1 ;;; ebnf-yac.el --- parser for Yacc/Bison
3 ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005
4 ;; Free Sofware Foundation, Inc.
6 ;; Author: Vinicius Jose Latorre <viniciusjl@ig.com.br>
7 ;; Maintainer: Vinicius Jose Latorre <viniciusjl@ig.com.br>
8 ;; Time-stamp: <2004/04/03 16:50:46 vinicius>
9 ;; Keywords: wp, ebnf, PostScript
12 ;; This file is part of GNU Emacs.
14 ;; GNU Emacs is free software; you can redistribute it and/or modify
15 ;; it under the terms of the GNU General Public License as published by
16 ;; the Free Software Foundation; either version 2, or (at your option)
19 ;; GNU Emacs is distributed in the hope that it will be useful,
20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 ;; GNU General Public License for more details.
24 ;; You should have received a copy of the GNU General Public License
25 ;; along with GNU Emacs; see the file COPYING. If not, write to the
26 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
27 ;; Boston, MA 02110-1301, USA.
31 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
34 ;; This is part of ebnf2ps package.
36 ;; This package defines a parser for Yacc/Bison.
38 ;; See ebnf2ps.el for documentation.
44 ;; YACC = { YACC-Definitions }* "%%" { YACC-Rule }* [ "%%" [ YACC-Code ] ].
46 ;; YACC-Definitions = ( "%token" | "%left" | "%right" | "%nonassoc" )
47 ;; [ "<" Name ">" ] Name-List
49 ;; | "any other Yacc definition"
52 ;; YACC-Code = "any C definition".
54 ;; YACC-Rule = Name ":" Alternative ";".
56 ;; Alternative = { Sequence || "|" }*.
58 ;; Sequence = { Factor }*.
61 ;; | "'" "character" "'"
63 ;; | "{" "C like commands" "}"
66 ;; Name-List = { Name || "," }*.
68 ;; Name = "[A-Za-z][A-Za-z0-9_.]*".
70 ;; Comment = "/*" "any character, but the sequence \"*/\"" "*/"
71 ;; | "//" "any character, but the newline \"\\n\"" "\\n".
74 ;; In other words, a valid Name begins with a letter (upper or lower case)
75 ;; followed by letters, decimal digits, underscore (_) or point (.). For
76 ;; example: this_is_a_valid.name, Another_EXAMPLE, mIxEd.CaSe.
82 ;; Thanks to Matthew K. Junker <junker@alum.mit.edu> for the suggestion to deal
83 ;; with %right, %left and %prec pragmas. His suggestion was extended to deal
84 ;; with %nonassoc pragma too.
87 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
95 (defvar ebnf-yac-lex nil
96 "Value returned by `ebnf-yac-lex' function.")
99 (defvar ebnf-yac-token-list nil
100 "List of `%TOKEN' names.")
103 (defvar ebnf-yac-skip-char nil
104 "Non-nil means skip printable characters with no grammatical meaning.")
107 (defvar ebnf-yac-error nil
108 "Non-nil means \"error\" occurred.")
111 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
112 ;; Syntactic analyzer
115 ;;; YACC = { YACC-Definitions }* "%%" { YACC-Rule }* [ "%%" [ YACC-Code ] ].
117 ;;; YACC-Code = "any C definition".
119 (defun ebnf-yac-parser (start)
121 (let ((total (+ (- ebnf-limit start
) 1))
124 syntax-list token rule
)
126 (setq token
(ebnf-yac-lex))
127 (and (eq token
'end-of-input
)
128 (error "Invalid Yacc/Bison file format"))
129 (or (eq (ebnf-yac-definitions token
) 'yac-separator
)
130 (error "Missing `%%%%'"))
131 (setq token
(ebnf-yac-lex))
132 (while (not (memq token
'(end-of-input yac-separator
)))
135 (/ (* (- (point) bias
) 100.0) total
))
136 (setq token
(ebnf-yac-rule token
)
139 (or (ebnf-add-empty-rule-list rule
)
140 (setq syntax-list
(cons rule syntax-list
))))
145 ;;; YACC-Definitions = ( "%token" | "%left" | "%right" | "%nonassoc" )
146 ;;; [ "<" Name ">" ] Name-List
148 ;;; | "any other Yacc definition"
151 (defun ebnf-yac-definitions (token)
152 (let ((ebnf-yac-skip-char t
))
153 (while (not (memq token
'(yac-separator end-of-input
)))
156 ;; ( "%token" | "%left" | "%right" | "%nonassoc" )
157 ;; [ "<" Name ">" ] Name-List
158 ((eq token
'yac-token
)
159 (setq token
(ebnf-yac-lex))
160 (when (eq token
'open-angle
)
161 (or (eq (ebnf-yac-lex) 'non-terminal
)
162 (error "Missing type name"))
163 (or (eq (ebnf-yac-lex) 'close-angle
)
164 (error "Missing `>'"))
165 (setq token
(ebnf-yac-lex)))
166 (setq token
(ebnf-yac-name-list token
)
167 ebnf-yac-token-list
(nconc (cdr token
)
168 ebnf-yac-token-list
))
171 ((eq token
'yac-prec
)
172 (or (eq (ebnf-yac-lex) 'non-terminal
)
173 (error "Missing prec name"))
175 ;; "any other Yacc definition"
182 ;;; YACC-Rule = Name ":" Alternative ";".
