1 ;;; ebnf-yac.el --- parser for Yacc/Bison
3 ;; Copyright (C) 1999, 2000, 2001 Free Sofware Foundation, Inc.
5 ;; Author: Vinicius Jose Latorre <vinicius@cpqd.com.br>
6 ;; Maintainer: Vinicius Jose Latorre <vinicius@cpqd.com.br>
7 ;; Keywords: wp, ebnf, PostScript
8 ;; Time-stamp: <2001/09/24 10:17:13 vinicius>
11 ;; This file is part of GNU Emacs.
13 ;; GNU Emacs is free software; you can redistribute it and/or modify
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)
18 ;; GNU Emacs is distributed in the hope that it will be useful,
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.
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.
30 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
33 ;; This is part of ebnf2ps package.
35 ;; This package defines a parser for Yacc/Bison.
37 ;; See ebnf2ps.el for documentation.
43 ;; YACC = { YACC-Definitions }* "%%" { YACC-Rule }* [ "%%" [ YACC-Code ] ].
45 ;; YACC-Definitions = "%token" [ "<" Name ">" ] Name-List
46 ;; | "any other Yacc definition"
49 ;; YACC-Code = "any C definition".
51 ;; YACC-Rule = Name ":" Alternative ";".
53 ;; Alternative = { Sequence || "|" }*.
55 ;; Sequence = { Factor }*.
58 ;; | "'" "character" "'"
60 ;; | "{" "C like commands" "}"
63 ;; Name-List = { Name || "," }*.
65 ;; Name = "[A-Za-z][A-Za-z0-9_.]*".
67 ;; Comment = "/*" "any character, but the sequence \"*/\"" "*/"
68 ;; | "//" "any character" "\\n".
71 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
79 (defvar ebnf-yac-lex nil
80 "Value returned by `ebnf-yac-lex' function.")
83 (defvar ebnf-yac-token-list nil
84 "List of `%TOKEN' names.")
87 (defvar ebnf-yac-skip-char nil
88 "Non-nil means skip printable characters with no grammatical meaning.")
91 (defvar ebnf-yac-error nil
92 "Non-nil means \"error\" occured.")
95 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
99 ;;; YACC = { YACC-Definitions }* "%%" { YACC-Rule }* [ "%%" [ YACC-Code ] ].
101 ;;; YACC-Code = "any C definition".
103 (defun ebnf-yac-parser (start)
105 (let ((total (+ (- ebnf-limit start) 1))
108 syntax-list token rule)
110 (setq token (ebnf-yac-lex))
111 (and (eq token 'end-of-input)
112 (error "Invalid Yacc/Bison file format"))
113 (or (eq (ebnf-yac-definitions token) 'yac-separator)
114 (error "Missing `%%%%'"))
115 (setq token (ebnf-yac-lex))
116 (while (not (memq token '(end-of-input yac-separator)))
119 (/ (* (- (point) bias) 100.0) total))
120 (setq token (ebnf-yac-rule token)
123 (or (ebnf-add-empty-rule-list rule)
124 (setq syntax-list (cons rule syntax-list))))
129 ;;; YACC-Definitions = "%token" [ "<" Name ">" ] Name-List
130 ;;; | "any other Yacc definition"
133 (defun ebnf-yac-definitions (token)
134 (let ((ebnf-yac-skip-char t))
135 (while (not (memq token '(yac-separator end-of-input)))
138 ;; "%token" [ "<" Name ">" ] Name-List
139 ((eq token 'yac-token)
140 (setq token (ebnf-yac-lex))
141 (when (eq token 'open-angle)
142 (or (eq (ebnf-yac-lex) 'non-terminal)
143 (error "Missing type name"))
144 (or (eq (ebnf-yac-lex) 'close-angle)
145 (error "Missing `>'"))
146 (setq token (ebnf-yac-lex)))
147 (setq token (ebnf-yac-name-list token)
148 ebnf-yac-token-list (nconc (cdr token)
149 ebnf-yac-token-list))
151 ;; "any other Yacc definition"
158 ;;; YACC-Rule = Name ":" Alternative ";".
