1;;; tempo.el --- Flexible template insertion
2
3;; Copyright (C) 1994, 1995, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: David K}gedal <davidk@lysator.liu.se>
7;; Created: 16 Feb 1994
8;; K}gedal's last version number: 1.2.4
9;; Keywords: extensions, languages, tools
10
11;; This file is part of GNU Emacs.
12
13;; GNU Emacs is free software; you can redistribute it and/or modify
14;; it under the terms of the GNU General Public License as published by
15;; the Free Software Foundation; either version 2, or (at your option)
16;; any later version.
17
18;; GNU Emacs is distributed in the hope that it will be useful,
19;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21;; GNU General Public License for more details.
22
23;; You should have received a copy of the GNU General Public License
24;; along with GNU Emacs; see the file COPYING.  If not, write to the
25;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
26;; Boston, MA 02110-1301, USA.
27
28;;; Commentary:
29
30;; This file provides a simple way to define powerful templates, or
31;; macros, if you wish. It is mainly intended for, but not limited to,
32;; other programmers to be used for creating shortcuts for editing
33;; certain kind of documents. It was originally written to be used by
34;; a HTML editing mode written by Nelson Minar <nelson@santafe.edu>,
35;; and his html-helper-mode.el is probably the best example of how to
36;; use this program.
37
38;; A template is defined as a list of items to be inserted in the
39;; current buffer at point. Some of the items can be simple strings,
40;; while other can control formatting or define special points of
41;; interest in the inserted text.
42
43;; If a template defines a "point of interest" that point is inserted
44;; in a buffer-local list of "points of interest" that the user can
45;; jump between with the commands `tempo-backward-mark' and
46;; `tempo-forward-mark'. If the template definer provides a prompt for
47;; the point, and the variable `tempo-interactive' is non-nil, the
48;; user will be prompted for a string to be inserted in the buffer,
49;; using the minibuffer.
50
51;; The template can also define one point to be replaced with the
52;; current region if the template command is called with a prefix (or
53;; a non-nil argument).
54
55;; More flexible templates can be created by including lisp symbols,
56;; which will be evaluated as variables, or lists, which will be
57;; evaluated as lisp expressions.
58
59;; See the documentation for tempo-define-template for the different
60;; items that can be used to define a tempo template.
61
62;; One of the more powerful features of tempo templates are automatic
63;; completion. With every template can be assigned a special tag that
64;; should be recognized by `tempo-complete-tag' and expanded to the
65;; complete template. By default the tags are added to a global list
66;; of template tags, and are matched against the last word before
67;; point. But if you assign your tags to a specific list, you can also
68;; specify another method for matching text in the buffer against the
69;; tags. In the HTML mode, for instance, the tags are matched against
70;; the text between the last `<' and point.
71
72;; When defining a template named `foo', a symbol named
73;; `tempo-template-foo' will be created whose value as a variable will
74;; be the template definition, and its function value will be an
75;; interactive function that inserts the template at the point.
76
77;; The latest tempo.el distribution can be fetched from
78;; ftp.lysator.liu.se in the directory /pub/emacs
79
80;; There is also a WWW page at
81;; http://www.lysator.liu.se/~davidk/elisp/ which has some information
82
83;;; Known bugs:
84
85;; If the 'o is the first element in a template, strange things can
86;; happen when the template is inserted at the beginning of a
87;; line. This is due to strange behaviour in open-line. But it should
88;; be easily avoided.
89
90;; The 'o tag is also a problem when including the region. This will
91;; be looked into.
92
93;; Clicking mouse-2 in the completion buffer gives strange results.
94
95;; There is a bug in some emacs versions that prevents completion from
96;; working. If it doesn't work for you, send me a note indicating your
97;; emacs version and your problems.
98
99;;; Contributors:
100
101;; These people have given me important feedback and new ideas for
102;; tempo.el. Thanks.
103
104;; Nelson Minar <nelson@santafe.edu>
105;; Richard Stallman <rms@gnu.org>
106;; Lars Lindberg <Lars.Lindberg@sypro.cap.se>
107;; Glen Whitney <Glen.Whitney@math.lsa.umich.edu>
108
109;;; Code:
110
111;;; User options
112
113(defgroup tempo nil
114  "Flexible template insertion."
