Merge from emacs-24; up to 2014-06-11T19:33:14Z!rgm@gnu.org

[bpt/emacs.git] / doc / lispref / customize.texi

diff --git a/doc/lispref/customize.texi b/doc/lispref/customize.texi
index e926030..0c6497f 100644 (file)
--- a/doc/lispref/customize.texi
+++ b/doc/lispref/customize.texi
@@ -1,6 +1,6 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1997-2013 Free Software Foundation, Inc.
+@c Copyright (C) 1997-2014 Free Software Foundation, Inc.
 @c See the file elisp.texi for copying conditions.
 @node Customization
 @chapter Customization Settings
@@ -287,13 +287,17 @@ customizable variable).  You should not quote @var{option}.
 
 The argument @var{standard} is an expression that specifies the
 standard value for @var{option}.  Evaluating the @code{defcustom} form
-evaluates @var{standard}, but does not necessarily install the
-standard value.  If @var{option} already has a default value,
-@code{defcustom} does not change it.  If the user has saved a
-customization for @var{option}, @code{defcustom} installs the user's
-customized value as @var{option}'s default value.  If neither of those
-cases applies, @code{defcustom} installs the result of evaluating
-@var{standard} as the default value.
+evaluates @var{standard}, but does not necessarily bind the option to
+that value.  If @var{option} already has a default value, it is left
+unchanged.  If the user has already saved a customization for
+@var{option}, the user's customized value is installed as the default
+value.  Otherwise, the result of evaluating @var{standard} is
+installed as the default value.
+
+Like @code{defvar}, this macro marks @code{option} as a special
+variable, meaning that it should always be dynamically bound.  If
+@var{option} is already lexically bound, that lexical binding remains
+in effect until the binding construct exits.  @xref{Variable Scoping}.
 
 The expression @var{standard} can be evaluated at various other times,
 too---whenever the customization facility needs to know @var{option}'s
@@ -349,8 +353,9 @@ option when using the Customize interface.  The function
 @var{setfunction} should take two arguments, a symbol (the option
 name) and the new value, and should do whatever is necessary to update
 the value properly for this option (which may not mean simply setting
-the option as a Lisp variable).  The default for @var{setfunction} is
-@code{set-default}.
+the option as a Lisp variable); preferably, though, it should not
+modify its value argument destructively.  The default for
+@var{setfunction} is @code{set-default}.
 
 If you specify this keyword, the variable's documentation string
 should describe how to do the same job in hand-written Lisp code.
@@ -567,7 +572,7 @@ The value must be an integer.
 The value must be a number (floating point or integer).
 
 @item float
-The value must be a floating point number.
+The value must be floating point.
 
 @item string
 The value must be a string.  The customization buffer shows the string
@@ -1428,6 +1433,17 @@ loaded into Emacs, whether or not the theme is enabled).  Otherwise,
 it returns @code{nil}.
 @end defun
 
+@defvar custom-known-themes
+The value of this variable is a list of themes loaded into Emacs.
+Each theme is represented by a Lisp symbol (the theme name).  The
+default value of this variable is a list containing two ``dummy''
+themes: @code{(user changed)}.  The @code{changed} theme stores
+settings made before any Custom themes are applied (e.g., variables
+set outside of Customize).  The @code{user} theme stores settings the
+user has customized and saved.  Any additional themes declared with
+the @code{deftheme} macro are added to the front of this list.
+@end defvar
+
 @deffn Command load-theme theme &optional no-confirm no-enable
 This function loads the Custom theme named @var{theme} from its source
 file, looking for the source file in the directories specified by the