Marked groups should always be visible in *Group* buffer
[emacs.git] / lisp / emacs-lisp / easy-mmode.el
blob6293d71470d50c4d57c37e2a48080fef873467e3
1 ;;; easy-mmode.el --- easy definition for major and minor modes
3 ;; Copyright (C) 1997, 2000-2017 Free Software Foundation, Inc.
5 ;; Author: Georges Brun-Cottan <Georges.Brun-Cottan@inria.fr>
6 ;; Maintainer: Stefan Monnier <monnier@gnu.org>
7 ;; Package: emacs
9 ;; Keywords: extensions lisp
11 ;; This file is part of GNU Emacs.
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 3 of the License, or
16 ;; (at your option) any later version.
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.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
26 ;;; Commentary:
28 ;; Minor modes are useful and common. This package makes defining a
29 ;; minor mode easy, by focusing on the writing of the minor mode
30 ;; functionalities themselves. Moreover, this package enforces a
31 ;; conventional naming of user interface primitives, making things
32 ;; natural for the minor-mode end-users.
34 ;; For each mode, easy-mmode defines the following:
35 ;; <mode> : The minor mode predicate. A buffer-local variable.
36 ;; <mode>-map : The keymap possibly associated to <mode>.
37 ;; see `define-minor-mode' documentation
39 ;; eval
40 ;; (pp (macroexpand '(define-minor-mode <your-mode> <doc>)))
41 ;; to check the result before using it.
43 ;; The order in which minor modes are installed is important. Keymap
44 ;; lookup proceeds down minor-mode-map-alist, and the order there
45 ;; tends to be the reverse of the order in which the modes were
46 ;; installed. Perhaps there should be a feature to let you specify
47 ;; orderings.
49 ;; Additionally to `define-minor-mode', the package provides convenient
50 ;; ways to define keymaps, and other helper functions for major and minor modes.
52 ;;; Code:
54 (defun easy-mmode-pretty-mode-name (mode &optional lighter)
55 "Turn the symbol MODE into a string intended for the user.
56 If provided, LIGHTER will be used to help choose capitalization by,
57 replacing its case-insensitive matches with the literal string in LIGHTER."
58 (let* ((case-fold-search t)
59 ;; Produce "Foo-Bar minor mode" from foo-bar-minor-mode.
60 (name (concat (replace-regexp-in-string
61 ;; If the original mode name included "-minor" (some
62 ;; of them don't, e.g. auto-revert-mode), then
63 ;; replace it with " minor".
64 "-Minor" " minor"
65 ;; "foo-bar-minor" -> "Foo-Bar-Minor"
66 (capitalize (replace-regexp-in-string
67 ;; "foo-bar-minor-mode" -> "foo-bar-minor"
68 "toggle-\\|-mode\\'" ""
69 (symbol-name mode))))
70 " mode")))
71 (setq name (replace-regexp-in-string "\\`Global-" "Global " name))
72 (if (not (stringp lighter)) name
73 ;; Strip leading and trailing whitespace from LIGHTER.
74 (setq lighter (replace-regexp-in-string "\\`\\s-+\\|\\s-+\\'" ""
75 lighter))
76 ;; Replace any (case-insensitive) matches for LIGHTER in NAME
77 ;; with a literal LIGHTER. E.g., if NAME is "Iimage mode" and
78 ;; LIGHTER is " iImag", then this will produce "iImage mode".
79 ;; (LIGHTER normally comes from the mode-line string passed to
80 ;; define-minor-mode, and normally includes at least one leading
81 ;; space.)
82 (replace-regexp-in-string (regexp-quote lighter) lighter name t t))))
84 ;;;###autoload
85 (defalias 'easy-mmode-define-minor-mode 'define-minor-mode)
86 ;;;###autoload
87 (defmacro define-minor-mode (mode doc &optional init-value lighter keymap &rest body)
88 "Define a new minor mode MODE.
