1;;; align.el --- align text to a specific column, by regexp
2
3;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: John Wiegley <johnw@gnu.org>
7;; Maintainer: FSF
8;; Keywords: convenience languages lisp
9
10;; This file is part of GNU Emacs.
11
12;; GNU Emacs is free software; you can redistribute it and/or modify
13;; it under the terms of the GNU General Public License as published by
14;; the Free Software Foundation; either version 2, or (at your option)
15;; any later version.
16
17;; GNU Emacs is distributed in the hope that it will be useful,
18;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20;; GNU General Public License for more details.
21
22;; You should have received a copy of the GNU General Public License
23;; along with GNU Emacs; see the file COPYING.  If not, write to the
24;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
25;; Boston, MA 02110-1301, USA.
26
27;;; Commentary:
28
29;; This mode allows you to align regions in a context-sensitive fashion.
30;; The classic use is to align assignments:
31;;
32;;    int a = 1;
33;;    short foo = 2;
34;;    double blah = 4;
35;;
36;; becomes
37;;
38;;    int    a    = 1;
39;;    short  foo  = 2;
40;;    double blah = 4;
41
42;;; Usage:
43
44;; There are several variables which define how certain "categories"
45;; of syntax are to be treated.  These variables go by the name
46;; `align-CATEGORY-modes'.  For example, "c++" is such a category.
47;; There are several rules which apply to c++, but since several other
48;; languages have a syntax similar to c++ (e.g., c, java, etc), these
49;; modes are treated as belonging to the same category.
50;;
51;; If you want to add a new mode under a certain category, just
52;; customize that list, or add the new mode manually.  For example, to
53;; make jde-mode a c++ category mode, use this code in your .emacs
54;; file:
55;;
56;;    (setq align-c++-modes (cons 'jde-mode align-c++-modes))
57
58;; In some programming modes, it's useful to have the aligner run only
59;; after indentation is performed.  To achieve this, customize or set
60;; the variable `align-indent-before-aligning' to t.
61
62;;; Module Authors:
63
64;; In order to incorporate align's functionality into your own
65;; modules, there are only a few steps you have to follow.
66
67;;  1. Require or load in the align.el library.
68;;
69;;  2. Define your alignment and exclusion rules lists, either
70;;     customizable or not.
71;;
72;;  3. In your mode function, set the variables
73;;     `align-mode-rules-list' and `align-mode-exclude-rules-list'
74;;     to your own rules lists.
75
76;; If there is any need to add your mode name to one of the
77;; align-?-modes variables (for example, `align-dq-string-modes'), use
78;; `add-to-list', or some similar function which checks first to see
79;; if the value is already there.  Since the user may customize that
80;; mode list, and then write your mode name into their .emacs file,
81;; causing the symbol already to be present the next time they load
82;; your package.
83
84;; Example:
85;;
86;;   (require 'align)
87;;
88;;   (defcustom my-align-rules-list
89;;     '((my-rule
90;;        (regexp . "Sample")))
91;;     :type align-rules-list-type
92;;     :group 'my-package)
93;;
94;;   (put 'my-align-rules-list 'risky-local-variable t)
95;;
96;;   (add-to-list 'align-dq-string-modes 'my-package-mode)
97;;   (add-to-list 'align-open-comment-modes 'my-package-mode)
98;;
99;;   (defun my-mode ()
100;;      ...
101;;      (setq align-mode-rules-list my-align-rules-list))
102;;
103;; Note that if you need to install your own exclusion rules, then you
104;; will also need to reproduce any double-quoted string, or open
105;; comment exclusion rules that are defined in the standard
106;; `align-exclude-rules-list'.  At the moment there is no convenient
107;; way to mix both mode-local and global rules lists.
108
109;;; History:
110
111;; Version 1.0 was created in the earlier part of 1996, using a very
112;; simple algorithm that understand only basic regular expressions.
113;; Parts of the code were broken up and included in vhdl-mode.el
114;; around this time.  After several comments from users, and a need to
115;; find a more robust, performant algorithm, 2.0 was born in late
116;; 1998.  Many different approaches were taken (mostly due to the
117;; complexity of TeX tables), but finally a scheme was discovered
118;; which worked fairly well for most common usage cases.  Development
119;; beyond version 2.8 is not planned, except for problems that users
120;; might encounter.
121
122;;; Code:
123
124(defgroup align nil
125  "Align text to a specific column, by regexp."
126  :version "21.1"
127  :group 'fill)
128
129;;; User Variables:
130
131(defcustom align-load-hook nil
132  "*Hook that gets run after the aligner has been loaded."
133  :type 'hook
134  :group 'align)
135
136(defcustom align-indent-before-aligning nil
137  "*If non-nil, indent the marked region before aligning it."
138  :type 'boolean
139  :group 'align)
140
141(defcustom align-default-spacing 1
142  "*An integer that represents the default amount of padding to use.
143If `align-to-tab-stop' is non-nil, this will represent the number of
144tab stops to use for alignment, rather than the number of spaces.
145Each alignment rule can optionally override both this variable.  See
146`align-mode-alist'."
147  :type 'integer
148  :group 'align)
149
150(defcustom align-to-tab-stop 'indent-tabs-mode
151  "*If non-nil, alignments will always fall on a tab boundary.
152It may also be a symbol, whose value will be taken."
153  :type '(choice (const nil) symbol)
154  :group 'align)
155
156(defcustom align-region-heuristic 500
157  "*If non-nil, used as a heuristic by `align-current'.
158Since each alignment rule can possibly have its own set of alignment
159sections (whenever `align-region-separate' is non-nil, and not a
160string), this heuristic is used to determine how far before and after
161point we should search in looking for a region separator.  Larger
162values can mean slower perform in large files, although smaller values
163may cause unexpected behavior at times."
164  :type 'integer
165  :group 'align)
166
167(defcustom align-highlight-change-face 'highlight
168  "*The face to highlight with if changes are necessary."
169  :type 'face
170  :group 'align)
171
172(defcustom align-highlight-nochange-face 'secondary-selection
173  "*The face to highlight with if no changes are necessary."
174  :type 'face
175  :group 'align)
176
177(defcustom align-large-region 10000
178  "*If an integer, defines what constitutes a \"large\" region.
179If nil,then no messages will ever be printed to the minibuffer."
180  :type 'integer
181  :group 'align)
182
183(defcustom align-c++-modes '(c++-mode c-mode java-mode)
184  "*A list of modes whose syntax resembles C/C++."
185  :type '(repeat symbol)
186  :group 'align)
187
188(defcustom align-perl-modes '(perl-mode cperl-mode)
189  "*A list of modes where perl syntax is to be seen."
190  :type '(repeat symbol)
191  :group 'align)
192
193(defcustom align-lisp-modes
194  '(emacs-lisp-mode lisp-interaction-mode lisp-mode scheme-mode)
195  "*A list of modes whose syntax resembles Lisp."
196  :type '(repeat symbol)
197  :group 'align)
198
199(defcustom align-tex-modes
200  '(tex-mode plain-tex-mode latex-mode slitex-mode)
201  "*A list of modes whose syntax resembles TeX (and family)."
202  :type '(repeat symbol)
203  :group 'align)
204
205(defcustom align-text-modes '(text-mode outline-mode)
206  "*A list of modes whose content is plain text."
207  :type '(repeat symbol)
208  :group 'align)
209
210(defcustom align-dq-string-modes
211  (append align-lisp-modes align-c++-modes align-perl-modes
212	  '(python-mode))
213  "*A list of modes where double quoted strings should be excluded."
214  :type '(repeat symbol)
215  :group 'align)
216
217(defcustom align-sq-string-modes
218  (append align-perl-modes '(python-mode))
219  "*A list of modes where single quoted strings should be excluded."
