Don't include string.h or strings.h.
[bpt/emacs.git] / lisp / indent.el
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1;;; indent.el --- indentation commands for Emacs
2
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3;; Copyright (C) 1985 Free Software Foundation, Inc.
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5;; Maintainer: FSF
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7;; This file is part of GNU Emacs.
8
9;; GNU Emacs is free software; you can redistribute it and/or modify
10;; it under the terms of the GNU General Public License as published by
e5167999 11;; the Free Software Foundation; either version 2, or (at your option)
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12;; any later version.
13
14;; GNU Emacs is distributed in the hope that it will be useful,
15;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17;; GNU General Public License for more details.
18
19;; You should have received a copy of the GNU General Public License
20;; along with GNU Emacs; see the file COPYING. If not, write to
21;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
22
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23;;; Commentary:
24
25;; Commands for making and changing indentation in text. These are
26;; described in the Emacs manual.
27
e5167999 28;;; Code:
483e630e 29
6503cec3 30(defvar indent-line-function 'indent-to-left-margin "\
7cf2444d 31Function to indent current line.")
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32
33(defun indent-according-to-mode ()
34 "Indent line in proper way for current major mode."
35 (interactive)
36 (funcall indent-line-function))
37
38(defun indent-for-tab-command ()
39 "Indent line in proper way for current major mode."
40 (interactive)
41 (if (eq indent-line-function 'indent-to-left-margin)
42 (insert-tab)
43 (funcall indent-line-function)))
44
45(defun insert-tab ()
46 (if abbrev-mode
47 (expand-abbrev))
48 (if indent-tabs-mode
49 (insert ?\t)
50 (indent-to (* tab-width (1+ (/ (current-column) tab-width))))))
51
52(defun indent-rigidly (start end arg)
53 "Indent all lines starting in the region sideways by ARG columns.
54Called from a program, takes three arguments, START, END and ARG."
55 (interactive "r\np")
56 (save-excursion
57 (goto-char end)
58 (setq end (point-marker))
59 (goto-char start)
60 (or (bolp) (forward-line 1))
61 (while (< (point) end)
62 (let ((indent (current-indentation)))
63 (delete-region (point) (progn (skip-chars-forward " \t") (point)))
64 (or (eolp)
65 (indent-to (max 0 (+ indent arg)) 0)))
66 (forward-line 1))
67 (move-marker end nil)))
68
69;; This is the default indent-line-function,
70;; used in Fundamental Mode, Text Mode, etc.
71(defun indent-to-left-margin ()
72 (or (= (current-indentation) left-margin)
73 (let (epos)
74 (save-excursion
75 (beginning-of-line)
76 (delete-region (point)
77 (progn (skip-chars-forward " \t")
78 (point)))
79 (indent-to left-margin)
80 (setq epos (point)))
81 (if (< (point) epos)
82 (goto-char epos)))))
83
84(defvar indent-region-function nil
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85 "Function which is short cut to indent region using indent-according-to-mode.
86A value of nil means really run indent-according-to-mode on each line.")
483e630e 87
88a2603a 88(defun indent-region (start end column)
483e630e 89 "Indent each nonblank line in the region.
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90With no argument, indent each line using `indent-according-to-mode',
91or use `indent-region-function' to do the whole region if that's non-nil.
92If there is a fill prefix, make each line start with the fill prefix.
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93With argument COLUMN, indent each line to that column.
94Called from a program, takes three args: START, END and COLUMN."
95 (interactive "r\nP")
88a2603a 96 (if (null column)
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97 (if fill-prefix
98 (save-excursion
99 (goto-char end)
100 (setq end (point-marker))
101 (goto-char start)
102 (let ((regexp (regexp-quote fill-prefix)))
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103 (while (< (point) end)
104 (or (looking-at regexp)
105 (and (bolp) (eolp))
106 (insert fill-prefix))
107 (forward-line 1))))
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108 (if indent-region-function
109 (funcall indent-region-function start end)
110 (save-excursion
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111 (goto-char end)
112 (setq end (point-marker))
113 (goto-char start)
114 (or (bolp) (forward-line 1))
115 (while (< (point) end)
232acca7 116 (or (and (bolp) (eolp))
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117 (funcall indent-line-function))
118 (forward-line 1))
119 (move-marker end nil))))
120 (setq column (prefix-numeric-value column))
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121 (save-excursion
122 (goto-char end)
123 (setq end (point-marker))
124 (goto-char start)
125 (or (bolp) (forward-line 1))
126 (while (< (point) end)
127 (delete-region (point) (progn (skip-chars-forward " \t") (point)))
128 (or (eolp)
88a2603a 129 (indent-to column 0))
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130 (forward-line 1))
131 (move-marker end nil))))
132
133(defun indent-relative-maybe ()
134 "Indent a new line like previous nonblank line."
135 (interactive)
136 (indent-relative t))
137
138(defun indent-relative (&optional unindented-ok)
139 "Space out to under next indent point in previous nonblank line.
140An indent point is a non-whitespace character following whitespace.
141If the previous nonblank line has no indent points beyond the
142column point starts at, `tab-to-tab-stop' is done instead."