89 This defines the toggle command MODE and (by default) a control variable
90 MODE (you can override this with the :variable keyword, see below).
91 DOC is the documentation for the mode toggle command.
93 The defined mode command takes one optional (prefix) argument.
94 Interactively with no prefix argument, it toggles the mode.
95 A prefix argument enables the mode if the argument is positive,
96 and disables it otherwise.
98 When called from Lisp, the mode command toggles the mode if the
99 argument is `toggle', disables the mode if the argument is a
100 non-positive integer, and enables the mode otherwise (including
101 if the argument is omitted or nil or a positive integer).
103 If DOC is nil, give the mode command a basic doc-string
104 documenting what its argument does.
106 Optional INIT-VALUE is the initial value of the mode's variable.
107 Optional LIGHTER is displayed in the mode line when the mode is on.
108 Optional KEYMAP is the default keymap bound to the mode keymap.
109 If non-nil, it should be a variable name (whose value is a keymap),
110 or an expression that returns either a keymap or a list of
111 (KEY . BINDING) pairs where KEY and BINDING are suitable for
112 `define-key'. If you supply a KEYMAP argument that is not a
113 symbol, this macro defines the variable MODE-map and gives it
114 the value that KEYMAP specifies.
116 BODY contains code to execute each time the mode is enabled or disabled.
117 It is executed after toggling the mode, and before running MODE-hook.
118 Before the actual body code, you can write keyword arguments, i.e.
119 alternating keywords and values. If you provide BODY, then you must
120 provide (even if just nil) INIT-VALUE, LIGHTER, and KEYMAP, or provide
121 at least one keyword argument, or both; otherwise, BODY would be
122 misinterpreted as the first omitted argument. The following special
123 keywords are supported (other keywords are passed to `defcustom' if
124 the minor mode is global):
126 :group GROUP Custom group name to use in all generated `defcustom' forms.
127 Defaults to MODE without the possible trailing \"-mode\".
128 Don't use this default group name unless you have written a
129 `defgroup' to define that group properly.
130 :global GLOBAL If non-nil specifies that the minor mode is not meant to be
131 buffer-local, so don't make the variable MODE buffer-local.
132 By default, the mode is buffer-local.
133 :init-value VAL Same as the INIT-VALUE argument.
134 Not used if you also specify :variable.
135 :lighter SPEC Same as the LIGHTER argument.
136 :keymap MAP Same as the KEYMAP argument.
137 :require SYM Same as in `defcustom'.
138 :variable PLACE The location to use instead of the variable MODE to store
139 the state of the mode. This can be simply a different
140 named variable, or a generalized variable.
141 PLACE can also be of the form (GET . SET), where GET is
142 an expression that returns the current state, and SET is
143 a function that takes one argument, the new state, and
144 sets it. If you specify a :variable, this function does
145 not define a MODE variable (nor any of the terms used
146 in :variable).
148 :after-hook A single lisp form which is evaluated after the mode hooks
149 have been run. It should not be quoted.
151 For example, you could write
152 (define-minor-mode foo-mode \"If enabled, foo on you!\"
153 :lighter \" Foo\" :require \\='foo :global t :group \\='hassle :version \"27.5\"
154 ...BODY CODE...)"
155 (declare (doc-string 2)
156 (debug (&define name string-or-null-p
157 [&optional [&not keywordp] sexp
158 &optional [&not keywordp] sexp
159 &optional [&not keywordp] sexp]
160 [&rest [keywordp sexp]]
161 def-body)))
163 ;; Allow skipping the first three args.
164 (cond
165 ((keywordp init-value)
166 (setq body (if keymap `(,init-value ,lighter ,keymap ,@body)
167 `(,init-value ,lighter))
168 init-value nil lighter nil keymap nil))
169 ((keywordp lighter)
170 (setq body `(,lighter ,keymap ,@body) lighter nil keymap nil))
171 ((keywordp keymap) (push keymap body) (setq keymap nil)))
173 (let* ((last-message (make-symbol "last-message"))
174 (mode-name (symbol-name mode))
175 (pretty-name (easy-mmode-pretty-mode-name mode lighter))
176 (globalp nil)
177 (set nil)
178 (initialize nil)
179 (group nil)
180 (type nil)
181 (extra-args nil)
182 (extra-keywords nil)
183 (variable nil) ;The PLACE where the state is stored.
184 (setter `(setq ,mode)) ;The beginning of the exp to set the mode var.
185 (getter mode) ;The exp to get the mode value.
186 (modefun mode) ;The minor mode function name we're defining.
187 (require t)
188 (after-hook nil)
189 (hook (intern (concat mode-name "-hook")))
190 (hook-on (intern (concat mode-name "-on-hook")))
191 (hook-off (intern (concat mode-name "-off-hook")))
192 keyw keymap-sym tmp)
194 ;; Check keys.
195 (while (keywordp (setq keyw (car body)))
196 (setq body (cdr body))
197 (pcase keyw
198 (`:init-value (setq init-value (pop body)))
199 (`:lighter (setq lighter (purecopy (pop body))))
200 (`:global (setq globalp (pop body))
201 (when (and globalp (symbolp mode))
202 (setq setter `(setq-default ,mode))
203 (setq getter `(default-value ',mode))))
204 (`:extra-args (setq extra-args (pop body)))
205 (`:set (setq set (list :set (pop body))))
206 (`:initialize (setq initialize (list :initialize (pop body))))
207 (`:group (setq group (nconc group (list :group (pop body)))))
208 (`:type (setq type (list :type (pop body))))
209 (`:require (setq require (pop body)))
210 (`:keymap (setq keymap (pop body)))
211 (`:variable (setq variable (pop body))
212 (if (not (and (setq tmp (cdr-safe variable))
213 (or (symbolp tmp)
214 (functionp tmp))))
215 ;; PLACE is not of the form (GET . SET).
216 (progn
217 (setq setter `(setf ,variable))
218 (setq getter variable))
219 (setq getter (car variable))
220 (setq setter `(funcall #',(cdr variable)))))
221 (`:after-hook (setq after-hook (pop body)))
222 (_ (push keyw extra-keywords) (push (pop body) extra-keywords))))
224 (setq keymap-sym (if (and keymap (symbolp keymap)) keymap
225 (intern (concat mode-name "-map"))))
227 (unless set (setq set '(:set #'custom-set-minor-mode)))
229 (unless initialize
230 (setq initialize '(:initialize 'custom-initialize-default)))
232 (unless group
233 ;; We might as well provide a best-guess default group.
234 (setq group
235 `(:group ',(intern (replace-regexp-in-string
236 "-mode\\'" "" mode-name)))))
238 ;; TODO? Mark booleans as safe if booleanp? Eg abbrev-mode.
239 (unless type (setq type '(:type 'boolean)))
241 `(progn
242 ;; Define the variable to enable or disable the mode.
243 ,(cond
244 ;; If :variable is specified, then the var will be
245 ;; declared elsewhere.
246 (variable nil)
247 ((not globalp)
248 `(progn
249 :autoload-end
250 (defvar ,mode ,init-value ,(format "Non-nil if %s is enabled.
251 Use the command `%s' to change this variable." pretty-name mode))
252 (make-variable-buffer-local ',mode)))
254 (let ((base-doc-string
255 (concat "Non-nil if %s is enabled.
256 See the `%s' command
257 for a description of this minor mode."
258 (if body "
259 Setting this variable directly does not take effect;
260 either customize it (see the info node `Easy Customization')
261 or call the function `%s'."))))
262 `(defcustom ,mode ,init-value
263 ,(format base-doc-string pretty-name mode mode)
264 ,@set
265 ,@initialize
266 ,@group
267 ,@type
268 ,@(unless (eq require t) `(:require ,require))
269 ,@(nreverse extra-keywords)))))
271 ;; The actual function.
272 (defun ,modefun (&optional arg ,@extra-args)
273 ,(or doc
274 (format (concat "Toggle %s on or off.
275 With a prefix argument ARG, enable %s if ARG is
276 positive, and disable it otherwise. If called from Lisp, enable
277 the mode if ARG is omitted or nil, and toggle it if ARG is `toggle'.