184 (defun ebnf-yac-rule (token)
185 (let ((header ebnf-yac-lex
)
188 (setq ebnf-action nil
)
189 (or (eq token
'non-terminal
)
190 (error "Invalid rule name"))
191 (or (eq (ebnf-yac-lex) 'colon
)
192 (error "Invalid rule: missing `:'"))
193 (setq body
(ebnf-yac-alternative))
194 (or (eq (car body
) 'period
)
195 (error "Invalid rule: missing `;'"))
196 (setq body
(cdr body
))
197 (ebnf-eps-add-production header
)
199 (ebnf-make-production header body action
))))
202 ;;; Alternative = { Sequence || "|" }*.
204 (defun ebnf-yac-alternative ()
206 (while (eq (car (setq sequence
(ebnf-yac-sequence)))
208 (and (setq sequence
(cdr sequence
))
209 (setq body
(cons sequence body
))))
210 (ebnf-token-alternative body sequence
)))
213 ;;; Sequence = { Factor }*.
215 (defun ebnf-yac-sequence ()
216 (let (ebnf-yac-error token seq factor
)
217 (while (setq token
(ebnf-yac-lex)
218 factor
(ebnf-yac-factor token
))
219 (setq seq
(cons factor seq
)))
221 (if (and ebnf-yac-ignore-error-recovery ebnf-yac-error
)
222 ;; ignore error recovery
224 (ebnf-token-sequence seq
)))))
228 ;;; | "'" "character" "'"
230 ;;; | "{" "C like commands" "}"
233 (defun ebnf-yac-factor (token)
236 ((eq token
'terminal
)
237 (ebnf-make-terminal ebnf-yac-lex
))
239 ((eq token
'non-terminal
)
240 (ebnf-make-non-terminal ebnf-yac-lex
))
242 ((eq token
'yac-error
)
243 (ebnf-make-special ebnf-yac-lex
))
250 ;;; Name-List = { Name || "," }*.
252 (defun ebnf-yac-name-list (token)
254 (when (eq token
'non-terminal
)
256 (setq names
(cons ebnf-yac-lex names
)
257 token
(ebnf-yac-lex))
259 (or (eq (ebnf-yac-lex) 'non-terminal
)
260 (error "Missing token name"))))
264 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
268 ;;; Name = "[A-Za-z][A-Za-z0-9_.]*".
270 ;;; Comment = "/*" "any character, but the sequence \"*/\"" "*/"
271 ;;; | "//" "any character" "\\n".
273 (defconst ebnf-yac-token-table
274 ;; control character & 8-bit character are set to `error'
275 (let ((table (make-vector 256 'error
)))
276 ;; upper & lower case letters:
279 (aset table char
'non-terminal
))
280 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")
281 ;; printable characters:
284 (aset table char
'character
))
285 "!#$&()*+-.0123456789=?@[\\]^_`~")
286 ;; Override space characters:
287 (aset table ?
\n 'space
) ; [NL] linefeed
288 (aset table ?
\r 'space
) ; [CR] carriage return
289 (aset table ?
\t 'space
) ; [HT] horizontal tab
290 (aset table ?\
'space
) ; [SP] space
291 ;; Override form feed character:
292 (aset table ?
\f 'form-feed
) ; [FF] form feed
293 ;; Override other lexical characters:
294 (aset table ?
< 'open-angle
)
295 (aset table ?
> 'close-angle
)
296 (aset table ?
, 'comma
)
297 (aset table ?%
'yac-pragma
)
298 (aset table ?
/ 'slash
)
299 (aset table ?\
{ 'yac-code
)
300 (aset table ?
\" 'string
)
301 (aset table ?
\' 'terminal
)
302 (aset table ?
: 'colon
)
303 (aset table ?|
'alternative
)
304 (aset table ?\
; 'period)
306 "Vector used to map characters to a lexical token.")
309 (defun ebnf-yac-initialize ()
310 "Initializations for Yacc/Bison parser."
311 (setq ebnf-yac-token-list nil
))
314 (defun ebnf-yac-lex ()
315 "Lexical analyzer for Yacc/Bison.