115  :prefix "tempo-"
116  :group 'tools)
117
118(defcustom tempo-interactive nil
119  "*Prompt user for strings in templates.
120If this variable is non-nil, `tempo-insert' prompts the
121user for text to insert in the templates."
122  :type 'boolean
123  :group 'tempo)
124
125(defcustom tempo-insert-region nil
126  "*Automatically insert current region when there is a `r' in the template
127If this variable is nil, `r' elements will be treated just like `p'
128elements, unless the template function is given a prefix (or a non-nil
129argument).  If this variable is non-nil, the behavior is reversed.
130
131In Transient Mark mode, this option is unused."
132  :type 'boolean
133  :group 'tempo)
134
135(defcustom tempo-show-completion-buffer t
136  "*If non-nil, show a buffer with possible completions, when only
137a partial completion can be found."
138  :type 'boolean
139  :group 'tempo)
140
141(defcustom tempo-leave-completion-buffer nil
142  "*If nil, a completion buffer generated by \\[tempo-complete-tag]
143disappears at the next keypress; otherwise, it remains forever."
144  :type 'boolean
145  :group 'tempo)
146
147;;; Internal variables
148
149(defvar tempo-insert-string-functions nil
150  "List of functions to run when inserting a string.
151Each function is called with a single arg, STRING and should return
152another string.  This could be used for making all strings upcase by
153setting it to '(upcase), for example.")
154
155(defvar tempo-tags nil
156  "An association list with tags and corresponding templates.")
157
158(defvar tempo-local-tags '((tempo-tags . nil))
159  "A list of locally installed tag completion lists.
160It is a association list where the car of every element is a symbol
161whose variable value is a template list.  The cdr part, if non-nil,
162is a function or a regexp that defines the string to match.  See the
163documentation for the function `tempo-complete-tag' for more info.
164
165`tempo-tags' is always in the last position in this list.")
166
167(defvar tempo-collection nil
168  "A collection of all the tags defined for the current buffer.")
169
170(defvar tempo-dirty-collection t
171  "Indicates if the tag collection needs to be rebuilt.")
172
173(defvar tempo-marks nil
174  "A list of marks to jump to with `\\[tempo-forward-mark]' and `\\[tempo-backward-mark]'.")
175
176(defvar tempo-match-finder "\\b\\([[:word:]]+\\)\\="
177  "The regexp or function used to find the string to match against tags.
178
179If `tempo-match-finder' is a string, it should contain a regular
180expression with at least one \\( \\) pair.  When searching for tags,
181`tempo-complete-tag' calls `re-search-backward' with this string, and
182the string between the first \\( and \\) is used for matching against
183each string in the tag list. If one is found, the whole text between
184the first \\( and the point is replaced with the inserted template.
185
186You will probably want to include \\=\\= at the end of the regexp to
187make sure that the string is matched only against text adjacent to the
188point.
189
190If `tempo-match-finder' is a symbol, it should be a function that
191returns a pair of the form (STRING . POS), where STRING is the string
192used for matching and POS is the buffer position after which text
193should be replaced with a template.")
194
195(defvar tempo-user-elements nil
196  "Element handlers for user-defined elements.
197A list of symbols which are bound to functions that take one argument.
198This function should return something to be sent to `tempo-insert' if
199it recognizes the argument, and nil otherwise.")
200
201(defvar tempo-named-insertions nil
202  "Temporary storage for named insertions.")
203
204(defvar tempo-region-start (make-marker)
205  "Region start when inserting around the region.")
206
207(defvar tempo-region-stop (make-marker)
208  "Region stop when inserting around the region.")
209
210;; Make some variables local to every buffer
211
212(make-variable-buffer-local 'tempo-marks)
213(make-variable-buffer-local 'tempo-local-tags)
214(make-variable-buffer-local 'tempo-match-finder)
215(make-variable-buffer-local 'tempo-collection)
216(make-variable-buffer-local 'tempo-dirty-collection)
217
218;;; Functions
219
220;;
221;; tempo-define-template
222
223(defun tempo-define-template (name elements &optional tag documentation taglist)
224  "Define a template.
