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diff --git a/lispref/intro.texi b/lispref/intro.texi index 6d2d63981eb..d6471a4ced1 100644 --- a/lispref/intro.texi +++ b/lispref/intro.texi @@ -418,12 +418,17 @@ closely integrated with the editing facilities; thus, editing commands are functions that can also conveniently be called from Lisp programs, and parameters for customization are ordinary Lisp variables. - This manual describes Emacs Lisp, presuming considerable familiarity -with the use of Emacs for editing. (See @cite{The GNU Emacs Manual} -for this basic information.) Generally speaking, the earlier chapters -describe features of Emacs Lisp that have counterparts in many -programming languages, and later chapters describe features that are -peculiar to Emacs Lisp or relate specifically to editing. + This manual attempts to be a full description of Emacs Lisp. For a +beginner's introduction to Emacs Lisp, see @cite{An Introduction to +Emacs Lisp Programming}, by Bob Chassell, also published by the Free +Software Foundation. This manual presumes considerable familiarity with +the use of Emacs for editing; see @cite{The GNU Emacs Manual} for this +basic information. + + Generally speaking, the earlier chapters describe features of Emacs +Lisp that have counterparts in many programming languages, and later +chapters describe features that are peculiar to Emacs Lisp or relate +specifically to editing. This is edition 2.5. @@ -431,6 +436,7 @@ peculiar to Emacs Lisp or relate specifically to editing. * Caveats:: Flaws and a request for help. * Lisp History:: Emacs Lisp is descended from Maclisp. * Conventions:: How the manual is formatted. +* Version Info:: Which Emacs version is running? * Acknowledgements:: The authors, editors, and sponsors of this manual. @end menu @@ -474,7 +480,7 @@ which you are criticizing. Please mail comments and corrections to @example -bug-lisp-manual@@prep.ai.mit.edu +bug-lisp-manual@@gnu.org @end example @noindent @@ -483,7 +489,7 @@ apply the corrections. Months, and sometimes years, go by between updates. So please attach no significance to the lack of a reply---your mail @emph{will} be acted on in due time. If you want to contact the Emacs maintainers more quickly, send mail to -@code{bug-gnu-emacs@@prep.ai.mit.edu}. +@code{bug-gnu-emacs@@gnu.org}. @display --Bil Lewis, Dan LaLiberte, Richard Stallman @@ -493,33 +499,38 @@ Emacs maintainers more quickly, send mail to @section Lisp History @cindex Lisp history - Lisp (LISt Processing language) was first developed in the late 1950's + Lisp (LISt Processing language) was first developed in the late 1950s at the Massachusetts Institute of Technology for research in artificial -intelligence. The great power of the Lisp language makes it superior +intelligence. The great power of the Lisp language makes it ideal for other purposes as well, such as writing editing commands. @cindex Maclisp @cindex Common Lisp 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 1960's at MIT's Project MAC. Eventually the +which was written in the 1960s at MIT's Project MAC. Eventually the implementors of the descendants of Maclisp came together and developed a -standard for Lisp systems, called Common Lisp. In the mean time, Gerry +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. GNU Emacs Lisp is largely inspired by Maclisp, and a little by Common Lisp. If you know Common Lisp, you will notice many similarities. -However, many of the features of Common Lisp have been omitted or +However, many features of Common Lisp have been omitted or simplified in order to reduce the memory requirements of GNU Emacs. Sometimes the simplifications are so drastic that a Common Lisp user might be very confused. We will occasionally point out how GNU Emacs Lisp differs from Common Lisp. If you don't know Common Lisp, don't worry about it; this manual is self-contained. +@pindex cl + A certain amount of Common Lisp emulation is available via the +@file{cl} library @xref{Top,, Common Lisp Extension, cl, Common Lisp +Extensions}. + Emacs Lisp is not at all influenced by Scheme; but the GNU project has -an implementation of Scheme, called Guile. We use Guile for -extensibility in all new GNU software that calls for extensibility. +an implementation of Scheme, called Guile. We use Guile in all new GNU +software that calls for extensibility. @node Conventions @section Conventions @@ -531,23 +542,22 @@ manual. You may want to skip this section and refer back to it later. * Some Terms:: Explanation of terms we use in this manual. * nil and t:: How the symbols @code{nil} and @code{t} are used. * Evaluation Notation:: The format we use for examples of evaluation. -* Printing Notation:: The format we use for examples that print output. +* Printing Notation:: The format we use when examples print text. * Error Messages:: The format we use for examples of errors. * Buffer Text Notation:: The format we use for buffer contents in examples. * Format of Descriptions:: Notation for describing