code.delx.au - gnu-emacs/blob - lisp/indent.el

   1 ;;; indent.el --- indentation commands for Emacs
   2
   3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6
   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
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  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
  23 ;;; Code:
  24
  25 (defvar indent-line-function 'indent-to-left-margin "\
  26 Function to indent current line.");Now in loaddefs.el
  27
  28 (defun indent-according-to-mode ()
  29   "Indent line in proper way for current major mode."
  30   (interactive)
  31   (funcall indent-line-function))
  32
  33 (defun indent-for-tab-command ()
  34   "Indent line in proper way for current major mode."
  35   (interactive)
  36   (if (eq indent-line-function 'indent-to-left-margin)
  37       (insert-tab)
  38     (funcall indent-line-function)))
  39
  40 (defun insert-tab ()
  41   (if abbrev-mode
  42       (expand-abbrev))
  43   (if indent-tabs-mode
  44       (insert ?\t)
  45     (indent-to (* tab-width (1+ (/ (current-column) tab-width))))))
  46
  47 (defun indent-rigidly (start end arg)
  48   "Indent all lines starting in the region sideways by ARG columns.
  49 Called from a program, takes three arguments, START, END and ARG."
  50   (interactive "r\np")
  51   (save-excursion
  52     (goto-char end)
  53     (setq end (point-marker))
  54     (goto-char start)
  55     (or (bolp) (forward-line 1))
  56     (while (< (point) end)
  57       (let ((indent (current-indentation)))
  58         (delete-region (point) (progn (skip-chars-forward " \t") (point)))
  59         (or (eolp)
  60             (indent-to (max 0 (+ indent arg)) 0)))
  61       (forward-line 1))
  62     (move-marker end nil)))
  63
  64 ;; This is the default indent-line-function,
  65 ;; used in Fundamental Mode, Text Mode, etc.
  66 (defun indent-to-left-margin ()
  67   (or (= (current-indentation) left-margin)
  68       (let (epos)
  69         (save-excursion
  70          (beginning-of-line)
  71          (delete-region (point)
  72                         (progn (skip-chars-forward " \t")
  73                                (point)))
  74          (indent-to left-margin)
  75          (setq epos (point)))
  76         (if (< (point) epos)
  77             (goto-char epos)))))
  78
  79 (defvar indent-region-function nil
  80   "Function which is short cut to indent each line in region with TAB.
  81 A value of nil means really perform TAB on each line.")
  82
  83 (defun indent-region (start end arg)
  84   "Indent each nonblank line in the region.
  85 With no argument, indent each line with TAB.
  86 \(If there is a fill prefix, make each line start with the fill prefix.)
  87 With argument COLUMN, indent each line to that column.
  88 Called from a program, takes three args: START, END and COLUMN."
  89   (interactive "r\nP")
  90   (if (null arg)
  91       (if fill-prefix
  92           (save-excursion
  93             (goto-char end)
  94             (setq end (point-marker))
  95             (goto-char start)
  96             (let ((regexp (regexp-quote fill-prefix)))
  97             (while (< (point) end)
  98               (or (looking-at regexp)
  99                   (insert fill-prefix))
 100               (forward-line 1))))
 101         (if indent-region-function
 102             (funcall indent-region-function start end)
 103           (save-excursion
 104           (goto-char end)
 105           (setq end (point-marker))
 106           (goto-char start)
 107           (or (bolp) (forward-line 1))
 108           (while (< (point) end)
 109             (funcall indent-line-function)
 110             (forward-line 1))
 111           (move-marker end nil))))
 112     (setq arg (prefix-numeric-value arg))
 113     (save-excursion
 114       (goto-char end)
 115       (setq end (point-marker))
 116       (goto-char start)
 117       (or (bolp) (forward-line 1))
 118       (while (< (point) end)
 119         (delete-region (point) (progn (skip-chars-forward " \t") (point)))
 120         (or (eolp)
 121         (indent-to arg 0))
 122         (forward-line 1))
 123       (move-marker end nil))))
 124
 125 (defun indent-relative-maybe ()
 126   "Indent a new line like previous nonblank line."
 127   (interactive)
 128   (indent-relative t))
 129
 130 (defun indent-relative (&optional unindented-ok)
 131   "Space out to under next indent point in previous nonblank line.
 132 An indent point is a non-whitespace character following whitespace.
 133 If the previous nonblank line has no indent points beyond the
 134 column point starts at, `tab-to-tab-stop' is done instead."
 135   (interactive "P")
 136   (if abbrev-mode (expand-abbrev))
 137   (let ((start-column (current-column))
 138         indent)
 139     (save-excursion
 140       (beginning-of-line)
 141       (if (re-search-backward "^[^\n]" nil t)
 142           (let ((end (save-excursion (forward-line 1) (point))))
 143             (move-to-column start-column)
 144             ;; Is start-column inside a tab on this line?
