@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990-1995, 1998-2011 Free Software Foundation, Inc.
+@c Copyright (C) 1990-1995, 1998-2013 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
-@setfilename ../../info/positions
-@node Positions, Markers, Frames, Top
+@node Positions
@chapter Positions
@cindex position (in buffer)
1, even if @var{start} and @var{end} are on the same line. This is
because the text between them, considered in isolation, must contain at
least one line unless it is empty.
+@end defun
-Here is an example of using @code{count-lines}:
+@deffn Command count-words start end
+@cindex words in region
+This function returns the number of words between the positions
+@var{start} and @var{end} in the current buffer.
-@example
-@group
-(defun current-line ()
- "Return the vertical position of point@dots{}"
- (+ (count-lines (window-start) (point))
- (if (= (current-column) 0) 1 0)))
-@end group
-@end example
-@end defun
+This function can also be called interactively. In that case, it
+prints a message reporting the number of lines, words, and characters
+in the buffer, or in the region if the region is active.
+@end deffn
@defun line-number-at-pos &optional pos
@cindex line number
@end defun
@node List Motion
-@comment node-name, next, previous, up
@subsection Moving over Balanced Expressions
@cindex sexp motion
@cindex Lisp expression motion
@end defvar
@node Skipping Characters
-@comment node-name, next, previous, up
@subsection Skipping Characters
@cindex skipping characters
Thus, @code{"a-zA-Z"} skips over all letters, stopping before the
first nonletter, and @code{"^a-zA-Z"} skips nonletters stopping before
the first letter. See @xref{Regular Expressions}. Character classes
-can also be used, e.g. @code{"[:alnum:]"}. See @pxref{Char Classes}.
+can also be used, e.g., @code{"[:alnum:]"}. See @pxref{Char Classes}.
If @var{limit} is supplied (it must be a number or a marker), it
specifies the maximum position in the buffer that point can be skipped
during an excursion:
@example
-Warning: @code{save-excursion} defeated by @code{set-buffer}
+Warning: Use `with-current-buffer' rather than
+ save-excursion+set-buffer
@end example
@noindent
@cindex window excursions
Likewise, @code{save-excursion} does not restore window-buffer
correspondences altered by functions such as @code{switch-to-buffer}.
-One way to restore these correspondences, and the selected window, is to
-use @code{save-window-excursion} inside @code{save-excursion}
-(@pxref{Window Configurations}).
@strong{Warning:} Ordinary insertion of text adjacent to the saved
point value relocates the saved value, just as it relocates all
remains addressable is called the @dfn{accessible portion} of the
buffer.
- Narrowing is specified with two buffer positions which become the
-beginning and end of the accessible portion. For most editing commands
-and most Emacs primitives, these positions replace the values of the
-beginning and end of the buffer. While narrowing is in effect, no text
-outside the accessible portion is displayed, and point cannot move
-outside the accessible portion.
-
- Values such as positions or line numbers, which usually count from the
-beginning of the buffer, do so despite narrowing, but the functions
-which use them refuse to operate on text that is inaccessible.
-
- The commands for saving buffers are unaffected by narrowing; they save
+ Narrowing is specified with two buffer positions, which become the
+beginning and end of the accessible portion. For most editing
+commands and primitives, these positions replace the values of the
+beginning and end of the buffer. While narrowing is in effect, no
+text outside the accessible portion is displayed, and point cannot
+move outside the accessible portion. Note that narrowing does not
+alter actual buffer positions (@pxref{Point}); it only determines
+which positions are considered the accessible portion of the buffer.
+Most functions refuse to operate on text that is outside the
+accessible portion.
+
+ Commands for saving buffers are unaffected by narrowing; they save
the entire buffer regardless of any narrowing.
If you need to display in a single buffer several very different
@end example
@end deffn
+@defun buffer-narrowed-p
+This function returns non-@code{nil} if the buffer is narrowed, and
+@code{nil} otherwise.
+@end defun
+
@defspec save-restriction body@dots{}
This special form saves the current bounds of the accessible portion,
evaluates the @var{body} forms, and finally restores the saved bounds,
HCoop / bpt / emacs.git / blobdiff