278 \\{%s}") pretty-name pretty-name keymap-sym))
279 ;; Use `toggle' rather than (if ,mode 0 1) so that using
280 ;; repeat-command still does the toggling correctly.
281 (interactive (list (or current-prefix-arg 'toggle)))
282 (let ((,last-message (current-message)))
283 (,@setter
284 (if (eq arg 'toggle)
285 (not ,getter)
286 ;; A nil argument also means ON now.
287 (> (prefix-numeric-value arg) 0)))
288 ,@body
289 ;; The on/off hooks are here for backward compatibility only.
290 (run-hooks ',hook (if ,getter ',hook-on ',hook-off))
291 (if (called-interactively-p 'any)
292 (progn
293 ,(if (and globalp (not variable))
294 `(customize-mark-as-set ',mode))
295 ;; Avoid overwriting a message shown by the body,
296 ;; but do overwrite previous messages.
297 (unless (and (current-message)
298 (not (equal ,last-message
299 (current-message))))
300 (let ((local ,(if globalp "" " in current buffer")))
301 (message ,(format "%s %%sabled%%s" pretty-name)
302 (if ,getter "en" "dis") local)))))
303 ,@(when after-hook `(,after-hook)))
304 (force-mode-line-update)
305 ;; Return the new setting.
306 ,getter)
308 ;; Autoloading a define-minor-mode autoloads everything
309 ;; up-to-here.
310 :autoload-end
312 (defvar ,hook nil)
313 (unless (get ',hook 'variable-documentation)
314 (put ',hook 'variable-documentation
315 ,(format "Hook run after entering or leaving `%s'.
316 No problems result if this variable is not bound.
317 `add-hook' automatically binds it. (This is true for all hook variables.)"
318 modefun)))
320 ;; Define the minor-mode keymap.
321 ,(unless (symbolp keymap) ;nil is also a symbol.
322 `(defvar ,keymap-sym
323 (let ((m ,keymap))
324 (cond ((keymapp m) m)
325 ((listp m) (easy-mmode-define-keymap m))
326 (t (error "Invalid keymap %S" m))))
327 ,(format "Keymap for `%s'." mode-name)))
329 ,(let ((modevar (pcase getter (`(default-value ',v) v) (_ getter))))
330 (if (not (symbolp modevar))
331 (if (or lighter keymap)
332 (error ":lighter and :keymap unsupported with mode expression %S" getter))
333 `(with-no-warnings
334 (add-minor-mode ',modevar ',lighter
335 ,(if keymap keymap-sym
336 `(if (boundp ',keymap-sym) ,keymap-sym))
338 ,(unless (eq mode modefun) `',modefun))))))))
341 ;;; make global minor mode
344 ;;;###autoload
345 (defalias 'easy-mmode-define-global-mode 'define-globalized-minor-mode)
346 ;;;###autoload
347 (defalias 'define-global-minor-mode 'define-globalized-minor-mode)
348 ;;;###autoload
349 (defmacro define-globalized-minor-mode (global-mode mode turn-on &rest keys)
350 "Make a global mode GLOBAL-MODE corresponding to buffer-local minor MODE.
351 TURN-ON is a function that will be called with no args in every buffer
352 and that should try to turn MODE on if applicable for that buffer.
353 KEYS is a list of CL-style keyword arguments. As the minor mode
354 defined by this function is always global, any :global keyword is
355 ignored. Other keywords have the same meaning as in `define-minor-mode',
356 which see. In particular, :group specifies the custom group.
357 The most useful keywords are those that are passed on to the
358 `defcustom'. It normally makes no sense to pass the :lighter
359 or :keymap keywords to `define-globalized-minor-mode', since these
360 are usually passed to the buffer-local version of the minor mode.
362 If MODE's set-up depends on the major mode in effect when it was
363 enabled, then disabling and reenabling MODE should make MODE work
364 correctly with the current major mode. This is important to
365 prevent problems with derived modes, that is, major modes that
366 call another major mode in their body.