220  :type '(repeat symbol)
221  :group 'align)
222
223(defcustom align-open-comment-modes
224  (append align-lisp-modes align-c++-modes align-perl-modes
225	  '(python-mode makefile-mode))
226  "*A list of modes with a single-line comment syntax.
227These are comments as in Lisp, which have a beginning but, end with
228the line (i.e., `comment-end' is an empty string)."
229  :type '(repeat symbol)
230  :group 'align)
231
232(defcustom align-region-separate "^\\s-*[{}]?\\s-*$"
233  "*Select the method by which alignment sections will be separated.
234If this is a symbol, that symbol's value will be used.
235
236For the sake of clarification, consider the following example, which
237will be referred to in the descriptions below.
238
239    int alpha = 1; /* one */
240    double beta = 2.0;
241    long gamma; /* ten */
242
243    unsigned int delta = 1; /* one */
244    long double epsilon = 3.0;
245    long long omega; /* ten */
246
247The possible settings for `align-region-separate' are:
248
249 `entire'  The entire region being aligned will be considered as a
250	   single alignment section.  Assuming that comments were not
251	   being aligned to a particular column, the example would
252	   become:
253
254	     int          alpha    = 1;   /* one */
255	     double       beta     = 2.0;
256	     long         gamma;          /* ten */
257
258	     unsigned int delta    = 1;   /* one */
259	     long double  epsilon;
260	     long long    chi      = 10;  /* ten */
261
262 `group'   Each contiguous set of lines where a specific alignment
263	   occurs is considered a section for that alignment rule.
264	   Note that each rule will may have any entirely different
265	   set of section divisions than another.
266
267	     int    alpha = 1; /* one */
268	     double beta  = 2.0;
269	     long   gamma; /* ten */
270
271	     unsigned int delta = 1; /* one */
272	     long double  epsilon;
273	     long long    chi = 10; /* ten */
274
275 `largest' When contiguous rule sets overlap, the largest section
276	   described will be taken as the alignment section for each
277	   rule touched by that section.
278
279	     int    alpha = 1;   /* one */
280	     double beta  = 2.0;
281	     long   gamma;       /* ten */
282
283	     unsigned int delta    = 1;  /* one */
284	     long double  epsilon;
285	     long long    chi      = 10; /* ten */
286
287	   NOTE: This option is not supported yet, due to algorithmic
288	   issues which haven't been satisfactorily resolved.  There
289	   are ways to do it, but they're both ugly and resource
290	   consumptive.
291
292 regexp    A regular expression string which defines the section
293	   divider.  If the mode you're in has a consistent divider
294	   between sections, the behavior will be very similar to
295	   `largest', and faster.  But if the mode does not use clear
296	   separators (for example, if you collapse your braces onto
297	   the preceding statement in C or perl), `largest' is
298	   probably the better alternative.
299
300 function  A function that will be passed the beginning and ending
301	   locations of the region in which to look for the section
302	   separator.  At the very beginning of the attempt to align,
303	   both of these parameters will be nil, in which case the
304	   function should return non-nil if it wants each rule to
305	   define its own section, or nil if it wants the largest
306	   section found to be used as the common section for all rules
307	   that occur there.
308
309 list      A list of markers within the buffer that represent where
310	   the section dividers lie.  Be certain to use markers!  For
311	   when the aligning begins, the ensuing contract/expanding of
312	   whitespace will throw off any non-marker positions.
313
314	   This method is intended for use in Lisp programs, and not
315	   by the user."
316  :type '(choice
317	  (const :tag "Entire region is one section" entire)
318	  (const :tag "Align by contiguous groups" group)
319;         (const largest)
320	  (regexp :tag "Regexp defines section boundaries")
321	  (function :tag "Function defines section boundaries"))
322  :group 'align)
323
324(put 'align-region-separate 'risky-local-variable t)
325
326(defvar align-rules-list-type
327  '(repeat
328    (cons
329     :tag "Alignment rule"
330     (symbol :tag "Title")
331     (cons :tag "Required attributes"
332	   (cons :tag "Regexp"
333		 (const :tag "(Regular expression to match)" regexp)
334		 (choice :value "\\(\\s-+\\)" regexp function))
335	   (repeat
336	    :tag "Optional attributes"
337	    (choice
338	     (cons :tag "Repeat"
339		   (const :tag "(Repeat this rule throughout line)"
340			  repeat)
341		   (boolean :value t))
342	     (cons :tag "Paren group"
343		   (const :tag "(Parenthesis group to use)" group)
344		   (choice :value 2
345			   integer (repeat integer)))
346	     (cons :tag "Modes"
347		   (const :tag "(Modes where this rule applies)" modes)
348		   (sexp :value (text-mode)))
349	     (cons :tag "Case-fold"
350		   (const :tag "(Should case be ignored for this rule)"
351			  case-fold)
352		   (boolean :value t))
353	     (cons :tag "To Tab Stop"
354		   (const :tag "(Should rule align to tab stops)"
355			  tab-stop)
356		   (boolean :value nil))
357	     (cons :tag "Valid"
358		   (const :tag "(Return non-nil if rule is valid)"
359			  valid)
360		   (function :value t))
361	     (cons :tag "Run If"
362		   (const :tag "(Return non-nil if rule should run)"
363			  run-if)
364		   (function :value t))
365	     (cons :tag "Column"
366		   (const :tag "(Column to fix alignment at)" column)
367		   (choice :value comment-column
368			   integer symbol))
369	     (cons :tag "Spacing"
370		   (const :tag "(Amount of spacing to use)" spacing)
371		   (integer :value 1))
372	     (cons :tag "Justify"
373		   (const :tag "(Should text be right justified)"
374			  justify)
375		   (boolean :value t))
376	     ;; make sure this stays up-to-date with any changes
377	     ;; in `align-region-separate'
378	     (cons :tag "Separate"
379		   (const :tag "(Separation to use for this rule)"
380			  separate)
381		   (choice :value "^\\s-*$"
382			   (const entire)
383			   (const group)
384;                          (const largest)
385			   regexp function)))))))
386  "The `type' form for any `align-rules-list' variable.")
387
388(defcustom align-rules-list
389  `((lisp-second-arg
390     (regexp   . "\\(^\\s-+[^( \t\n]\\|(\\(\\S-+\\)\\s-+\\)\\S-+\\(\\s-+\\)")
391     (group    . 3)
392     (modes    . align-lisp-modes)
393     (run-if   . ,(function (lambda () current-prefix-arg))))
394
395    (lisp-alist-dot
396     (regexp   . "\\(\\s-*\\)\\.\\(\\s-*\\)")
397     (group    . (1 2))
398     (modes    . align-lisp-modes))
399
400    (open-comment
401     (regexp   . ,(function
402		   (lambda (end reverse)
403		     (funcall (if reverse 're-search-backward
404				're-search-forward)
405			      (concat "[^ \t\n\\\\]"
406				      (regexp-quote comment-start)
407				      "\\(.+\\)$") end t))))
408     (modes    . align-open-comment-modes))
409
410    (c-macro-definition
411     (regexp   . "^\\s-*#\\s-*define\\s-+\\S-+\\(\\s-+\\)")
412     (modes    . align-c++-modes))
413
414    (c-variable-declaration
415     (regexp   . ,(concat "[*&0-9A-Za-z_]>?[&*]*\\(\\s-+[*&]*\\)"
416			  "[A-Za-z_][0-9A-Za-z:_]*\\s-*\\(\\()\\|"
417			  "=[^=\n].*\\|(.*)\\|\\(\\[.*\\]\\)*\\)?"