317 Return a lexical token.
319 See documentation for variable `ebnf-yac-lex'."
320 (if (>= (point) ebnf-limit
)
323 ;; skip spaces, code blocks and comments
324 (while (if (> (following-char) 255)
328 (setq token
(aref ebnf-yac-token-table
(following-char)))
330 ((or (eq token
'space
)
331 (and ebnf-yac-skip-char
332 (eq token
'character
)))
333 (ebnf-yac-skip-spaces))
334 ((eq token
'yac-code
)
335 (ebnf-yac-skip-code))
337 (ebnf-yac-handle-comment))
338 ((eq token
'form-feed
)
340 (setq ebnf-action
'form-feed
))
345 ((>= (point) ebnf-limit
)
349 (error "Invalid character"))
352 (setq ebnf-yac-lex
(ebnf-get-string))
355 ((eq token
'terminal
)
356 (setq ebnf-yac-lex
(ebnf-string " -&(-~" ?
\' "terminal"))
358 ;; non-terminal, terminal or "error"
359 ((eq token
'non-terminal
)
360 (setq ebnf-yac-lex
(ebnf-buffer-substring "0-9A-Za-z_."))
361 (cond ((member ebnf-yac-lex ebnf-yac-token-list
)
363 ((string= ebnf-yac-lex
"error")
364 (setq ebnf-yac-error t
)
369 ;; %% and Yacc pragmas (%TOKEN, %START, etc).
370 ((eq token
'yac-pragma
)
374 ((eq (following-char) ?%
)
377 ;; %TOKEN, %RIGHT, %LEFT, %PREC, %NONASSOC
378 ((cdr (assoc (upcase (ebnf-buffer-substring "0-9A-Za-z_"))
379 '(("TOKEN" . yac-token
)
380 ("RIGHT" . yac-token
)
382 ("NONASSOC" . yac-token
)
383 ("PREC" . yac-prec
)))))
384 ;; other Yacc pragmas
395 (defun ebnf-yac-skip-spaces ()
397 (if ebnf-yac-skip-char
398 "\n\r\t !#$&()*+-.0123456789=?@[\\\\]^_`~"
401 (< (point) ebnf-limit
))
404 ;; replace the range "\177-\377" (see `ebnf-range-regexp').
405 (defconst ebnf-yac-skip-chars
406 (ebnf-range-regexp "^{}/'\"\000-\010\013\016-\037" ?
\177 ?
\377))
409 (defun ebnf-yac-skip-code ()
413 (skip-chars-forward ebnf-yac-skip-chars ebnf-limit
)
415 ((= (following-char) ?
{)
417 (setq pair
(1+ pair
)))
418 ((= (following-char) ?
})
420 (setq pair
(1- pair
)))
421 ((= (following-char) ?
/)
422 (ebnf-yac-handle-comment))
423 ((= (following-char) ?
\")
425 ((= (following-char) ?
\')
426 (ebnf-string " -&(-~" ?
\' "character"))
428 (error "Invalid character"))
430 (ebnf-yac-skip-spaces))
433 (defun ebnf-yac-handle-comment ()
437 ((= (following-char) ?
*)
438 (ebnf-yac-skip-comment)
439 (ebnf-yac-skip-spaces))
441 ((= (following-char) ?
/)
443 (ebnf-yac-skip-spaces))
449 ;; replace the range "\177-\237" (see `ebnf-range-regexp').
450 (defconst ebnf-yac-comment-chars
451 (ebnf-range-regexp "^*\000-\010\013\016-\037" ?
\177 ?
\237))
454 (defun ebnf-yac-skip-comment ()
458 ((and ebnf-eps-executing
(= (following-char) ?\
[))
459 (ebnf-eps-add-context (ebnf-yac-eps-filename)))
461 ((and ebnf-eps-executing
(= (following-char) ?\
]))
462 (ebnf-eps-remove-context (ebnf-yac-eps-filename)))
463 ;; any other action in comment
465 (setq ebnf-action
(aref ebnf-comment-table
(following-char))))
469 (skip-chars-forward ebnf-yac-comment-chars ebnf-limit
)
470 (cond ((>= (point) ebnf-limit
)
471 (error "Missing end of comment: `*/'"))
472 ((= (following-char) ?
*)
473 (skip-chars-forward "*" ebnf-limit
)
474 (when (= (following-char) ?
/)
479 (error "Invalid character"))
483 (defun ebnf-yac-eps-filename ()
485 (buffer-substring-no-properties
487 (let ((chars (concat ebnf-yac-comment-chars
"\n"))
490 (skip-chars-forward chars ebnf-limit
)
492 (cond ((>= (point) ebnf-limit
)
494 ((= (following-char) ?
*)
495 (skip-chars-forward "*" ebnf-limit
)
496 (if (/= (following-char) ?\
/)
506 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
512 ;;; arch-tag: 8a96989c-0b1d-42ba-a020-b2901f9a2a4d
513 ;;; ebnf-yac.el ends here