diff man/lispref/symbols.texi @ 412:697ef44129c6 r21-2-14

Import from CVS: tag r21-2-14
author cvs
date Mon, 13 Aug 2007 11:20:41 +0200
parents 74fd4e045ea6
children
line wrap: on
line diff
--- a/man/lispref/symbols.texi	Mon Aug 13 11:19:22 2007 +0200
+++ b/man/lispref/symbols.texi	Mon Aug 13 11:20:41 2007 +0200
@@ -378,14 +378,14 @@
 @cindex plist, symbol
 
   A @dfn{property list} (@dfn{plist} for short) is a list of paired
-elements, often stored in the property list cell of a symbol.  Each of
-the pairs associates a property name (usually a symbol) with a property
-or value.  Property lists are generally used to record information about
-a symbol, such as its documentation as a variable, the name of the file
+elements stored in the property list cell of a symbol.  Each of the
+pairs associates a property name (usually a symbol) with a property or
+value.  Property lists are generally used to record information about a
+symbol, such as its documentation as a variable, the name of the file
 where it was defined, or perhaps even the grammatical class of the
 symbol (representing a word) in a language-understanding system.
 
-  Some objects which are not symbols also have property lists associated
+  Many objects other than symbols can have property lists associated
 with them, and XEmacs provides a full complement of functions for
 working with property lists.  @xref{Property Lists}.
 
@@ -405,7 +405,7 @@
 @menu
 * Plists and Alists::           Comparison of the advantages of property
                                   lists and association lists.
-* Object Plists::               Functions to access objects' property lists.
+* Symbol Plists::               Functions to access symbols' property lists.
 * Other Plists::                Accessing property lists stored elsewhere.
 @end menu
 
@@ -441,22 +441,13 @@
 are pushed on the front of the list and later discarded; this is not
 possible with a property list.
 
-@node Object Plists
-@subsection Property List Functions for Objects
-
-Once upon a time, only symbols had property lists.  Now, several other
-object types, including strings, extents, faces and glyphs also have
-property lists.
+@node Symbol Plists
+@subsection Property List Functions for Symbols
 
 @defun symbol-plist symbol
 This function returns the property list of @var{symbol}.
 @end defun
 
-@defun object-plist object
-This function returns the property list of @var{object}.  If
-@var{object} is a symbol, this is identical to @code{symbol-plist}.
-@end defun
-
 @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
@@ -472,24 +463,23 @@
 For symbols in special obarrays, which are not used for ordinary
 purposes, it may make sense to use the property list cell in a
 nonstandard fashion; in fact, the abbrev mechanism does so
-(@pxref{Abbrevs}).  But generally, its use is discouraged.  Use
-@code{put} instead.  @code{setplist} can only be used with symbols, not
-other object types.
+(@pxref{Abbrevs}).
 @end defun
 
-@defun get object property &optional default
+@defun get symbol property
 This function finds the value of the property named @var{property} in
-@var{object}'s property list.  If there is no such property,
-@code{default} (which itself defaults to @code{nil}) is returned.
+@var{symbol}'s property list.  If there is no such property, @code{nil}
+is returned.  Thus, there is no distinction between a value of
+@code{nil} and the absence of the property.
 
-@var{property} is compared with the existing properties using @code{eq},
-so any object is a legitimate property.
+The name @var{property} is compared with the existing property names
+using @code{eq}, so any object is a legitimate property.
 
 See @code{put} for an example.
 @end defun
 
-@defun put object property value
-This function puts @var{value} onto @var{object}'s property list under
+@defun put symbol property value
+This function puts @var{value} onto @var{symbol}'s property list under
 the property name @var{property}, replacing any previous property value.
 The @code{put} function returns @var{value}.
 
@@ -500,24 +490,13 @@
      @result{} (a buzzing little bug)
 (get 'fly 'verb)
      @result{} transitive
-(object-plist 'fly)
+(symbol-plist 'fly)
      @result{} (verb transitive noun (a buzzing little bug))
 @end smallexample
 @end defun
 
-@defun remprop object property
-This function removes the entry for @var{property} from the property
-list of @var{object}.  It returns @code{t} if the property was
-indeed found and removed, or @code{nil} if there was no such property.
-(This function was probably omitted from Emacs originally because,
-since @code{get} did not allow a @var{default}, it was very difficult
-to distinguish between a missing property and a property whose value
-was @code{nil}; thus, setting a property to @code{nil} was close
-enough to @code{remprop} for most purposes.)
-@end defun
-
 @node Other Plists
-@subsection Property Lists Not Associated with Objects
+@subsection Property Lists Outside Symbols
 
   These functions are useful for manipulating property lists
 that are stored in places other than symbols: