1;;; map-ynp.el --- General-purpose boolean question-asker. 2 3;;; Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc. 4 5;; Author: Roland McGrath <roland@gnu.ai.mit.edu> 6;; Keywords: lisp, extensions 7 8;;; This program is free software; you can redistribute it and/or modify 9;;; it under the terms of the GNU General Public License as published by 10;;; the Free Software Foundation; either version 2, or (at your option) 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. 22 23;;; Commentary: 24 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 33;;; Code: 34 35;;;###autoload 36(defun map-y-or-n-p (prompter actor list &optional help action-alist 37 no-cursor-in-echo-area) 38 "Ask a series of boolean questions. 39Takes args PROMPTER ACTOR LIST, and optional args HELP and ACTION-ALIST. 40 41LIST is a list of objects, or a function of no arguments to return the next 42object or nil. 43 44If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\). If not 45a string, PROMPTER is a function of one arg (an object from LIST), which 46returns a string to be used as the prompt for that object. If the return 47value is not a string, it is eval'd to get the answer; it may be nil to 48ignore the object, t to act on the object without asking the user, or a 49form to do a more complex prompt. 50 51ACTOR is a function of one arg (an object from LIST), 52which gets called with each object that the user answers `yes' for. 53 54If HELP is given, it is a list (OBJECT OBJECTS ACTION), 55where OBJECT is a string giving the singular noun for an elt of LIST; 56OBJECTS is the plural noun for elts of LIST, and ACTION is a transitive 57verb describing ACTOR. The default is \(\"object\" \"objects\" \"act on\"\). 58 59At the prompts, the user may enter y, Y, or SPC to act on that object; 60n, N, or DEL to skip that object; ! to act on all following objects; 61ESC or q to exit (skip all following objects); . (period) to act on the 62current object and then exit; or \\[help-command] to get help. 63 64If ACTION-ALIST is given, it is an alist (KEY FUNCTION HELP) of extra keys 65that will be accepted. KEY is a character; FUNCTION is a function of one 66arg (an object from LIST); HELP is a string. When the user hits KEY, 67FUNCTION 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 69nil, the prompt is repeated for the same object. 70 71Final optional argument NO-CURSOR-IN-ECHO-AREA non-nil says not to set 72`cursor-in-echo-area' while prompting. 73 74This function uses `query-replace-map' to define the standard responses, 75but not all of the responses which `query-replace' understands 76are meaningful here. 77 78Returns the number of actions taken." 79 (let* ((actions 0) 80 user-keys mouse-event map prompt char elt tail def 81 delayed-switch-frame 82 (next (if (or (and list (symbolp list)) 83 (subrp list) 84 (byte-code-function-p list) 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)))))) 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) 107 (cons (capitalize (nth 2 elt)) 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)))) 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. 137 (if mouse-event 138 (setq def (or (x-popup-dialog mouse-event 139 (cons prompt map)) 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" 149 prompt user-keys 150 (key-description (vector help-char)) 151 (single-key-description char)) 152 (setq def (lookup-key map (vector char)))) 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. 164 (funcall actor elt) 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; 191DEL or `n' to skip the current %s; 192! to %s all remaining %s; 193ESC or `q' to exit;\n" 194 action object object action objects) 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 \ 204the current %s and exit." 205 action object))))) 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." 229 (key-description (vector help-char))) 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)))) 242 ;; Clear the last prompt from the minibuffer. 243 (message "") 244 ;; Return the number of actions that were taken. 245 actions)) 246 247;;; map-ynp.el ends here 248