2135
|
1 ;;; derived.el --- allow inheritance of major modes
|
|
2 ;;; (formerly mode-clone.el)
|
428
|
3
|
2135
|
4 ;; Copyright (C) 1993, 1994, 1999, 2003 Free Software Foundation, Inc.
|
428
|
5
|
|
6 ;; Author: David Megginson (dmeggins@aix1.uottawa.ca)
|
|
7 ;; Maintainer: XEmacs Development Team
|
|
8 ;; Keywords: extensions, dumped
|
|
9
|
|
10 ;; This file is part of XEmacs.
|
|
11
|
|
12 ;; XEmacs is free software; you can redistribute it and/or modify it
|
|
13 ;; 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 ;; XEmacs is distributed in the hope that it will be useful, but
|
|
18 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
20 ;; General Public License for more details.
|
|
21
|
|
22 ;; You should have received a copy of the GNU General Public License
|
|
23 ;; along with XEmacs; see the file COPYING. If not, write to the Free
|
|
24 ;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
|
|
25 ;; 02111-1307, USA.
|
|
26
|
2135
|
27 ;;; Synched up with: FSF 21.3.
|
428
|
28
|
|
29 ;;; Commentary:
|
|
30
|
|
31 ;; This file is dumped with XEmacs.
|
|
32
|
613
|
33 ;; XEmacs is already, in a sense, object oriented -- each object
|
428
|
34 ;; (buffer) belongs to a class (major mode), and that class defines
|
|
35 ;; the relationship between messages (input events) and methods
|
|
36 ;; (commands) by means of a keymap.
|
|
37 ;;
|
|
38 ;; The only thing missing is a good scheme of inheritance. It is
|
|
39 ;; possible to simulate a single level of inheritance with generous
|
|
40 ;; use of hooks and a bit of work -- sgml-mode, for example, also runs
|
|
41 ;; the hooks for text-mode, and keymaps can inherit from other keymaps
|
|
42 ;; -- but generally, each major mode ends up reinventing the wheel.
|
|
43 ;; Ideally, someone should redesign all of Emacs's major modes to
|
|
44 ;; follow a more conventional object-oriented system: when defining a
|
|
45 ;; new major mode, the user should need only to name the existing mode
|
|
46 ;; it is most similar to, then list the (few) differences.
|
|
47 ;;
|
|
48 ;; In the mean time, this package offers most of the advantages of
|
|
49 ;; full inheritance with the existing major modes. The macro
|
|
50 ;; `define-derived-mode' allows the user to make a variant of an existing
|
|
51 ;; major mode, with its own keymap. The new mode will inherit the key
|
|
52 ;; bindings of its parent, and will, in fact, run its parent first
|
|
53 ;; every time it is called. For example, the commands
|
|
54 ;;
|
|
55 ;; (define-derived-mode hypertext-mode text-mode "Hypertext"
|
|
56 ;; "Major mode for hypertext.\n\n\\{hypertext-mode-map}"
|
|
57 ;; (setq case-fold-search nil))
|
|
58 ;;
|
|
59 ;; (define-key hypertext-mode-map [down-mouse-3] 'do-hyper-link)
|
|
60 ;;
|
|
61 ;; will create a function `hypertext-mode' with its own (sparse)
|
3061
|
62 ;; keymap `hypertext-mode-map'. The command M-x hypertext-mode will
|
428
|
63 ;; perform the following actions:
|
|
64 ;;
|
|
65 ;; - run the command (text-mode) to get its default setup
|
3061
|
66 ;; - replace the current keymap with 'hypertext-mode-map', which will
|
428
|
67 ;; inherit from 'text-mode-map'.
|
|
68 ;; - replace the current syntax table with
|
|
69 ;; 'hypertext-mode-syntax-table', which will borrow its defaults
|
|
70 ;; from the current text-mode-syntax-table.
|
|
71 ;; - replace the current abbrev table with
|
|
72 ;; 'hypertext-mode-abbrev-table', which will borrow its defaults
|
|
73 ;; from the current text-mode-abbrev table
|
|
74 ;; - change the mode line to read "Hypertext"
|
|
75 ;; - assign the value 'hypertext-mode' to the 'major-mode' variable
|
|
76 ;; - run the body of commands provided in the macro -- in this case,
|
|
77 ;; set the local variable `case-fold-search' to nil.
