Commit | Line | Data |
---|---|---|
6594deb0 ER |
1 | ;;; map-ynp.el --- General-purpose boolean question-asker. |
2 | ||
e5167999 ER |
3 | ;; Author: Roland McGrath <roland@gnu.ai.mit.edu> |
4 | ;; Last-Modified: 14 Mar 1992 | |
5 | ||
03759fe0 | 6 | ;;; Copyright (C) 1991, 1992 Free Software Foundation, Inc. |
60205e0b RM |
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 | |
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: |
34 | ||
60205e0b RM |
35 | (defun map-y-or-n-p-help (object objects action) |
36 | (format "Type SPC or `y' to %s the current %s; | |
37 | DEL or `n' to skip the current %s; | |
38 | ! to %s all remaining %s; | |
39 | ESC or `q' to exit; | |
40 | or . (period) to %s the current %s and exit." | |
41 | action object object action objects action object)) | |
42 | ||
43 | ;;;###autoload | |
44 | (defun map-y-or-n-p (prompter actor list &optional help) | |
45 | "Ask a series of boolean questions. | |
46 | Takes args PROMPTER ACTOR LIST, and optional arg HELP. | |
47 | ||
48 | LIST is a list of objects, or a function of no arguments to return the next | |
49 | object or nil. | |
50 | ||
9fd54390 | 51 | If PROMPTER is a string, the prompt is \(format PROMPTER OBJECT\). If not |
03759fe0 RM |
52 | a string, PROMPTER is a function of one arg (an object from LIST), which |
53 | returns a string to be used as the prompt for that object. If the return | |
54 | value is not a string, it is eval'd to get the answer; it may be nil to | |
55 | ignore the object, t to act on the object without asking the user, or a | |
56 | form to do a more complex prompt. | |
57 | ||
60205e0b RM |
58 | |
59 | ACTOR is a function of one arg (an object from LIST), | |
60 | which gets called with each object that the user answers `yes' for. | |
61 | ||
62 | If HELP is given, it is a list (OBJECT OBJECTS ACTION), | |
63 | where OBJECT is a string giving the singular noun for an elt of LIST; | |
64 | OBJECTS is the plural noun for elts of LIST, and ACTION is a transitive | |
65 | verb describing ACTOR. The default is \(\"object\" \"objects\" \"act on\"\). | |
66 | ||
67 | At the prompts, the user may enter y, Y, or SPC to act on that object; | |
68 | n, N, or DEL to skip that object; ! to act on all following objects; | |
69 | ESC or q to exit (skip all following objects); . (period) to act on the | |
70 | current object and then exit; or \\[help-command] to get help. | |
71 | ||
72 | Returns the number of actions taken." | |
aa228418 JB |
73 | (let* ((old-help-form help-form) |
74 | (help-form (cons 'map-y-or-n-p-help | |
75 | (or help '("object" "objects" "act on")))) | |
76 | (actions 0) | |
77 | prompt | |
78 | char | |
79 | elt | |
80 | (next (if (or (symbolp list) | |
81 | (subrp list) | |
82 | (compiled-function-p list) | |
83 | (and (consp list) | |
84 | (eq (car list) 'lambda))) | |
85 | (function (lambda () | |
86 | (setq elt (funcall list)))) | |
87 | (function (lambda () | |
88 | (if list | |
89 | (progn | |
90 | (setq elt (car list) | |
91 | list (cdr list)) | |
92 | t) | |
93 | nil)))))) | |
60205e0b RM |
94 | (if (stringp prompter) |
95 | (setq prompter (` (lambda (object) | |
96 | (format (, prompter) object))))) | |
ef0ba3e3 | 97 | (while (funcall next) |
60205e0b RM |
98 | (setq prompt (funcall prompter elt)) |
99 | (if (stringp prompt) | |
100 | (progn | |
101 | ;; Prompt the user about this object. | |
102 | (let ((cursor-in-echo-area t)) | |
103 | (message "%s(y, n, ! ., q, or %s)" | |
104 | prompt (key-description (char-to-string help-char))) | |
105 | (setq char (read-char))) | |
106 | (cond ((or (= ?q char) | |
107 | (= ?\e char)) | |
108 | (setq next (function (lambda () nil)))) | |
109 | ((or (= ?y char) | |
110 | (= ?Y char) | |
111 | (= ? char)) | |
112 | ;; Act on the object. | |
113 | (let ((help-form old-help-form)) | |
114 | (funcall actor elt)) | |
115 | (setq actions (1+ actions))) | |
116 | ((or (= ?n char) | |
117 | (= ?N char) | |
118 | (= ?\^? char)) | |
119 | ;; Skip the object. | |
120 | ) | |
121 | ((= ?. char) | |
122 | ;; Act on the object and then exit. | |
123 | (funcall actor elt) | |
124 | (setq actions (1+ actions) | |
125 | next (function (lambda () nil)))) | |
126 | ((= ?! char) | |
0af46a8b RM |
127 | ;; Act on this and all following objects. |
128 | (if (eval (funcall prompter elt)) | |
129 | (progn | |
130 | (funcall actor elt) | |
131 | (setq actions (1+ actions)))) | |
aa228418 | 132 | (while (funcall next) |
0af46a8b | 133 | (if (eval (funcall prompter elt)) |
60205e0b RM |
134 | (progn |
135 | (funcall actor elt) | |
bed40c39 | 136 | (setq actions (1+ actions)))))) |
60205e0b RM |
137 | ((= ?? char) |
138 | (setq unread-command-char help-char) | |
0af46a8b RM |
139 | (setq next (` (lambda () |
140 | (setq next '(, next)) | |
141 | '(, elt))))) | |
60205e0b RM |
142 | (t |
143 | ;; Random char. | |
144 | (message "Type %s for help." | |
145 | (key-description (char-to-string help-char))) | |
146 | (beep) | |
147 | (sit-for 1) | |
0af46a8b RM |
148 | (setq next (` (lambda () |
149 | (setq next '(, next)) | |
150 | '(, elt))))))) | |
60205e0b RM |
151 | (if (eval prompt) |
152 | (progn | |
0af46a8b RM |
153 | (funcall actor elt) |
154 | (setq actions (1+ actions)))))) | |
60205e0b RM |
155 | ;; Clear the last prompt from the minibuffer. |
156 | (message "") | |
157 | ;; Return the number of actions that were taken. | |
158 | actions)) | |
6594deb0 ER |
159 | |
160 | ;;; map-ynp.el ends here |