418			  "\\s-*[;,]\\|)\\s-*$\\)"))
419     (group    . 1)
420     (modes    . align-c++-modes)
421     (justify  . t)
422     (valid
423      . ,(function
424	  (lambda ()
425	    (not (or (save-excursion
426		       (goto-char (match-beginning 1))
427		       (backward-word 1)
428		       (looking-at
429			"\\(goto\\|return\\|new\\|delete\\|throw\\)"))
430		     (if (and (boundp 'font-lock-mode) font-lock-mode)
431			 (eq (get-text-property (point) 'face)
432			     'font-lock-comment-face)
433		       (eq (caar (c-guess-basic-syntax)) 'c))))))))
434
435    (c-assignment
436     (regexp   . ,(concat "[^-=!^&*+<>/| \t\n]\\(\\s-*[-=!^&*+<>/|]*\\)"
437			  "=\\(\\s-*\\)\\([^= \t\n]\\|$\\)"))
438     (group    . (1 2))
439     (modes    . align-c++-modes)
440     (justify  . t)
441     (tab-stop . nil))
442
443    (perl-assignment
444     (regexp   . ,(concat "[^=!^&*-+<>/| \t\n]\\(\\s-*\\)=[~>]?"
445			  "\\(\\s-*\\)\\([^>= \t\n]\\|$\\)"))
446     (group    . (1 2))
447     (modes    . align-perl-modes)
448     (tab-stop . nil))
449
450    (python-assignment
451     (regexp   . ,(concat "[^=!<> \t\n]\\(\\s-*\\)="
452			  "\\(\\s-*\\)\\([^>= \t\n]\\|$\\)"))
453     (group    . (1 2))
454     (modes    . '(python-mode))
455     (tab-stop . nil))
456
457    (make-assignment
458     (regexp   . "^\\s-*\\w+\\(\\s-*\\):?=\\(\\s-*\\)\\([^\t\n \\\\]\\|$\\)")
459     (group    . (1 2))
460     (modes    . '(makefile-mode))
461     (tab-stop . nil))
462
463    (c-comma-delimiter
464     (regexp   . ",\\(\\s-*\\)[^/ \t\n]")
465     (repeat   . t)
466     (modes    . align-c++-modes)
467     (run-if   . ,(function (lambda () current-prefix-arg))))
468					;      (valid
469					;       . ,(function
470					;	  (lambda ()
471					;	    (memq (caar (c-guess-basic-syntax))
472					;		  '(brace-list-intro
473					;		    brace-list-entry
474					;		    brace-entry-open))))))
475
476    ;; With a prefix argument, comma delimiter will be aligned.  Since
477    ;; perl-mode doesn't give us enough syntactic information (and we
478    ;; don't do our own parsing yet), this rule is too destructive to
479    ;; run normally.
480    (basic-comma-delimiter
481     (regexp   . ",\\(\\s-*\\)[^# \t\n]")
482     (repeat   . t)
483     (modes    . (append align-perl-modes '(python-mode)))
484     (run-if   . ,(function (lambda () current-prefix-arg))))
485
486    (c++-comment
487     (regexp   . "\\(\\s-*\\)\\(//.*\\|/\\*.*\\*/\\s-*\\)$")
488     (modes    . align-c++-modes)
489     (column   . comment-column)
490     (valid    . ,(function
491		   (lambda ()
492		     (save-excursion
493		       (goto-char (match-beginning 1))
494		       (not (bolp)))))))
495
496    (c-chain-logic
497     (regexp   . "\\(\\s-*\\)\\(&&\\|||\\|\\<and\\>\\|\\<or\\>\\)")
498     (modes    . align-c++-modes)
499     (valid    . ,(function
500		   (lambda ()
501		     (save-excursion
502		       (goto-char (match-end 2))
503		       (looking-at "\\s-*\\(/[*/]\\|$\\)"))))))
504
505    (perl-chain-logic
506     (regexp   . "\\(\\s-*\\)\\(&&\\|||\\|\\<and\\>\\|\\<or\\>\\)")
507     (modes    . align-perl-modes)
508     (valid    . ,(function
509		   (lambda ()
510		     (save-excursion
511		       (goto-char (match-end 2))
512		       (looking-at "\\s-*\\(#\\|$\\)"))))))
513
514    (python-chain-logic
515     (regexp   . "\\(\\s-*\\)\\(\\<and\\>\\|\\<or\\>\\)")
516     (modes    . '(python-mode))
517     (valid    . ,(function
518		   (lambda ()
519		     (save-excursion
520		       (goto-char (match-end 2))
521		       (looking-at "\\s-*\\(#\\|$\\|\\\\\\)"))))))
522
523    (c-macro-line-continuation
524     (regexp   . "\\(\\s-*\\)\\\\$")
525     (modes    . align-c++-modes)
526     (column   . c-backslash-column))
527					;      (valid
528					;       . ,(function
529					;	  (lambda ()
530					;	    (memq (caar (c-guess-basic-syntax))
531					;		  '(cpp-macro cpp-macro-cont))))))
532
533    (basic-line-continuation
534     (regexp   . "\\(\\s-*\\)\\\\$")
535     (modes    . '(python-mode makefile-mode)))
536
537    (tex-record-separator
538     (regexp . ,(function
539		 (lambda (end reverse)
540		   (align-match-tex-pattern "&" end reverse))))
541     (group    . (1 2))
542     (modes    . align-tex-modes)
543     (repeat   . t))
544
545    (tex-tabbing-separator
546     (regexp   . ,(function
547		   (lambda (end reverse)
548		     (align-match-tex-pattern "\\\\[=>]" end reverse))))
549     (group    . (1 2))
550     (modes    . align-tex-modes)
551     (repeat   . t)
552     (run-if   . ,(function
553		   (lambda ()
554		     (eq major-mode 'latex-mode)))))
555
556    (tex-record-break
557     (regexp   . "\\(\\s-*\\)\\\\\\\\")
558     (modes    . align-tex-modes))
559
560    ;; With a numeric prefix argument, or C-u, space delimited text
561    ;; tables will be aligned.
562    (text-column
563     (regexp   . "\\(^\\|\\S-\\)\\([ \t]+\\)\\(\\S-\\|$\\)")
564     (group    . 2)
565     (modes    . align-text-modes)
566     (repeat   . t)
567     (run-if   . ,(function
568		   (lambda ()
569		     (and current-prefix-arg
570			  (not (eq '- current-prefix-arg)))))))
571
572    ;; With a negative prefix argument, lists of dollar figures will
573    ;; be aligned.
574    (text-dollar-figure
575     (regexp   . "\\$?\\(\\s-+[0-9]+\\)\\.")
576     (modes    . align-text-modes)
577     (justify  . t)
578     (run-if   . ,(function
579		   (lambda ()
580		     (eq '- current-prefix-arg)))))
581
582    (css-declaration
583     (regexp . "^\\s-*\\w+:\\(\\s-*\\).*;")
584     (group . (1))
585     (modes . '(css-mode html-mode))))
586  "*A list describing all of the available alignment rules.
587The format is:
588
589   ((TITLE
590     (ATTRIBUTE . VALUE) ...)
591    ...)
592
593The following attributes are meaningful:
594
595`regexp'    This required attribute must be either a string describing
596	    a regular expression, or a function (described below).
597	    For every line within the section that this regular
598	    expression matches, the given rule will be applied to that
599	    line.  The exclusion rules denote which part(s) of the
600	    line should not be modified; the alignment rules cause the
601	    identified whitespace group to be contracted/expanded such
602	    that the \"alignment character\" (the character
603	    immediately following the identified parenthesis group),
604	    occurs in the same column for every line within the
605	    alignment section (see `align-region-separate' for a
606	    description of how the region is broken up into alignment
607	    sections).
