1;;; icon.el --- mode for editing Icon code
2
3;; Copyright (C) 1989, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4;; Free Software Foundation, Inc.
5
6;; Author: Chris Smith <csmith@convex.com>
7;; Created: 15 Feb 89
8;; Keywords: languages
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;; A major mode for editing the Icon programming language.
30
31;;; Code:
32
33(defvar icon-mode-abbrev-table nil
34  "Abbrev table in use in Icon-mode buffers.")
35(define-abbrev-table 'icon-mode-abbrev-table ())
36
37(defvar icon-mode-map ()
38  "Keymap used in Icon mode.")
39(if icon-mode-map
40    ()
41  (let ((map (make-sparse-keymap "Icon")))
42    (setq icon-mode-map (make-sparse-keymap))
43    (define-key icon-mode-map "{" 'electric-icon-brace)
44    (define-key icon-mode-map "}" 'electric-icon-brace)
45    (define-key icon-mode-map "\e\C-h" 'mark-icon-function)
46    (define-key icon-mode-map "\e\C-a" 'beginning-of-icon-defun)
47    (define-key icon-mode-map "\e\C-e" 'end-of-icon-defun)
48    (define-key icon-mode-map "\e\C-q" 'indent-icon-exp)
49    (define-key icon-mode-map "\177" 'backward-delete-char-untabify)
50
51    (define-key icon-mode-map [menu-bar] (make-sparse-keymap "Icon"))
52    (define-key icon-mode-map [menu-bar icon]
53      (cons "Icon" map))
54    (define-key map [beginning-of-icon-defun] '("Beginning of function" . beginning-of-icon-defun))
55    (define-key map [end-of-icon-defun] '("End of function" . end-of-icon-defun))
56    (define-key map [comment-region] '("Comment Out Region" . comment-region))
57    (define-key map [indent-region] '("Indent Region" . indent-region))
58    (define-key map [indent-line] '("Indent Line" . icon-indent-command))
59    (put 'eval-region 'menu-enable 'mark-active)
60    (put 'comment-region 'menu-enable 'mark-active)
61    (put 'indent-region 'menu-enable 'mark-active)))
62
63(defvar icon-mode-syntax-table nil
64  "Syntax table in use in Icon-mode buffers.")
65
66(if icon-mode-syntax-table
67    ()
68  (setq icon-mode-syntax-table (make-syntax-table))
69  (modify-syntax-entry ?\\ "\\" icon-mode-syntax-table)
70  (modify-syntax-entry ?# "<" icon-mode-syntax-table)
71  (modify-syntax-entry ?\n ">" icon-mode-syntax-table)
72  (modify-syntax-entry ?$ "." icon-mode-syntax-table)
73  (modify-syntax-entry ?/ "." icon-mode-syntax-table)
74  (modify-syntax-entry ?* "." icon-mode-syntax-table)
75  (modify-syntax-entry ?+ "." icon-mode-syntax-table)
76  (modify-syntax-entry ?- "." icon-mode-syntax-table)
77  (modify-syntax-entry ?= "." icon-mode-syntax-table)
78  (modify-syntax-entry ?% "." icon-mode-syntax-table)
79  (modify-syntax-entry ?< "." icon-mode-syntax-table)
80  (modify-syntax-entry ?> "." icon-mode-syntax-table)
81  (modify-syntax-entry ?& "." icon-mode-syntax-table)
82  (modify-syntax-entry ?| "." icon-mode-syntax-table)
83  (modify-syntax-entry ?\' "\"" icon-mode-syntax-table))
84
85(defgroup icon nil
86  "Mode for editing Icon code."
87  :link '(custom-group-link :tag "Font Lock Faces group" font-lock-faces)
88  :group 'languages)
89
90(defcustom icon-indent-level 4
91  "*Indentation of Icon statements with respect to containing block."
92  :type 'integer
93  :group 'icon)
94
95(defcustom icon-brace-imaginary-offset 0
96  "*Imagined indentation of a Icon open brace that actually follows a statement."
97  :type 'integer
98  :group 'icon)
99
100(defcustom icon-brace-offset 0
101  "*Extra indentation for braces, compared with other text in same context."
102  :type 'integer
103  :group 'icon)
104
105(defcustom icon-continued-statement-offset 4
106  "*Extra indent for Icon lines not starting new statements."