225This function creates a template variable `tempo-template-NAME' and an
226interactive function `tempo-template-NAME' that inserts the template
227at the point.  The created function is returned.
228
229NAME is a string that contains the name of the template, ELEMENTS is a
230list of elements in the template, TAG is the tag used for completion,
231DOCUMENTATION is the documentation string for the insertion command
232created, and TAGLIST (a symbol) is the tag list that TAG (if provided)
233should be added to.  If TAGLIST is nil and TAG is non-nil, TAG is
234added to `tempo-tags'.
235
236The elements in ELEMENTS can be of several types:
237
238 - A string: It is sent to the hooks in `tempo-insert-string-functions',
239   and the result is inserted.
240 - The symbol `p': This position is saved in `tempo-marks'.
241 - The symbol `r': If `tempo-insert' is called with ON-REGION non-nil
242   the current region is placed here.  Otherwise it works like `p'.
243 - (p PROMPT <NAME> <NOINSERT>): If `tempo-interactive' is non-nil, the
244   user is prompted in the minibuffer with PROMPT for a string to be
245   inserted.  If the optional parameter NAME is non-nil, the text is
246   saved for later insertion with the `s' tag.  If there already is
247   something saved under NAME that value is used instead and no
248   prompting is made.  If NOINSERT is provided and non-nil, nothing is
249   inserted, but text is still saved when a NAME is provided.  For
250   clarity, the symbol `noinsert' should be used as argument.
251 - (P PROMPT <NAME> <NOINSERT>): Works just like the previous tag, but
252   forces `tempo-interactive' to be true.
253 - (r PROMPT <NAME> <NOINSERT>): Like the previous tag, but if
254   `tempo-interactive' is nil and `tempo-insert' is called with
255   ON-REGION non-nil, the current region is placed here.  This usually
256   happens when you call the template function with a prefix argument.
257 - (s NAME): Inserts text previously read with the (p ..) construct.
258   Finds the insertion saved under NAME and inserts it.  Acts like `p'
259   if tempo-interactive is nil.
260 - `&': If there is only whitespace between the line start and point,
261   nothing happens.  Otherwise a newline is inserted.
262 - `%': If there is only whitespace between point and end of line,
263   nothing happens.  Otherwise a newline is inserted.
264 - `n': Inserts a newline.
265 - `>': The line is indented using `indent-according-to-mode'.  Note
266   that you often should place this item after the text you want on
267   the line.
268 - `r>': Like `r', but it also indents the region.
269 - (r> PROMPT <NAME> <NOINSERT>): Like (r ...), but is also indents
270   the region.
271 - `n>': Inserts a newline and indents line.
272 - `o': Like `%' but leaves the point before the newline.
273 - nil: It is ignored.
274 - Anything else: It is evaluated and the result is treated as an
275   element to be inserted.  One additional tag is useful for these
276   cases.  If an expression returns a list '(l foo bar), the elements
277   after `l' will be inserted according to the usual rules.  This makes
278   it possible to return several elements from one expression."
279  (let* ((template-name (intern (concat "tempo-template-"
280				       name)))
281	 (command-name template-name))
282    (set template-name elements)
283    (fset command-name (list 'lambda (list '&optional 'arg)
284			     (or documentation
285				 (concat "Insert a " name "."))
286			     (list 'interactive "*P")
287			     (list 'tempo-insert-template (list 'quote
288								template-name)
289				   (list 'if 'tempo-insert-region
290					 (list 'not 'arg) 'arg))))
291    (and tag
292	 (tempo-add-tag tag template-name taglist))
293    command-name))
294
295;;;
296;;; tempo-insert-template
297
298(defun tempo-insert-template (template on-region)
299  "Insert a template.
300TEMPLATE is the template to be inserted.  If ON-REGION is non-nil the
301`r' elements are replaced with the current region.  In Transient Mark
302mode, ON-REGION is ignored and assumed true if the region is active."