functions, variables, etc. -* Version Info:: Which Emacs version is running? @end menu @node Some Terms @subsection Some Terms Throughout this manual, the phrases ``the Lisp reader'' and ``the Lisp -printer'' are used to refer to those routines in Lisp that convert -textual representations of Lisp objects into actual Lisp objects, and vice +printer'' refer to those routines in Lisp that convert textual +representations of Lisp objects into actual Lisp objects, and vice versa. @xref{Printed Representation}, for more details. You, the person reading this manual, are thought of as ``the programmer'' and are -addressed as ``you''. ``The user'' is the person who uses Lisp programs, -including those you write. +addressed as ``you''. ``The user'' is the person who uses Lisp +programs, including those you write. @cindex fonts Examples of Lisp code appear in this font or form: @code{(list 1 2 @@ -590,7 +600,8 @@ in Lisp programs also. is considered to be @var{true}. However, @code{t} is the preferred way to represent the truth value @var{true}. When you need to choose a value which represents @var{true}, and there is no other basis for -choosing, use @code{t}. The symbol @code{t} always has value @code{t}. +choosing, use @code{t}. The symbol @code{t} always has the value +@code{t}. In Emacs Lisp, @code{nil} and @code{t} are special symbols that always evaluate to themselves. This is so that you do not need to quote them @@ -618,7 +629,7 @@ You can read this as ``@code{(car '(1 2))} evaluates to 1''. When a form is a macro call, it expands into a new form for Lisp to evaluate. We show the result of the expansion with -@samp{@expansion{}}. We may or may not show the actual result of the +@samp{@expansion{}}. We may or may not show the result of the evaluation of the expanded form. @example @@ -741,10 +752,11 @@ indicates that the subsequent arguments may be omitted (omitted arguments default to @code{nil}). Do not write @code{&optional} when you call the function. - The keyword @code{&rest} (which will always be followed by a single -argument name) indicates that any number of arguments can follow. The value -of the single following arguments name will be a list of all these arguments. -Do not write @code{&rest} when you call the function. + The keyword @code{&rest} (which must be followed by a single argument +name) indicates that any number of arguments can follow. The single +following argument name will have a value, as a variable, which is a +list of all these remaining arguments. Do not write @code{&rest} when +you call the function. Here is a description of an imaginary function @code{foo}: @@ -791,7 +803,7 @@ interactively; macros process their arguments differently from functions 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{@code{@r{[}@var{optional-arg}@r{]}}} means that @var{optional-arg} is +@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: @@ -800,7 +812,7 @@ additional levels of list structure. Here is an example: This imaginary special form implements a loop that executes the @var{body} forms and then increments the variable @var{var} on each iteration. On the first iteration, the variable has the value -@var{from}; on subsequent iterations, it is incremented by 1 (or by +@var{from}; on subsequent iterations, it is incremented by one (or by @var{inc} if that is given). The loop exits before executing @var{body} if @var{var} equals @var{to}. Here is an example: @@ -811,7 +823,7 @@ if @var{var} equals @var{to}. Here is an example: (terpri)) @end example -If @var{from} and @var{to} are omitted, then @var{var} is bound to +If @var{from} and @var{to} are omitted, @var{var} is bound to @code{nil} before the loop begins, and the loop exits if @var{var} is non-@code{nil} at the beginning of an iteration. Here is an example: @@ -855,33 +867,34 @@ replaced by `User Option'. @node Version Info @section Version Information - These functions and variables provide information about which -version of Emacs is in use. + These facilities provide information about which version of Emacs is +in use. @deffn Command emacs-version This function returns a string describing the version of Emacs that is running. It is useful to include this string in bug reports. -@example +@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" @end group -@end example +@end smallexample Called interactively, the function prints the same information in the echo area. @end deffn @defvar emacs-build-time -The value of this variable is the time at which Emacs was built at the -local site. +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}). @example @group emacs-build-time - @result{} "Tue Jun 6 14:55:57 1995" + @result{} (13623 62065 344633) @end group @end example @end defvar @@ -893,7 +906,7 @@ really part of the Emacs release version number; it is incremented each time you build Emacs in any given directory. @end defvar - The following two variables have existed since Emacs version 19.23, + 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 |