107  :type 'integer
108  :group 'icon)
109
110(defcustom icon-continued-brace-offset 0
111  "*Extra indent for Icon substatements that start with open-braces.
112This is in addition to `icon-continued-statement-offset'."
113  :type 'integer
114  :group 'icon)
115
116(defcustom icon-auto-newline nil
117  "*Non-nil means automatically newline before and after braces Icon code.
118This applies when braces are inserted."
119  :type 'boolean
120  :group 'icon)
121
122(defcustom icon-tab-always-indent t
123  "*Non-nil means TAB in Icon mode should always reindent the current line.
124It will then reindent, regardless of where in the line point is
125when the TAB command is used."
126  :type 'boolean
127  :group 'icon)
128
129(defvar icon-imenu-generic-expression
130      '((nil "^[ \t]*procedure[ \t]+\\(\\sw+\\)[ \t]*("  1))
131  "Imenu expression for Icon mode.  See `imenu-generic-expression'.")
132
133
134
135;;;###autoload
136(defun icon-mode ()
137  "Major mode for editing Icon code.
138Expression and list commands understand all Icon brackets.
139Tab indents for Icon code.
140Paragraphs are separated by blank lines only.
141Delete converts tabs to spaces as it moves back.
142\\{icon-mode-map}
143Variables controlling indentation style:
144 icon-tab-always-indent
145    Non-nil means TAB in Icon mode should always reindent the current line,
146    regardless of where in the line point is when the TAB command is used.
147 icon-auto-newline
148    Non-nil means automatically newline before and after braces
149    inserted in Icon code.
150 icon-indent-level
151    Indentation of Icon statements within surrounding block.
152    The surrounding block's indentation is the indentation
153    of the line on which the open-brace appears.
154 icon-continued-statement-offset
155    Extra indentation given to a substatement, such as the
156    then-clause of an if or body of a while.
157 icon-continued-brace-offset
158    Extra indentation given to a brace that starts a substatement.
159    This is in addition to `icon-continued-statement-offset'.
160 icon-brace-offset
161    Extra indentation for line if it starts with an open brace.
162 icon-brace-imaginary-offset
163    An open brace following other text is treated as if it were
164    this far to the right of the start of its line.
165
166Turning on Icon mode calls the value of the variable `icon-mode-hook'
167with no args, if that value is non-nil."
168  (interactive)
169  (kill-all-local-variables)
170  (use-local-map icon-mode-map)
171  (setq major-mode 'icon-mode)
172  (setq mode-name "Icon")
173  (setq local-abbrev-table icon-mode-abbrev-table)
174  (set-syntax-table icon-mode-syntax-table)
175  (make-local-variable 'paragraph-start)
176  (setq paragraph-start (concat "$\\|" page-delimiter))
177  (make-local-variable 'paragraph-separate)
178  (setq paragraph-separate paragraph-start)
179  (make-local-variable 'indent-line-function)
180  (setq indent-line-function 'icon-indent-line)
181  (make-local-variable 'require-final-newline)
182  (setq require-final-newline mode-require-final-newline)
183  (make-local-variable 'comment-start)
184  (setq comment-start "# ")
185  (make-local-variable 'comment-end)
186  (setq comment-end "")
187  (make-local-variable 'comment-start-skip)
188  (setq comment-start-skip "# *")
189  (make-local-variable 'comment-indent-function)
190  (setq comment-indent-function 'icon-comment-indent)
191  (set (make-local-variable 'indent-line-function) 'icon-indent-line)
192  ;; font-lock support
193  (setq font-lock-defaults
194	'((icon-font-lock-keywords
195	   icon-font-lock-keywords-1 icon-font-lock-keywords-2)
196	  nil nil ((?_ . "w")) beginning-of-defun
197	  ;; Obsoleted by Emacs 19.35 parse-partial-sexp's COMMENTSTOP.
198	  ;(font-lock-comment-start-regexp . "#")
199	  (font-lock-mark-block-function . mark-defun)))
200  ;; imenu support
201  (make-local-variable 'imenu-generic-expression)
202  (setq imenu-generic-expression icon-imenu-generic-expression)
203  ;; hideshow support
204  ;; we start from the assertion that `hs-special-modes-alist' is autoloaded.
