-@c -*-texinfo-*-
+@c -*-coding: iso-latin-1-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 2001, 2002, 2003, 2004,
-@c 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+@c Copyright (C) 1990-1994, 2001-2012 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
-@setfilename ../../info/intro
@node Introduction, Lisp Data Types, Top, Top
@comment node-name, next, previous, up
Dozens of Lisp implementations have been built over the years, each
with its own idiosyncrasies. Many of them were inspired by Maclisp,
which was written in the 1960s at MIT's Project MAC. Eventually the
-implementors of the descendants of Maclisp came together and developed a
+implementers of the descendants of Maclisp came together and developed a
standard for Lisp systems, called Common Lisp. In the meantime, Gerry
Sussman and Guy Steele at MIT developed a simplified but very powerful
dialect of Lisp, called Scheme.
@cindex @code{nil}
@cindex false
- In Lisp, the symbol @code{nil} has three separate meanings: it
+ In Emacs Lisp, the symbol @code{nil} has three separate meanings: it
is a symbol with the name @samp{nil}; it is the logical truth value
@var{false}; and it is the empty list---the list of zero elements.
When used as a variable, @code{nil} always has the value @code{nil}.
Variables}.
@defun booleanp object
-Return non-nil if @var{object} is one of the two canonical boolean
-values: @code{t} or @code{nil}.
+Return non-@code{nil} if @var{object} is one of the two canonical
+boolean values: @code{t} or @code{nil}.
@end defun
@node Evaluation Notation
Many of the examples in this manual print text when they are
evaluated. If you execute example code in a Lisp Interaction buffer
-(such as the buffer @samp{*scratch*}), the printed text is inserted into
+(such as the buffer @file{*scratch*}), the printed text is inserted into
the buffer. If you execute the example by other means (such as by
evaluating the function @code{eval-region}), the printed text is
displayed in the echo area.
interactively; macros process their arguments differently from functions
(the arguments are not evaluated), but are presented the same way.
- Special form descriptions use a more complex notation to specify
-optional and repeated arguments because they can break the argument
-list down into separate arguments in more complicated ways.
-@samp{@r{[}@var{optional-arg}@r{]}} means that @var{optional-arg} is
-optional and @samp{@var{repeated-args}@dots{}} stands for zero or more
-arguments. Parentheses are used when several arguments are grouped into
-additional levels of list structure. Here is an example:
+ The descriptions of macros and special forms use a more complex
+notation to specify optional and repeated arguments, because they can
+break the argument list down into separate arguments in more
+complicated ways. @samp{@r{[}@var{optional-arg}@r{]}} means that
+@var{optional-arg} is optional and @samp{@var{repeated-args}@dots{}}
+stands for zero or more arguments. Parentheses are used when several
+arguments are grouped into additional levels of list structure. Here
+is an example:
@defspec count-loop (@var{var} [@var{from} @var{to} [@var{inc}]]) @var{body}@dots{}
This imaginary special form implements a loop that executes the
@smallexample
@group
(emacs-version)
- @result{} "GNU Emacs 20.3.5 (i486-pc-linux-gnulibc1, X toolkit)
- of Sat Feb 14 1998 on psilocin.gnu.org"
+ @result{} "GNU Emacs 23.1 (i686-pc-linux-gnu, GTK+ Version 2.14.4)
+ of 2009-06-01 on cyd.mit.edu"
@end group
@end smallexample
If @var{here} is non-@code{nil}, it inserts the text in the buffer
-before point, and returns @code{nil}. Called interactively, the
-function prints the same information in the echo area, but giving a
-prefix argument makes @var{here} non-@code{nil}.
+before point, and returns @code{nil}. When this function is called
+interactively, it prints the same information in the echo area, but
+giving a prefix argument makes @var{here} non-@code{nil}.
@end deffn
@defvar emacs-build-time
-The value of this variable indicates the time at which Emacs was built
-at the local site. It is a list of three integers, like the value
-of @code{current-time} (@pxref{Time of Day}).
+The value of this variable indicates the time at which Emacs was
+built. It is a list of three integers, like the value of
+@code{current-time} (@pxref{Time of Day}).
@example
@group
emacs-build-time
- @result{} (13623 62065 344633)
+ @result{} (18846 52016 156039)
@end group
@end example
@end defvar
@defvar emacs-version
The value of this variable is the version of Emacs being run. It is a
-string such as @code{"20.3.1"}. The last number in this string is not
-really part of the Emacs release version number; it is incremented each
-time you build Emacs in any given directory. A value with four numeric
-components, such as @code{"20.3.9.1"}, indicates an unreleased test
-version.
