;;; indent.el --- indentation commands for Emacs
-;; Copyright (C) 1985, 1995 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1995, 2001 Free Software Foundation, Inc.
;; Maintainer: FSF
:group 'indent
:type 'integer)
-(defvar indent-line-function 'indent-to-left-margin
- "Function to indent current line.")
+(defvar indent-line-function 'indent-relative
+ "Function to indent the current line.
+This function will be called with no arguments.
+If it is called somewhere where auto-indentation cannot be done
+\(f.ex. inside a string), the function should simply return `noindent'.
+Setting this function is all you need to make TAB indent appropriately.
+Don't rebind TAB unless you really need to.")
+
+(defcustom tab-always-indent t
+ "*Controls the operation of the TAB key.
+If t, hitting TAB always just indents the current line.
+If nil, hitting TAB indents the current line if point is at the left margin
+ or in the line's indentation, otherwise it insert a \"real\" tab character."
+ :group 'indent
+ :type '(choice (const nil) (const t) (const always)))
(defun indent-according-to-mode ()
- "Indent line in proper way for current major mode."
+ "Indent line in proper way for current major mode.
+The buffer-local variable `indent-line-function' determines how to do this,
+but the functions `indent-relative' and `indent-relative-maybe' are
+special; we don't actually use them here."
(interactive)
- (funcall indent-line-function))
-
-(defun indent-for-tab-command (&optional prefix-arg)
- "Indent line in proper way for current major mode."
+ (if (memq indent-line-function
+ '(indent-relative indent-relative-maybe))
+ ;; These functions are used for tabbing, but can't be used for
+ ;; indenting. Replace with something ad-hoc.
+ (let ((column (save-excursion
+ (beginning-of-line)
+ (skip-chars-backward "\n \t")
+ (beginning-of-line)
+ (current-indentation))))
+ (if (<= (current-column) (current-indentation))
+ (indent-line-to column)
+ (save-excursion (indent-line-to column))))
+ ;; The normal case.
+ (funcall indent-line-function)))
+
+(defun indent-for-tab-command (&optional arg)
+ "Indent line in proper way for current major mode or insert a tab.
+Depending on `tab-always-indent', either insert a tab or indent.
+If initial point was within line's indentation, position after
+the indentation. Else stay at same point in text.
+The function actually called to indent is determined by the value of
+`indent-line-function'."
(interactive "P")
- (if (eq indent-line-function 'indent-to-left-margin)
- (insert-tab prefix-arg)
- (if prefix-arg
- (funcall indent-line-function prefix-arg)
- (funcall indent-line-function))))
-
-(defun insert-tab (&optional prefix-arg)
- (let ((count (prefix-numeric-value prefix-arg)))
+ (cond
+ ((or ;; indent-to-left-margin is only meant for indenting,
+ ;; so we force it to always insert a tab here.
+ (eq indent-line-function 'indent-to-left-margin)
+ (and (not tab-always-indent)
+ (or (> (current-column) (current-indentation))
+ (eq this-command last-command))))
+ (insert-tab arg))
+ ;; Those functions are meant specifically for tabbing and not for
+ ;; indenting, so we can't pass them to indent-according-to-mode.
+ ((memq indent-line-function '(indent-relative indent-relative-maybe))
+ (funcall indent-line-function))
+ (t ;; The normal case.
+ (indent-according-to-mode))))
+
+(defun insert-tab (&optional arg)
+ (let ((count (prefix-numeric-value arg)))
(if (and abbrev-mode
(eq (char-syntax (preceding-char)) ?w))
(expand-abbrev))
(defun indent-rigidly (start end arg)
"Indent all lines starting in the region sideways by ARG columns.
-Called from a program, takes three arguments, START, END and ARG."
+Called from a program, takes three arguments, START, END and ARG.
+You can remove all indentation from a region by giving a large negative ARG."
(interactive "r\np")
(save-excursion
(goto-char end)
((and force (< cc lm))
(indent-to-left-margin)))))
-;; This is the default indent-line-function,
+;; This used to be the default indent-line-function,
;; used in Fundamental Mode, Text Mode, etc.
(defun indent-to-left-margin ()
"Indent current line to the column given by `current-left-margin'."
With optional argument, move forward N-1 lines first.
From the beginning of the line, moves past the left-margin indentation, the
fill-prefix, and any indentation used for centering or right-justifying the
-line, but does not move past any whitespace that was explicitly inserted
+line, but does not move past any whitespace that was explicitly inserted
\(such as a tab used to indent the first line of a paragraph)."