205  (unless (assq 'icon-mode hs-special-modes-alist)
206    (setq hs-special-modes-alist
207	  (cons '(icon-mode  "\\<procedure\\>" "\\<end\\>" nil
208			     icon-forward-sexp-function)
209		hs-special-modes-alist)))
210  (run-mode-hooks 'icon-mode-hook))
211
212;; This is used by indent-for-comment to decide how much to
213;; indent a comment in Icon code based on its context.
214(defun icon-comment-indent ()
215  (if (looking-at "^#") 0 comment-column))
216
217(defun electric-icon-brace (arg)
218  "Insert character and correct line's indentation."
219  (interactive "P")
220  (let (insertpos)
221    (if (and (not arg)
222	     (eolp)
223	     (or (save-excursion
224		   (skip-chars-backward " \t")
225		   (bolp))
226		 (if icon-auto-newline
227		     (progn (icon-indent-line) (newline) t)
228		   nil)))
229	(progn
230	  (insert last-command-char)
231	  (icon-indent-line)
232	  (if icon-auto-newline
233	      (progn
234		(newline)
235		;; (newline) may have done auto-fill
236		(setq insertpos (- (point) 2))
237		(icon-indent-line)))
238	  (save-excursion
239	    (if insertpos (goto-char (1+ insertpos)))
240	    (delete-char -1))))
241    (if insertpos
242	(save-excursion
243	  (goto-char insertpos)
244	  (self-insert-command (prefix-numeric-value arg)))
245      (self-insert-command (prefix-numeric-value arg)))))
246
247(defun icon-indent-command (&optional whole-exp)
248  "Indent current line as Icon code, or in some cases insert a tab character.
249If `icon-tab-always-indent' is non-nil (the default), always indent current
250line.  Otherwise, indent the current line only if point is at the left margin
251or in the line's indentation; otherwise insert a tab.
252
253A numeric argument, regardless of its value, means indent rigidly all the
254lines of the expression starting after point so that this line becomes
255properly indented.  The relative indentation among the lines of the
256expression are preserved."
257  (interactive "P")
258  (if whole-exp
259      ;; If arg, always indent this line as Icon
260      ;; and shift remaining lines of expression the same amount.
261      (let ((shift-amt (icon-indent-line))
262	    beg end)
263	(save-excursion
264	  (if icon-tab-always-indent
265	      (beginning-of-line))
266	  (setq beg (point))
267	  (forward-sexp 1)
268	  (setq end (point))
269	  (goto-char beg)
270	  (forward-line 1)
271	  (setq beg (point)))
272	(if (> end beg)
273	    (indent-code-rigidly beg end shift-amt "#")))
274    (if (and (not icon-tab-always-indent)
275	     (save-excursion
276	       (skip-chars-backward " \t")
277	       (not (bolp))))
278	(insert-tab)
279      (icon-indent-line))))
280
281(defun icon-indent-line ()
282  "Indent current line as Icon code.
283Return the amount the indentation changed by."
284  (let ((indent (calculate-icon-indent nil))
285	beg shift-amt
286	(case-fold-search nil)
287	(pos (- (point-max) (point))))
288    (beginning-of-line)
289    (setq beg (point))
290    (cond ((eq indent nil)
291	   (setq indent (current-indentation)))
292	  ((looking-at "^#")
293	   (setq indent 0))
294	  (t
295	   (skip-chars-forward " \t")
296	   (if (listp indent) (setq indent (car indent)))
297	   (cond ((and (looking-at "else\\b")
298		       (not (looking-at "else\\s_")))
299		  (setq indent (save-excursion
300				 (icon-backward-to-start-of-if)
301				 (current-indentation))))
302		 ((or (= (following-char) ?})
303		      (looking-at "end\\b"))
304		  (setq indent (- indent icon-indent-level)))
305		 ((= (following-char) ?{)
306		  (setq indent (+ indent icon-brace-offset))))))
307    (skip-chars-forward " \t")
308    (setq shift-amt (- indent (current-column)))
309    (if (zerop shift-amt)
310	(if (> (- (point-max) pos) (point))
311	    (goto-char (- (point-max) pos)))
312      (delete-region beg (point))
313      (indent-to indent)
314      ;; If initial point was within line's indentation,
315      ;; position after the indentation.  Else stay at same point in text.
