[bpt/emacs.git] / lisp / map-ynp.el

;;; map-ynp.el --- General-purpose boolean question-asker.

;;; Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc.

;; Author: Roland McGrath <roland@gnu.ai.mit.edu>
;; Keywords: lisp, extensions

;;; This program is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2, or (at your option)
;;; any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; A copy of the GNU General Public License can be obtained from this
;;; program's author (send electronic mail to roland@ai.mit.edu) or from
;;; the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA
;;; 02139, USA.

;;; Commentary:

;;; map-y-or-n-p is a general-purpose question-asking function.
;;; It asks a series of y/n questions (a la y-or-n-p), and decides to
;;; applies an action to each element of a list based on the answer.
;;; The nice thing is that you also get some other possible answers
;;; to use, reminiscent of query-replace: ! to answer y to all remaining
;;; questions; ESC or q to answer n to all remaining questions; . to answer
;;; y once and then n for the remainder; and you can get help with C-h.

;;; Code:

;;;###autoload
(defun map-y-or-n-p (prompter actor list &optional help action-alist
			      no-cursor-in-echo-area)
  "Ask a series of boolean questions.
Takes args PROMPTER ACTOR LIST, and optional args HELP and ACTION-ALIST.

LIST is a list of objects, or a function of no arguments to return the next
object or nil.

If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\).  If not
a string, PROMPTER is a function of one arg (an object from LIST), which
returns a string to be used as the prompt for that object.  If the return
value is not a string, it is eval'd to get the answer; it may be nil to
ignore the object, t to act on the object without asking the user, or a
form to do a more complex prompt.

ACTOR is a function of one arg (an object from LIST),
which gets called with each object that the user answers `yes' for.

If HELP is given, it is a list (OBJECT OBJECTS ACTION),
where OBJECT is a string giving the singular noun for an elt of LIST;
OBJECTS is the plural noun for elts of LIST, and ACTION is a transitive
verb describing ACTOR.  The default is \(\"object\" \"objects\" \"act on\"\).

At the prompts, the user may enter y, Y, or SPC to act on that object;
n, N, or DEL to skip that object; ! to act on all following objects;
ESC or q to exit (skip all following objects); . (period) to act on the
current object and then exit; or \\[help-command] to get help.

If ACTION-ALIST is given, it is an alist (KEY FUNCTION HELP) of extra keys
that will be accepted.  KEY is a character; FUNCTION is a function of one
arg (an object from LIST); HELP is a string.  When the user hits KEY,
FUNCTION is called.  If it returns non-nil, the object is considered
\"acted upon\", and the next object from LIST is processed.  If it returns
nil, the prompt is repeated for the same object.

Final optional argument NO-CURSOR-IN-ECHO-AREA non-nil says not to set
`cursor-in-echo-area' while prompting.

This function uses `query-replace-map' to define the standard responses,
but not all of the responses which `query-replace' understands
are meaningful here.