368 When a major mode is initialized, MODE is actually turned on just
369 after running the major mode's hook. However, MODE is not turned
370 on if the hook has explicitly disabled it."
371 (declare (doc-string 2))
372 (let* ((global-mode-name (symbol-name global-mode))
373 (mode-name (symbol-name mode))
374 (pretty-name (easy-mmode-pretty-mode-name mode))
375 (pretty-global-name (easy-mmode-pretty-mode-name global-mode))
376 (group nil)
377 (extra-keywords nil)
378 (MODE-buffers (intern (concat global-mode-name "-buffers")))
379 (MODE-enable-in-buffers
380 (intern (concat global-mode-name "-enable-in-buffers")))
381 (MODE-check-buffers
382 (intern (concat global-mode-name "-check-buffers")))
383 (MODE-cmhh (intern (concat global-mode-name "-cmhh")))
384 (minor-MODE-hook (intern (concat mode-name "-hook")))
385 (MODE-set-explicitly (intern (concat mode-name "-set-explicitly")))
386 (MODE-major-mode (intern (concat (symbol-name mode) "-major-mode")))
387 keyw)
389 ;; Check keys.
390 (while (keywordp (setq keyw (car keys)))
391 (setq keys (cdr keys))
392 (pcase keyw
393 (`:group (setq group (nconc group (list :group (pop keys)))))
394 (`:global (setq keys (cdr keys)))
395 (_ (push keyw extra-keywords) (push (pop keys) extra-keywords))))
397 (unless group
398 ;; We might as well provide a best-guess default group.
399 (setq group
400 `(:group ',(intern (replace-regexp-in-string
401 "-mode\\'" "" (symbol-name mode))))))
403 `(progn
404 (progn
405 :autoload-end
406 (defvar ,MODE-major-mode nil)
407 (make-variable-buffer-local ',MODE-major-mode))
408 ;; The actual global minor-mode
409 (define-minor-mode ,global-mode
410 ;; Very short lines to avoid too long lines in the generated
411 ;; doc string.
412 ,(format "Toggle %s in all buffers.
413 With prefix ARG, enable %s if ARG is positive;
414 otherwise, disable it. If called from Lisp, enable the mode if
415 ARG is omitted or nil.
417 %s is enabled in all buffers where
418 `%s' would do it.
419 See `%s' for more information on %s."
420 pretty-name pretty-global-name
421 pretty-name turn-on mode pretty-name)
422 :global t ,@group ,@(nreverse extra-keywords)
424 ;; Setup hook to handle future mode changes and new buffers.
425 (if ,global-mode
426 (progn
427 (add-hook 'after-change-major-mode-hook
428 ',MODE-enable-in-buffers)
429 (add-hook 'find-file-hook ',MODE-check-buffers)
430 (add-hook 'change-major-mode-hook ',MODE-cmhh))
431 (remove-hook 'after-change-major-mode-hook ',MODE-enable-in-buffers)
432 (remove-hook 'find-file-hook ',MODE-check-buffers)
433 (remove-hook 'change-major-mode-hook ',MODE-cmhh))
435 ;; Go through existing buffers.
436 (dolist (buf (buffer-list))
437 (with-current-buffer buf
438 (if ,global-mode (funcall #',turn-on) (when ,mode (,mode -1))))))
440 ;; Autoloading define-globalized-minor-mode autoloads everything
441 ;; up-to-here.
442 :autoload-end
444 ;; MODE-set-explicitly is set in MODE-set-explicitly and cleared by
445 ;; kill-all-local-variables.
446 (defvar-local ,MODE-set-explicitly nil)
447 (defun ,MODE-set-explicitly ()
448 (setq ,MODE-set-explicitly t))
449 (put ',MODE-set-explicitly 'definition-name ',global-mode)
451 ;; A function which checks whether MODE has been disabled in the major
452 ;; mode hook which has just been run.
453 (add-hook ',minor-MODE-hook ',MODE-set-explicitly)
455 ;; List of buffers left to process.
