicius@cpqd.com.br> |
984ae001 | 6 | ;; Maintainer: Vinicius Jose Latorre <vinicius@cpqd.com.br> |
1475cbb3 | 7 | ;; Keywords: wp, ebnf, PostScript |
f504d516 | 8 | ;; Time-stamp: <2003-02-10 10:29:48 jbarranquero> |
40b35c64 | 9 | ;; Version: 1.7 |
984ae001 | 10 | |
8d9ea7b1 | 11 | ;; This file is part of GNU Emacs. |
984ae001 | 12 | |
8d9ea7b1 | 13 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
984ae001 GM |
14 | ;; it under the terms of the GNU General Public License as published by |
15 | ;; the Free Software Foundation; either version 2, or (at your option) | |
16 | ;; any later version. | |
17 | ||
8d9ea7b1 | 18 | ;; GNU Emacs is distributed in the hope that it will be useful, |
984ae001 GM |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
24 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
25 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
26 | ;; Boston, MA 02111-1307, USA. | |
27 | ||
28 | ;;; Commentary: | |
29 | ||
30 | ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
31 | ;; | |
32 | ;; | |
33 | ;; This is part of ebnf2ps package. | |
34 | ;; | |
35 | ;; This package defines a parser for EBNF. | |
36 | ;; | |
37 | ;; See ebnf2ps.el for documentation. | |
38 | ;; | |
39 | ;; | |
40 | ;; EBNF Syntax | |
41 | ;; ----------- | |
42 | ;; | |
43 | ;; The current EBNF that ebnf2ps accepts has the following constructions: | |
44 | ;; | |
45 | ;; ; comment (until end of line) | |
46 | ;; A non-terminal | |
47 | ;; "C" terminal | |
48 | ;; ?C? special | |
49 | ;; $A default non-terminal | |
50 | ;; $"C" default terminal | |
51 | ;; $?C? default special | |
52 | ;; A = B. production (A is the header and B the body) | |
53 | ;; C D sequence (C occurs before D) | |
54 | ;; C | D alternative (C or D occurs) | |
55 | ;; A - B exception (A excluding B, B without any non-terminal) | |
56 | ;; n * A repetition (A repeats n (integer) times) | |
57 | ;; (C) group (expression C is grouped together) | |
58 | ;; [C] optional (C may or not occurs) | |
59 | ;; C+ one or more occurrences of C | |
60 | ;; {C}+ one or more occurrences of C | |
61 | ;; {C}* zero or more occurrences of C | |
62 | ;; {C} zero or more occurrences of C | |
63 | ;; C / D equivalent to: C {D C}* | |
64 | ;; {C || D}+ equivalent to: C {D C}* | |
65 | ;; {C || D}* equivalent to: [C {D C}*] | |
66 | ;; {C || D} equivalent to: [C {D C}*] | |
67 | ;; | |
68 | ;; The EBNF syntax written using the notation above is: | |
69 | ;; | |
70 | ;; EBNF = {production}+. | |
71 | ;; | |
72 | ;; production = non_terminal "=" body ".". ;; production | |
73 | ;; | |
74 | ;; body = {sequence || "|"}*. ;; alternative | |
75 | ;; | |
76 | ;; sequence = {exception}*. ;; sequence | |
77 | ;; | |
78 | ;; exception = repeat [ "-" repeat]. ;; exception | |
79 | ;; | |
80 | ;; repeat = [ integer "*" ] term. ;; repetition | |
81 | ;; | |
82 | ;; term = factor | |
83 | ;; | [factor] "+" ;; one-or-more | |