Returns the number of actions taken."
  (let* ((actions 0)
	 user-keys mouse-event map prompt char elt tail def
	 delayed-switch-frame
	 (next (if (or (and list (symbolp list))
		       (subrp list)
		       (byte-code-function-p list)
		       (and (consp list)
			    (eq (car list) 'lambda)))
		   (function (lambda ()
			       (setq elt (funcall list))))
		 (function (lambda ()
			     (if list
				 (progn
				   (setq elt (car list)
					 list (cdr list))
				   t)
			       nil))))))
    (if (listp last-nonmenu-event)
	;; Make a list describing a dialog box.
	(let ((object (capitalize (nth 0 help)))
	      (objects (capitalize (nth 1 help)))
	      (action (capitalize (nth 2 help))))
	  (setq map (` (("Yes" . act) ("No" . skip) ("Quit" . exit)
			((, (if help (concat action " " object " And Quit")
			      "Do it and Quit")) . act-and-exit)
			((, (if help (concat action " All " objects)
			      "Do All")) . automatic)
			(,@ (mapcar (lambda (elt)
				      (cons (capitalize (nth 2 elt))
					    (vector (nth 1 elt))))
				    action-alist))))
		mouse-event last-nonmenu-event))			       
      (setq user-keys (if action-alist
			  (concat (mapconcat (function
					      (lambda (elt)
						(key-description
						 (char-to-string (car elt)))))
					     action-alist ", ")
				  " ")
			"")
	    ;; Make a map that defines each user key as a vector containing
	    ;; its definition.
	    map (cons 'keymap
		      (append (mapcar (lambda (elt)
					(cons (car elt) (vector (nth 1 elt))))
				      action-alist)
			      query-replace-map))))
    (unwind-protect
	(progn
	  (if (stringp prompter)
	      (setq prompter (` (lambda (object)
				  (format (, prompter) object)))))
	  (while (funcall next)
	    (setq prompt (funcall prompter elt))
	    (if (stringp prompt)
		(progn
		  (setq quit-flag nil)
		  ;; Prompt the user about this object.
		  (if mouse-event
		      (setq def (or (x-popup-dialog mouse-event
						    (cons prompt map))
				    'quit))
		    ;; Prompt in the echo area.
		    (let ((cursor-in-echo-area (not no-cursor-in-echo-area)))
		      (message "%s(y, n, !, ., q, %sor %s) "
			       prompt user-keys
			       (key-description (vector help-char)))
		      (setq char (read-event)))
		    ;; Show the answer to the question.
		    (message "%s(y, n, !, ., q, %sor %s) %s"
			     prompt user-keys
			     (key-description (vector help-char))
			     (single-key-description char))
		    (setq def (lookup-key map (vector char))))
		  (cond ((eq def 'exit)
			 (setq next (function (lambda () nil))))
			((eq def 'act)
			 ;; Act on the object.
			 (funcall actor elt)
			 (setq actions (1+ actions)))
			((eq def 'skip)
			 ;; Skip the object.
			 )
			((eq def 'act-and-exit)
			 ;; Act on the object and then exit.
			 (funcall actor elt)
			 (setq actions (1+ actions)
			       next (function (lambda () nil))))
			((eq def 'quit)
			 (setq quit-flag t)
			 (setq next (` (lambda ()
					 (setq next '(, next))
					 '(, elt)))))
			((eq def 'automatic)
			 ;; Act on this and all following objects.
			 (if (eval (funcall prompter elt))
			     (progn
			       (funcall actor elt)
			       (setq actions (1+ actions))))
			 (while (funcall next)
			   (if (eval (funcall prompter elt))
			       (progn
				 (funcall actor elt)
				 (setq actions (1+ actions))))))
			((eq def 'help)
			 (with-output-to-temp-buffer "*Help*"
			   (princ
			    (let ((object (if help (nth 0 help) "object"))
				  (objects (if help (nth 1 help) "objects"))
				  (action (if help (nth 2 help) "act on")))
			      (concat
			       (format "Type SPC or `y' to %s the current %s;
DEL or `n' to skip the current %s;
! to %s all remaining %s;
ESC or `q' to exit;\n"
				       action object object action objects)
			       (mapconcat (function
					   (lambda (elt)
					     (format "%c to %s"
						     (nth 0 elt)
						     (nth 2 elt))))
					  action-alist
					  ";\n")
			       (if action-alist ";\n")
			       (format "or . (period) to %s \
the current %s and exit."
				       action object)))))