316      (if (> (- (point-max) pos) (point))
317	  (goto-char (- (point-max) pos))))
318    shift-amt))
319
320(defun calculate-icon-indent (&optional parse-start)
321  "Return appropriate indentation for current line as Icon code.
322In usual case returns an integer: the column to indent to.
323Returns nil if line starts inside a string, t if in a comment."
324  (save-excursion
325    (beginning-of-line)
326    (let ((indent-point (point))
327	  (case-fold-search nil)
328	  state
329	  containing-sexp
330	  toplevel)
331      (if parse-start
332	  (goto-char parse-start)
333	(setq toplevel (beginning-of-icon-defun)))
334      (while (< (point) indent-point)
335	(setq parse-start (point))
336	(setq state (parse-partial-sexp (point) indent-point 0))
337	(setq containing-sexp (car (cdr state))))
338      (cond ((or (nth 3 state) (nth 4 state))
339	     ;; return nil or t if should not change this line
340	     (nth 4 state))
341	    ((and containing-sexp
342		  (/= (char-after containing-sexp) ?{))
343	     ;; line is expression, not statement:
344	     ;; indent to just after the surrounding open.
345	     (goto-char (1+ containing-sexp))
346	     (current-column))
347	    (t
348	      (if toplevel
349		  ;; Outside any procedures.
350		  (progn (icon-backward-to-noncomment (point-min))
351			 (if (icon-is-continuation-line)
352			     icon-continued-statement-offset 0))
353		;; Statement level.
354		(if (null containing-sexp)
355		    (progn (beginning-of-icon-defun)
356			   (setq containing-sexp (point))))
357		(goto-char indent-point)
358		;; Is it a continuation or a new statement?
359		;; Find previous non-comment character.
360		(icon-backward-to-noncomment containing-sexp)
361		;; Now we get the answer.
362		(if (icon-is-continuation-line)
363		    ;; This line is continuation of preceding line's statement;
364		    ;; indent  icon-continued-statement-offset  more than the
365		    ;; first line of the statement.
366		    (progn
367		      (icon-backward-to-start-of-continued-exp containing-sexp)
368		      (+ icon-continued-statement-offset (current-column)
369			 (if (save-excursion (goto-char indent-point)
370					     (skip-chars-forward " \t")
371					     (eq (following-char) ?{))
372			     icon-continued-brace-offset 0)))
373		  ;; This line starts a new statement.
374		  ;; Position following last unclosed open.
375		  (goto-char containing-sexp)
376		  ;; Is line first statement after an open-brace?
377		  (or
378		    ;; If no, find that first statement and indent like it.
379		    (save-excursion
380		      (if (looking-at "procedure\\s ")
381			  (forward-sexp 3)
382			(forward-char 1))
383		      (while (progn (skip-chars-forward " \t\n")
384				    (looking-at "#"))
385			;; Skip over comments following openbrace.
386			(forward-line 1))
387		      ;; The first following code counts
388		      ;; if it is before the line we want to indent.
389		      (and (< (point) indent-point)
390			   (current-column)))
391		    ;; If no previous statement,
392		    ;; indent it relative to line brace is on.
393		    ;; For open brace in column zero, don't let statement
394		    ;; start there too.  If icon-indent-level is zero,
395		    ;; use icon-brace-offset + icon-continued-statement-offset
396		    ;; instead.
397		    ;; For open-braces not the first thing in a line,
398		    ;; add in icon-brace-imaginary-offset.
399		    (+ (if (and (bolp) (zerop icon-indent-level))
400			   (+ icon-brace-offset
401			      icon-continued-statement-offset)
402			 icon-indent-level)
403		       ;; Move back over whitespace before the openbrace.
404		       ;; If openbrace is not first nonwhite thing on the line,
405		       ;; add the icon-brace-imaginary-offset.
406		       (progn (skip-chars-backward " \t")
407			      (if (bolp) 0 icon-brace-imaginary-offset))
408		       ;; Get initial indentation of the line we are on.
409		       (current-indentation))))))))))
410
411;; List of words to check for as the last thing on a line.