160 (defun ebnf-yac-rule (token)
161 (let ((header ebnf-yac-lex)
164 (setq ebnf-action nil)
165 (or (eq token 'non-terminal)
166 (error "Invalid rule name"))
167 (or (eq (ebnf-yac-lex) 'colon)
168 (error "Invalid rule: missing `:'"))
169 (setq body (ebnf-yac-alternative))
170 (or (eq (car body) 'period)
171 (error "Invalid rule: missing `;'"))
172 (setq body (cdr body))
173 (ebnf-eps-add-production header)
175 (ebnf-make-production header body action))))
178 ;;; Alternative = { Sequence || "|" }*.
180 (defun ebnf-yac-alternative ()
182 (while (eq (car (setq sequence (ebnf-yac-sequence)))
184 (and (setq sequence (cdr sequence))
185 (setq body (cons sequence body))))
186 (ebnf-token-alternative body sequence)))
189 ;;; Sequence = { Factor }*.
191 (defun ebnf-yac-sequence ()
192 (let (ebnf-yac-error token seq factor)
193 (while (setq token (ebnf-yac-lex)
194 factor (ebnf-yac-factor token))
195 (setq seq (cons factor seq)))
198 ;; ignore error recovery
199 ((and ebnf-yac-ignore-error-recovery ebnf-yac-error)
204 ;; sequence with only one element
209 (ebnf-make-sequence (nreverse seq)))
214 ;;; | "'" "character" "'"
216 ;;; | "{" "C like commands" "}"
219 (defun ebnf-yac-factor (token)
222 ((eq token 'terminal)
223 (ebnf-make-terminal ebnf-yac-lex))
225 ((eq token 'non-terminal)
226 (ebnf-make-non-terminal ebnf-yac-lex))
228 ((eq token 'yac-error)
229 (ebnf-make-special ebnf-yac-lex))
236 ;;; Name-List = { Name || "," }*.
238 (defun ebnf-yac-name-list (token)
240 (when (eq token 'non-terminal)
242 (setq names (cons ebnf-yac-lex names)
243 token (ebnf-yac-lex))
245 (or (eq (ebnf-yac-lex) 'non-terminal)
246 (error "Missing token name"))))
250 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
254 ;;; Name = "[A-Za-z][A-Za-z0-9_.]*".
256 ;;; Comment = "/*" "any character, but the sequence \"*/\"" "*/"
257 ;;; | "//" "any character" "\\n".
259 (defconst ebnf-yac-token-table
260 ;; control character & 8-bit character are set to `error'
261 (let ((table (make-vector 256 'error)))
262 ;; upper & lower case letters:
265 (aset table char 'non-terminal))
266 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")
267 ;; printable characters:
270 (aset table char 'character))
271 "!#$&()*+-.0123456789=?@[\\]^_`~")
272 ;; Override space characters:
273 (aset table ?\n 'space) ; [NL] linefeed
274 (aset table ?\r 'space) ; [CR] carriage return
275 (aset table ?\t 'space) ; [HT] horizontal tab
276 (aset table ?\ 'space) ; [SP] space
277 ;; Override form feed character:
278 (aset table ?\f 'form-feed) ; [FF] form feed
279 ;; Override other lexical characters:
280 (aset table ?< 'open-angle)
281 (aset table ?> 'close-angle)
282 (aset table ?, 'comma)
283 (aset table ?% 'yac-pragma)
284 (aset table ?/ 'slash)
285 (aset table ?\{ 'yac-code)
286 (aset table ?\" 'string)
287 (aset table ?\' 'terminal)
288 (aset table ?: 'colon)
289 (aset table ?| 'alternative)
290 (aset table ?\; 'period)
292 "Vector used to map characters to a lexical token.")
295 (defun ebnf-yac-initialize ()
296 "Initializations for Yacc/Bison parser."
297 (setq ebnf-yac-token-list nil))
300 (defun ebnf-yac-lex ()
301 "Lexical analyser for Yacc/Bison.
