@setfilename ../info/cl
@settitle Common Lisp Extensions
-@dircategory Emacs
-@direntry
-* CL: (cl). Partial Common Lisp support for Emacs Lisp.
-@end direntry
+@copying
+This file documents the GNU Emacs Common Lisp emulation package.
-@iftex
-@finalout
-@end iftex
+Copyright (C) 1993, 2002 Free Software Foundation, Inc.
-@ifinfo
-This file documents the GNU Emacs Common Lisp emulation package.
+@quotation
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.1 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with the Front-Cover texts being ``A GNU
+Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
+license is included in the section entitled ``GNU Free Documentation
+License'' in the Emacs manual.
-Copyright (C) 1993 Free Software Foundation, Inc.
+(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
+this GNU Manual, like GNU software. Copies published by the Free
+Software Foundation raise funds for GNU development.''
-Permission is granted to make and distribute verbatim copies of this
-manual provided the copyright notice and this permission notice are
-preserved on all copies.
+This document is part of a collection distributed under the GNU Free
+Documentation License. If you want to distribute this document
+separately from the collection, you can do so by adding a copy of the
+license to the document, as described in section 6 of the license.
+@end quotation
+@end copying
-@ignore
-Permission is granted to process this file through TeX and print the
-results, provided the printed document carries copying permission notice
-identical to this one except for the removal of this paragraph (this
-paragraph not being relevant to the printed manual).
+@dircategory Emacs
+@direntry
+* CL: (cl). Partial Common Lisp support for Emacs Lisp.
+@end direntry
-@end ignore
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided also that the
-section entitled ``GNU General Public License'' is included exactly as
-in the original, and provided that the entire resulting derived work is
-distributed under the terms of a permission notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that the section entitled ``GNU General Public License'' may be
-included in a translation approved by the author instead of in the
-original English.
-@end ifinfo
+@finalout
@titlepage
@sp 6
@center Dave Gillespie
@center daveg@@synaptics.com
@page
-
@vskip 0pt plus 1filll
-Copyright @copyright{} 1993 Free Software Foundation, Inc.
-
-Permission is granted to make and distribute verbatim copies of
-this manual provided the copyright notice and this permission notice
-are preserved on all copies.
-
-@ignore
-Permission is granted to process this file through TeX and print the
-results, provided the printed document carries copying permission notice
-identical to this one except for the removal of this paragraph (this
-paragraph not being relevant to the printed manual).
-
-@end ignore
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided also that the
-section entitled ``GNU General Public License'' is included exactly as
-in the original, and provided that the entire resulting derived work is
-distributed under the terms of a permission notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that the section entitled ``GNU General Public License'' may be
-included in a translation approved by the author instead of in the
-original English.
+@insertcopying
@end titlepage
@node Top, Overview, (dir), (dir)
-@chapter Common Lisp Extensions
+@chapter Introduction
@noindent
This document describes a set of Emacs Lisp facilities borrowed from
@end menu
@node Overview, Program Structure, Top, Top
-@ifinfo
+@ifnottex
@chapter Overview
-@end ifinfo
-@iftex
-@section Overview
-@end iftex
+@end ifnottex
@noindent
Common Lisp is a huge language, and Common Lisp systems tend to be
implementation of Common Lisp, @dfn{CL} adds enough functionality
to make Emacs Lisp programming significantly more convenient.
+@strong{Please note:} the @dfn{CL} functions are not standard parts of
+the Emacs Lisp name space, so it is legitimate for users to define
+them with other, conflicting meanings. To avoid conflicting with
+those user activities, we have a policy that packages installed in
+Emacs must not load @dfn{CL} at run time. (It is ok for them to load
+@dfn{CL} at compile time only, with @code{eval-when-compile}, and use
+the macros it provides.) If you are writing packages that you plan to
+distribute and invite widespread use for, you might want to observe
+the same rule.
+
Some Common Lisp features have been omitted from this package
for various reasons:
member* assoc* rassoc* get*
remove* delete* mapcar* sort*
floor* ceiling* truncate* round*
-mod* rem* random* last*
+mod* rem* random*
@end example
Internal function and variable names in the package are prefixed
@example
eql floatp-safe endp
evenp oddp plusp minusp
-butlast nbutlast caaar .. cddddr
+caaar .. cddddr
list* ldiff rest first .. tenth
copy-list subst mapcar* [2]
adjoin [3] acons pairlis pop [4]
keep both @code{find-thing} and @code{member*} from complaining
about each others' keywords in the arguments.