 145             (if (> (current-column) start-column)
 146                 (backward-char 1))
 147             (or (looking-at "[ \t]")
 148                 unindented-ok
 149                 (skip-chars-forward "^ \t" end))
 150             (skip-chars-forward " \t" end)
 151             (or (= (point) end) (setq indent (current-column))))))
 152     (if indent
 153         (let ((opoint (point-marker)))
 154           (delete-region (point) (progn (skip-chars-backward " \t") (point)))
 155           (indent-to indent 0)
 156           (if (> opoint (point))
 157               (goto-char opoint))
 158           (move-marker opoint nil))
 159       (tab-to-tab-stop))))
 160
 161 (defvar tab-stop-list
 162   '(8 16 24 32 40 48 56 64 72 80 88 96 104 112 120)
 163   "*List of tab stop positions used by `tab-to-tab-stops'.")
 164
 165 (defvar edit-tab-stops-map nil "Keymap used in `edit-tab-stops'.")
 166 (if edit-tab-stops-map
 167     nil
 168   (setq edit-tab-stops-map (make-sparse-keymap))
 169   (define-key edit-tab-stops-map "\C-x\C-s" 'edit-tab-stops-note-changes)
 170   (define-key edit-tab-stops-map "\C-c\C-c" 'edit-tab-stops-note-changes))
 171
 172 (defvar edit-tab-stops-buffer nil
 173   "Buffer whose tab stops are being edited--in case
 174 the variable `tab-stop-list' is local in that buffer.")
 175
 176 (defun edit-tab-stops ()
 177   "Edit the tab stops used by `tab-to-tab-stop'.
 178 Creates a buffer *Tab Stops* containing text describing the tab stops.
 179 A colon indicates a column where there is a tab stop.
 180 You can add or remove colons and then do \\<edit-tab-stops-map>\\[edit-tab-stops-note-changes] to make changes take effect."
 181   (interactive)
 182   (setq edit-tab-stops-buffer (current-buffer))
 183   (switch-to-buffer (get-buffer-create "*Tab Stops*"))
 184   (use-local-map edit-tab-stops-map)
 185   (make-local-variable 'indent-tabs-mode)
 186   (setq indent-tabs-mode nil)
 187   (overwrite-mode 1)
 188   (setq truncate-lines t)
 189   (erase-buffer)
 190   (let ((tabs tab-stop-list))
 191     (while tabs
 192       (indent-to (car tabs) 0)
 193       (insert ?:)
 194       (setq tabs (cdr tabs))))
 195   (let ((count 0))
 196     (insert ?\n)
 197     (while (< count 8)
 198       (insert (+ count ?0))
 199     (insert "         ")
 200       (setq count (1+ count)))
 201     (insert ?\n)
 202     (while (> count 0)
 203       (insert "0123456789")
 204       (setq count (1- count))))
 205   (insert "\nTo install changes, type C-c C-c")
 206   (goto-char (point-min)))
 207
 208 (defun edit-tab-stops-note-changes ()
 209   "Put edited tab stops into effect."
 210   (interactive)
 211     (let (tabs)
 212       (save-excursion
 213         (goto-char 1)
 214         (end-of-line)
 215         (while (search-backward ":" nil t)
 216           (setq tabs (cons (current-column) tabs))))
 217       (bury-buffer (prog1 (current-buffer)
 218                           (switch-to-buffer edit-tab-stops-buffer)))
 219       (setq tab-stop-list tabs))
 220   (message "Tab stops installed"))
 221
 222 (defun tab-to-tab-stop ()
 223   "Insert spaces or tabs to next defined tab-stop column.
 224 The variable `tab-stop-list' is a list of columns at which there are tab stops.
 225 Use \\[edit-tab-stops] to edit them interactively."
 226   (interactive)
 227   (if abbrev-mode (expand-abbrev))
 228   (let ((tabs tab-stop-list))
 229     (while (and tabs (>= (current-column) (car tabs)))
 230       (setq tabs (cdr tabs)))
 231     (if tabs
 232         (indent-to (car tabs))
 233       (insert ?\ ))))
 234
 235 (defun move-to-tab-stop ()
 236   "Move point to next defined tab-stop column.
 237 The variable `tab-stop-list' is a list of columns at which there are tab stops.
 238 Use \\[edit-tab-stops] to edit them interactively."
 239   (interactive)
 240   (let ((tabs tab-stop-list))
 241     (while (and tabs (>= (current-column) (car tabs)))
 242       (setq tabs (cdr tabs)))
 243     (if tabs
 244         (move-to-column (car tabs) t))))
 245
 246 (define-key global-map "\t" 'indent-for-tab-command)
 247 (define-key esc-map "\034" 'indent-region)
 248 (define-key ctl-x-map "\t" 'indent-rigidly)
 249 (define-key esc-map "i" 'tab-to-tab-stop)
 250
 251 ;;; indent.el ends here