303  (unwind-protect
304      (progn
305	(if (or (and (boundp 'transient-mark-mode) ; For Emacs
306		     transient-mark-mode
307		     mark-active)
308		(if (featurep 'xemacs)
309		    (and zmacs-regions (mark))))
310	    (setq on-region t))
311	(and on-region
312	     (set-marker tempo-region-start (min (mark) (point)))
313	     (set-marker tempo-region-stop (max (mark) (point))))
314	(if on-region
315	    (goto-char tempo-region-start))
316	(save-excursion
317	  (tempo-insert-mark (point-marker))
318	  (mapcar (function (lambda (elt)
319			      (tempo-insert elt on-region)))
320		  (symbol-value template))
321	  (tempo-insert-mark (point-marker)))
322	(tempo-forward-mark))
323    (tempo-forget-insertions)
324    ;; Should I check for zmacs here too???
325    (and (boundp 'transient-mark-mode)
326	 transient-mark-mode
327	 (deactivate-mark))))
328
329;;;
330;;; tempo-insert
331
332(defun tempo-insert (element on-region)
333  "Insert a template element.
334Insert one element from a template. If ON-REGION is non-nil the `r'
335elements are replaced with the current region.
336
337See documentation for `tempo-define-template' for the kind of elements
338possible."
339  (cond ((stringp element) (tempo-process-and-insert-string element))
340	((and (consp element)
341	      (eq (car element) 'p)) (tempo-insert-prompt-compat
342				      (cdr element)))
343	((and (consp element)
344	      (eq (car element) 'P)) (let ((tempo-interactive t))
345				       (tempo-insert-prompt-compat
346					(cdr element))))
347;;;	((and (consp element)
348;;;	      (eq (car element) 'v)) (tempo-save-named
349;;;				      (nth 1 element)
350;;;				      nil
351;;;				      (nth 2 element)))
352	((and (consp element)
353	      (eq (car element) 'r)) (if on-region
354					 (goto-char tempo-region-stop)
355				       (tempo-insert-prompt-compat
356					(cdr element))))
357        ((and (consp element)
358              (eq (car element) 'r>)) (if on-region
359                                          (progn
360                                            (goto-char tempo-region-stop)
361                                            (indent-region (mark) (point) nil))
362                                        (tempo-insert-prompt-compat
363                                         (cdr element))))
364	((and (consp element)
365	      (eq (car element) 's)) (tempo-insert-named (car (cdr element))))
366	((and (consp element)
367	      (eq (car element) 'l)) (mapcar (function
368					      (lambda (elt)
369						(tempo-insert elt on-region)))
370					     (cdr element)))
371	((eq element 'p) (tempo-insert-mark (point-marker)))
372	((eq element 'r) (if on-region
373			     (goto-char tempo-region-stop)
374			   (tempo-insert-mark (point-marker))))
375	((eq element 'r>) (if on-region
376			      (progn
377				(goto-char tempo-region-stop)
378				(indent-region (mark) (point) nil))
379			    (tempo-insert-mark (point-marker))))
380	((eq element '>) (indent-according-to-mode))
381	((eq element '&) (if (not (or (= (current-column) 0)
382				      (save-excursion
383					(re-search-backward
384					 "^\\s-*\\=" nil t))))
385			     (insert "\n")))
386	((eq element '%) (if (not (or (eolp)
387				      (save-excursion
388					(re-search-forward
389					 "\\=\\s-*$" nil t))))
390			     (insert "\n")))
391	((eq element 'n) (insert "\n"))
392	((eq element 'n>) (insert "\n") (indent-according-to-mode))
393	;; Bug: If the 'o is the first element in a template, strange
394	;; things can happen when the template is inserted at the
395	;; beginning of a line.
396	((eq element 'o) (if (not (or on-region
397				      (eolp)
398				      (save-excursion
399					(re-search-forward
400					 "\\=\\s-*$" nil t))))
401			     (open-line 1)))
402	((null element))
403	(t (tempo-insert (or (tempo-is-user-element element)
404			     (eval element))
405			 on-region))))
406
407;;;
408;;; tempo-insert-prompt
409
410(defun tempo-insert-prompt-compat (prompt)
411  "Compatibility hack for `tempo-insert-prompt'.
412PROMPT can be either a prompt string, or a list of arguments to
413`tempo-insert-prompt', or nil."