412;; If cdr is t, next line is a continuation of the same statement,
413;; if cdr is nil, next line starts a new (possibly indented) statement.
414
415(defconst icon-resword-alist
416  '(("by" . t) ("case" . t) ("create") ("do") ("dynamic" . t) ("else")
417    ("every" . t) ("if" . t) ("global" . t) ("initial" . t)
418    ("link" . t) ("local" . t) ("of") ("record" . t) ("repeat" . t)
419    ("static" . t) ("then") ("to" . t) ("until" . t) ("while" . t)))
420
421(defun icon-is-continuation-line ()
422  (let* ((ch (preceding-char))
423	 (ch-syntax (char-syntax ch)))
424    (if (eq ch-syntax ?w)
425	(assoc (buffer-substring
426		(progn (forward-word -1) (point))
427		(progn (forward-word 1) (point)))
428	       icon-resword-alist)
429      (not (memq ch '(0 ?\; ?\} ?\{ ?\) ?\] ?\" ?\' ?\# ?\, ?\. ?\n))))))
430
431(defun icon-backward-to-noncomment (lim)
432  (let (opoint stop)
433    (while (not stop)
434      (skip-chars-backward " \t\n\f" lim)
435      (setq opoint (point))
436      (beginning-of-line)
437      (if (and (nth 5 (parse-partial-sexp (point) opoint))
438	       (< lim (point)))
439	  (search-backward "#")
440	(setq stop t)))))
441
442(defun icon-backward-to-start-of-continued-exp (lim)
443  (if (memq (preceding-char) '(?\) ?\]))
444      (forward-sexp -1))
445  (beginning-of-line)
446  (skip-chars-forward " \t")
447  (cond
448   ((<= (point) lim) (goto-char (1+ lim)))
449   ((not (icon-is-continued-line)) 0)
450   ((and (eq (char-syntax (following-char)) ?w)
451	 (cdr
452	  (assoc (buffer-substring (point)
453				   (save-excursion (forward-word 1) (point)))
454		 icon-resword-alist))) 0)
455   (t (end-of-line 0) (icon-backward-to-start-of-continued-exp lim))))
456
457(defun icon-is-continued-line ()
458  (save-excursion
459    (end-of-line 0)
460    (icon-is-continuation-line)))
461
462(defun icon-backward-to-start-of-if (&optional limit)
463  "Move to the start of the last \"unbalanced\" if."
464  (or limit (setq limit (save-excursion (beginning-of-icon-defun) (point))))
465  (let ((if-level 1)
466	(case-fold-search nil))
467    (while (not (zerop if-level))
468      (backward-sexp 1)
469      (cond ((looking-at "else\\b")
470	     (setq if-level (1+ if-level)))
471	    ((looking-at "if\\b")
472	     (setq if-level (1- if-level)))
473	    ((< (point) limit)
474	     (setq if-level 0)
475	     (goto-char limit))))))
476
477(defun mark-icon-function ()
478  "Put mark at end of Icon function, point at beginning."
479  (interactive)
480  (push-mark (point))
481  (end-of-icon-defun)
482  (push-mark (point))
483  (beginning-of-line 0)
484  (beginning-of-icon-defun))
485
486(defun beginning-of-icon-defun ()
487  "Go to the start of the enclosing procedure; return t if at top level."
488  (interactive)
489  (if (re-search-backward "^procedure\\s \\|^end[ \t\n]" (point-min) 'move)
490      (looking-at "e")
491    t))
492
493(defun end-of-icon-defun ()
494  (interactive)
495  (if (not (bobp)) (forward-char -1))
496  (re-search-forward "\\(\\s \\|^\\)end\\(\\s \\|$\\)" (point-max) 'move)
497  (forward-word -1)
498  (forward-line 1))
499
500(defun indent-icon-exp ()
501  "Indent each line of the Icon grouping following point."
502  (interactive)
503  (let ((indent-stack (list nil))
504	(contain-stack (list (point)))
505	(case-fold-search nil)
506	restart outer-loop-done inner-loop-done state ostate
507	this-indent last-sexp last-depth
508	at-else at-brace at-do
509	(opoint (point))
510	(next-depth 0))
511    (save-excursion
512      (forward-sexp 1))
513    (save-excursion
514      (setq outer-loop-done nil)
515      (while (and (not (eobp)) (not outer-loop-done))
516	(setq last-depth next-depth)
517	;; Compute how depth changes over this line
518	;; plus enough other lines to get to one that
519	;; does not end inside a comment or string.