-As a (significant) performance optimization, this package
-implements the scan for keyword arguments by calling @code{memq}
-to search for keywords in a ``rest'' argument. Technically
-speaking, this is incorrect, since @code{memq} looks at the
-odd-numbered values as well as the even-numbered keywords.
-The net effect is that if you happen to pass a keyword symbol
-as the @emph{value} of another keyword argument, where that
-keyword symbol happens to equal the name of a valid keyword
-argument of the same function, then the keyword parser will
-become confused. This minor bug can only affect you if you
-use keyword symbols as general-purpose data in your program;
-this practice is strongly discouraged in Emacs Lisp.
-
The fifth section of the argument list consists of @dfn{auxiliary
variables}. These are not really arguments at all, but simply
variables which are bound to @code{nil} or to the specified
The following Emacs-specific functions are also @code{setf}-able.
@smallexample
-buffer-file-name marker-position
-buffer-modified-p match-data
-buffer-name mouse-position
-buffer-string overlay-end
-buffer-substring overlay-get
-current-buffer overlay-start
-current-case-table point
-current-column point-marker
-current-global-map point-max
-current-input-mode point-min
-current-local-map process-buffer
-current-window-configuration process-filter
-default-file-modes process-sentinel
-default-value read-mouse-position
-documentation-property screen-height
-extent-data screen-menubar
-extent-end-position screen-width
-extent-start-position selected-window
-face-background selected-screen
-face-background-pixmap selected-frame
-face-font standard-case-table
-face-foreground syntax-table
-face-underline-p window-buffer
-file-modes window-dedicated-p
-frame-height window-display-table
-frame-parameters window-height
-frame-visible-p window-hscroll
-frame-width window-point
-get-register window-start
-getenv window-width
-global-key-binding x-get-cut-buffer
-keymap-parent x-get-cutbuffer
+buffer-file-name marker-position
+buffer-modified-p match-data
+buffer-name mouse-position
+buffer-string overlay-end
+buffer-substring overlay-get
+current-buffer overlay-start
+current-case-table point
+current-column point-marker
+current-global-map point-max
+current-input-mode point-min
+current-local-map process-buffer
+current-window-configuration process-filter
+default-file-modes process-sentinel
+default-value read-mouse-position
+documentation-property screen-height
+extent-data screen-menubar
+extent-end-position screen-width
+extent-start-position selected-window
+face-background selected-screen
+face-background-pixmap selected-frame
+face-font standard-case-table
+face-foreground syntax-table
+face-underline-p window-buffer
+file-modes window-dedicated-p
+frame-height window-display-table
+frame-parameters window-height
+frame-visible-p window-hscroll
+frame-width window-point
+get-register window-start
+getenv window-width
+global-key-binding x-get-cut-buffer
+keymap-parent x-get-cutbuffer
local-key-binding x-get-secondary-selection
-mark x-get-selection
-mark-marker
+mark x-get-selection
+mark-marker
@end smallexample
Most of these have directly corresponding ``set'' functions, like
Because they are implemented in terms of Emacs Lisp @code{catch}
and @code{throw}, blocks have the same overhead as actual
@code{catch} constructs (roughly two function calls). However,
-the optimizing byte compiler will optimize away the @code{catch}
+the optimizing byte compiler will optimize away the @code{catch}
if the block does
not in fact contain any @code{return} or @code{return-from} calls
that jump to it. This means that @code{do} loops and @code{defun*}
(defsubst foo (...) ...) ; instead of defun
@end example
-@strong{Note:} This declaration remains in effect after the
+@strong{Please note:} this declaration remains in effect after the
containing source file is done. It is correct to use it to
request that a function you have defined should be inlined,
but it is impolite to use it to request inlining of an external
* Predicates on Numbers:: `plusp', `oddp', `floatp-safe', etc.
* Numerical Functions:: `abs', `floor*', etc.
* Random Numbers:: `random*', `make-random-state'
-* Implementation Parameters:: `most-positive-fixnum', `most-positive-float'
+* Implementation Parameters:: `most-positive-float'
@end menu
@iftex
@noindent
This package defines several useful constants having to with numbers.