84 | ;; | [factor] "/" [factor] ;; one-or-more | |
85 | ;; . | |
86 | ;; | |
87 | ;; factor = [ "$" ] "\"" terminal "\"" ;; terminal | |
88 | ;; | [ "$" ] non_terminal ;; non-terminal | |
89 | ;; | [ "$" ] "?" special "?" ;; special | |
90 | ;; | "(" body ")" ;; group | |
91 | ;; | "[" body "]" ;; zero-or-one | |
92 | ;; | "{" body [ "||" body ] "}+" ;; one-or-more | |
93 | ;; | "{" body [ "||" body ] "}*" ;; zero-or-more | |
94 | ;; | "{" body [ "||" body ] "}" ;; zero-or-more | |
95 | ;; . | |
96 | ;; | |
1475cbb3 | 97 | ;; non_terminal = "[!#%&'*-,0-:<>@-Z\\\\^-z~\\240-\\377]+". |
984ae001 GM |
98 | ;; |
99 | ;; terminal = "\\([^\"\\]\\|\\\\[ -~\\240-\\377]\\)+". | |
100 | ;; | |
101 | ;; special = "[^?\\n\\000-\\010\\016-\\037\\177-\\237]*". | |
102 | ;; | |
103 | ;; integer = "[0-9]+". | |
104 | ;; | |
105 | ;; comment = ";" "[^\\n\\000-\\010\\016-\\037\\177-\\237]*" "\\n". | |
106 | ;; | |
107 | ;; | |
108 | ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
109 | ||
e8af40ee | 110 | ;;; Code: |
984ae001 GM |
111 | |
112 | ||
113 | (require 'ebnf-otz) | |
114 | ||
115 | ||
116 | (defvar ebnf-bnf-lex nil | |
117 | "Value returned by `ebnf-bnf-lex' function.") | |
118 | ||
119 | \f | |
120 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
f504d516 | 121 | ;; Syntactic analyzer |
984ae001 GM |
122 | |
123 | ||
124 | ;;; EBNF = {production}+. | |
125 | ||
126 | (defun ebnf-bnf-parser (start) | |
127 | "EBNF parser." | |
128 | (let ((total (+ (- ebnf-limit start) 1)) | |
129 | (bias (1- start)) | |
130 | (origin (point)) | |
131 | prod-list token rule) | |
132 | (goto-char start) | |
133 | (setq token (ebnf-bnf-lex)) | |
134 | (and (eq token 'end-of-input) | |
e8af40ee | 135 | (error "Invalid EBNF file format")) |
984ae001 GM |
136 | (while (not (eq token 'end-of-input)) |
137 | (ebnf-message-float | |
138 | "Parsing...%s%%" | |
139 | (/ (* (- (point) bias) 100.0) total)) | |
140 | (setq token (ebnf-production token) | |
141 | rule (cdr token) | |
142 | token (car token)) | |
143 | (or (ebnf-add-empty-rule-list rule) | |
144 | (setq prod-list (cons rule prod-list)))) | |
145 | (goto-char origin) | |
146 | prod-list)) | |
147 | ||
148 | ||
149 | ;;; production = non-terminal "=" body ".". | |
150 | ||
151 | (defun ebnf-production (token) | |
152 | (let ((header ebnf-bnf-lex) | |
153 | (action ebnf-action) | |
154 | body) | |
155 | (setq ebnf-action nil) | |
156 | (or (eq token 'non-terminal) | |
e8af40ee | 157 | (error "Invalid header production")) |
984ae001 | 158 | (or (eq (ebnf-bnf-lex) 'equal) |
e8af40ee | 159 | (error "Invalid production: missing `='")) |
984ae001 GM |
160 | (setq body (ebnf-body)) |
161 | (or (eq (car body) 'period) | |
e8af40ee | 162 | (error "Invalid production: missing `.'")) |
984ae001 GM |
163 | (setq body (cdr body)) |
164 | (ebnf-eps-add-production header) | |
165 | (cons (ebnf-bnf-lex) | |
166 | (ebnf-make-production header body action)))) | |