608
609	    The `regexp' attribute describes how the text should be
610	    treated.  Within this regexp, there must be at least one
611	    group of characters (typically whitespace) identified by
612	    the special opening and closing parens used in regexp
613	    expressions (`\\\\(' and `\\\\)') (see the Emacs manual on
614	    the syntax of regular expressions for more info).
615
616	    If `regexp' is a function, it will be called as a
617	    replacement for `re-search-forward'.  This means that it
618	    should return nil if nothing is found to match the rule,
619	    or it should set the match data appropriately, move point
620	    to the end of the match, and return the value of point.
621
622`group'     For exclusion rules, the group identifies the range of
623	    characters that should be ignored.  For alignment rules,
624	    these are the characters that will be deleted/expanded for
625	    the purposes of alignment.  The \"alignment character\" is
626	    always the first character immediately following this
627	    parenthesis group.  This attribute may also be a list of
628	    integer, in which case multiple alignment characters will
629	    be aligned, with the list of integer identifying the
630	    whitespace groups which precede them.  The default for
631	    this attribute is 1.
632
633`modes'     The `modes' attribute, if set, should name a list of
634	    major modes -- or evaluate to such a value -- in which the
635	    rule is valid.  If not set, the rule will apply to all
636	    modes.
637
638`case-fold' If `regexp' is an ordinary regular expression string
639	    containing alphabetic character, sometimes you may want
640	    the search to proceed case-insensitively (for languages
641	    that ignore case, such as pascal for example).  In that
642	    case, set `case-fold' to a non-nil value, and the regular
643	    expression search will ignore case.  If `regexp' is set to
644	    a function, that function must handle the job of ignoring
645	    case by itself.
646
647`tab-stop'  If the `tab-stop' attribute is set, and non-nil, the
648	    alignment character will always fall on a tab stop
649	    (whether it uses tabs to get there or not depends on the
650	    value of `indent-tabs-mode').  If the `tab-stop' attribute
651	    is set to nil, tab stops will never be used.  Otherwise,
652	    the value of `align-to-tab-stop' determines whether or not
653	    to align to a tab stop.  The `tab-stop' attribute may also
654	    be a list of t or nil values, corresponding to the number
655	    of parenthesis groups specified by the `group' attribute.
656
657`repeat'    If the `repeat' attribute is present, and non-nil, the
658	    rule will be applied to the line continuously until no
659	    further matches are found.
660
661`valid'     If the `valid' attribute is set, it will be used to
662	    determine whether the rule should be invoked.  This form
663	    is evaluated after the regular expression match has been
664	    performed, so that it is possible to use the results of
665	    that match to determine whether the alignment should be
666	    performed.  The buffer should not be modified during the
667	    evaluation of this form.
668
669`run-if'    Like `valid', the `run-if' attribute tests whether the
670	    rule should be run at all -- even before any searches are
671	    done to determine if the rule applies to the alignment
672	    region.  This can save time, since `run-if' will only be
673	    run once for each rule.  If it returns nil, the rule will
674	    not be attempted.
675
676`column'    For alignment rules, if the `column' attribute is set --
677	    which must be an integer, or a symbol whose value is an
678	    integer -- it will be used as the column in which to align
679	    the alignment character.  If the text on a particular line
680	    happens to overrun that column, a single space character,
681	    or tab stop (see `align-to-tab-stop') will be added
682	    between the last text character and the alignment
683	    character.
684
685`spacing'   Alignment rules may also override the amount of spacing
686	    that would normally be used by providing a `spacing'
687	    attribute.  This must be an integer, or a list of integers
688	    corresponding to the number of parenthesis groups matched
689	    by the `group' attribute.  If a list of value is used, and
690	    any of those values is nil, `align-default-spacing' will
691	    be used for that subgroup.  See `align-default-spacing'
692	    for more details on spacing, tab stops, and how to
693	    indicate how much spacing should be used.  If TAB-STOP is
694	    present, it will override the value of `align-to-tab-stop'
695	    for that rule.
696
697`justify'   It is possible with `regexp' and `group' to identify a
698	    character group that contains more than just whitespace
699	    characters.  By default, any non-whitespace characters in
700	    that group will also be deleted while aligning the
701	    alignment character.  However, if the `justify' attribute
702	    is set to a non-nil value, only the initial whitespace
703	    characters within that group will be deleted.  This has
704	    the effect of right-justifying the characters that remain,
705	    and can be used for outdenting or just plain old right-
706	    justification.
707
708`separate'  Each rule can define its own section separator, which
709	    describes how to identify the separation of \"sections\"
710	    within the region to be aligned.  Setting the `separate'
711	    attribute overrides the value of `align-region-separate'
712	    (see the documentation of that variable for possible
713	    values), and any separation argument passed to `align'."
714  :type align-rules-list-type
715  :group 'align)
716
717(put 'align-rules-list 'risky-local-variable t)
718
719(defvar align-exclude-rules-list-type
720  '(repeat
721    (cons
722     :tag "Exclusion rule"
723     (symbol :tag "Title")
724     (cons :tag "Required attributes"
725	   (cons :tag "Regexp"
726		 (const :tag "(Regular expression to match)" regexp)
727		 (choice :value "\\(\\s-+\\)" regexp function))
728	   (repeat
729	    :tag "Optional attributes"
730	    (choice
731	     (cons :tag "Repeat"
732		   (const :tag "(Repeat this rule throughout line)"
733			  repeat)
734		   (boolean :value t))
735	     (cons :tag "Paren group"
736		   (const :tag "(Parenthesis group to use)" group)
737		   (choice :value 2
738			   integer (repeat integer)))
739	     (cons :tag "Modes"
740		   (const :tag "(Modes where this rule applies)" modes)
741		   (sexp :value (text-mode)))
742	     (cons :tag "Case-fold"
743		   (const :tag "(Should case be ignored for this rule)"
744			  case-fold)
745		   (boolean :value t)))))))
746  "The `type' form for any `align-exclude-rules-list' variable.")
747
748(defcustom align-exclude-rules-list
749  `((exc-dq-string
750     (regexp . "\"\\([^\"\n]+\\)\"")
751     (repeat . t)
752     (modes  . align-dq-string-modes))
753
754    (exc-sq-string
755     (regexp . "'\\([^'\n]+\\)'")
756     (repeat . t)
757     (modes  . align-sq-string-modes))
758
759    (exc-open-comment
760     (regexp
761      . ,(function
762	  (lambda (end reverse)
763	    (funcall (if reverse 're-search-backward
764		       're-search-forward)
765		     (concat "[^ \t\n\\\\]"
766			     (regexp-quote comment-start)
767			     "\\(.+\\)$") end t))))
768     (modes  . align-open-comment-modes))
769
770    (exc-c-comment
771     (regexp . "/\\*\\(.+\\)\\*/")
772     (repeat . t)
773     (modes  . align-c++-modes))
774
775    (exc-c-func-params
776     (regexp . "(\\([^)\n]+\\))")
777     (repeat . t)
778     (modes  . align-c++-modes))
779
780    (exc-c-macro
781     (regexp . "^\\s-*#\\s-*\\(if\\w*\\|endif\\)\\(.*\\)$")
782     (group  . 2)
783     (modes  . align-c++-modes)))
784  "*A list describing text that should be excluded from alignment.
785See the documentation for `align-rules-list' for more info."
786  :type align-exclude-rules-list-type
787  :group 'align)
788
789(put 'align-exclude-rules-list 'risky-local-variable t)
790
791;;; Internal Variables:
792
793(defvar align-mode-rules-list nil
794  "Alignment rules specific to the current major mode.
795See the variable `align-rules-list' for more details.")
