@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2000, 2001
@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/positions
@var{count} is negative). ``Moving one word'' means moving until point
crosses a word-constituent character and then encounters a
word-separator character. However, this function cannot move point past
-the boundary of the accessible part of the buffer, or across a field
+the boundary of the accessible portion of the buffer, or across a field
boundary (@pxref{Fields}). The most common case of a field boundary is
the end of the prompt in the minibuffer.
In an interactive call, @var{count} is set to the numeric prefix
argument.
-This function is rarely used in programs, as it is more efficient to
-call @code{forward-word} with a negative argument.
+@c [Now optimized by compiler.]
+@c This function is rarely used in programs, as it is more efficient to
+@c call @code{forward-word} with a negative argument.
@end deffn
@defvar words-include-escapes
argument @var{count} not @code{nil} or 1, it moves forward
@var{count}@minus{}1 lines and then to the beginning of the line.
+This function does not move point across a field boundary
+(@pxref{Fields}) unless doing so would move beyond there to a
+different line; therefore, if @var{count} is @code{nil} or 1, and
+point starts at a field boundary, point does not move. To ignore
+field boundaries, either bind @code{inhibit-field-text-motion} to
+@code{t}, or use the @code{forward-line} function instead. For
+instance, @code{(forward-line 0)} does the same thing as
+@code{(beginning-of-line)}, except that it ignores field boundaries.
+
If this function reaches the end of the buffer (or of the accessible
portion, if narrowing is in effect), it positions point there. No error
is signaled.
argument @var{count} not @code{nil} or 1, it moves forward
@var{count}@minus{}1 lines and then to the end of the line.
+This function does not move point across a field boundary
+(@pxref{Fields}) unless doing so would move beyond there to a
+different line; therefore, if @var{count} is @code{nil} or 1, and
+point starts at a field boundary, point does not move. To ignore
+field boundaries, bind @code{inhibit-field-text-motion} to @code{t}.
+
If this function reaches the end of the buffer (or of the accessible
portion, if narrowing is in effect), it positions point there. No error
is signaled.
use them heavily, Emacs provides caches which may improve the
performance of your code. @xref{Truncation, cache-long-line-scans}.
-
@defun vertical-motion count &optional window
This function moves point to the start of the screen line @var{count}
screen lines down from the screen line containing point. If @var{count}
@var{window} currently displays some other buffer.
@end defun
+@defun count-screen-lines &optional beg end count-final-newline window
+This function returns the number of screen lines in the text from
+@var{beg} to @var{end}. The number of screen lines may be different
+from the number of actual lines, due to line continuation, the display
+table, etc. If @var{beg} and @var{end} are @code{nil} or omitted,
+they default to the beginning and end of the accessible portion of the
+buffer.
+
+If the region ends with a newline, that is ignored unless the optional
+third argument @var{count-final-newline} is non-@code{nil}.
+
+The optional fourth argument @var{window} specifies the window for
+obtaining parameters such as width, horizontal scrolling, and so on.
+The default is to use the selected window's parameters.
+
+Like @code{vertical-motion}, @code{count-screen-lines} always uses the
+current buffer, regardless of which buffer is displayed in
+@var{window}. This makes possible to use @code{count-screen-lines} in
+any buffer, whether or not it is currently displayed in some window.
+@end defun
+
@deffn Command move-to-window-line count
This function moves point with respect to the text currently displayed
in the selected window. It moves point to the beginning of the screen
@deffn Command forward-sexp &optional arg
This function moves forward across @var{arg} (default 1) balanced expressions.
Balanced expressions include both those delimited by parentheses and
-other kinds, such as words and string constants. For example,
+other kinds, such as words and string constants
+@xref{Parsing Expressions}. For example,
@example
@group
open-parenthesis syntax.
@end defopt
+@defopt open-paren-in-column-0-is-defun-start
+If this variable's value is non-@code{nil}, an open parenthesis in
+column 0 is considered to be the start of a defun. If it is
+@code{nil}, an open parenthesis in column 0 has no special meaning.
+The default is @code{t}.
+@end defopt
+
@defvar beginning-of-defun-function
@tindex beginning-of-defun-function
If non-@code{nil}, this variable holds a function for finding the
value were outside the limits of the temporary narrowing, this would
fail to restore it accurately.
-The @code{save-restriction} special form records the values of the
-beginning and end of the accessible portion as distances from the
-beginning and end of the buffer. In other words, it records the amount
-of inaccessible text before and after the accessible portion.
-
-This method yields correct results if @var{body} does further narrowing.
-However, @code{save-restriction} can become confused if the body widens
-and then makes changes outside the range of the saved narrowing. When
-this is what you want to do, @code{save-restriction} is not the right
-tool for the job. Here is what you must use instead:
-
-@example
-@group
-(let ((beg (point-min-marker))
- (end (point-max-marker)))
- (unwind-protect
- (progn @var{body})
- (save-excursion
- (set-buffer (marker-buffer beg))
- (narrow-to-region beg end))))
-@end group
-@end example
-
Here is a simple example of correct use of @code{save-restriction}:
@example
HCoop / bpt / emacs.git / blobdiff