167 | ||
168 | ||
169 | ;;; body = {sequence || "|"}*. | |
170 | ||
171 | (defun ebnf-body () | |
172 | (let (body sequence) | |
173 | (while (eq (car (setq sequence (ebnf-sequence))) 'alternative) | |
174 | (setq sequence (cdr sequence) | |
175 | body (cons sequence body))) | |
176 | (ebnf-token-alternative body sequence))) | |
177 | ||
178 | ||
179 | ;;; sequence = {exception}*. | |
180 | ||
181 | (defun ebnf-sequence () | |
182 | (let ((token (ebnf-bnf-lex)) | |
183 | seq term) | |
184 | (while (setq term (ebnf-exception token) | |
185 | token (car term) | |
186 | term (cdr term)) | |
187 | (setq seq (cons term seq))) | |
188 | (cons token | |
189 | (cond | |
190 | ;; null sequence | |
191 | ((null seq) | |
192 | (ebnf-make-empty)) | |
193 | ;; sequence with only one element | |
194 | ((= (length seq) 1) | |
195 | (car seq)) | |
196 | ;; a real sequence | |
197 | (t | |
198 | (ebnf-make-sequence (nreverse seq))) | |
199 | )))) | |
200 | ||
201 | ||
202 | ;;; exception = repeat [ "-" repeat]. | |
203 | ||
204 | (defun ebnf-exception (token) | |
205 | (let ((term (ebnf-repeat token))) | |
206 | (if (not (eq (car term) 'except)) | |
207 | ;; repeat | |
208 | term | |
209 | ;; repeat - repeat | |
210 | (let ((exception (ebnf-repeat (ebnf-bnf-lex)))) | |
211 | (ebnf-no-non-terminal (cdr exception)) | |
212 | (ebnf-token-except (cdr term) exception))))) | |
213 | ||
214 | ||
215 | (defun ebnf-no-non-terminal (node) | |
216 | (and (vectorp node) | |
217 | (let ((kind (ebnf-node-kind node))) | |
218 | (cond | |
219 | ((eq kind 'ebnf-generate-non-terminal) | |
e8af40ee | 220 | (error "Exception sequence should not contain a non-terminal")) |
984ae001 GM |
221 | ((eq kind 'ebnf-generate-repeat) |
222 | (ebnf-no-non-terminal (ebnf-node-separator node))) | |
223 | ((memq kind '(ebnf-generate-optional ebnf-generate-except)) | |
224 | (ebnf-no-non-terminal (ebnf-node-list node))) | |
225 | ((memq kind '(ebnf-generate-one-or-more ebnf-generate-zero-or-more)) | |
226 | (ebnf-no-non-terminal (ebnf-node-list node)) | |
227 | (ebnf-no-non-terminal (ebnf-node-separator node))) | |
228 | ((memq kind '(ebnf-generate-alternative ebnf-generate-sequence)) | |
229 | (let ((seq (ebnf-node-list node))) | |
230 | (while seq | |
231 | (ebnf-no-non-terminal (car seq)) | |
232 | (setq seq (cdr seq))))) | |
233 | )))) | |
234 | ||
235 | ||
236 | ;;; repeat = [ integer "*" ] term. | |
237 | ||
238 | (defun ebnf-repeat (token) | |
239 | (if (not (eq token 'integer)) | |
240 | (ebnf-term token) | |
241 | (let ((times ebnf-bnf-lex)) | |
242 | (or (eq (ebnf-bnf-lex) 'repeat) | |
e8af40ee | 243 | (error "Missing `*'")) |
984ae001 GM |
244 | (ebnf-token-repeat times (ebnf-term (ebnf-bnf-lex)))))) |
245 | ||
246 | ||
247 | ;;; term = factor | |
248 | ;;; | [factor] "+" ;; one-or-more | |
249 | ;;; | [factor] "/" [factor] ;; one-or-more | |
250 | ;;; . | |
251 | ||