|
|
78 ;;
|
|
79 ;; The advantages of this system are threefold. First, text mode is
|
3061
|
80 ;; untouched -- if you had added the new keystroke to `text-mode-map',
|
428
|
81 ;; possibly using hooks, you would have added it to all text buffers
|
|
82 ;; -- here, it appears only in hypertext buffers, where it makes
|
|
83 ;; sense. Second, it is possible to build even further, and make
|
|
84 ;; a derived mode from a derived mode. The commands
|
|
85 ;;
|
|
86 ;; (define-derived-mode html-mode hypertext-mode "HTML")
|
|
87 ;; [various key definitions]
|
2135
|
88 ;;
|
428
|
89 ;; will add a new major mode for HTML with very little fuss.
|
|
90 ;;
|
2135
|
91 ;; Note also the function `derived-mode-p' which can tell if the current
|
|
92 ;; mode derives from another. In a hypertext-mode, buffer, for example,
|
|
93 ;; (derived-mode-p 'text-mode) would return non-nil. This should always
|
|
94 ;; be used in place of (eq major-mode 'text-mode).
|
428
|
95
|
|
96 ;;; Code:
|
|
97
|
2135
|
98 ;;; PRIVATE: defsubst must be defined before they are first used
|
|
99
|
|
100 (defsubst derived-mode-hook-name (mode)
|
|
101 "Construct the mode hook name based on mode name MODE."
|
|
102 (intern (concat (symbol-name mode) "-hook")))
|
|
103
|
|
104 (defsubst derived-mode-map-name (mode)
|
|
105 "Construct a map name based on a MODE name."
|
|
106 (intern (concat (symbol-name mode) "-map")))
|
|
107
|
|
108 (defsubst derived-mode-syntax-table-name (mode)
|
|
109 "Construct a syntax-table name based on a MODE name."
|
|
110 (intern (concat (symbol-name mode) "-syntax-table")))
|
|
111
|
|
112 (defsubst derived-mode-abbrev-table-name (mode)
|
|
113 "Construct an abbrev-table name based on a MODE name."
|
|
114 (intern (concat (symbol-name mode) "-abbrev-table")))
|
|
115
|
428
|
116 ;; PUBLIC: define a new major mode which inherits from an existing one.
|
|
117
|
|
118 ;; XEmacs -- no autoload
|
|
119 (defmacro define-derived-mode (child parent name &optional docstring &rest body)
|
|
120 "Create a new mode as a variant of an existing mode.
|
|
121
|
|
122 The arguments to this command are as follow:
|
|
123
|
|
124 CHILD: the name of the command for the derived mode.
|
2135
|
125 PARENT: the name of the command for the parent mode (e.g. `text-mode')
|
|
126 or nil if there is no parent.
|
|
127 NAME: a string which will appear in the status line (e.g. \"Hypertext\")
|
428
|
128 DOCSTRING: an optional documentation string--if you do not supply one,
|
|
129 the function will attempt to invent something useful.
|
|
130 BODY: forms to execute just before running the
|
2135
|
131 hooks for the new mode. Do not use `interactive' here.
|
|
132
|
|
133 BODY can start with a bunch of keyword arguments. The following keyword
|
|
134 arguments are currently understood:
|
|
135 :group GROUP
|
|
136 Declare the customization group that corresponds to this mode.
|
|
137 :syntax-table TABLE
|
|
138 Use TABLE instead of the default.
|
|
139 A nil value means to simply use the same syntax-table as the parent.
|
|
140 :abbrev-table TABLE
|
|
141 Use TABLE instead of the default.
|
|
142 A nil value means to simply use the same abbrev-table as the parent.
|
428
|
143
|
|
144 Here is how you could define LaTeX-Thesis mode as a variant of LaTeX mode:
|
|
145
|
|
146 (define-derived-mode LaTeX-thesis-mode LaTeX-mode \"LaTeX-Thesis\")
|
|
147
|
|
148 You could then make new key bindings for `LaTeX-thesis-mode-map'
|
|
149 without changing regular LaTeX mode. In this example, BODY is empty,
|
|
150 and DOCSTRING is generated by default.