(interactive "p")
(beginning-of-line n)
(skip-chars-forward " \t")
;; Skip over fill-prefix.
- (if (and fill-prefix
+ (if (and fill-prefix
(not (string-equal fill-prefix "")))
(if (equal fill-prefix
- (buffer-substring
+ (buffer-substring
(point) (min (point-max) (+ (length fill-prefix) (point)))))
(forward-char (length fill-prefix)))
(if (and adaptive-fill-mode adaptive-fill-regexp
"Short cut function to indent region using `indent-according-to-mode'.
A value of nil means really run `indent-according-to-mode' on each line.")
-(defun indent-region (start end column)
+(defun indent-region (start end &optional column)
"Indent each nonblank line in the region.
-With no argument, indent each line using `indent-according-to-mode',
-or use `indent-region-function' to do the whole region if that's non-nil.
-If there is a fill prefix, make each line start with the fill prefix.
-With argument COLUMN, indent each line to that column.
-Called from a program, takes three args: START, END and COLUMN."
+A numeric prefix argument specifies a column: indent each line to that column.
+
+With no prefix argument, the command chooses one of these methods and
+indents all the lines with it:
+
+ 1) If `fill-prefix' is non-nil, insert `fill-prefix' at the
+ beginning of each line in the region that does not already begin
+ with it.
+ 2) If `indent-region-function' is non-nil, call that function
+ to indent the region.
+ 3) Indent each line as specified by the variable `indent-line-function'.
+
+Called from a program, START and END specify the region to indent.
+If the third argument COLUMN is an integer, it specifies the
+column to indent to; if it is nil, use one of the three methods above."
(interactive "r\nP")
(if (null column)
(if fill-prefix
(if indent-region-function
(funcall indent-region-function start end)
(save-excursion
- (goto-char end)
- (setq end (point-marker))
+ (setq end (copy-marker end))
(goto-char start)
- (or (bolp) (forward-line 1))
(while (< (point) end)
(or (and (bolp) (eolp))
(funcall indent-line-function))
(move-marker end nil))))
(defun indent-relative-maybe ()
- "Indent a new line like previous nonblank line."
+ "Indent a new line like previous nonblank line.
+If the previous nonblank line has no indent points beyond the
+column point starts at, this command does nothing.
+
+See also `indent-relative'."
(interactive)
(indent-relative t))
The following line shows the indentation points in this line.
^ ^ ^ ^ ^ ^ ^ ^ ^
If the previous nonblank line has no indent points beyond the
-column point starts at, `tab-to-tab-stop' is done instead."
+column point starts at, `tab-to-tab-stop' is done instead, unless
+this command is invoked with a numeric argument, in which case it
+does nothing.
+
+See also `indent-relative-maybe'."
(interactive "P")
(if (and abbrev-mode
(eq (char-syntax (preceding-char)) ?w))
(or (= (point) end) (setq indent (current-column))))))
(if indent
(let ((opoint (point-marker)))
- (delete-region (point) (progn (skip-chars-backward " \t") (point)))
(indent-to indent 0)
(if (> opoint (point))
(goto-char opoint))
:group 'indent
:type '(repeat integer))
-(defvar edit-tab-stops-map nil "Keymap used in `edit-tab-stops'.")
-(if edit-tab-stops-map
- nil
- (setq edit-tab-stops-map (make-sparse-keymap))
- (define-key edit-tab-stops-map "\C-x\C-s" 'edit-tab-stops-note-changes)
- (define-key edit-tab-stops-map "\C-c\C-c" 'edit-tab-stops-note-changes))
+(defvar edit-tab-stops-map
+ (let ((map (make-sparse-keymap)))
+ (define-key map "\C-x\C-s" 'edit-tab-stops-note-changes)
+ (define-key map "\C-c\C-c" 'edit-tab-stops-note-changes)
+ map)
+ "Keymap used in `edit-tab-stops'.")
(defvar edit-tab-stops-buffer nil
"Buffer whose tab stops are being edited--in case
(setq tabs (cdr tabs)))
(if tabs
(let ((opoint (point)))
- (skip-chars-backward " \t")
- (delete-region (point) opoint)
+ (delete-horizontal-space t)
(indent-to (car tabs)))
(insert ?\ ))))
(delete-region (point) before))))))))
(define-key global-map "\t" 'indent-for-tab-command)
-(define-key esc-map "\034" 'indent-region)
+(define-key esc-map "\C-\\" 'indent-region)
(define-key ctl-x-map "\t" 'indent-rigidly)
(define-key esc-map "i" 'tab-to-tab-stop)