252 | (defun ebnf-term (token) | |
253 | (let ((factor (ebnf-factor token))) | |
254 | (and factor | |
255 | (setq token (ebnf-bnf-lex))) | |
256 | (cond | |
257 | ;; [factor] + | |
258 | ((eq token 'one-or-more) | |
259 | (cons (ebnf-bnf-lex) | |
260 | (and factor | |
261 | (let ((kind (ebnf-node-kind factor))) | |
262 | (cond | |
263 | ;; { A }+ + ==> { A }+ | |
264 | ;; { A }* + ==> { A }* | |
265 | ((memq kind '(ebnf-generate-zero-or-more | |
266 | ebnf-generate-one-or-more)) | |
267 | factor) | |
268 | ;; [ A ] + ==> { A }* | |
269 | ((eq kind 'ebnf-generate-optional) | |
270 | (ebnf-make-zero-or-more (list factor))) | |
271 | ;; A + | |
272 | (t | |
273 | (ebnf-make-one-or-more (list factor))) | |
274 | ))))) | |
275 | ;; [factor] / [factor] | |
276 | ((eq token 'list) | |
277 | (setq token (ebnf-bnf-lex)) | |
278 | (let ((sep (ebnf-factor token))) | |
279 | (and sep | |
280 | (setq factor (or factor (ebnf-make-empty)))) | |
281 | (cons (if sep | |
282 | (ebnf-bnf-lex) | |
283 | token) | |
284 | (and factor | |
285 | (ebnf-make-one-or-more factor sep))))) | |
286 | ;; factor | |
287 | (t | |
288 | (cons token factor)) | |
289 | ))) | |
290 | ||
291 | ||
292 | ;;; factor = [ "$" ] "\"" terminal "\"" ;; terminal | |
293 | ;;; | [ "$" ] non_terminal ;; non-terminal | |
294 | ;;; | [ "$" ] "?" special "?" ;; special | |
295 | ;;; | "(" body ")" ;; group | |
296 | ;;; | "[" body "]" ;; zero-or-one | |
297 | ;;; | "{" body [ "||" body ] "}+" ;; one-or-more | |
298 | ;;; | "{" body [ "||" body ] "}*" ;; zero-or-more | |
299 | ;;; | "{" body [ "||" body ] "}" ;; zero-or-more | |
300 | ;;; . | |
301 | ||
302 | (defun ebnf-factor (token) | |
303 | (cond | |
304 | ;; terminal | |
305 | ((eq token 'terminal) | |
306 | (ebnf-make-terminal ebnf-bnf-lex)) | |
307 | ;; non-terminal | |
308 | ((eq token 'non-terminal) | |
309 | (ebnf-make-non-terminal ebnf-bnf-lex)) | |
310 | ;; special | |
311 | ((eq token 'special) | |
312 | (ebnf-make-special ebnf-bnf-lex)) | |
313 | ;; group | |
314 | ((eq token 'begin-group) | |
315 | (let ((body (ebnf-body))) | |
316 | (or (eq (car body) 'end-group) | |
e8af40ee | 317 | (error "Missing `)'")) |
984ae001 GM |
318 | (cdr body))) |
319 | ;; optional | |
320 | ((eq token 'begin-optional) | |
321 | (let ((body (ebnf-body))) | |
322 | (or (eq (car body) 'end-optional) | |
e8af40ee | 323 | (error "Missing `]'")) |
984ae001 GM |
324 | (ebnf-token-optional (cdr body)))) |
325 | ;; list | |
326 | ((eq token 'begin-list) | |
327 | (let* ((body (ebnf-body)) | |
328 | (token (car body)) | |
329 | (list-part (cdr body)) | |
330 | sep-part) | |
331 | (and (eq token 'list-separator) | |
332 | ;; { A || B } | |
333 | (setq body (ebnf-body) ; get separator | |
334 | token (car body) | |
335 | sep-part (cdr body))) | |
336 | (cond | |
337 | ;; { A }+ | |
338 | ((eq token 'end-one-or-more) | |
339 | (ebnf-make-one-or-more list-part sep-part)) | |
