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authorChong Yidong <cyd@stupidchicken.com>2009-04-06 01:20:55 +0000
committerChong Yidong <cyd@stupidchicken.com>2009-04-06 01:20:55 +0000
commit47af2f4b96cd4ef4c2a28ca6b217409b8d1ae384 (patch)
tree4e3b923124f2007eb1d0ff5a416bb183856cf772 /doc/lispref/markers.texi
parent38145b39b915ef131188875bf9f4ce4882a42a9e (diff)
downloademacs-47af2f4b96cd4ef4c2a28ca6b217409b8d1ae384.tar.gz
* markers.texi (The Mark): Copyedits. Improve description of
handle-shift-selection. (The Region): Move use-region-p here from The Mark.
Diffstat (limited to 'doc/lispref/markers.texi')
-rw-r--r--doc/lispref/markers.texi150
1 files changed, 63 insertions, 87 deletions
diff --git a/doc/lispref/markers.texi b/doc/lispref/markers.texi
index 54b674b4669..78dbbefd790 100644
--- a/doc/lispref/markers.texi
+++ b/doc/lispref/markers.texi
@@ -392,44 +392,42 @@ This is another name for @code{set-marker}.
@cindex mark, the
@cindex mark ring
- One special marker in each buffer is designated @dfn{the mark}. It
-specifies a position to bound a range of text for commands such as
-@code{kill-region} and @code{indent-rigidly}. Lisp programs should
-set the mark only to values that have a potential use to the user, and
-never for their own internal purposes. For example, the
-@code{replace-regexp} command sets the mark to the value of point
-before doing any replacements, because this enables the user to move
-back there conveniently after the replace is finished.
-
- Many commands are designed to operate on the text between point and
-the mark when called interactively. If you are writing such a
-command, don't examine the mark directly; instead, use
+ Each buffer has a special marker, which is designated @dfn{the
+mark}. When a buffer is newly created, this marker exists but does
+not point anywhere; this means that the mark ``doesn't exist'' in that
+buffer yet. Subsequent commands can set the mark.
+
+ The mark specifies a position to bound a range of text for many
+commands, such as @code{kill-region} and @code{indent-rigidly}. These
+commands typically act on the text between point and the mark, which
+is called the @dfn{region}. If you are writing a command that
+operates on the region, don't examine the mark directly; instead, use
@code{interactive} with the @samp{r} specification. This provides the
values of point and the mark as arguments to the command in an
interactive call, but permits other Lisp programs to specify arguments
explicitly. @xref{Interactive Codes}.
- Each buffer has a marker which represents the value of the mark in
-that buffer, independent of any other buffer. When a buffer is newly
-created, this marker exists but does not point anywhere. That means
-the mark ``doesn't exist'' in that buffer as yet.
+ Some commands set the mark as a side-effect. Commands should do
+this only if it has a potential use to the user, and never for their
+own internal purposes. For example, the @code{replace-regexp} command
+sets the mark to the value of point before doing any replacements,
+because this enables the user to move back there conveniently after
+the replace is finished.
Once the mark ``exists'' in a buffer, it normally never ceases to
-exist. However, it may become @dfn{inactive}, if Transient Mark mode is
-enabled. The variable @code{mark-active}, which is always buffer-local
-in all buffers, indicates whether the mark is active: non-@code{nil}
-means yes. A command can request deactivation of the mark upon return
-to the editor command loop by setting @code{deactivate-mark} to a
-non-@code{nil} value (but this causes deactivation only if Transient
-Mark mode is enabled).
-
- Certain editing commands that normally apply to text near point,
-work on the region when Transient Mode is enabled and the mark is
+exist. However, it may become @dfn{inactive}, if Transient Mark mode
+is enabled. The buffer-local variable @code{mark-active}, if
+non-@code{nil}, means that the mark is active. A command can call the
+function @code{deactivate-mark} to deactivate the mark directly, or it
+can request deactivation of the mark upon return to the editor command
+loop by setting the variable @code{deactivate-mark} to a
+non-@code{nil} value.
+
+ If Transient Mode is enabled, certain editing commands that normally
+apply to text near point, apply instead to the region when the mark is
active. This is the main motivation for using Transient Mark mode.
-
- Another motivation for using Transient Mark mode is that this mode
-also enables highlighting of the region when the mark is active.
-@xref{Display}.
+(Another is that this enables highlighting of the region when the mark
+is active. @xref{Display}.)
In addition to the mark, each buffer has a @dfn{mark ring} which is a
list of markers containing previous values of the mark. When editing
@@ -450,8 +448,8 @@ or @code{nil} if no mark has ever been set in this buffer.
If Transient Mark mode is enabled, and @code{mark-even-if-inactive} is
@code{nil}, @code{mark} signals an error if the mark is inactive.
However, if @var{force} is non-@code{nil}, then @code{mark} disregards
-inactivity of the mark, and returns the mark position anyway (or
-@code{nil}).
+inactivity of the mark, and returns the mark position (or @code{nil})
+anyway.
@end defun
@defun mark-marker
@@ -481,20 +479,6 @@ it is the mark, it will yield perfectly consistent, but rather odd,
results. We recommend that you not do it!
@end defun
-@ignore
-@deffn Command set-mark-command jump
-If @var{jump} is @code{nil}, this command sets the mark to the value
-of point and pushes the previous value of the mark on the mark ring. The
-message @samp{Mark set} is also displayed in the echo area.
