@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) 1997-2015 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@node Customization
@chapter Customization Settings
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
@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.
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
@node Defining New Types
@subsection Defining New Types
+@cindex customization types, define new
+@cindex define new customization types
In the previous sections we have described how to construct elaborate
type specifications for @code{defcustom}. In some cases you may want
@node Applying Customizations
@section Applying Customizations
+@cindex applying customizations
The following functions are responsible for installing the user's
customization settings for variables and faces, respectively. When
@node Custom Themes
@section Custom Themes
+@cindex custom themes
@dfn{Custom themes} are collections of settings that can be enabled
or disabled as a unit. @xref{Custom Themes,,, emacs, The GNU Emacs
Manual}. Each Custom theme is defined by an Emacs Lisp source file,
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