|
|
151
|
2135
|
152 On a more complicated level, the following command uses `sgml-mode' as
|
428
|
153 the parent, and then sets the variable `case-fold-search' to nil:
|
|
154
|
|
155 (define-derived-mode article-mode sgml-mode \"Article\"
|
|
156 \"Major mode for editing technical articles.\"
|
|
157 (setq case-fold-search nil))
|
|
158
|
|
159 Note that if the documentation string had been left out, it would have
|
2135
|
160 been generated automatically, with a reference to the keymap.
|
|
161
|
|
162 The new mode runs the hook constructed by the function
|
|
163 `derived-mode-hook-name'."
|
|
164 (declare (debug (&define name symbolp sexp [&optional stringp]
|
|
165 [&rest keywordp sexp] def-body)))
|
|
166
|
|
167 (when (and docstring (not (stringp docstring)))
|
|
168 ;; Some trickiness, since what appears to be the docstring may really be
|
|
169 ;; the first element of the body.
|
|
170 (push docstring body)
|
|
171 (setq docstring nil))
|
|
172
|
|
173 (when (eq parent 'fundamental-mode) (setq parent nil))
|
|
174
|
|
175 (let ((map (derived-mode-map-name child))
|
|
176 (syntax (derived-mode-syntax-table-name child))
|
|
177 (abbrev (derived-mode-abbrev-table-name child))
|
|
178 (declare-abbrev t)
|
|
179 (declare-syntax t)
|
|
180 (hook (derived-mode-hook-name child))
|
|
181 (group nil))
|
428
|
182
|
2135
|
183 ;; Process the keyword args.
|
|
184 (while (keywordp (car body))
|
|
185 (case (pop body)
|
|
186 (:group (setq group (pop body)))
|
|
187 (:abbrev-table (setq abbrev (pop body)) (setq declare-abbrev nil))
|
|
188 (:syntax-table (setq syntax (pop body)) (setq declare-syntax nil))
|
|
189 (t (pop body))))
|
|
190
|
|
191 (setq docstring (derived-mode-make-docstring
|
|
192 parent child docstring syntax abbrev))
|
428
|
193
|
2135
|
194 `(progn
|
|
195 (defvar ,hook nil ,(format "Hook run when entering %s mode." name))
|
|
196 (defvar ,map (make-sparse-keymap))
|
|
197 ,(if declare-syntax
|
|
198 `(defvar ,syntax (make-syntax-table)))
|
|
199 ,(if declare-abbrev
|
|
200 `(defvar ,abbrev
|
|
201 (progn (define-abbrev-table ',abbrev nil) ,abbrev)))
|
|
202 (put ',child 'derived-mode-parent ',parent)
|
|
203 ,(if group `(put ',child 'custom-mode-group ,group))
|
|
204
|
428
|
205 (defun ,child ()
|
|
206 ,docstring
|
|
207 (interactive)
|
|
208 ; Run the parent.
|
2135
|
209 (delay-mode-hooks
|
|
210
|
|
211 (,(or parent 'kill-all-local-variables))
|
|
212 ; Identify the child mode.
|
|
213 (setq major-mode (quote ,child))
|
|
214 (setq mode-name ,name)
|
428
|
215 ; Identify special modes.
|
2135
|
216 ,(when parent
|
|
217 `(progn
|
|
218 (if (get (quote ,parent) 'mode-class)
|
|
219 (put (quote ,child) 'mode-class
|
|
220 (get (quote ,parent) 'mode-class)))
|
428
|
221 ; Set up maps and tables.