-
-If @var{jump} is not @code{nil}, this command sets point to the value
-of the mark, and sets the mark to the previous saved mark value, which
-is popped off the mark ring.
-
-This function is @emph{only} intended for interactive use.
-@end deffn
-@end ignore
-
@defun set-mark position
This function sets the mark to @var{position}, and activates the mark.
The old value of the mark is @emph{not} pushed onto the mark ring.
@@ -522,14 +506,6 @@ example:
@end example
@end defun
-@c for interactive use only
-@ignore
-@deffn Command exchange-point-and-mark
-This function exchanges the positions of point and the mark.
-It is intended for interactive use.
-@end deffn
-@end ignore
-
@defun push-mark &optional position nomsg activate
This function sets the current buffer's mark to @var{position}, and
pushes a copy of the previous mark onto @code{mark-ring}. If
@@ -553,16 +529,15 @@ The return value is not meaningful.
@end defun
@defopt transient-mark-mode
-@c @cindex Transient Mark mode Redundant
-This variable if non-@code{nil} enables Transient Mark mode, in which
-every buffer-modifying primitive sets @code{deactivate-mark}. The
-consequence of this is that commands that modify the buffer normally
-make the mark inactive.
+This variable, if non-@code{nil}, enables Transient Mark mode. In
+Transient Mark mode, every buffer-modifying primitive sets
+@code{deactivate-mark}. As a consequence, most commands that modify
+the buffer also deactivate the mark.
-Certain commands normally apply to text near point, but in Transient
-Mark mode when the mark is active, they apply to the region instead.
-These commands should call @code{use-region-p} to test whether they
-should operate on the region.
+When Transient Mark mode is enabled and the mark is active, many
+commands that normally apply to the text near point instead apply to
+the region. Such commands should use the function @code{use-region-p}
+to test whether they should operate on the region. @xref{The Region}.
Lisp programs can set @code{transient-mark-mode} to non-@code{nil},
non-@code{t} values to enable Transient Mark mode temporarily. If the
@@ -575,14 +550,6 @@ any subsequent command that moves point and is not shift-translated
action that would normally deactivate the mark.
@end defopt
-@defun use-region-p
-This function returns @code{t} if Transient Mark mode is enabled, the
-mark is active, and there's a valid region in the buffer. Commands
-that operate on the region (instead of on text near point) when
-there's an active mark should use this subroutine to test whether to
-do that.
-@end defun
-
@defopt mark-even-if-inactive
If this is non-@code{nil}, Lisp programs and the Emacs user can use the
mark even when it is inactive. This option affects the behavior of
@@ -619,7 +586,7 @@ The mark is active when this variable is non-@code{nil}. This
variable is always buffer-local in each buffer. Do @emph{not} use the
value of this variable to decide whether a command that normally
operates on text near point should operate on the region instead. Use
-the @code{use-region-p} subroutine (see above) for that.
+the function @code{use-region-p} for that (@pxref{The Region}).
@end defvar
@defvar activate-mark-hook
@@ -630,6 +597,23 @@ also run at the end of a command if the mark is active and it is
possible that the region may have changed.
@end defvar
+@defun handle-shift-selection
+This function implements the ``shift-selection'' behavior of
+point-motion commands. @xref{Shift Selection,,, emacs, The GNU Emacs
+Manual}. It is called automatically by the Emacs command loop
+whenever a command with a @samp{^} character in its @code{interactive}
+spec is invoked, before the command itself is executed
+(@pxref{Interactive Codes, ^}).
+
+If @code{shift-select-mode} is non-@code{nil} and the current command
+was invoked via shift translation (@pxref{Key Sequence Input,
+shift-translation}), this function sets the mark and temporarily
+activates the region, unless the region was already temporarily
+activated in this way. Otherwise, if the region has been activated
+temporarily, it deactivates the mark and restores the variable
+@code{transient-mark-mode} to its earlier value.
+@end defun
+
@defvar mark-ring
The value of this buffer-local variable is the list of saved former
marks of the current buffer, most recent first.
@@ -650,21 +634,6 @@ more marks than this are pushed onto the @code{mark-ring},
@code{push-mark} discards an old mark when it adds a new one.
@end defopt
-@defun handle-shift-selection
-This function checks whether the current command was invoked via shift
-translation (@pxref{Key Sequence Input, shift-translation}), and if
-so, sets the mark and temporarily activates the region, unless the
-region is already temporarily activated in this way. If the command
-was invoked without shift translation and the region is temporarily
-active, or if the region was activated by the mouse, the function
-deactivates the mark.
-
-This function is called whenever a command with a @samp{^} character
-in its @code{interactive} spec (@pxref{Interactive Codes, ^}) is
-invoked while @code{shift-select-mode} (@pxref{Shift Selection,,,
-emacs, The GNU Emacs Manual}) is non-@code{nil}.
-@end defun
-
@node The Region
@section The Region
@cindex region (between point and mark)
@@ -698,6 +667,13 @@ to find the beginning and end of the region. This lets other Lisp
programs specify the bounds explicitly as arguments. (@xref{Interactive
Codes}.)
+@defun use-region-p
+This function returns @code{t} if Transient Mark mode is enabled, the
+mark is active, and there's a valid region in the buffer. Commands
+that operate on the region (instead of on text near point) when
+there's an active mark should use this to test whether to do that.
+@end defun
+
@ignore
arch-tag: b1ba2e7a-a0f3-4c5e-875c-7d8e22d73299
@end ignore