# auctex / texmathp.el

  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 ;; texmathp.el -- Code to check if point is inside LaTeX math environment ;; Copyright (c) 1998 Carsten Dominik ;; Copyright (C) 2004 Free Software Foundation, Inc. ;; texmathp.el,v 1.28 1998/11/23 15:19:44 dominik Exp ;; Author: Carsten Dominik ;; Keywords: tex ;; ;; New versions: http://strw.leidenuniv.nl/~dominik/Tools ;; ;; This file is not part of GNU Emacs ;; ;; COPYRIGHT NOTICE ;; ;; This program 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 2 of the License, or (at your option) ;; any later version. ;; ;; This program 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 you did not, write to the Free Software Foundation, ;; Inc., 675 Mass Ave., Cambridge, MA 02139, USA. ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;;; Commentary: ;; ;; This code provides a function to determine if point in a buffer is ;; inside a (La)TeX math environment. This is not trivial since many ;; different ways are used to switch between the two. Examples: ;; ;; $$...$$ ;; $...$ ;; $$...$$ ;; $...$ ;; \ensuremath{...} ;; \mbox{...} ;; ;; To install, put this file on your load-path and compile it. ;; ;; To use this in a Lisp program, do ;; ;; (require 'texmathp) ;; ;; You can then write code like this: ;; ;; (if (texmathp) ...) ;; ;; The call to texmathp' leaves some extra information in the ;; variable texmathp-why'. It's value is a cons cell (MATCH . POSITION), ;; specifying which command at what position is responsible for math ;; mode being on or off. ;; ;; To configure which macros and environments influence LaTeX math mode, ;; customize the variable texmathp-tex-commands'. By default ;; it recognizes the LaTeX core as well as AMS-LaTeX (see the variable ;; texmathp-tex-commands-default', also as an example). ;; ;; To try out the code interactively, use M-x texmathp RET'. ;; ;; Of course, in order to work this function has to assume that the ;; LaTeX above point is syntactically correct. In particular: ;; ;; o The different math delimiters are paired correctly. Thus if ;; you do things like " " or "$... \)" ;; the result of (texmathp) is undefined. It is in fact possible ;; in LaTeX to pair \[ with and $$with , but this will confuse ;; texmathp (and human readers as well). ;; ;; o However, texmathp will correctly work with nested delimiters. ;; Something like the following will be parsed correctly at any point: ;; ;; ;; x = y \mbox{abc \ensuremath{\alpha} cba 2^3} ;; ;; ;; o texmathp is somewhat forgiving if you have an empty line inside ;; the current math environment, which is not legal in TeX but may ;; easily happen during editing. Depending upon the variable ;; texmathp-search-n-paragraphs' several paragraphs are checked ;; backwards, by default 2. Paragraph here means something limited ;; by an empty line. ;;-------------------------------------------------------------------------- ;; ;; BUGS: ;; ;; If any of the the special macros like \mbox or \ensuremath has optional ;; arguments, math mode inside these optional arguments is *not* influenced ;; by the macro. ;;-------------------------------------------------------------------------- ;;; Code: ;; Safety-check for the old customize package. (eval-and-compile (condition-case () (require 'custom) (error nil)) (if (and (featurep 'custom) (fboundp 'custom-declare-variable)) nil (defmacro defgroup (&rest args) nil) (defmacro defcustom (var value doc &rest args) ( (defvar (, var) (, value) (, doc)))))) (defgroup texmathp nil "Testing TeX and LaTeX documents for math mode." :tag "Test For TeX and LaTeX Math Mode" :prefix "texmathp-" :group 'tex) ;; Some internal variables which are computed from texmathp-tex-commands' ;; and texmathp-tex-commands-default'. (defvar texmathp-environments nil) (defvar texmathp-macros nil) (defvar texmathp-onoff-regexp nil) (defvar texmathp-toggle-regexp nil) (defvar texmathp-tex-commands1 nil) (defvar texmathp-memory nil) (defvar texmathp-tex-commands) ; silence the compiler (defvar texmathp-tex-commands-default '(;; Plain TeX ("" sw-toggle) ("" sw-toggle) ("\\hbox" arg-off) ("\\vbox" arg-off) ("\\vtop" arg-off) ("\\vcenter" arg-off) ;; Standard LaTeX ("equation" env-on) ("equation*" env-on) ("eqnarray" env-on) ("eqnarray*" env-on) ("math" env-on) ("displaymath" env-on) ("\\fbox" arg-off) ("\\mbox" arg-off) ("\\label" arg-off) ("\\(" sw-on) ("\$$" sw-off) ("\\[" sw-on) ("\$" sw-off) ("\\ensuremath" arg-on) ;; AMS-LaTeX ("align" env-on) ("align*" env-on) ("gather" env-on) ("gather*" env-on) ("multline" env-on) ("multline*" env-on) ("flalign" env-on) ("flalign*" env-on) ("alignat" env-on) ("alignat*" env-on) ("xalignat" env-on) ("xalignat*" env-on) ("xxalignat" env-on) ("xxalignat*" env-on) ("\\text" arg-off) ("\\intertext" arg-off)) "The default entries for texmathp-tex-commands', which see.") (defun texmathp-compile () "Compile the value of texmathp-tex-commands' into the internal lists. Call this when you have changed the value of that variable without using customize (customize calls it when setting the variable)." (interactive) ;; Extract lists and regexp. (setq texmathp-macros nil texmathp-environments nil) (setq texmathp-memory (cons texmathp-tex-commands texmathp-tex-commands-default)) (setq texmathp-tex-commands1 (append texmathp-tex-commands texmathp-tex-commands-default)) (let ((list (reverse texmathp-tex-commands1)) var entry type switches togglers) (while (setq entry (car list)) (setq type (nth 1 entry) list (cdr list) var (cond ((memq type '(env-on env-off)) 'texmathp-environments) ((memq type '(arg-on arg-off)) 'texmathp-macros) ((memq type '(sw-on sw-off)) 'switches) ((memq type '(sw-toggle)) 'togglers))) (set var (cons (car entry) (symbol-value var)))) (setq texmathp-onoff-regexp (concat "[^\\\\]\$$" (mapconcat 'regexp-quote switches "\\|") "\$$") texmathp-toggle-regexp (concat "\$$[^\\\\\\]\\|\\\$$\$$" (mapconcat 'regexp-quote togglers "\\|") "\$$")))) (defcustom texmathp-tex-commands nil "List of environments and macros influencing (La)TeX math mode. This user-defined list is used in addition to LaTeX and AMSLaTeX defaults. The structure of each entry is (NAME TYPE) - The first item in each entry is the name of an environment or macro. If it's a macro, include the backslash. - The second item is a symbol indicating how the command works: env-on' Environment: turns math mode for its body on env-off' Environment: turns math mode for its body off arg-on' Command: turns math mode for its arguments on arg-off' Command: turns math mode for its arguments off sw-on' Switch: turns math-mode of following text on sw-off' Switch: turns math-mode of following text off sw-toggle' Switch: toggles math mode of following text" :group 'texmathp :set '(lambda (symbol value) (set-default symbol value) (texmathp-compile)) :type '(repeat (list :value ("" env-on) (string :tag "Name") (choice :tag "Type" (const :tag "Environment: turns math mode for its body on" env-on) (const :tag "Environment: turns math mode for its body off" env-off) (const :tag "Command: turns math mode for its argument on" arg-on) (const :tag "Command: turns math-mode for its argument off" arg-off) (const :tag "Switch: turns math-mode of following text on" sw-on) (const :tag "Switch: turns math-mode of following text off" sw-off) (const :tag "Switch: toggles math mode of following text" sw-toggle))))) (defcustom texmathp-search-n-paragraphs 2 "*Number of paragraphs to check before point. Normally, you cannot have an empty line in a math environment in (La)TeX. The fastest method to test for math mode is then limiting the search backward to the nearest empty line. However, during editing it happens that such lines exist temporarily. Therefore we look a little further. This variable determines how many empty lines we go back to fix the search limit." :group 'texmathp :type 'number) (defcustom texmathp-allow-detached-args nil "*Non-nil means, allow arguments of macros to be detached by whitespace. When this is t, aaa' will be interpreted as an argument of \bb in the following construct: \bbb [xxx] {aaa} This is legal in TeX. The disadvantage is that any number of braces expressions will be considered arguments of the macro independent of its definition." :group 'texmathp :type 'boolean) (defvar texmathp-why nil "After a call to texmathp' this variable shows why math-mode is on or off. The value is a cons cell (MATCH . POSITION). MATCH is a string like a car of an entry in texmathp-tex-commands', e.q. \"equation\" or \"\\ensuremath\" or \"\$\" or \"\". POSITION is the buffer position of the match. If there was no match, it points to the limit used for searches, usually two paragraphs up.") ;; We need our own syntax table to play with the syntax of () [] and {} ;; For speed reasons we define it statically instead of copying it each time. (defvar texmathp-syntax-table (make-syntax-table) "Syntax table used while texmathp is parsing.") (mapcar (lambda (x) (modify-syntax-entry (car x) (cdr x) texmathp-syntax-table)) '((?\\ . "\\") (?