414  (if (consp prompt)			; not nil either
415      (apply 'tempo-insert-prompt prompt)
416    (tempo-insert-prompt prompt)))
417
418(defun tempo-insert-prompt (prompt &optional save-name no-insert)
419  "Prompt for a text string and insert it in the current buffer.
420If the variable `tempo-interactive' is non-nil the user is prompted
421for a string in the minibuffer, which is then inserted in the current
422buffer.  If `tempo-interactive' is nil, the current point is placed on
423`tempo-mark'.
424
425PROMPT is the prompt string, SAVE-NAME is a name to save the inserted
426text under.  If the optional argument NO-INSERT is non-nil, no text is
427inserted.  This can be useful when there is a SAVE-NAME.
428
429If there already is a value for SAVE-NAME, it is used and the user is
430never prompted."
431  (let (insertion
432	(previous (and save-name
433		       (tempo-lookup-named save-name))))
434    (cond
435     ;; Insert  previous value, unless no-insert is non-nil
436     ((and previous
437	   (not no-insert))
438      (tempo-insert-named save-name)) ; A double lookup here, but who
439				      ; cares
440     ;; If no-insert is non-nil, don't insert the previous value. Just
441     ;; keep it
442     (previous
443      nil)
444     ;; No previous value. Prompt or insert mark
445     (tempo-interactive
446      (if (not (stringp prompt))
447	  (error "tempo: The prompt (%s) is not a string" prompt))
448      (setq insertion (read-string prompt))
449      (or no-insert
450	  (insert insertion))
451      (if save-name
452	  (tempo-save-named save-name insertion)))
453     (t
454      (tempo-insert-mark (point-marker))))))
455
456;;;
457;;; tempo-is-user-element
458
459(defun tempo-is-user-element (element)
460  "Tries all the user-defined element handlers in `tempo-user-elements'."
461  ;; Sigh... I need (some list)
462  (catch 'found
463    (mapcar (function (lambda (handler)
464			(let ((result (funcall handler element)))
465			  (if result (throw 'found result)))))
466	    tempo-user-elements)
467    (throw 'found nil)))
468
469;;;
470;;; tempo-forget-insertions
471
472(defun tempo-forget-insertions ()
473  "Forget all the saved named insertions."
474  (setq tempo-named-insertions nil))
475
476;;;
477;;; tempo-save-named
478
479(defun tempo-save-named (name data)	; Had an optional prompt for 'v
480  "Save some data for later insertion
481The contents of DATA is saved under the name NAME.
482
483The data can later be retrieved with `tempo-lookup-named'.
484
485This function returns nil, so it can be used in a template without
486inserting anything."
487  (setq tempo-named-insertions
488	(cons (cons name data)
489	      tempo-named-insertions))
490  nil)
491
492;;;
493;;; tempo-lookup-named
494
495(defun tempo-lookup-named (name)
496  "Lookup some saved data under the name NAME.
497Returns the data if NAME was found, and nil otherwise."
498  (cdr (assq name tempo-named-insertions)))
499
500;;;
501;;; tempo-insert-named
502
503(defun tempo-insert-named (name)
504  "Insert the previous insertion saved under a named specified in NAME.
505If there is no such name saved, a tempo mark is inserted.
506
507Note that if the data is a string, it will not be run through the string
508processor."
509  (let* ((insertion (tempo-lookup-named name)))
510    (cond ((null insertion)
511	   (tempo-insert-mark (point-marker)))
512	  ((stringp insertion)
513	   (insert insertion))
514	  (t
515	   (tempo-insert insertion nil)))))
516
517
518;;;
519;;; tempo-process-and-insert-string
520
521(defun tempo-process-and-insert-string (string)
522  "Insert a string from a template.
523Run a string through the preprocessors in `tempo-insert-string-functions'
524and insert the results."