456 (defvar ,MODE-buffers nil)
458 ;; The function that calls TURN-ON in each buffer.
459 (defun ,MODE-enable-in-buffers ()
460 (dolist (buf ,MODE-buffers)
461 (when (buffer-live-p buf)
462 (with-current-buffer buf
463 (unless ,MODE-set-explicitly
464 (unless (eq ,MODE-major-mode major-mode)
465 (if ,mode
466 (progn
467 (,mode -1)
468 (funcall #',turn-on))
469 (funcall #',turn-on))))
470 (setq ,MODE-major-mode major-mode)))))
471 (put ',MODE-enable-in-buffers 'definition-name ',global-mode)
473 (defun ,MODE-check-buffers ()
474 (,MODE-enable-in-buffers)
475 (setq ,MODE-buffers nil)
476 (remove-hook 'post-command-hook ',MODE-check-buffers))
477 (put ',MODE-check-buffers 'definition-name ',global-mode)
479 ;; The function that catches kill-all-local-variables.
480 (defun ,MODE-cmhh ()
481 (add-to-list ',MODE-buffers (current-buffer))
482 (add-hook 'post-command-hook ',MODE-check-buffers))
483 (put ',MODE-cmhh 'definition-name ',global-mode))))
486 ;;; easy-mmode-defmap
489 (defun easy-mmode-set-keymap-parents (m parents)
490 (set-keymap-parent
491 m (if (cdr parents) (make-composed-keymap parents) (car parents))))
493 ;;;###autoload
494 (defun easy-mmode-define-keymap (bs &optional name m args)
495 "Return a keymap built from bindings BS.
496 BS must be a list of (KEY . BINDING) where
497 KEY and BINDINGS are suitable for `define-key'.
498 Optional NAME is passed to `make-sparse-keymap'.
499 Optional map M can be used to modify an existing map.
500 ARGS is a list of additional keyword arguments.
502 Valid keywords and arguments are:
504 :name Name of the keymap; overrides NAME argument.
505 :dense Non-nil for a dense keymap.
506 :inherit Parent keymap.
507 :group Ignored.
508 :suppress Non-nil to call `suppress-keymap' on keymap,
509 `nodigits' to suppress digits as prefix arguments."
510 (let (inherit dense suppress)
511 (while args
512 (let ((key (pop args))
513 (val (pop args)))
514 (pcase key
515 (`:name (setq name val))
516 (`:dense (setq dense val))
517 (`:inherit (setq inherit val))
518 (`:suppress (setq suppress val))
519 (`:group)
520 (_ (message "Unknown argument %s in defmap" key)))))
521 (unless (keymapp m)
522 (setq bs (append m bs))
523 (setq m (if dense (make-keymap name) (make-sparse-keymap name))))
524 (when suppress
525 (suppress-keymap m (eq suppress 'nodigits)))
526 (dolist (b bs)
527 (let ((keys (car b))
528 (binding (cdr b)))
529 (dolist (key (if (consp keys) keys (list keys)))
530 (cond
531 ((symbolp key)
532 (substitute-key-definition key binding m global-map))
533 ((null binding)
534 (unless (keymapp (lookup-key m key)) (define-key m key binding)))
535 ((let ((o (lookup-key m key)))
536 (or (null o) (numberp o) (eq o 'undefined)))
537 (define-key m key binding))))))
538 (cond
539 ((keymapp inherit) (set-keymap-parent m inherit))
540 ((consp inherit) (easy-mmode-set-keymap-parents m inherit)))
543 ;;;###autoload
544 (defmacro easy-mmode-defmap (m bs doc &rest args)
545 "Define a constant M whose value is the result of `easy-mmode-define-keymap'.
546 The M, BS, and ARGS arguments are as per that function. DOC is
547 the constant's documentation."