\f .">") (?\n . ">") (?% . "<") (?\[ . ".") (?$ . ".") (?\{ . "(}") (?\} . "){") (?$$. ".") (?$$ . ".") (?\" . ".") (?& . ".") (?_ . ".") (?@ . "_") (?~ . " ") (? . "\$") (?' . "w") )) ;;;###autoload (defun texmathp () "Determine if point is inside (La)TeX math mode. Returns t or nil. Additional info is placed into texmathp-why'. The functions assumes that you have (almost) syntactically correct (La)TeX in the buffer. See the variable texmathp-tex-commands' about which commands are checked." (interactive) (let* ((pos (point)) math-on sw-match (bound (save-excursion (if (re-search-backward "[\n\t][ \t]*[\n\r]" nil 1 texmathp-search-n-paragraphs) (match-beginning 0) (point-min)))) (mac-match (texmathp-match-macro bound)) (env-match (texmathp-match-environment (if (and mac-match (> (cdr mac-match) bound)) (cdr mac-match) bound))) (match (cons nil bound))) ;; Select the nearer match (and env-match (setq match env-match)) (and mac-match (> (cdr mac-match) (cdr match)) (setq match mac-match)) (setq math-on (memq (nth 1 (assoc (car match) texmathp-tex-commands1)) '(env-on arg-on))) ;; Check for switches (and (not math-on) (setq sw-match (texmathp-match-switch bound)) (> (cdr sw-match) (cdr match)) (eq (nth 1 (assoc (car sw-match) texmathp-tex-commands1)) 'sw-on) (setq match sw-match math-on t)) ;; Check for togglers (if (not math-on) (save-excursion (goto-char (cdr match)) (while (re-search-forward texmathp-toggle-regexp pos t) (if (setq math-on (not math-on)) (setq sw-match (cons (match-string 2) (match-beginning 2))) (setq sw-match nil))) (and math-on sw-match (setq match sw-match)))) ;; Store info, show as message when interactive, and return (setq texmathp-why match) (and (interactive-p) (message "math-mode is %s: %s begins at buffer position %d" (if math-on "on" "off") (or (car match) "new paragraph") (cdr match))) (and math-on t))) (defun texmathp-match-environment (bound) "Find out if point is inside any of the math environments. Limit searched to BOUND. The return value is like (\"equation\" . (point))." (catch 'exit (save-excursion (and (null texmathp-environments) (throw 'exit nil)) (let (end-list env) (while (re-search-backward "\\\\\$$begin\\|end\$${\$$[^}]+\$$}" bound t) (setq env (buffer-substring-no-properties (match-beginning 2) (match-end 2))) (cond ((string= (match-string 1) "end") (setq end-list (cons env end-list))) ((equal env (car end-list)) (setq end-list (cdr end-list))) ((member env texmathp-environments) (throw 'exit (cons env (point)))))) nil)))) (defun texmathp-match-macro (bound) "Find out if point is within the arguments of any of the Math macros. Limit searches to BOUND. The return value is like (\"\\macro\" . (point))." (catch 'exit (and (null texmathp-macros) (throw 'exit nil)) (let (pos cmd (syntax-table (syntax-table))) (unwind-protect (save-restriction (save-excursion (set-syntax-table texmathp-syntax-table) (narrow-to-region (max 1 bound) (point)) ;; Move back out of the current parenthesis (while (condition-case nil (progn (up-list -1) t) (error nil)) ;; Move back over any touching sexps (in fact also non-touching) (while (and (cond ((memq (preceding-char) '(?\] ?\}))) ((and texmathp-allow-detached-args (re-search-backward "[]}][ \t]*[\n\r]?\$$[ \t]*%[^\n\r]*[\n\r]\$$*[ \t]*\\=" bound t)) (goto-char (1+ (match-beginning 0))) t)) (if (eq (preceding-char) ?\}) ;; Jump back over {} (condition-case nil (progn (backward-sexp) t) (error nil)) ;; Jump back over []. Modify syntax temporarily for this. (unwind-protect (progn (modify-syntax-entry ?\{ ".") (modify-syntax-entry ?\} ".") (modify-syntax-entry ?$"(]") (modify-syntax-entry ?$ ")[") (condition-case nil (progn (backward-sexp) t) (error nil))) (modify-syntax-entry ?\{ "(}") (modify-syntax-entry ?\} "){") (modify-syntax-entry ?$".") (modify-syntax-entry ?$ ".") nil)))) (setq pos (point)) (and (memq (following-char) '(?\[ ?\{)) (re-search-backward "\\\\[*a-zA-Z]+\\=" nil t) (setq cmd (buffer-substring-no-properties (match-beginning 0) (match-end 0))) (member cmd texmathp-macros) (throw 'exit (cons cmd (point)))) (goto-char pos)) (throw 'exit nil))) (set-syntax-table syntax-table))))) (defun texmathp-match-switch (bound) "Search backward for any of the math switches. Limit searched to BOUND." ;; The return value is like ("\\(" . (point)). (save-excursion (if (re-search-backward texmathp-onoff-regexp bound t) (cons (buffer-substring-no-properties (match-beginning 1) (match-end 1)) (match-beginning 1)) nil))) (provide 'texmathp) ;;; texmathp.el ends here