525  (cond ((null tempo-insert-string-functions)
526	 nil)
527	((symbolp tempo-insert-string-functions)
528	 (setq string
529	       (funcall tempo-insert-string-functions string)))
530	((listp tempo-insert-string-functions)
531	 (dolist (fn tempo-insert-string-functions)
532	   (setq string (funcall fn string))))
533	(t
534	 (error "Bogus value in tempo-insert-string-functions: %s"
535		tempo-insert-string-functions)))
536  (insert string))
537
538;;;
539;;; tempo-insert-mark
540
541(defun tempo-insert-mark (mark)
542  "Insert a mark `tempo-marks' while keeping it sorted."
543  (cond ((null tempo-marks) (setq tempo-marks (list mark)))
544	((< mark (car tempo-marks)) (setq tempo-marks (cons mark tempo-marks)))
545	(t (let ((lp tempo-marks))
546	     (while (and (cdr lp)
547			 (<= (car (cdr lp)) mark))
548	       (setq lp (cdr lp)))
549	     (if (not (= mark (car lp)))
550		 (setcdr lp (cons mark (cdr lp))))))))
551
552;;;
553;;; tempo-forward-mark
554
555(defun tempo-forward-mark ()
556  "Jump to the next mark in `tempo-forward-mark-list'."
557  (interactive)
558  (let ((next-mark (catch 'found
559		     (mapcar
560		      (function
561		       (lambda (mark)
562			 (if (< (point) mark)
563			     (throw 'found mark))))
564		      tempo-marks)
565		     ;; return nil if not found
566		     nil)))
567    (if next-mark
568	(goto-char next-mark))))
569
570;;;
571;;; tempo-backward-mark
572
573(defun tempo-backward-mark ()
574  "Jump to the previous mark in `tempo-back-mark-list'."
575  (interactive)
576  (let ((prev-mark (catch 'found
577		     (let (last)
578		       (mapcar
579			(function
580			 (lambda (mark)
581			   (if (<= (point) mark)
582			       (throw 'found last))
583			   (setq last mark)))
584			tempo-marks)
585		       last))))
586    (if prev-mark
587	(goto-char prev-mark))))
588
589;;;
590;;; tempo-add-tag
591
592(defun tempo-add-tag (tag template &optional tag-list)
593  "Add a template tag.
594Add the TAG, that should complete to TEMPLATE to the list in TAG-LIST,
595or to `tempo-tags' if TAG-LIST is nil."
596
597  (interactive "sTag: \nCTemplate: ")
598  (if (null tag-list)
599      (setq tag-list 'tempo-tags))
600  (if (not (assoc tag (symbol-value tag-list)))
601      (set tag-list (cons (cons tag template) (symbol-value tag-list))))
602  (tempo-invalidate-collection))
603
604;;;
605;;; tempo-use-tag-list
606
607(defun tempo-use-tag-list (tag-list &optional completion-function)
608  "Install TAG-LIST to be used for template completion in the current buffer.
609TAG-LIST is a symbol whose variable value is a tag list created with
610`tempo-add-tag'.
611
612COMPLETION-FUNCTION is an obsolete option for specifying an optional
613function or string that is used by `\\[tempo-complete-tag]' to find a
614string to match the tag against.  It has the same definition as the
615variable `tempo-match-finder'.  In this version, supplying a
616COMPLETION-FUNCTION just sets `tempo-match-finder' locally."
617  (let ((old (assq tag-list tempo-local-tags)))
618    (if old
619	(setcdr old completion-function)
620      (setq tempo-local-tags (cons (cons tag-list completion-function)
621				   tempo-local-tags))))
622  (if completion-function
623      (setq tempo-match-finder completion-function))
624  (tempo-invalidate-collection))
625
626;;;
627;;; tempo-invalidate-collection
628
629(defun tempo-invalidate-collection ()
630  "Marks the tag collection as obsolete.
631Whenever it is needed again it will be rebuilt."
632  (setq tempo-dirty-collection t))
633
634;;;
635;;; tempo-build-collection
636
637(defun tempo-build-collection ()
638  "Build a collection of all the tags and return it.
639If `tempo-dirty-collection' is nil, the old collection is reused."