796
797(make-variable-buffer-local 'align-mode-rules-list)
798
799(defvar align-mode-exclude-rules-list nil
800  "Alignment exclusion rules specific to the current major mode.
801See the variable `align-exclude-rules-list' for more details.")
802
803(make-variable-buffer-local 'align-mode-exclude-rules-list)
804
805(defvar align-highlight-overlays nil
806  "The current overlays highlighting the text matched by a rule.")
807
808;; Sample extension rule set, for vhdl-mode.  This should properly be
809;; in vhdl-mode.el itself.
810
811(defcustom align-vhdl-rules-list
812  `((vhdl-declaration
813     (regexp   . "\\(signal\\|variable\\|constant\\)\\(\\s-+\\)\\S-")
814     (group    . 2))
815
816    (vhdl-case
817     (regexp   . "\\(others\\|[^ \t\n=<]\\)\\(\\s-*\\)=>\\(\\s-*\\)\\S-")
818     (group    . (2 3))
819     (valid
820      . ,(function
821	  (lambda ()
822	    (not (string= (downcase (match-string 1))
823			  "others"))))))
824
825    (vhdl-colon
826     (regexp   . "[^ \t\n:]\\(\\s-*\\):\\(\\s-*\\)[^=\n]")
827     (group    . (1 2)))
828
829    (direction
830     (regexp   . ":\\s-*\\(in\\|out\\|inout\\|buffer\\)\\(\\s-*\\)")
831     (group    . 2))
832
833    (sig-assign
834     (regexp   . "[^ \t\n=<]\\(\\s-*\\)<=\\(\\s-*\\)\\S-")
835     (group    . (1 2)))
836
837    (var-assign
838     (regexp   . "[^ \t\n:]\\(\\s-*\\):="))
839
840    (use-entity
841     (regexp   . "\\(\\s-+\\)use\\s-+entity")))
842  "*Alignment rules for `vhdl-mode'.  See `align-rules-list' for more info."
843  :type align-rules-list-type
844  :group 'align)
845
846(put 'align-vhdl-rules-list 'risky-local-variable t)
847
848(defun align-set-vhdl-rules ()
849  "Setup the `align-mode-rules-list' variable for `vhdl-mode'."
850  (setq align-mode-rules-list align-vhdl-rules-list))
851
852(add-hook 'vhdl-mode-hook 'align-set-vhdl-rules)
853
854(add-to-list 'align-dq-string-modes 'vhdl-mode)
855(add-to-list 'align-open-comment-modes 'vhdl-mode)
856
857;;; User Functions:
858
859;;;###autoload
860(defun align (beg end &optional separate rules exclude-rules)
861  "Attempt to align a region based on a set of alignment rules.
862BEG and END mark the region.  If BEG and END are specifically set to
863nil (this can only be done programmatically), the beginning and end of
864the current alignment section will be calculated based on the location
865of point, and the value of `align-region-separate' (or possibly each
866rule's `separate' attribute).
867
868If SEPARATE is non-nil, it overrides the value of
869`align-region-separate' for all rules, except those that have their
870`separate' attribute set.
871
872RULES and EXCLUDE-RULES, if either is non-nil, will replace the
873default rule lists defined in `align-rules-list' and
874`align-exclude-rules-list'.  See `align-rules-list' for more details
875on the format of these lists."
876  (interactive "r")
877  (let ((separator
878	 (or separate
879	     (if (and (symbolp align-region-separate)
880		      (boundp align-region-separate))
881		 (symbol-value align-region-separate)
882	       align-region-separate)
883	     'entire)))
884    (if (not (or ;(eq separator 'largest)
885		 (and (functionp separator)
886		      (not (funcall separator nil nil)))))
887	(align-region beg end separator
888		      (or rules align-mode-rules-list align-rules-list)
889		      (or exclude-rules align-mode-exclude-rules-list
890			  align-exclude-rules-list))
891      (let ((sec-first end)
892	    (sec-last beg))
893	(align-region beg end
894		      (or exclude-rules
895			  align-mode-exclude-rules-list
896			  align-exclude-rules-list) nil
897		      separator
898		      (function
899		       (lambda (b e mode)
900			 (when (and mode (listp mode))
901			   (setq sec-first (min sec-first b)
902				 sec-last  (max sec-last e))))))
903	(if (< sec-first sec-last)
904	    (align-region sec-first sec-last 'entire
905			  (or rules align-mode-rules-list align-rules-list)
906			  (or exclude-rules align-mode-exclude-rules-list
907			      align-exclude-rules-list)))))))
908
909;;;###autoload
910(defun align-regexp (beg end regexp &optional group spacing repeat)
911  "Align the current region using an ad-hoc rule read from the minibuffer.
912BEG and END mark the limits of the region.  This function will prompt
913for the REGEXP to align with.  If no prefix arg was specified, you
914only need to supply the characters to be lined up and any preceding
915whitespace is replaced.  If a prefix arg was specified, the full
916regexp with parenthesized whitespace should be supplied; it will also
917prompt for which parenthesis GROUP within REGEXP to modify, the amount
918of SPACING to use, and whether or not to REPEAT the rule throughout
919the line.  See `align-rules-list' for more information about these
920options.
921
922For example, let's say you had a list of phone numbers, and wanted to
923align them so that the opening parentheses would line up:
924
925    Fred (123) 456-7890
926    Alice (123) 456-7890
927    Mary-Anne (123) 456-7890
928    Joe (123) 456-7890
929
930There is no predefined rule to handle this, but you could easily do it
931using a REGEXP like \"(\". All you would have to do is to mark the
932region, call `align-regexp' and type in that regular expression."
933  (interactive
934   (append
935    (list (region-beginning) (region-end))
936    (if current-prefix-arg
937	(list (read-string "Complex align using regexp: "
938			   "\\(\\s-*\\)")
939	      (string-to-number
940	       (read-string
941		"Parenthesis group to modify (justify if negative): " "1"))
942	      (string-to-number
943	       (read-string "Amount of spacing (or column if negative): "
944			    (number-to-string align-default-spacing)))
945	      (y-or-n-p "Repeat throughout line? "))
946      (list (concat "\\(\\s-*\\)"
947		    (read-string "Align regexp: "))
948	    1 align-default-spacing nil))))
949  (let ((rule
950	 (list (list nil (cons 'regexp regexp)
951		     (cons 'group (abs group))
952		     (if (< group 0)
953			 (cons 'justify t)
954		       (cons 'bogus nil))
955		     (if (>= spacing 0)
956			 (cons 'spacing spacing)
957		       (cons 'column (abs spacing)))
958		     (cons 'repeat repeat)))))
959    (align-region beg end 'entire rule nil nil)))
960
961;;;###autoload
962(defun align-entire (beg end &optional rules exclude-rules)
963  "Align the selected region as if it were one alignment section.
964BEG and END mark the extent of the region.  If RULES or EXCLUDE-RULES
965is set to a list of rules (see `align-rules-list'), it can be used to
966override the default alignment rules that would have been used to
967align that section."
968  (interactive "r")
969  (align beg end 'entire rules exclude-rules))
970
971;;;###autoload
972(defun align-current (&optional rules exclude-rules)
973  "Call `align' on the current alignment section.
974This function assumes you want to align only the current section, and
975so saves you from having to specify the region.  If RULES or
976EXCLUDE-RULES is set to a list of rules (see `align-rules-list'), it
977can be used to override the default alignment rules that would have
978been used to align that section."
979  (interactive)
980  (align nil nil nil rules exclude-rules))
981
982;;;###autoload
983(defun align-highlight-rule (beg end title &optional rules exclude-rules)
984  "Highlight the whitespace which a given rule would have modified.