520	;; Meanwhile, do appropriate indentation on comment lines.
521	(setq inner-loop-done nil)
522	(while (and (not inner-loop-done)
523		    (not (and (eobp) (setq outer-loop-done t))))
524	  (setq ostate state)
525	  (setq state (parse-partial-sexp (point) (progn (end-of-line) (point))
526					  nil nil state))
527	  (setq next-depth (car state))
528	  (if (and (car (cdr (cdr state)))
529		   (>= (car (cdr (cdr state))) 0))
530	      (setq last-sexp (car (cdr (cdr state)))))
531	  (if (or (nth 4 ostate))
532	      (icon-indent-line))
533	  (if (or (nth 3 state))
534	      (forward-line 1)
535	    (setq inner-loop-done t)))
536	(if (<= next-depth 0)
537	    (setq outer-loop-done t))
538	(if outer-loop-done
539	    nil
540	  (if (/= last-depth next-depth)
541	      (setq last-sexp nil))
542	  (while (> last-depth next-depth)
543	    (setq indent-stack (cdr indent-stack)
544		  contain-stack (cdr contain-stack)
545		  last-depth (1- last-depth)))
546	  (while (< last-depth next-depth)
547	    (setq indent-stack (cons nil indent-stack)
548		  contain-stack (cons nil contain-stack)
549		  last-depth (1+ last-depth)))
550	  (if (null (car contain-stack))
551	      (setcar contain-stack (or (car (cdr state))
552					(save-excursion (forward-sexp -1)
553							(point)))))
554	  (forward-line 1)
555	  (skip-chars-forward " \t")
556	  (if (eolp)
557	      nil
558	    (if (and (car indent-stack)
559		     (>= (car indent-stack) 0))
560		;; Line is on an existing nesting level.
561		;; Lines inside parens are handled specially.
562		(if (/= (char-after (car contain-stack)) ?{)
563		    (setq this-indent (car indent-stack))
564		  ;; Line is at statement level.
565		  ;; Is it a new statement?  Is it an else?
566		  ;; Find last non-comment character before this line
567		  (save-excursion
568		    (setq at-else (looking-at "else\\W"))
569		    (setq at-brace (= (following-char) ?{))
570		    (icon-backward-to-noncomment opoint)
571		    (if (icon-is-continuation-line)
572			;; Preceding line did not end in comma or semi;
573			;; indent this line  icon-continued-statement-offset
574			;; more than previous.
575			(progn
576			  (icon-backward-to-start-of-continued-exp (car contain-stack))
577			  (setq this-indent
578				(+ icon-continued-statement-offset (current-column)
579				   (if at-brace icon-continued-brace-offset 0))))
580		      ;; Preceding line ended in comma or semi;
581		      ;; use the standard indent for this level.
582		      (if at-else
583			  (progn (icon-backward-to-start-of-if opoint)
584				 (setq this-indent (current-indentation)))
585			(setq this-indent (car indent-stack))))))
586	      ;; Just started a new nesting level.
587	      ;; Compute the standard indent for this level.
588	      (let ((val (calculate-icon-indent
589			   (if (car indent-stack)
590			       (- (car indent-stack))))))
591		(setcar indent-stack
592			(setq this-indent val))))
593	    ;; Adjust line indentation according to its contents
594	    (if (or (= (following-char) ?})
595		    (looking-at "end\\b"))
596		(setq this-indent (- this-indent icon-indent-level)))
597	    (if (= (following-char) ?{)
598		(setq this-indent (+ this-indent icon-brace-offset)))
599	    ;; Put chosen indentation into effect.
600	    (or (= (current-column) this-indent)
601		(progn
602		  (delete-region (point) (progn (beginning-of-line) (point)))
603		  (indent-to this-indent)))
604	    ;; Indent any comment following the text.
605	    (or (looking-at comment-start-skip)
606		(if (re-search-forward comment-start-skip (save-excursion (end-of-line) (point)) t)
607		    (progn (indent-for-comment) (beginning-of-line))))))))))
608
609(defconst icon-font-lock-keywords-1
610  (eval-when-compile
611    (list
612     ;; Fontify procedure name definitions.