640  (prog1
641      (or (and (not tempo-dirty-collection)
642	       tempo-collection)
643	  (setq tempo-collection
644		(apply (function append)
645		       (mapcar (function (lambda (tag-list)
646					; If the format for
647					; tempo-local-tags changes,
648					; change this
649					   (eval (car tag-list))))
650			       tempo-local-tags))))
651    (setq tempo-dirty-collection nil)))
652
653;;;
654;;; tempo-find-match-string
655
656(defun tempo-find-match-string (finder)
657  "Find a string to be matched against a tag list.
658FINDER is a function or a string.  Returns (STRING . POS), or nil
659if no reasonable string is found."
660  (cond ((stringp finder)
661	 (let (successful)
662	   (save-excursion
663	     (or (setq successful (re-search-backward finder nil t))
664		 0))
665	   (if successful
666	       (cons (buffer-substring (match-beginning 1)
667				       (match-end 1)) ; This seems to be a
668					; bug in emacs
669		     (match-beginning 1))
670	     nil)))
671	(t
672	 (funcall finder))))
673
674;;;
675;;; tempo-complete-tag
676
677(defun tempo-complete-tag (&optional silent)
678  "Look for a tag and expand it.
679All the tags in the tag lists in `tempo-local-tags'
680\(this includes `tempo-tags') are searched for a match for the text
681before the point.  The way the string to match for is determined can
682be altered with the variable `tempo-match-finder'.  If
683`tempo-match-finder' returns nil, then the results are the same as
684no match at all.
685
686If a single match is found, the corresponding template is expanded in
687place of the matching string.
688
689If a partial completion or no match at all is found, and SILENT is
690non-nil, the function will give a signal.
691
692If a partial completion is found and `tempo-show-completion-buffer' is
693non-nil, a buffer containing possible completions is displayed."
694
695  ;; This function may look like a hack, but this is how I want it to
696  ;; work.
697  (interactive "*")
698  (let* ((collection (tempo-build-collection))
699	 (match-info (tempo-find-match-string tempo-match-finder))
700	 (match-string (car match-info))
701	 (match-start (cdr match-info))
702	 (exact (assoc match-string collection))
703	 (compl (or (car exact)
704		    (and match-info (try-completion match-string collection)))))
705    (if compl (delete-region match-start (point)))
706    (cond ((null match-info) (or silent (ding)))
707	  ((null compl) (or silent (ding)))
708	  ((eq compl t) (tempo-insert-template
709			 (cdr (assoc match-string
710				     collection))
711			 nil))
712	  (t (if (setq exact (assoc compl collection))
713		 (tempo-insert-template (cdr exact) nil)
714	       (insert compl)
715	       (or silent (ding))
716	       (if tempo-show-completion-buffer
717		   (tempo-display-completions match-string
718					      collection)))))))
719
720
721;;;
722;;; tempo-display-completions
723
724(defun tempo-display-completions (string tag-list)
725  "Show a buffer containing possible completions for STRING."
726  (if tempo-leave-completion-buffer
727      (with-output-to-temp-buffer "*Completions*"
728	(display-completion-list
729	 (all-completions string tag-list)
730	 string))
731    (save-window-excursion
732      (with-output-to-temp-buffer "*Completions*"
733	(display-completion-list
734	 (all-completions string tag-list)
735	 string))
736      (sit-for 32767))))
737
738;;;
739;;; tempo-expand-if-complete
740
741(defun tempo-expand-if-complete ()
742  "Expand the tag before point if it is complete.
743Returns non-nil if an expansion was made and nil otherwise.
744
745This could as an example be used in a command that is bound to the
746space bar, and looks something like this:
747
748\(defun tempo-space ()
749  (interactive \"*\")
750  (or (tempo-expand-if-complete)
751      (insert \" \")))"
752
753  (interactive "*")
754  (let* ((collection (tempo-build-collection))
755	 (match-info (tempo-find-match-string tempo-match-finder))
756	 (match-string (car match-info))
757	 (match-start (cdr match-info))
758	 (exact (assoc match-string collection)))
759    (if exact
760	(progn
761	  (delete-region match-start (point))
762	  (tempo-insert-template (cdr exact) nil)
763	  t)
764      nil)))
765
766(provide 'tempo)
767
768;;; arch-tag: b3c0ee36-db3b-47bc-875f-091b4e27a063
769;;; tempo.el ends here
770