303 Return a lexical token.
305 See documentation for variable `ebnf-yac-lex'."
306 (if (>= (point) ebnf-limit)
309 ;; skip spaces, code blocks and comments
310 (while (if (> (following-char) 255)
314 (setq token (aref ebnf-yac-token-table (following-char)))
316 ((or (eq token 'space)
317 (and ebnf-yac-skip-char
318 (eq token 'character)))
319 (ebnf-yac-skip-spaces))
320 ((eq token 'yac-code)
321 (ebnf-yac-skip-code))
323 (ebnf-yac-handle-comment))
324 ((eq token 'form-feed)
326 (setq ebnf-action 'form-feed))
331 ((>= (point) ebnf-limit)
335 (error "Illegal character"))
338 (setq ebnf-yac-lex (ebnf-get-string))
341 ((eq token 'terminal)
342 (setq ebnf-yac-lex (ebnf-string " -&(-~" ?\' "terminal"))
344 ;; non-terminal, terminal or "error"
345 ((eq token 'non-terminal)
346 (setq ebnf-yac-lex (ebnf-buffer-substring "0-9A-Za-z_."))
347 (cond ((member ebnf-yac-lex ebnf-yac-token-list)
349 ((string= ebnf-yac-lex "error")
350 (setq ebnf-yac-error t)
355 ;; %% and Yacc pragmas (%TOKEN, %START, etc).
356 ((eq token 'yac-pragma)
360 ((eq (following-char) ?%)
364 ((string= (upcase (ebnf-buffer-substring "0-9A-Za-z_")) "TOKEN")
366 ;; other Yacc pragmas
377 (defun ebnf-yac-skip-spaces ()
379 (if ebnf-yac-skip-char
380 "\n\r\t !#$&()*+-.0123456789=?@[\\\\]^_`~"
383 (< (point) ebnf-limit))
386 ;; replace the range "\177-\377" (see `ebnf-range-regexp').
387 (defconst ebnf-yac-skip-chars
388 (ebnf-range-regexp "^{}/'\"\000-\010\013\016-\037" ?\177 ?\377))
391 (defun ebnf-yac-skip-code ()
395 (skip-chars-forward ebnf-yac-skip-chars ebnf-limit)
397 ((= (following-char) ?{)
399 (setq pair (1+ pair)))
400 ((= (following-char) ?})
402 (setq pair (1- pair)))
403 ((= (following-char) ?/)
404 (ebnf-yac-handle-comment))
405 ((= (following-char) ?\")
407 ((= (following-char) ?\')
408 (ebnf-string " -&(-~" ?\' "character"))
410 (error "Illegal character"))
412 (ebnf-yac-skip-spaces))
415 (defun ebnf-yac-handle-comment ()
419 ((= (following-char) ?*)
420 (ebnf-yac-skip-comment)
421 (ebnf-yac-skip-spaces))
423 ((= (following-char) ?/)
425 (ebnf-yac-skip-spaces))
431 ;; replace the range "\177-\237" (see `ebnf-range-regexp').
432 (defconst ebnf-yac-comment-chars
433 (ebnf-range-regexp "^*\000-\010\013\016-\037" ?\177 ?\237))
436 (defun ebnf-yac-skip-comment ()
440 ((and ebnf-eps-executing (= (following-char) ?\[))
441 (ebnf-eps-add-context (ebnf-yac-eps-filename)))
443 ((and ebnf-eps-executing (= (following-char) ?\]))
444 (ebnf-eps-remove-context (ebnf-yac-eps-filename)))
445 ;; any other action in comment
447 (setq ebnf-action (aref ebnf-comment-table (following-char))))
451 (skip-chars-forward ebnf-yac-comment-chars ebnf-limit)
452 (cond ((>= (point) ebnf-limit)
453 (error "Missing end of comment: `*/'"))
454 ((= (following-char) ?*)
455 (skip-chars-forward "*" ebnf-limit)
456 (when (= (following-char) ?/)
461 (error "Illegal character"))
465 (defun ebnf-yac-eps-filename ()
467 (buffer-substring-no-properties
469 (let ((chars (concat ebnf-yac-comment-chars "\n"))
472 (skip-chars-forward chars ebnf-limit)
474 (cond ((>= (point) ebnf-limit)
476 ((= (following-char) ?*)
477 (skip-chars-forward "*" ebnf-limit)
478 (if (/= (following-char) ?\/)
488 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
494 ;;; ebnf-yac.el ends here