613       '("^[ \t]*\\(procedure\\)\\>[ \t]*\\(\\sw+\\)?"
614       (1 font-lock-builtin-face) (2 font-lock-function-name-face nil t))))
615  "Subdued level highlighting for Icon mode.")
616
617(defconst icon-font-lock-keywords-2
618  (append
619   icon-font-lock-keywords-1
620   (eval-when-compile
621     (list
622      ;; Fontify all type specifiers.
623      (cons
624       (regexp-opt  '("null" "string" "co-expression" "table" "integer"
625		      "cset"  "set" "real" "file" "list") 'words)
626       'font-lock-type-face)
627      ;; Fontify all keywords.
628      ;;
629      (cons
630       (regexp-opt
631	'("break" "do" "next" "repeat" "to" "by" "else" "if" "not" "return"
632	  "until" "case" "of" "while" "create" "every" "suspend" "default"
633	  "fail" "record" "then") 'words)
634       'font-lock-keyword-face)
635      ;; "end" "initial"
636      (cons (regexp-opt '("end" "initial") 'words)
637	    'font-lock-builtin-face)
638      ;; Fontify all system variables.
639      (cons
640       (regexp-opt
641	'("&allocated" "&ascii" "&clock" "&col" "&collections" "&column"
642	  "&control" "&cset" "&current" "&date" "&dateline" "&digits" "&dump"
643	  "&e" "&error" "&errornumber" "&errortext" "&errorvalue" "&errout"
644	  "&eventcode" "&eventsource" "&eventvalue" "&fail" "&features"
645	  "&file" "&host" "&input" "&interval" "&lcase" "&ldrag" "&letters"
646	  "&level" "&line" "&lpress" "&lrelease" "&main" "&mdrag" "&meta"
647	  "&mpress" "&mrelease" "&null" "&output" "&phi" "&pi" "&pos"
648	  "&progname" "&random" "&rdrag" "&regions" "&resize" "&row"
649	  "&rpress" "&rrelease" "&shift" "&source" "&storage" "&subject"
650	  "&time" "&trace" "&ucase" "&version" "&window" "&x" "&y") t)
651       'font-lock-constant-face)
652      (cons      ;; global local static declarations and link files
653       (concat
654	"^[ \t]*"
655	(regexp-opt '("global" "link" "local" "static") t)
656	"\\(\\sw+\\>\\)*")
657       '((1 font-lock-builtin-face)
658	 (font-lock-match-c-style-declaration-item-and-skip-to-next
659	  (goto-char (or (match-beginning 2) (match-end 1))) nil
660	  (1 (if (match-beginning 2)
661		 font-lock-function-name-face
662	       font-lock-variable-name-face)))))
663
664      (cons      ;; $define $elif $ifdef $ifndef $undef
665       (concat "^"
666	       (regexp-opt'("$define" "$elif" "$ifdef" "$ifndef" "$undef") t)
667	       "\\>[ \t]*\\([^ \t\n]+\\)?")
668	    '((1 font-lock-builtin-face)
669	      (4 font-lock-variable-name-face nil t)))
670      (cons      ;; $dump $endif $else $include
671       (concat
672	"^" (regexp-opt'("$dump" "$endif" "$else" "$include") t) "\\>" )
673       'font-lock-builtin-face)
674      (cons      ;; $warning $error
675       (concat "^" (regexp-opt '("$warning" "$error") t)
676	       "\\>[ \t]*\\(.+\\)?")
677       '((1 font-lock-builtin-face) (3 font-lock-warning-face nil t))))))
678  "Gaudy level highlighting for Icon mode.")
679
680(defvar icon-font-lock-keywords icon-font-lock-keywords-1
681  "Default expressions to highlight in `icon-mode'.")
682
683;;;used by hs-minor-mode
684(defun icon-forward-sexp-function (arg)
685  (if (< arg 0)
686      (beginning-of-icon-defun)
687    (end-of-icon-defun)
688    (forward-char -1)))
689
690(provide 'icon)
691
692;;; arch-tag: 8abf8c99-e7df-44af-a58f-ef5ed2ee52cb
693;;; icon.el ends here
694