|
2135
|
222 (unless (keymap-parent ,map)
|
2140
|
223 (set-keymap-parents ,map (list (current-local-map))))
|
2135
|
224 ,(when declare-syntax
|
2140
|
225 ;; XEmacs change: we do not have char-table-parent
|
|
226 `(derived-mode-merge-syntax-tables
|
2142
|
227 (syntax-table) ,syntax))))
|
2135
|
228
|
|
229 (use-local-map ,map)
|
|
230 ,(when syntax `(set-syntax-table ,syntax))
|
|
231 ,(when abbrev `(setq local-abbrev-table ,abbrev))
|
428
|
232 ; Splice in the body (if any).
|
2135
|
233 ,@body
|
|
234 )
|
|
235 ;; Run the hooks, if any.
|
|
236 ;; Make the generated code work in older Emacs versions
|
|
237 ;; that do not yet have run-mode-hooks.
|
|
238 (if (fboundp 'run-mode-hooks)
|
|
239 (run-mode-hooks ',hook)
|
|
240 (run-hooks ',hook))))))
|
428
|
241
|
|
242 ;; PUBLIC: find the ultimate class of a derived mode.
|
|
243
|
|
244 (defun derived-mode-class (mode)
|
2135
|
245 "Find the class of a major MODE.
|
428
|
246 A mode's class is the first ancestor which is NOT a derived mode.
|
2135
|
247 Use the `derived-mode-parent' property of the symbol to trace backwards.
|
|
248 Since major-modes might all derive from `fundamental-mode', this function
|
|
249 is not very useful."
|
428
|
250 (while (get mode 'derived-mode-parent)
|
|
251 (setq mode (get mode 'derived-mode-parent)))
|
|
252 mode)
|
2135
|
253 (make-obsolete 'derived-mode-class 'derived-mode-p)
|
428
|
254
|
906
|
255 ;; PUBLIC: find if the current mode derives from another.
|
|
256 ;; from GNU Emacs 21 subr.el
|
|
257
|
|
258 (defun derived-mode-p (&rest modes)
|
|
259 "Non-nil if the current major mode is derived from one of MODES.
|
|
260 Uses the `derived-mode-parent' property of the symbol to trace backwards."
|
|
261 (let ((parent major-mode))
|
|
262 (while (and (not (memq parent modes))
|
|
263 (setq parent (get parent 'derived-mode-parent))))
|
|
264 parent))
|
|
265
|
428
|
266
|
2135
|
267 ;;; PRIVATE
|
|
268
|
|
269 (defun derived-mode-make-docstring (parent child &optional
|
|
270 docstring syntax abbrev)
|
|
271 "Construct a docstring for a new mode if none is provided."
|
|
272
|
|
273 (let ((map (derived-mode-map-name child))
|
|
274 (hook (derived-mode-hook-name child)))
|
|
275
|
|
276 (unless (stringp docstring)
|
|
277 ;; Use a default docstring.
|
|
278 (setq docstring
|
|
279 (if (null parent)
|
|
280 (format "Major-mode.
|
|
281 Uses keymap `%s', abbrev table `%s' and syntax-table `%s'." map abbrev syntax)
|
|
282 (format "Major mode derived from `%s' by `define-derived-mode'.
|
|
283 It inherits all of the parent's attributes, but has its own keymap,
|
|
284 abbrev table and syntax table:
|
|
285
|
|
286 `%s', `%s' and `%s'
|
|
287
|
|
288 which more-or-less shadow %s's corresponding tables."
|
|
289 parent map abbrev syntax parent))))
|
|
290
|
|
291 (unless (string-match (regexp-quote (symbol-name hook)) docstring)
|
|
292 ;; Make sure the docstring mentions the mode's hook.
|
|
293 (setq docstring
|
|
294 (concat docstring
|
|
295 (if (null parent)
|
|
296 "\n\nThis mode "
|
|
297 (concat
|
|
298 "\n\nIn addition to any hooks its parent mode "
|
|
299 (if (string-match (regexp-quote (format "`%s'" parent))
|
|
300 docstring) nil
|
|
301 (format "`%s' " parent))
|
|
302 "might have run,\nthis mode "))
|
|
303 (format "runs the hook `%s'" hook)
|
|
304 ", as the final step\nduring initialization.")))
|
|
305
|
|
306 (unless (string-match "\\\\[{[]" docstring)
|
|
307 ;; And don't forget to put the mode's keymap.