+string such as @code{"23.1.1"}. The last number in this string is not
+really part of the Emacs release version number; it is incremented
+each time you build Emacs in any given directory. A value with four
+numeric components, such as @code{"22.0.91.1"}, indicates an
+unreleased test version.
@end defvar
The following two variables have existed since Emacs version 19.23:
@defvar emacs-major-version
The major version number of Emacs, as an integer. For Emacs version
-20.3, the value is 20.
+23.1, the value is 23.
@end defvar
@defvar emacs-minor-version
The minor version number of Emacs, as an integer. For Emacs version
-20.3, the value is 3.
+23.1, the value is 1.
@end defvar
@node Acknowledgements
@section Acknowledgements
- This manual was written by Robert Krawitz, Bil Lewis, Dan LaLiberte,
-Richard@tie{}M. Stallman and Chris Welty, the volunteers of the GNU
-manual group, in an effort extending over several years.
+ This manual was originally written by Robert Krawitz, Bil Lewis, Dan
+LaLiberte, Richard@tie{}M. Stallman and Chris Welty, the volunteers of
+the GNU manual group, in an effort extending over several years.
Robert@tie{}J. Chassell helped to review and edit the manual, with the
support of the Defense Advanced Research Projects Agency, ARPA Order
6082, arranged by Warren@tie{}A. Hunt, Jr.@: of Computational Logic,
-Inc.
-
- Corrections were supplied by Karl Berry, Jim Blandy, Bard Bloom,
-Stephane Boucher, David Boyes, Alan Carroll, Richard Davis, Lawrence
-R. Dodd, Peter Doornbosch, David A. Duff, Chris Eich, Beverly
-Erlebacher, David Eckelkamp, Ralf Fassel, Eirik Fuller, Stephen Gildea,
-Bob Glickstein, Eric Hanchrow, George Hartzell, Nathan Hess, Masayuki
-Ida, Dan Jacobson, Jak Kirman, Bob Knighten, Frederick M. Korz, Joe
-Lammens, Glenn M. Lewis, K. Richard Magill, Brian Marick, Roland
-McGrath, Skip Montanaro, John Gardiner Myers, Thomas A. Peterson,
-Francesco Potorti, Friedrich Pukelsheim, Arnold D. Robbins, Raul
-Rockwell, Per Starb@"ack, Shinichirou Sugou, Kimmo Suominen, Edward Tharp,
-Bill Trost, Rickard Westman, Jean White, Matthew Wilding, Carl Witty,
-Dale Worley, Rusty Wright, and David D. Zuhn.
-
-@ignore
- arch-tag: d156593f-82f8-4708-a844-204e48f7f2aa
-@end ignore
+Inc. Additional sections have since been written by Miles Bader, Lars
+Brinkhoff, Chong Yidong, Kenichi Handa, Lute Kamstra, Juri Linkov,
+Glenn Morris, Thien-Thi Nguyen, Dan Nicolaescu, Martin Rudalics, Kim
+F. Storm, Luc Teirlinck, and Eli Zaretskii, and others.
+
+ Corrections were supplied by Drew Adams, Juanma Barranquero, Karl
+Berry, Jim Blandy, Bard Bloom, Stephane Boucher, David Boyes, Alan
+Carroll, Richard Davis, Lawrence R. Dodd, Peter Doornbosch, David
+A. Duff, Chris Eich, Beverly Erlebacher, David Eckelkamp, Ralf Fassel,
+Eirik Fuller, Stephen Gildea, Bob Glickstein, Eric Hanchrow, Jesper
+Harder, George Hartzell, Nathan Hess, Masayuki Ida, Dan Jacobson, Jak
+Kirman, Bob Knighten, Frederick M. Korz, Joe Lammens, Glenn M. Lewis,
+K. Richard Magill, Brian Marick, Roland McGrath, Stefan Monnier, Skip
+Montanaro, John Gardiner Myers, Thomas A. Peterson, Francesco Potorti,
+Friedrich Pukelsheim, Arnold D. Robbins, Raul Rockwell, Jason Rumney,
+Per Starbäck, Shinichirou Sugou, Kimmo Suominen, Edward Tharp, Bill
+Trost, Rickard Westman, Jean White, Eduard Wiebe, Matthew Wilding,
+Carl Witty, Dale Worley, Rusty Wright, and David D. Zuhn.
+
+ For a more complete list of contributors, please see the relevant
+ChangeLog file in the Emacs sources.