			 (setq next (` (lambda ()
					 (setq next '(, next))
					 '(, elt)))))
			((vectorp def)
			 ;; A user-defined key.
			 (if (funcall (aref def 0) elt) ;Call its function.
			     ;; The function has eaten this object.
			     (setq actions (1+ actions))
			   ;; Regurgitated; try again.
			   (setq next (` (lambda ()
					   (setq next '(, next))
					   '(, elt))))))
			((and (consp char)
			      (eq (car char) 'switch-frame))
			 ;; switch-frame event.  Put it off until we're done.
			 (setq delayed-switch-frame char)
			 (setq next (` (lambda ()
					 (setq next '(, next))
					 '(, elt)))))
			(t
			 ;; Random char.
			 (message "Type %s for help."
				  (key-description (vector help-char)))
			 (beep)
			 (sit-for 1)
			 (setq next (` (lambda ()
					 (setq next '(, next))
					 '(, elt)))))))
	      (if (eval prompt)
		  (progn
		    (funcall actor elt)
		    (setq actions (1+ actions)))))))
      (if delayed-switch-frame
	  (setq unread-command-events
		(cons delayed-switch-frame unread-command-events))))
    ;; Clear the last prompt from the minibuffer.
    (message "")
    ;; Return the number of actions that were taken.
    actions))