985BEG and END mark the extent of the region.  TITLE identifies the rule
986that should be highlighted.  If RULES or EXCLUDE-RULES is set to a
987list of rules (see `align-rules-list'), it can be used to override the
988default alignment rules that would have been used to identify the text
989to be colored."
990  (interactive
991   (list (region-beginning) (region-end)
992	 (completing-read
993	  "Title of rule to highlight: "
994	  (mapcar
995	   (function
996	    (lambda (rule)
997	      (list (symbol-name (car rule)))))
998	   (append (or align-mode-rules-list align-rules-list)
999		   (or align-mode-exclude-rules-list
1000		       align-exclude-rules-list))) nil t)))
1001  (let ((ex-rule (assq (intern title)
1002		       (or align-mode-exclude-rules-list
1003			   align-exclude-rules-list)))
1004	face)
1005    (align-unhighlight-rule)
1006    (align-region
1007     beg end 'entire
1008     (or rules (if ex-rule
1009		   (or exclude-rules align-mode-exclude-rules-list
1010		       align-exclude-rules-list)
1011		 (or align-mode-rules-list align-rules-list)))
1012     (unless ex-rule (or exclude-rules align-mode-exclude-rules-list
1013			 align-exclude-rules-list))
1014     (function
1015      (lambda (b e mode)
1016	(if (and mode (listp mode))
1017	    (if (equal (symbol-name (car mode)) title)
1018		(setq face (cons align-highlight-change-face
1019				 align-highlight-nochange-face))
1020	      (setq face nil))
1021	  (when face
1022	    (let ((overlay (make-overlay b e)))
1023	      (setq align-highlight-overlays
1024		    (cons overlay align-highlight-overlays))
1025	      (overlay-put overlay 'face
1026			   (if mode
1027			       (car face)
1028			     (cdr face)))))))))))
1029
1030;;;###autoload
1031(defun align-unhighlight-rule ()
1032  "Remove any highlighting that was added by `align-highlight-rule'."
1033  (interactive)
1034  (while align-highlight-overlays
1035    (delete-overlay (car align-highlight-overlays))
1036    (setq align-highlight-overlays
1037	  (cdr align-highlight-overlays))))
1038
1039;;;###autoload
1040(defun align-newline-and-indent ()
1041  "A replacement function for `newline-and-indent', aligning as it goes."
1042  (interactive)
1043  (let ((separate (or (if (and (symbolp align-region-separate)
1044			       (boundp align-region-separate))
1045			  (symbol-value align-region-separate)
1046			align-region-separate)
1047		      'entire))
1048	(end (point)))
1049    (call-interactively 'newline-and-indent)
1050    (save-excursion
1051      (forward-line -1)
1052      (while (not (or (bobp)
1053		      (align-new-section-p (point) end separate)))
1054	(forward-line -1))
1055      (align (point) end))))
1056
1057;;; Internal Functions:
1058
1059(defun align-match-tex-pattern (regexp end &optional reverse)
1060  "Match REGEXP in TeX mode, counting backslashes appropriately.
1061END denotes the end of the region to be searched, while REVERSE, if
1062non-nil, indicates that the search should proceed backward from the
1063current position."
1064  (let (result)
1065    (while
1066	(and (setq result
1067		   (funcall
1068		    (if reverse 're-search-backward
1069		      're-search-forward)
1070		    (concat "\\(\\s-*\\)" regexp
1071			    "\\(\\s-*\\)") end t))
1072	     (let ((pos (match-end 1))
1073		   (count 0))
1074	       (while (and (> pos (point-min))
1075			   (eq (char-before pos) ?\\))
1076		 (setq count (1+ count) pos (1- pos)))
1077	       (eq (mod count 2) 1))
1078	     (goto-char (match-beginning (if reverse 1 2)))))
1079    result))
1080
1081(defun align-new-section-p (beg end separator)
1082  "Is there a section divider between BEG and END?
1083SEPARATOR specifies how to look for the section divider.  See the
1084documentation for `align-region-separate' for more details."
1085  (cond ((or (not separator)
1086	     (eq separator 'entire))
1087	 nil)
1088	((eq separator 'group)
1089	 (let ((amount 2))
1090	   (save-excursion
1091	     (goto-char end)
1092	     (if (bolp)
1093		 (setq amount 1)))
1094	   (> (count-lines beg end) amount)))
1095	((stringp separator)
1096	 (save-excursion
1097	   (goto-char beg)
1098	   (re-search-forward separator end t)))
1099	((functionp separator)
1100	 (funcall separator beg end))
1101	((listp separator)
1102	 (let ((seps separator) yes)
1103	   (while seps
1104	     (if (and (>= (car seps) beg)
1105		      (<= (car seps) end))
1106		 (setq yes t seps nil)
1107	     (setq seps (cdr seps))))
1108	   yes))))
1109
1110(defun align-adjust-col-for-rule (column rule spacing tab-stop)
1111  "Adjust COLUMN according to the given RULE.
1112SPACING specifies how much spacing to use.
1113TAB-STOP specifies whether SPACING refers to tab-stop boundaries."
1114  (unless spacing
1115    (setq spacing align-default-spacing))
1116  (if (<= spacing 0)
1117      column
1118    (if (not tab-stop)
1119	(+ column spacing)
1120      (let ((stops tab-stop-list))
1121	(while stops
1122	  (if (and (> (car stops) column)
1123		   (= (setq spacing (1- spacing)) 0))
1124	      (setq column (car stops)
1125		    stops nil)
1126	    (setq stops (cdr stops)))))
1127      column)))
1128
1129(defsubst align-column (pos)
1130  "Given a position in the buffer, state what column it's in.
1131POS is the position whose column will be taken.  Note that this
1132function will change the location of point."
1133  (goto-char pos)
1134  (current-column))
1135
1136(defsubst align-regions (regions props rule func)
1137  "Align the regions specified in REGIONS, a list of cons cells.
1138PROPS describes formatting features specific to the given regions.
1139RULE specifies exactly how to perform the alignments.
1140If FUNC is specified, it will be called with each region that would
1141have been aligned, rather than modifying the text."
1142  (while regions
1143    (save-excursion
1144      (align-areas (car regions) (car props) rule func))
1145    (setq regions (cdr regions)
1146	  props (cdr props))))
1147
1148(defun align-areas (areas props rule func)
1149  "Given a list of AREAS and formatting PROPS, align according to RULE.
1150AREAS should be a list of cons cells containing beginning and ending
1151markers.  This function sweeps through all of the beginning markers,
1152finds out which one starts in the furthermost column, and then deletes
1153and inserts text such that all of the ending markers occur in the same
1154column.
1155
1156If FUNC is non-nil, it will be called for each text region that would
1157have been aligned.  No changes will be made to the buffer."
1158  (let* ((column (cdr (assq 'column rule)))
1159	 (fixed (if (symbolp column)
1160		    (symbol-value column)
1161		  column))
1162	 (justify (cdr (assq 'justify rule)))
1163	 (col (or fixed 0))
1164	 (width 0)
1165	 ecol change look)
1166
1167    ;; Determine the alignment column.
1168    (let ((a areas))
1169      (while a
1170	(unless fixed
1171	  (setq col (max col (align-column (caar a)))))
1172	(unless change
1173	  (goto-char (cdar a))
1174	  (if ecol
1175	      (if (/= ecol (current-column))
1176		  (setq change t))
1177	    (setq ecol (current-column))))
1178	(when justify
1179	  (goto-char (caar a))
1180	  (if (and (re-search-forward "\\s-*" (cdar a) t)
1181		   (/= (point) (cdar a)))
1182	      (let ((bcol (current-column)))
1183		(setcdr (car a) (cons (point-marker) (cdar a)))
1184		(goto-char (cdr (cdar a)))
1185		(setq width (max width (- (current-column) bcol))))))
1186	(setq a (cdr a))))
1187
1188    (unless fixed
1189      (setq col (+ (align-adjust-col-for-rule
1190		    col rule (car props) (cdr props)) width)))
1191
1192    ;; Make all ending positions to occur in the goal column.  Since
1193    ;; the whitespace to be modified was already deleted by
1194    ;; `align-region', all we have to do here is indent.