340 | ;; { A }* | |
341 | ((eq token 'end-zero-or-more) | |
342 | (ebnf-make-zero-or-more list-part sep-part)) | |
343 | (t | |
e8af40ee | 344 | (error "Missing `}+', `}*' or `}'")) |
984ae001 GM |
345 | ))) |
346 | ;; no term | |
347 | (t | |
348 | nil) | |
349 | )) | |
350 | ||
351 | \f | |
352 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
353 | ;; Lexical analyzer | |
354 | ||
355 | ||
356 | (defconst ebnf-bnf-token-table (make-vector 256 'error) | |
357 | "Vector used to map characters to a lexical token.") | |
358 | ||
359 | ||
360 | (defun ebnf-bnf-initialize () | |
361 | "Initialize EBNF token table." | |
362 | ;; control character & control 8-bit character are set to `error' | |
363 | (let ((char ?\040)) | |
364 | ;; printable character: | |
365 | (while (< char ?\060) | |
366 | (aset ebnf-bnf-token-table char 'non-terminal) | |
367 | (setq char (1+ char))) | |
368 | ;; digits: | |
369 | (while (< char ?\072) | |
370 | (aset ebnf-bnf-token-table char 'integer) | |
371 | (setq char (1+ char))) | |
372 | ;; printable character: | |
373 | (while (< char ?\177) | |
374 | (aset ebnf-bnf-token-table char 'non-terminal) | |
375 | (setq char (1+ char))) | |
376 | ;; European 8-bit accentuated characters: | |
377 | (setq char ?\240) | |
378 | (while (< char ?\400) | |
379 | (aset ebnf-bnf-token-table char 'non-terminal) | |
380 | (setq char (1+ char))) | |
381 | ;; Override space characters: | |
382 | (aset ebnf-bnf-token-table ?\013 'space) ; [VT] vertical tab | |
383 | (aset ebnf-bnf-token-table ?\n 'space) ; [NL] linefeed | |
384 | (aset ebnf-bnf-token-table ?\r 'space) ; [CR] carriage return | |
385 | (aset ebnf-bnf-token-table ?\t 'space) ; [HT] horizontal tab | |
386 | (aset ebnf-bnf-token-table ?\ 'space) ; [SP] space | |
387 | ;; Override form feed character: | |
388 | (aset ebnf-bnf-token-table ?\f 'form-feed) ; [FF] form feed | |
389 | ;; Override other lexical characters: | |
390 | (aset ebnf-bnf-token-table ?\" 'terminal) | |
391 | (aset ebnf-bnf-token-table ?\? 'special) | |
392 | (aset ebnf-bnf-token-table ?\( 'begin-group) | |
393 | (aset ebnf-bnf-token-table ?\) 'end-group) | |
394 | (aset ebnf-bnf-token-table ?* 'repeat) | |
395 | (aset ebnf-bnf-token-table ?- 'except) | |
396 | (aset ebnf-bnf-token-table ?= 'equal) | |
397 | (aset ebnf-bnf-token-table ?\[ 'begin-optional) | |
398 | (aset ebnf-bnf-token-table ?\] 'end-optional) | |
399 | (aset ebnf-bnf-token-table ?\{ 'begin-list) | |
400 | (aset ebnf-bnf-token-table ?| 'alternative) | |
401 | (aset ebnf-bnf-token-table ?\} 'end-list) | |
402 | (aset ebnf-bnf-token-table ?/ 'list) | |
403 | (aset ebnf-bnf-token-table ?+ 'one-or-more) | |
404 | (aset ebnf-bnf-token-table ?$ 'default) | |
405 | ;; Override comment character: | |
406 | (aset ebnf-bnf-token-table ebnf-lex-comment-char 'comment) | |
407 | ;; Override end of production character: | |
408 | (aset ebnf-bnf-token-table ebnf-lex-eop-char 'period))) | |
