From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Mon, 1 May 2006 13:30:59 +0000 (+0000)
Subject: (nil and t): Add `booleanp' predicate.
X-Git-Tag: emacs-pretest-22.0.90~2866
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=0ccc83d9d3e17856aa962e7748277cafcf76d921;p=emacs.git

(nil and t): Add `booleanp' predicate.
---

diff --git a/lispref/intro.texi b/lispref/intro.texi
index b2294be4c2d..61dfca64b97 100644
--- a/lispref/intro.texi
+++ b/lispref/intro.texi
@@ -212,6 +212,11 @@ to use them as constants in a program.  An attempt to change their
 values results in a @code{setting-constant} error.  @xref{Constant
 Variables}.
 
+@defun booleanp object
+Return non-nil iff @var{object} is one of the two canonical boolean
+values: @code{t} or @code{nil}.
+@end defun
+
 @node Evaluation Notation
 @subsection Evaluation Notation
 @cindex evaluation notation