548 (declare (indent 1))
549 `(defconst ,m
550 (easy-mmode-define-keymap ,bs nil (if (boundp ',m) ,m) ,(cons 'list args))
551 ,doc))
555 ;;; easy-mmode-defsyntax
558 (defun easy-mmode-define-syntax (css args)
559 (let ((st (make-syntax-table (plist-get args :copy)))
560 (parent (plist-get args :inherit)))
561 (dolist (cs css)
562 (let ((char (car cs))
563 (syntax (cdr cs)))
564 (if (sequencep char)
565 (mapc (lambda (c) (modify-syntax-entry c syntax st)) char)
566 (modify-syntax-entry char syntax st))))
567 (if parent (set-char-table-parent
568 st (if (symbolp parent) (symbol-value parent) parent)))
569 st))
571 ;;;###autoload
572 (defmacro easy-mmode-defsyntax (st css doc &rest args)
573 "Define variable ST as a syntax-table.
574 CSS contains a list of syntax specifications of the form (CHAR . SYNTAX)."
575 (declare (indent 1))
576 `(progn
577 (autoload 'easy-mmode-define-syntax "easy-mmode")
578 (defconst ,st (easy-mmode-define-syntax ,css ,(cons 'list args)) ,doc)))
583 ;;; easy-mmode-define-navigation
586 (defmacro easy-mmode-define-navigation (base re &optional name endfun narrowfun
587 &rest body)
588 "Define BASE-next and BASE-prev to navigate in the buffer.
589 RE determines the places the commands should move point to.
590 NAME should describe the entities matched by RE. It is used to build
591 the docstrings of the two functions.
592 BASE-next also tries to make sure that the whole entry is visible by
593 searching for its end (by calling ENDFUN if provided or by looking for
594 the next entry) and recentering if necessary.
595 ENDFUN should return the end position (with or without moving point).
596 NARROWFUN non-nil means to check for narrowing before moving, and if
597 found, do `widen' first and then call NARROWFUN with no args after moving.
598 BODY is executed after moving to the destination location."
599 (declare (indent 5) (debug (exp exp exp def-form def-form &rest def-body)))
600 (let* ((base-name (symbol-name base))
601 (prev-sym (intern (concat base-name "-prev")))
602 (next-sym (intern (concat base-name "-next")))
603 (when-narrowed
604 (lambda (body)
605 (if (null narrowfun) body
606 `(let ((was-narrowed
607 (prog1 (or (< (- (point-max) (point-min)) (buffer-size)))
608 (widen))))
609 ,body
610 (when was-narrowed (funcall #',narrowfun)))))))
611 (unless name (setq name base-name))
612 `(progn
613 (defun ,next-sym (&optional count)
614 ,(format "Go to the next COUNT'th %s." name)
615 (interactive "p")
616 (unless count (setq count 1))
617 (if (< count 0) (,prev-sym (- count))
618 (if (looking-at ,re) (setq count (1+ count)))
619 ,(funcall when-narrowed
620 `(if (not (re-search-forward ,re nil t count))
621 (if (looking-at ,re)
622 (goto-char (or ,(if endfun `(funcall #',endfun)) (point-max)))
623 (user-error "No next %s" ,name))
624 (goto-char (match-beginning 0))
625 (when (and (eq (current-buffer) (window-buffer))
626 (called-interactively-p 'interactive))
627 (let ((endpt (or (save-excursion
628 ,(if endfun `(funcall #',endfun)
629 `(re-search-forward ,re nil t 2)))
630 (point-max))))
631 (unless (pos-visible-in-window-p endpt nil t)
632 (recenter '(0)))))))
633 ,@body))
634 (put ',next-sym 'definition-name ',base)
635 (defun ,prev-sym (&optional count)
636 ,(format "Go to the previous COUNT'th %s" (or name base-name))
637 (interactive "p")
638 (unless count (setq count 1))
639 (if (< count 0) (,next-sym (- count))
640 ,(funcall when-narrowed
641 `(unless (re-search-backward ,re nil t count)
642 (user-error "No previous %s" ,name)))
643 ,@body))
644 (put ',prev-sym 'definition-name ',base))))
647 (provide 'easy-mmode)
649 ;;; easy-mmode.el ends here