|
|
308 (setq docstring (concat docstring "\n\n\\{" (symbol-name map) "}")))
|
|
309
|
|
310 docstring))
|
|
311
|
|
312
|
|
313 ;;; OBSOLETE
|
|
314 ;; The functions below are only provided for backward compatibility with
|
|
315 ;; code byte-compiled with versions of derived.el prior to Emacs-21.
|
428
|
316
|
|
317 (defsubst derived-mode-setup-function-name (mode)
|
2135
|
318 "Construct a setup-function name based on a MODE name."
|
428
|
319 (intern (concat (symbol-name mode) "-setup")))
|
|
320
|
|
321
|
|
322 ;; Utility functions for defining a derived mode.
|
|
323
|
|
324 ;; XEmacs -- don't autoload
|
|
325 (defun derived-mode-init-mode-variables (mode)
|
2135
|
326 "Initialise variables for a new MODE.
|
428
|
327 Right now, if they don't already exist, set up a blank keymap, an
|
|
328 empty syntax table, and an empty abbrev table -- these will be merged
|
|
329 the first time the mode is used."
|
|
330
|
|
331 (if (boundp (derived-mode-map-name mode))
|
|
332 t
|
|
333 (eval `(defvar ,(derived-mode-map-name mode)
|
|
334 ;; XEmacs change
|
|
335 (make-sparse-keymap (derived-mode-map-name mode))
|
|
336 ,(format "Keymap for %s." mode)))
|
|
337 (put (derived-mode-map-name mode) 'derived-mode-unmerged t))
|
|
338
|
|
339 (if (boundp (derived-mode-syntax-table-name mode))
|
|
340 t
|
|
341 (eval `(defvar ,(derived-mode-syntax-table-name mode)
|
|
342 ;; XEmacs change
|
|
343 ;; Make a syntax table which doesn't specify anything
|
|
344 ;; for any char. Valid data will be merged in by
|
|
345 ;; derived-mode-merge-syntax-tables.
|
|
346 ;; (make-char-table 'syntax-table nil)
|
|
347 (make-syntax-table)
|
|
348 ,(format "Syntax table for %s." mode)))
|
|
349 (put (derived-mode-syntax-table-name mode) 'derived-mode-unmerged t))
|
|
350
|
|
351 (if (boundp (derived-mode-abbrev-table-name mode))
|
|
352 t
|
|
353 (eval `(defvar ,(derived-mode-abbrev-table-name mode)
|
2135
|
354 (progn
|
|
355 (define-abbrev-table (derived-mode-abbrev-table-name mode) nil)
|
|
356 (make-abbrev-table))
|
428
|
357 ,(format "Abbrev table for %s." mode)))))
|
|
358
|
|
359 ;; Utility functions for running a derived mode.
|
|
360
|
|
361 (defun derived-mode-set-keymap (mode)
|
2135
|
362 "Set the keymap of the new MODE, maybe merging with the parent."
|
428
|
363 (let* ((map-name (derived-mode-map-name mode))
|
|
364 (new-map (eval map-name))
|
|
365 (old-map (current-local-map)))
|
|
366 (and old-map
|
|
367 (get map-name 'derived-mode-unmerged)
|
|
368 (derived-mode-merge-keymaps old-map new-map))
|
|
369 (put map-name 'derived-mode-unmerged nil)
|
|
370 (use-local-map new-map)))
|
|
371
|
2135
|
372 (defun derived-mode-set-syntax-table (mode)
|
|
373 "Set the syntax table of the new MODE, maybe merging with the parent."
|
428
|
374 (let* ((table-name (derived-mode-syntax-table-name mode))
|
|
375 (old-table (syntax-table))
|
|
376 (new-table (eval table-name)))
|
|
377 (if (get table-name 'derived-mode-unmerged)
|
|
378 (derived-mode-merge-syntax-tables old-table new-table))
|
|
379 (put table-name 'derived-mode-unmerged nil)
|
|
380 (set-syntax-table new-table)))
|
|
381
|
|
382 (defun derived-mode-set-abbrev-table (mode)
|
2135
|
383 "Set the abbrev table for MODE if it exists.