409 | ||
410 | ||
40b35c64 GM |
411 | ;; replace the range "\240-\377" (see `ebnf-range-regexp'). |
412 | (defconst ebnf-bnf-non-terminal-chars | |
413 | (ebnf-range-regexp "!#%&'*-,0-:<>@-Z\\\\^-z~" ?\240 ?\377)) | |
414 | ||
415 | ||
984ae001 GM |
416 | (defun ebnf-bnf-lex () |
417 | "Lexical analyser for EBNF. | |
418 | ||
419 | Return a lexical token. | |
420 | ||
421 | See documentation for variable `ebnf-bnf-lex'." | |
422 | (if (>= (point) ebnf-limit) | |
423 | 'end-of-input | |
424 | (let (token) | |
425 | ;; skip spaces and comments | |
426 | (while (if (> (following-char) 255) | |
427 | (progn | |
428 | (setq token 'error) | |
429 | nil) | |
430 | (setq token (aref ebnf-bnf-token-table (following-char))) | |
431 | (cond | |
432 | ((eq token 'space) | |
433 | (skip-chars-forward " \013\n\r\t" ebnf-limit) | |
434 | (< (point) ebnf-limit)) | |
435 | ((eq token 'comment) | |
436 | (ebnf-bnf-skip-comment)) | |
437 | ((eq token 'form-feed) | |
438 | (forward-char) | |
439 | (setq ebnf-action 'form-feed)) | |
440 | (t nil) | |
441 | ))) | |
442 | (setq ebnf-default-p nil) | |
443 | (cond | |
444 | ;; end of input | |
445 | ((>= (point) ebnf-limit) | |
446 | 'end-of-input) | |
447 | ;; error | |
448 | ((eq token 'error) | |
e8af40ee | 449 | (error "Illegal character")) |
984ae001 GM |
450 | ;; default |
451 | ((eq token 'default) | |
452 | (forward-char) | |
453 | (if (memq (aref ebnf-bnf-token-table (following-char)) | |
454 | '(terminal non-terminal special)) | |
455 | (prog1 | |
456 | (ebnf-bnf-lex) | |
457 | (setq ebnf-default-p t)) | |
e8af40ee | 458 | (error "Illegal `default' element"))) |
984ae001 GM |
459 | ;; integer |
460 | ((eq token 'integer) | |
461 | (setq ebnf-bnf-lex (ebnf-buffer-substring "0-9")) | |
462 | 'integer) | |
463 | ;; special: ?special? | |
464 | ((eq token 'special) | |
465 | (setq ebnf-bnf-lex (concat "?" | |
466 | (ebnf-string " ->@-~" ?\? "special") | |
467 | "?")) | |
468 | 'special) | |
469 | ;; terminal: "string" | |
470 | ((eq token 'terminal) | |
471 | (setq ebnf-bnf-lex (ebnf-unescape-string (ebnf-get-string))) | |
472 | 'terminal) | |
473 | ;; non-terminal or terminal | |
474 | ((eq token 'non-terminal) | |
40b35c64 | 475 | (setq ebnf-bnf-lex (ebnf-buffer-substring ebnf-bnf-non-terminal-chars)) |
984ae001 GM |
476 | (let ((case-fold-search ebnf-case-fold-search) |
477 | match) | |
478 | (if (and ebnf-terminal-regexp | |
479 | (setq match (string-match ebnf-terminal-regexp | |
480 | ebnf-bnf-lex)) | |
481 | (zerop match) | |
482 | (= (match-end 0) (length ebnf-bnf-lex))) | |
483 | 'terminal | |
484 | 'non-terminal))) | |
485 | ;; end of list: }+, }*, } | |
486 | ((eq token 'end-list) | |
487 | (forward-char) | |
488 | (cond | |
489 | ((= (following-char) ?+) | |
490 | (forward-char) | |
491 | 'end-one-or-more) | |
492 | ((= (following-char) ?*) | |
493 | (forward-char) | |
494 | 'end-zero-or-more) | |