-@defvar most-positive-fixnum
-This constant equals the largest value a Lisp integer can hold.
-It is typically @code{2^23-1} or @code{2^25-1}.
-@end defvar
-
-@defvar most-negative-fixnum
-This constant equals the smallest (most negative) value a Lisp
-integer can hold.
-@end defvar
-
The following parameters have to do with floating-point numbers.
This package determines their values by exercising the computer's
floating-point arithmetic in various ways. Because this operation
@end defun
@defun mapc function seq &rest more-seqs
-This function is like @code{mapcar*}, except that the values
-returned by @var{function} are ignored and thrown away rather
-than being collected into a list. The return value of @code{mapc}
-is @var{seq}, the first sequence.
+This function is like @code{mapcar*}, except that the values returned
+by @var{function} are ignored and thrown away rather than being
+collected into a list. The return value of @code{mapc} is @var{seq},
+the first sequence. This function is more general than the Emacs
+primitive @code{mapc}.
@end defun
@defun mapl function list &rest more-lists
The functions described here operate on lists.
@menu
-* List Functions:: `caddr', `first', `last*', `list*', etc.
+* List Functions:: `caddr', `first', `list*', etc.
* Substitution of Expressions:: `subst', `sublis', etc.
* Lists as Sets:: `member*', `adjoin', `union', etc.
* Association Lists:: `assoc*', `rassoc*', `acons', `pairlis'
@code{length} function would get stuck if given a circular list.)
@end defun
-@defun last* x &optional n
-This function returns the last cons, or the @var{n}th-to-last cons,
-of the list @var{x}. If @var{n} is omitted it defaults to 1.
-The ``last cons'' means the first cons cell of the list whose
-@code{cdr} is not another cons cell. (For normal lists, the
-@code{cdr} of the last cons will be @code{nil}.) This function
-returns @code{nil} if @var{x} is @code{nil} or shorter than
-@var{n}. Note that the last @emph{element} of the list is
-@code{(car (last @var{x}))}.
-
-The Emacs function @code{last} does the same thing
-except that it does not handle the optional argument @var{n}.
-@end defun
-
-@defun butlast x &optional n
-This function returns the list @var{x} with the last element,
-or the last @var{n} elements, removed. If @var{n} is greater
-than zero it makes a copy of the list so as not to damage the
-original list. In general, @code{(append (butlast @var{x} @var{n})
-(last @var{x} @var{n}))} will return a list equal to @var{x}.
-@end defun
-
-@defun nbutlast x &optional n
-This is a version of @code{butlast} that works by destructively
-modifying the @code{cdr} of the appropriate element, rather than
-making a copy of the list.
-@end defun
-
@defun list* arg &rest others
This function constructs a list of its arguments. The final
argument becomes the @code{cdr} of the last cell constructed.
Common Lisp compliance has in general not been sacrificed for the
sake of efficiency. A few exceptions have been made for cases
where substantial gains were possible at the expense of marginal
-incompatibility. One example is the use of @code{memq} (which is
-treated very efficiently by the byte-compiler) to scan for keyword
-arguments; this can become confused in rare cases when keyword
-symbols are used as both keywords and data values at once. This
-is extremely unlikely to occur in practical code, and the use of
-@code{memq} allows functions with keyword arguments to be nearly
-as fast as functions that use @code{&optional} arguments.
+incompatibility.
The Common Lisp standard (as embodied in Steele's book) uses the
phrase ``it is an error if'' to indicate a situation which is not
keyword does not work in @code{defmacro} argument lists (except
inside recursive argument lists).
-In order to allow an efficient implementation, keyword arguments use
-a slightly cheesy parser which may be confused if a keyword symbol
-is passed as the @emph{value} of another keyword argument.
-(Specifically, @code{(memq :@var{keyword} @var{rest-of-arguments})}
-is used to scan for @code{:@var{keyword}} among the supplied
-keyword arguments.)
-
The @code{eql} and @code{equal} predicates do not distinguish
between IEEE floating-point plus and minus zero. The @code{equalp}
predicate has several differences with Common Lisp; @pxref{Predicates}.
@setchapternewpage odd
@contents
@bye
+
+@ignore
+ arch-tag: b61e7200-3bfa-4a70-a9d3-095e152696f8
+@end ignore