|
428
|
384 Always merge its parent into it, since the merge is non-destructive."
|
|
385 (let* ((table-name (derived-mode-abbrev-table-name mode))
|
|
386 (old-table local-abbrev-table)
|
|
387 (new-table (eval table-name)))
|
|
388 (derived-mode-merge-abbrev-tables old-table new-table)
|
|
389 (setq local-abbrev-table new-table)))
|
|
390
|
|
391 ;;;(defun derived-mode-run-setup-function (mode)
|
|
392 ;;; "Run the setup function if it exists."
|
|
393
|
|
394 ;;; (let ((fname (derived-mode-setup-function-name mode)))
|
|
395 ;;; (if (fboundp fname)
|
|
396 ;;; (funcall fname))))
|
|
397
|
|
398 (defun derived-mode-run-hooks (mode)
|
2135
|
399 "Run the mode hook for MODE."
|
|
400 (let ((hooks-name (derived-mode-hook-name mode)))
|
428
|
401 (if (boundp hooks-name)
|
|
402 (run-hooks hooks-name))))
|
|
403
|
|
404 ;; Functions to merge maps and tables.
|
|
405
|
|
406 (defun derived-mode-merge-keymaps (old new)
|
2135
|
407 "Merge an OLD keymap into a NEW one.
|
|
408 The old keymap is set to be the last cdr of the new one, so that there will
|
428
|
409 be automatic inheritance."
|
2135
|
410 ;; XEmacs change. FSF 19.30 to 21.3 has a whole bunch of weird crap here
|
428
|
411 ;; for merging prefix keys and such. Hopefully none of this is
|
|
412 ;; necessary in XEmacs.
|
|
413 (set-keymap-parents new (list old)))
|
|
414
|
|
415 (defun derived-mode-merge-syntax-tables (old new)
|
2135
|
416 "Merge an OLD syntax table into a NEW one.
|
428
|
417 Where the new table already has an entry, nothing is copied from the old one."
|
2135
|
418 ;; XEmacs change: on the other hand, Emacs 21.3 just has
|
|
419 ;; (set-char-table-parent new old) here.
|
|
420 ;; We use map-char-table, not map-syntax-table, so we can explicitly
|
|
421 ;; check for inheritance.
|
3163
|
422 (map-char-table
|
|
423 #'(lambda (key value)
|
|
424 (let ((newval (get-range-char-table key new 'multi)))
|
|
425 (cond ((eq newval 'multi) ; OK, dive into the class hierarchy
|
|
426 (map-char-table
|
|
427 #'(lambda (key1 value1)
|
|
428 (when (eq ?@ (char-syntax-from-code
|
|
429 (get-range-char-table key new ?@)))
|
|
430 (put-char-table key1 value new))
|
|
431 nil)
|
|
432 new
|
|
433 key))
|
|
434 ((eq ?@ (char-syntax-from-code newval)) ;; class at once
|
|
435 (put-char-table key value new))))
|
|
436 nil)
|
|
437 old))
|
428
|
438
|
|
439 ;; Merge an old abbrev table into a new one.
|
|
440 ;; This function requires internal knowledge of how abbrev tables work,
|
|
441 ;; presuming that they are obarrays with the abbrev as the symbol, the expansion
|
|
442 ;; as the value of the symbol, and the hook as the function definition.
|
|
443 (defun derived-mode-merge-abbrev-tables (old new)
|
|
444 (if old
|
2135
|
445 (mapatoms
|
|
446 #'(lambda (symbol)
|
|
447 (or (intern-soft (symbol-name symbol) new)
|
|
448 (define-abbrev new (symbol-name symbol)
|
|
449 (symbol-value symbol) (symbol-function symbol))))
|
428
|
450 old)))
|
2135
|
451
|
428
|
452 (provide 'derived)
|
|
453
|
2135
|
454 ;;; arch-tag: 630be248-47d1-4f02-afa0-8207de0ebea0
|
428
|
455 ;;; derived.el ends here
|