495 | (t | |
496 | 'end-zero-or-more) | |
497 | )) | |
498 | ;; alternative: |, || | |
499 | ((eq token 'alternative) | |
500 | (forward-char) | |
501 | (if (/= (following-char) ?|) | |
502 | 'alternative | |
503 | (forward-char) | |
504 | 'list-separator)) | |
505 | ;; miscellaneous: {, (, ), [, ], ., =, /, +, -, * | |
506 | (t | |
507 | (forward-char) | |
508 | token) | |
509 | )))) | |
510 | ||
511 | ||
b1f380ec GM |
512 | ;; replace the range "\177-\237" (see `ebnf-range-regexp'). |
513 | (defconst ebnf-bnf-comment-chars | |
514 | (ebnf-range-regexp "^\n\000-\010\016-\037" ?\177 ?\237)) | |
984ae001 GM |
515 | |
516 | ||
517 | (defun ebnf-bnf-skip-comment () | |
518 | (forward-char) | |
519 | (cond | |
520 | ;; open EPS file | |
521 | ((and ebnf-eps-executing (= (following-char) ?\[)) | |
522 | (ebnf-eps-add-context (ebnf-bnf-eps-filename))) | |
523 | ;; close EPS file | |
524 | ((and ebnf-eps-executing (= (following-char) ?\])) | |
525 | (ebnf-eps-remove-context (ebnf-bnf-eps-filename))) | |
526 | ;; any other action in comment | |
527 | (t | |
528 | (setq ebnf-action (aref ebnf-comment-table (following-char))) | |
529 | (skip-chars-forward ebnf-bnf-comment-chars ebnf-limit)) | |
530 | ) | |
531 | ;; check for a valid end of comment | |
532 | (cond ((>= (point) ebnf-limit) | |
533 | nil) | |
534 | ((= (following-char) ?\n) | |
535 | (forward-char) | |
536 | t) | |
537 | (t | |
e8af40ee | 538 | (error "Illegal character")) |
984ae001 GM |
539 | )) |
540 | ||
541 | ||
542 | (defun ebnf-bnf-eps-filename () | |
543 | (forward-char) | |
544 | (ebnf-buffer-substring ebnf-bnf-comment-chars)) | |
545 | ||
546 | ||
547 | (defun ebnf-unescape-string (str) | |
548 | (let* ((len (length str)) | |
549 | (size (1- len)) | |
550 | (istr 0) | |
551 | (n-esc 0)) | |
552 | ;; count number of escapes | |
553 | (while (< istr size) | |
554 | (setq istr (+ istr | |
555 | (if (= (aref str istr) ?\\) | |
556 | (progn | |
557 | (setq n-esc (1+ n-esc)) | |
558 | 2) | |
559 | 1)))) | |
560 | (if (zerop n-esc) | |
561 | ;; no escapes | |
562 | str | |
563 | ;; at least one escape | |
564 | (let ((new (make-string (- len n-esc) ?\ )) | |
565 | (inew 0)) | |
566 | ;; eliminate all escapes | |
567 | (setq istr 0) | |
568 | (while (> n-esc 0) | |
569 | (and (= (aref str istr) ?\\) | |
570 | (setq istr (1+ istr) | |
571 | n-esc (1- n-esc))) | |
572 | (aset new inew (aref str istr)) | |
573 | (setq inew (1+ inew) | |
574 | istr (1+ istr))) | |
575 | ;; remaining string has no escape | |
576 | (while (< istr len) | |
577 | (aset new inew (aref str istr)) | |
578 | (setq inew (1+ inew) | |
579 | istr (1+ istr))) | |
580 | new)))) | |
581 | ||
582 | \f | |
583 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
584 | ||
585 | ||
586 | (provide 'ebnf-bnf) | |
587 | ||
588 | ||
ab5796a9 | 589 | ;;; arch-tag: 3b1834d3-8367-475b-80d5-8e0bbd00ce50 |
984ae001 | 590 | ;;; ebnf-bnf.el ends here |