1195
1196    (unless change
1197      (setq change (and ecol (/= col ecol))))
1198
1199    (when (or func change)
1200      (while areas
1201	(let ((area (car areas))
1202	      (gocol col) cur)
1203	  (when area
1204	    (if func
1205		(funcall func (car area) (cdr area) change)
1206	      (if (not (and justify
1207			    (consp (cdr area))))
1208		  (goto-char (cdr area))
1209		(goto-char (cddr area))
1210		(let ((ecol (current-column)))
1211		  (goto-char (cadr area))
1212		  (setq gocol (- col (- ecol (current-column))))))
1213	      (setq cur (current-column))
1214	      (cond ((< gocol 0) t)     ; don't do anything
1215		    ((= cur gocol) t)   ; don't need to
1216		    ((< cur gocol)      ; just add space
1217		     ;; FIXME: It is stated above that "...the
1218		     ;;	       whitespace to be modified was already
1219		     ;;	       deleted by `align-region', all we have
1220		     ;;	       to do here is indent."  However, this
1221		     ;;	       doesn't seem to be true, so we first
1222		     ;;	       delete the whitespace to avoid tabs
1223		     ;;	       after spaces.
1224		     (delete-horizontal-space t)
1225		     (indent-to gocol))
1226		    (t
1227		     ;; This code works around an oddity in the
1228		     ;; FORCE argument of `move-to-column', which
1229		     ;; tends to screw up markers if there is any
1230		     ;; tabbing.
1231		     (let ((endcol (align-column
1232				    (if (and justify
1233					     (consp (cdr area)))
1234					(cadr area)
1235				      (cdr area))))
1236			   (abuts (<= gocol
1237				      (align-column (car area)))))
1238		       (if abuts
1239			   (goto-char (car area))
1240			 (move-to-column gocol t))
1241		       (let ((here (point)))
1242			 (move-to-column endcol t)
1243			 (delete-region here (point))
1244			 (if abuts
1245			     (indent-to (align-adjust-col-for-rule
1246					 (current-column) rule
1247					 (car props) (cdr props)))))))))))
1248	(setq areas (cdr areas))))))
1249
1250(defun align-region (beg end separate rules exclude-rules
1251			 &optional func)
1252  "Align a region based on a given set of alignment rules.
1253BEG and END specify the region to be aligned.  Either may be nil, in
1254which case the range will stop at the nearest section division (see
1255`align-region-separate', and `align-region-heuristic' for more
1256information').
1257
1258The region will be divided into separate alignment sections based on
1259the value of SEPARATE.
1260
1261RULES and EXCLUDE-RULES are a pair of lists describing how to align
1262the region, and which text areas within it should be excluded from
1263alignment.  See the `align-rules-list' for more information on the
1264required format of these two lists.
1265
1266If FUNC is specified, no text will be modified.  What `align-region'
1267will do with the rules is to search for the alignment areas, as it
1268regularly would, taking account for exclusions, and then call FUNC,
1269first with the beginning and ending of the region to be aligned
1270according to that rule (this can be different for each rule, if BEG
1271and END were nil), and then with the beginning and ending of each
1272text region that the rule would have applied to.
1273
1274The signature of FUNC should thus be:
1275
1276 (defun my-align-function (beg end mode)
1277   \"If MODE is a rule (a list), return t if BEG to END are to be searched.
1278Otherwise BEG to END will be a region of text that matches the rule's
1279definition, and MODE will be non-nil if any changes are necessary.\"
1280   (unless (and mode (listp mode))
1281     (message \"Would have aligned from %d to %d...\" beg end)))
1282
1283This feature (of passing a FUNC) is used internally to locate the
1284position of exclusion areas, but could also be used for any other
1285purpose where you might want to know where the regions that the
1286aligner would have dealt with are."
1287  (let ((end-mark (and end (copy-marker end t)))
1288	(real-beg beg)
1289	(real-end end)
1290	(report (and (not func) align-large-region beg end
1291		     (>= (- end beg) align-large-region)))
1292	(rule-index 1)
1293	(rule-count (length rules)))
1294    (if (and align-indent-before-aligning real-beg end-mark)
1295	(indent-region real-beg end-mark nil))
1296    (while rules
1297      (let* ((rule (car rules))
1298	     (run-if (assq 'run-if rule))
1299	     (modes (assq 'modes rule)))
1300	;; unless the `run-if' form tells us not to, look for the
1301	;; rule..
1302	(unless (or (and modes (not (memq major-mode
1303					  (eval (cdr modes)))))
1304		    (and run-if (not (funcall (cdr run-if)))))
1305	  (let* ((current-case-fold case-fold-search)
1306		 (case-fold (assq 'case-fold rule))
1307		 (regexp  (cdr (assq 'regexp rule)))
1308		 (regfunc (and (functionp regexp) regexp))
1309		 (rulesep (assq 'separate rule))
1310		 (thissep (if rulesep (cdr rulesep) separate))
1311		 same (eol 0)
1312		 group group-c
1313		 spacing spacing-c
1314		 tab-stop tab-stop-c
1315		 repeat repeat-c
1316		 valid valid-c
1317		 pos-list first
1318		 regions index
1319		 last-point b e
1320		 save-match-data
1321		 exclude-p
1322		 align-props)
1323	    (save-excursion
1324	      ;; if beg and end were not given, figure out what the
1325	      ;; current alignment region should be.  Depending on the
1326	      ;; value of `align-region-separate' it's possible for
1327	      ;; each rule to have its own definition of what that
1328	      ;; current alignment section is.
1329	      (if real-beg
1330		  (goto-char beg)
1331		(if (or (not thissep) (eq thissep 'entire))
1332		    (error "Cannot determine alignment region for '%s'"
1333			   (symbol-name (cdr (assq 'title rule)))))
1334		(beginning-of-line)
1335		(while (and (not (eobp))
1336			    (looking-at "^\\s-*$"))
1337		  (forward-line))
1338		(let* ((here (point))
1339		       (start here))
1340		  (while (and here
1341			      (let ((terminus
1342				     (and align-region-heuristic
1343					  (- (point)
1344					     align-region-heuristic))))
1345				(if regfunc
1346				    (funcall regfunc terminus t)
1347				  (re-search-backward regexp
1348						      terminus t))))
1349		    (if (align-new-section-p (point) here thissep)
1350			(setq beg here
1351			      here nil)
1352		      (setq here (point))))
1353		  (if (not here)
1354		      (goto-char beg))
1355		  (beginning-of-line)
1356		  (setq beg (point))
1357		  (goto-char start)
1358		  (setq here (point))
1359		  (while (and here
1360			      (let ((terminus
1361				     (and align-region-heuristic
1362					  (+ (point)
1363					     align-region-heuristic))))
1364				(if regfunc
1365				    (funcall regfunc terminus nil)
1366				  (re-search-forward regexp terminus t))))
1367		    (if (align-new-section-p here (point) thissep)
1368			(setq end here
1369			      here nil)
1370		      (setq here (point))))
1371		  (if (not here)
1372		      (goto-char end))
1373		  (forward-line)
1374		  (setq end (point)
1375			end-mark (copy-marker end t))
1376		  (goto-char beg)))
1377
1378	      ;; If we have a region to align, and `func' is set and
1379	      ;; reports back that the region is ok, then align it.