143 (interactive "P")
144 (if abbrev-mode (expand-abbrev))
145 (let ((start-column (current-column))
146 indent)
147 (save-excursion
148 (beginning-of-line)
149 (if (re-search-backward "^[^\n]" nil t)
150 (let ((end (save-excursion (forward-line 1) (point))))
151 (move-to-column start-column)
152 ;; Is start-column inside a tab on this line?
153 (if (> (current-column) start-column)
154 (backward-char 1))
155 (or (looking-at "[ \t]")
156 unindented-ok
157 (skip-chars-forward "^ \t" end))
158 (skip-chars-forward " \t" end)
159 (or (= (point) end) (setq indent (current-column))))))
160 (if indent
161 (let ((opoint (point-marker)))
162 (delete-region (point) (progn (skip-chars-backward " \t") (point)))
163 (indent-to indent 0)
164 (if (> opoint (point))
165 (goto-char opoint))
166 (move-marker opoint nil))
167 (tab-to-tab-stop))))
168
169(defvar tab-stop-list
170 '(8 16 24 32 40 48 56 64 72 80 88 96 104 112 120)
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171 "*List of tab stop positions used by `tab-to-tab-stops'.
172This should be a list of integers, ordered from smallest to largest.")
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173
174(defvar edit-tab-stops-map nil "Keymap used in `edit-tab-stops'.")
175(if edit-tab-stops-map
176 nil
177 (setq edit-tab-stops-map (make-sparse-keymap))
178 (define-key edit-tab-stops-map "\C-x\C-s" 'edit-tab-stops-note-changes)
179 (define-key edit-tab-stops-map "\C-c\C-c" 'edit-tab-stops-note-changes))
180
181(defvar edit-tab-stops-buffer nil
182 "Buffer whose tab stops are being edited--in case
183the variable `tab-stop-list' is local in that buffer.")
184
185(defun edit-tab-stops ()
186 "Edit the tab stops used by `tab-to-tab-stop'.
187Creates a buffer *Tab Stops* containing text describing the tab stops.
188A colon indicates a column where there is a tab stop.
189You can add or remove colons and then do \\<edit-tab-stops-map>\\[edit-tab-stops-note-changes] to make changes take effect."
190 (interactive)
191 (setq edit-tab-stops-buffer (current-buffer))
192 (switch-to-buffer (get-buffer-create "*Tab Stops*"))
193 (use-local-map edit-tab-stops-map)
194 (make-local-variable 'indent-tabs-mode)
195 (setq indent-tabs-mode nil)
196 (overwrite-mode 1)
197 (setq truncate-lines t)
198 (erase-buffer)
199 (let ((tabs tab-stop-list))
200 (while tabs
201 (indent-to (car tabs) 0)
202 (insert ?:)
203 (setq tabs (cdr tabs))))
204 (let ((count 0))
205 (insert ?\n)
206 (while (< count 8)
207 (insert (+ count ?0))
208 (insert " ")
209 (setq count (1+ count)))
210 (insert ?\n)
211 (while (> count 0)
212 (insert "0123456789")
213 (setq count (1- count))))
214 (insert "\nTo install changes, type C-c C-c")
215 (goto-char (point-min)))
216
217(defun edit-tab-stops-note-changes ()
218 "Put edited tab stops into effect."
219 (interactive)
220 (let (tabs)
221 (save-excursion
222 (goto-char 1)
223 (end-of-line)
224 (while (search-backward ":" nil t)
225 (setq tabs (cons (current-column) tabs))))
226 (bury-buffer (prog1 (current-buffer)
227 (switch-to-buffer edit-tab-stops-buffer)))
228 (setq tab-stop-list tabs))
229 (message "Tab stops installed"))
230
231(defun tab-to-tab-stop ()
232 "Insert spaces or tabs to next defined tab-stop column.
233The variable `tab-stop-list' is a list of columns at which there are tab stops.
234Use \\[edit-tab-stops] to edit them interactively."
235 (interactive)
236 (if abbrev-mode (expand-abbrev))
237 (let ((tabs tab-stop-list))
238 (while (and tabs (>= (current-column) (car tabs)))
239 (setq tabs (cdr tabs)))
240 (if tabs
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241 (let ((opoint (point)))
242 (skip-chars-backward " \t")
243 (delete-region (point) opoint)
244 (indent-to (car tabs)))
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245 (insert ?\ ))))
246
247(defun move-to-tab-stop ()
248 "Move point to next defined tab-stop column.
249The variable `tab-stop-list' is a list of columns at which there are tab stops.
250Use \\[edit-tab-stops] to edit them interactively."
251 (interactive)
252 (let ((tabs tab-stop-list))
253 (while (and tabs (>= (current-column) (car tabs)))
254 (setq tabs (cdr tabs)))
255 (if tabs
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256 (progn
257 (if (eq last-command 'move-to-tab-stop)
258 (let ((opoint (point)))
259 (skip-chars-backward " \t")
260 (delete-region (point) opoint)))
261 (move-to-column (car tabs) t)))))
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262
263(define-key global-map "\t" 'indent-for-tab-command)
264(define-key esc-map "\034" 'indent-region)
265(define-key ctl-x-map "\t" 'indent-rigidly)
266(define-key esc-map "i" 'tab-to-tab-stop)
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267
268;;; indent.el ends here