;;; map-ynp.el ends here
Commit	Line	Data
6594deb0 ER	1	;;; map-ynp.el --- General-purpose boolean question-asker.
6594deb0 ER	2
c5068ec5	3	;;; Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
eea8d4ef	4
e5167999	5	;; Author: Roland McGrath <roland@gnu.ai.mit.edu>
fd7fa35a	6	;; Keywords: lisp, extensions
e5167999	7
60205e0b RM	8	;;; This program is free software; you can redistribute it and/or modify
60205e0b RM	9	;;; it under the terms of the GNU General Public License as published by
e5167999	10	;;; the Free Software Foundation; either version 2, or (at your option)
60205e0b RM	11	;;; any later version.
	12	;;;
	13	;;; This program is distributed in the hope that it will be useful,
	14	;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	;;; GNU General Public License for more details.
	17	;;;
	18	;;; A copy of the GNU General Public License can be obtained from this
	19	;;; program's author (send electronic mail to roland@ai.mit.edu) or from
	20	;;; the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA
	21	;;; 02139, USA.
e5167999 ER	22
	23	;;; Commentary:
	24
60205e0b RM	25	;;; map-y-or-n-p is a general-purpose question-asking function.
	26	;;; It asks a series of y/n questions (a la y-or-n-p), and decides to
	27	;;; applies an action to each element of a list based on the answer.
	28	;;; The nice thing is that you also get some other possible answers
	29	;;; to use, reminiscent of query-replace: ! to answer y to all remaining
	30	;;; questions; ESC or q to answer n to all remaining questions; . to answer
	31	;;; y once and then n for the remainder; and you can get help with C-h.
	32
e5167999 ER	33	;;; Code:
e5167999 ER	34
60205e0b	35	;;;###autoload
fd95709e RM	36	(defun map-y-or-n-p (prompter actor list &optional help action-alist
fd95709e RM	37	no-cursor-in-echo-area)
60205e0b	38	"Ask a series of boolean questions.
907482b9	39	Takes args PROMPTER ACTOR LIST, and optional args HELP and ACTION-ALIST.
60205e0b RM	40
	41	LIST is a list of objects, or a function of no arguments to return the next
	42	object or nil.
	43
9fd54390	44	If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\). If not
03759fe0 RM	45	a string, PROMPTER is a function of one arg (an object from LIST), which
	46	returns a string to be used as the prompt for that object. If the return
	47	value is not a string, it is eval'd to get the answer; it may be nil to
	48	ignore the object, t to act on the object without asking the user, or a
	49	form to do a more complex prompt.
	50
60205e0b RM	51	ACTOR is a function of one arg (an object from LIST),
	52	which gets called with each object that the user answers `yes' for.
	53
	54	If HELP is given, it is a list (OBJECT OBJECTS ACTION),
	55	where OBJECT is a string giving the singular noun for an elt of LIST;
	56	OBJECTS is the plural noun for elts of LIST, and ACTION is a transitive
	57	verb describing ACTOR. The default is \(\"object\" \"objects\" \"act on\"\).
	58
	59	At the prompts, the user may enter y, Y, or SPC to act on that object;
	60	n, N, or DEL to skip that object; ! to act on all following objects;
	61	ESC or q to exit (skip all following objects); . (period) to act on the
	62	current object and then exit; or \\[help-command] to get help.
	63
907482b9 RM	64	If ACTION-ALIST is given, it is an alist (KEY FUNCTION HELP) of extra keys
	65	that will be accepted. KEY is a character; FUNCTION is a function of one
	66	arg (an object from LIST); HELP is a string. When the user hits KEY,
	67	FUNCTION is called. If it returns non-nil, the object is considered
	68	\"acted upon\", and the next object from LIST is processed. If it returns
	69	nil, the prompt is repeated for the same object.
	70
fd95709e RM	71	Final optional argument NO-CURSOR-IN-ECHO-AREA non-nil says not to set
	72	`cursor-in-echo-area' while prompting.
	73
0a2eb25e RS	74	This function uses `query-replace-map' to define the standard responses,
	75	but not all of the responses which `query-replace' understands
	76	are meaningful here.
	77
60205e0b	78	Returns the number of actions taken."
c5068ec5 RM	79	(let* ((actions 0)
	80	user-keys mouse-event map prompt char elt tail def
	81	delayed-switch-frame
fba98516	82	(next (if (or (and list (symbolp list))
aa228418	83	(subrp list)
dbc4e1c1	84	(byte-code-function-p list)
aa228418 JB	85	(and (consp list)
	86	(eq (car list) 'lambda)))
	87	(function (lambda ()
	88	(setq elt (funcall list))))
	89	(function (lambda ()
	90	(if list
	91	(progn
	92	(setq elt (car list)
	93	list (cdr list))
	94	t)
	95	nil))))))
c5068ec5 RM	96	(if (listp last-nonmenu-event)
	97	;; Make a list describing a dialog box.
	98	(let ((object (capitalize (nth 0 help)))
	99	(objects (capitalize (nth 1 help)))