1380	      (when (or (not func)
1381			(funcall func beg end rule))
1382		(unwind-protect
1383		    (let (exclude-areas)
1384		      ;; determine first of all where the exclusions
1385		      ;; lie in this region
1386		      (when exclude-rules
1387			;; guard against a problem with recursion and
1388			;; dynamic binding vs. lexical binding, since
1389			;; the call to `align-region' below will
1390			;; re-enter this function, and rebind
1391			;; `exclude-areas'
1392			(set (setq exclude-areas
1393				   (make-symbol "align-exclude-areas"))
1394			     nil)
1395			(align-region
1396			 beg end 'entire
1397			 exclude-rules nil
1398			 `(lambda (b e mode)
1399			    (or (and mode (listp mode))
1400				(set (quote ,exclude-areas)
1401				     (cons (cons b e)
1402					   ,exclude-areas)))))
1403			(setq exclude-areas
1404			      (sort (symbol-value exclude-areas)
1405				    (function
1406				     (lambda (l r)
1407				       (>= (car l) (car r)))))))
1408
1409		      ;; set `case-fold-search' according to the
1410		      ;; (optional) `case-fold' property
1411		      (and case-fold
1412			   (setq case-fold-search (cdr case-fold)))
1413
1414		      ;; while we can find the rule in the alignment
1415		      ;; region..
1416		      (while (and (< (point) end-mark)
1417				  (if regfunc
1418				      (funcall regfunc end-mark nil)
1419				    (re-search-forward regexp
1420						       end-mark t)))
1421
1422			;; give the user some indication of where we
1423			;; are, if it's a very large region being
1424			;; aligned
1425			(if report
1426			    (let ((symbol (car rule)))
1427			      (if (and symbol (symbolp symbol))
1428				  (message
1429				   "Aligning `%s' (rule %d of %d) %d%%..."
1430				   (symbol-name symbol) rule-index rule-count
1431				   (/ (* (- (point) real-beg) 100)
1432				      (- end-mark real-beg)))
1433				(message
1434				 "Aligning %d%%..."
1435				 (/ (* (- (point) real-beg) 100)
1436				    (- end-mark real-beg))))))
1437
1438			;; if the search ended us on the beginning of
1439			;; the next line, move back to the end of the
1440			;; previous line.
1441			(if (bolp)
1442			    (forward-char -1))
1443
1444			;; lookup the `group' attribute the first time
1445			;; that we need it
1446			(unless group-c
1447			  (setq group (or (cdr (assq 'group rule)) 1))
1448			  (if (listp group)
1449			      (setq first (car group))
1450			    (setq first group group (list group)))
1451			  (setq group-c t))
1452
1453			(unless spacing-c
1454			  (setq spacing (cdr (assq 'spacing rule))
1455				spacing-c t))
1456
1457			(unless tab-stop-c
1458			  (setq tab-stop
1459				(let ((rule-ts (assq 'tab-stop rule)))
1460				  (if rule-ts
1461				      (cdr rule-ts)
1462				    (if (symbolp align-to-tab-stop)
1463					(symbol-value align-to-tab-stop)
1464				      align-to-tab-stop)))
1465				tab-stop-c t))
1466
1467			;; test whether we have found a match on the same
1468			;; line as a previous match
1469			(if (> (point) eol)
1470			    (setq same nil
1471				  eol (save-excursion
1472					(end-of-line)
1473					(point-marker))))
1474
1475			;; lookup the `repeat' attribute the first time
1476			(or repeat-c
1477			    (setq repeat (cdr (assq 'repeat rule))
1478				  repeat-c t))
1479
1480			;; lookup the `valid' attribute the first time
1481			(or valid-c
1482			    (setq valid (assq 'valid rule)
1483				  valid-c t))
1484
1485			;; remember the beginning position of this rule
1486			;; match, and save the match-data, since either
1487			;; the `valid' form, or the code that searches for
1488			;; section separation, might alter it
1489			(setq b (match-beginning first)
1490			      save-match-data (match-data))
1491
1492			;; unless the `valid' attribute is set, and tells
1493			;; us that the rule is not valid at this point in
1494			;; the code..
1495			(unless (and valid (not (funcall (cdr valid))))
1496
1497			  ;; look to see if this match begins a new
1498			  ;; section.  If so, we should align what we've
1499			  ;; collected so far, and then begin collecting
1500			  ;; anew for the next alignment section
1501			  (if (and last-point
1502				   (align-new-section-p last-point b
1503							thissep))
1504			      (progn
1505				(align-regions regions align-props
1506					       rule func)
1507				(setq last-point (copy-marker b t)
1508				      regions nil
1509				      align-props nil))
1510			    (setq last-point (copy-marker b t)))
1511
1512			  ;; restore the match data
1513			  (set-match-data save-match-data)
1514
1515			  ;; check whether the region to be aligned
1516			  ;; straddles an exclusion area
1517			  (let ((excls exclude-areas))
1518			    (setq exclude-p nil)
1519			    (while excls
1520			      (if (and (< (match-beginning (car group))
1521					  (cdar excls))
1522				       (> (match-end (car (last group)))
1523					  (caar excls)))
1524				  (setq exclude-p t
1525					excls nil)
1526				(setq excls (cdr excls)))))
1527
1528			  ;; go through the list of parenthesis groups
1529			  ;; matching whitespace text to be
1530			  ;; contracted/expanded (or possibly
1531			  ;; justified, if the `justify' attribute was
1532			  ;; set)
1533			  (unless exclude-p
1534			    (let ((g group))
1535			      (while g
1536
1537				;; we have to use markers, since
1538				;; `align-areas' may modify the buffer
1539				(setq b (copy-marker
1540					 (match-beginning (car g)) t)
1541				      e (copy-marker (match-end (car g)) t))
1542
1543				;; record this text region for alignment
1544				(setq index (if same (1+ index) 0))
1545				(let ((region (cons b e))
1546				      (props (cons
1547					      (if (listp spacing)
1548						  (car spacing)
1549						spacing)
1550					      (if (listp tab-stop)
1551						  (car tab-stop)
1552						tab-stop))))
1553				  (if (nth index regions)
1554				      (setcar (nthcdr index regions)
1555					      (cons region
1556						    (nth index regions)))
1557				    (if regions
1558					(progn
1559					  (nconc regions
1560						 (list (list region)))
1561					  (nconc align-props (list props)))
1562				      (setq regions
1563					    (list (list region)))
1564				      (setq align-props (list props)))))
1565
1566				;; if any further rule matches are
1567				;; found before `eol', then they are
1568				;; on the same line as this one; this
1569				;; can only happen if the `repeat'
1570				;; attribute is non-nil
1571				(if (listp spacing)
1572				    (setq spacing (cdr spacing)))
1573				(if (listp tab-stop)
1574				    (setq tab-stop (cdr tab-stop)))
1575				(setq same t g (cdr g))))
1576
1577			    ;; if `repeat' has not been set, move to
1578			    ;; the next line; don't bother searching
1579			    ;; anymore on this one
1580			    (if (and (not repeat) (not (bolp)))
1581				(forward-line)))))
1582
1583		      ;; when they are no more matches for this rule,
1584		      ;; align whatever was left over
1585		      (if regions
1586			  (align-regions regions align-props rule func)))
1587
1588		  (setq case-fold-search current-case-fold)))))))
1589      (setq rules (cdr rules)
1590	    rule-index (1+ rule-index)))
1591
1592    (if report
1593	(message "Aligning...done"))))
1594
1595;; Provide:
1596
1597(provide 'align)
1598
1599(run-hooks 'align-load-hook)
1600
1601;;; arch-tag: ef79cccf-1db8-4888-a8a1-d7ce2d1532f7
1602;;; align.el ends here
1603