(ielm-prompt-read-only): New user option.

[gnu-emacs] / lispref / symbols.texi

diff --git a/lispref/symbols.texi b/lispref/symbols.texi
index 290b57269ec4d12d8a13c27c17e739a3cd70b55d..632f2cc51745dfb5de58ad6706436b7ab142b6b0 100644 (file)
--- a/lispref/symbols.texi
+++ b/lispref/symbols.texi
@@ -1,7 +1,7 @@
 @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   Free Software Foundation, Inc. 
+@c   Free Software Foundation, Inc.
 @c See the file elisp.texi for copying conditions.
 @setfilename ../info/symbols
 @node Symbols, Evaluation, Hash Tables, Top
@@ -85,14 +85,15 @@ value.  Certain symbols have values that cannot be changed; these
 include @code{nil} and @code{t}, and any symbol whose name starts with
 @samp{:} (those are called @dfn{keywords}).  @xref{Constant Variables}.
 
-  In normal usage, the function cell usually contains a function
+  We often refer to ``the function @code{foo}'' when we really mean
+the function stored in the function cell of the symbol @code{foo}.  We
+make the distinction explicit only when necessary.  In normal
+usage, the function cell usually contains a function
 (@pxref{Functions}) or a macro (@pxref{Macros}), as that is what the
 Lisp interpreter expects to see there (@pxref{Evaluation}).  Keyboard
-macros (@pxref{Keyboard Macros}), keymaps (@pxref{Keymaps}) and autoload
-objects (@pxref{Autoloading}) are also sometimes stored in the function
-cells of symbols.  We often refer to ``the function @code{foo}'' when we
-really mean the function stored in the function cell of the symbol
-@code{foo}.  We make the distinction only when necessary.
+macros (@pxref{Keyboard Macros}), keymaps (@pxref{Keymaps}) and
+autoload objects (@pxref{Autoloading}) are also sometimes stored in
+the function cells of symbols.
 
   The property list cell normally should hold a correctly formatted
 property list (@pxref{Property Lists}), as a number of functions expect
@@ -359,6 +360,7 @@ This variable is the standard obarray for use by @code{intern} and
 @code{read}.
 @end defvar
 
+@anchor{Definition of mapatoms}
 @defun mapatoms function &optional obarray
 This function calls @var{function} once with each symbol in the obarray
 @var{obarray}.  Then it returns @code{nil}.  If @var{obarray} is
@@ -474,7 +476,7 @@ This function returns the property list of @var{symbol}.
 @defun setplist symbol plist
 This function sets @var{symbol}'s property list to @var{plist}.
 Normally, @var{plist} should be a well-formed property list, but this is
-not enforced.
+not enforced.  The return value is @var{plist}.
 
 @smallexample
 (setplist 'foo '(a 1 b (2 3) c nil))
@@ -521,7 +523,7 @@ The @code{put} function returns @var{value}.
 @node Other Plists
 @subsection Property Lists Outside Symbols
 
-  These two functions are useful for manipulating property lists
+  These functions are useful for manipulating property lists
 that are stored in places other than symbols:
 
 @defun plist-get plist property
@@ -558,3 +560,26 @@ in the place where you got @var{plist}.  For example,
   (setplist symbol
             (plist-put (symbol-plist symbol) prop value)))
 @end example
+
+@defun lax-plist-get plist property
+Like @code{plist-get} except that it compares properties
+using @code{equal} instead of @code{eq}.
+@end defun
+
+@defun lax-plist-put plist property value
+Like @code{plist-put} except that it compares properties
+using @code{equal} instead of @code{eq}.
+@end defun
+
+@defun plist-member plist property
+@tindex plist-member
+This returns non-@code{nil} if @var{plist} contains the given
+@var{property}.  Unlike @code{plist-get}, this allows you to distinguish
+between a missing property and a property with the value @code{nil}.
+The value is actually the tail of @var{plist} whose @code{car} is
+@var{property}.
+@end defun
+
+@ignore
+   arch-tag: 8750b7d2-de4c-4923-809a-d35fc39fd8ce
+@end ignore