	100	(action (capitalize (nth 2 help))))
	101	(setq map (` (("Yes" . act) ("No" . skip) ("Quit" . exit)
	102	((, (if help (concat action " " object " And Quit")
	103	"Do it and Quit")) . act-and-exit)
	104	((, (if help (concat action " All " objects)
	105	"Do All")) . automatic)
	106	(,@ (mapcar (lambda (elt)
230ac7f6	107	(cons (capitalize (nth 2 elt))
c5068ec5 RM	108	(vector (nth 1 elt))))
	109	action-alist))))
	110	mouse-event last-nonmenu-event))
	111	(setq user-keys (if action-alist
	112	(concat (mapconcat (function
	113	(lambda (elt)
	114	(key-description
	115	(char-to-string (car elt)))))
	116	action-alist ", ")
	117	" ")
	118	"")
	119	;; Make a map that defines each user key as a vector containing
	120	;; its definition.
	121	map (cons 'keymap
	122	(append (mapcar (lambda (elt)
	123	(cons (car elt) (vector (nth 1 elt))))
	124	action-alist)
	125	query-replace-map))))
3eea8aa2 JB	126	(unwind-protect
	127	(progn
	128	(if (stringp prompter)
	129	(setq prompter (` (lambda (object)
	130	(format (, prompter) object)))))
	131	(while (funcall next)
	132	(setq prompt (funcall prompter elt))
	133	(if (stringp prompt)
	134	(progn
	135	(setq quit-flag nil)
	136	;; Prompt the user about this object.
c5068ec5 RM	137	(if mouse-event
c5068ec5 RM	138	(setq def (or (x-popup-dialog mouse-event
6f4387dd	139	(cons prompt map))
c5068ec5 RM	140	'quit))
	141	;; Prompt in the echo area.
	142	(let ((cursor-in-echo-area (not no-cursor-in-echo-area)))
	143	(message "%s(y, n, !, ., q, %sor %s) "
	144	prompt user-keys
	145	(key-description (vector help-char)))
	146	(setq char (read-event)))
	147	;; Show the answer to the question.
	148	(message "%s(y, n, !, ., q, %sor %s) %s"
3eea8aa2	149	prompt user-keys
c5068ec5 RM	150	(key-description (vector help-char))
	151	(single-key-description char))
	152	(setq def (lookup-key map (vector char))))
3eea8aa2 JB	153	(cond ((eq def 'exit)
	154	(setq next (function (lambda () nil))))
	155	((eq def 'act)
	156	;; Act on the object.
	157	(funcall actor elt)
	158	(setq actions (1+ actions)))
	159	((eq def 'skip)
	160	;; Skip the object.
	161	)
	162	((eq def 'act-and-exit)
	163	;; Act on the object and then exit.
0af46a8b	164	(funcall actor elt)
3eea8aa2 JB	165	(setq actions (1+ actions)
	166	next (function (lambda () nil))))
	167	((eq def 'quit)
	168	(setq quit-flag t)
	169	(setq next (` (lambda ()
	170	(setq next '(, next))
	171	'(, elt)))))
	172	((eq def 'automatic)
	173	;; Act on this and all following objects.
	174	(if (eval (funcall prompter elt))
	175	(progn
	176	(funcall actor elt)
	177	(setq actions (1+ actions))))
	178	(while (funcall next)
	179	(if (eval (funcall prompter elt))
	180	(progn
	181	(funcall actor elt)
	182	(setq actions (1+ actions))))))
	183	((eq def 'help)
	184	(with-output-to-temp-buffer "Help"
	185	(princ
	186	(let ((object (if help (nth 0 help) "object"))
	187	(objects (if help (nth 1 help) "objects"))
	188	(action (if help (nth 2 help) "act on")))
	189	(concat
	190	(format "Type SPC or `y' to %s the current %s;
0a2eb25e RS	191	DEL or `n' to skip the current %s;
	192	! to %s all remaining %s;
	193	ESC or `q' to exit;\n"
3eea8aa2	194	action object object action objects)
c5068ec5 RM	195	(mapconcat (function
	196	(lambda (elt)
	197	(format "%c to %s"
	198	(nth 0 elt)
	199	(nth 2 elt))))
	200	action-alist
	201	";\n")
	202	(if action-alist ";\n")
	203	(format "or . (period) to %s \
0a2eb25e	204	the current %s and exit."
c5068ec5	205	action object)))))
3eea8aa2 JB	206
	207	(setq next (` (lambda ()
	208	(setq next '(, next))
	209	'(, elt)))))
	210	((vectorp def)
	211	;; A user-defined key.
	212	(if (funcall (aref def 0) elt) ;Call its function.
	213	;; The function has eaten this object.
	214	(setq actions (1+ actions))
	215	;; Regurgitated; try again.
	216	(setq next (` (lambda ()
	217	(setq next '(, next))
	218	'(, elt))))))
	219	((and (consp char)
	220	(eq (car char) 'switch-frame))
	221	;; switch-frame event. Put it off until we're done.
	222	(setq delayed-switch-frame char)
	223	(setq next (` (lambda ()
	224	(setq next '(, next))
	225	'(, elt)))))
	226	(t
	227	;; Random char.
	228	(message "Type %s for help."
b26f0e4e	229	(key-description (vector help-char)))
3eea8aa2 JB	230	(beep)
	231	(sit-for 1)
	232	(setq next (` (lambda ()
	233	(setq next '(, next))
	234	'(, elt)))))))
	235	(if (eval prompt)
	236	(progn
	237	(funcall actor elt)
	238	(setq actions (1+ actions)))))))
	239	(if delayed-switch-frame
	240	(setq unread-command-events
	241	(cons delayed-switch-frame unread-command-events))))
60205e0b RM	242	;; Clear the last prompt from the minibuffer.
	243	(message "")
	244	;; Return the number of actions that were taken.
	245	actions))
6594deb0 ER	246
6594deb0 ER	247	;;; map-ynp.el ends here