@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998 Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999
+@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/help
@node Documentation, Files, Modes, Top
@c Wordy to prevent overfull hbox. --rjc 15mar92
The @file{emacs/lib-src} directory contains two utilities that you can
use to print nice-looking hardcopy for the file
-@file{emacs/etc/DOC-@var{version}}. These are @file{sorted-doc.c} and
-@file{digest-doc.c}.
+@file{emacs/etc/DOC-@var{version}}. These are @file{sorted-doc} and
+@file{digest-doc}.
@node Accessing Documentation
@section Access to Documentation Strings
@defun documentation-property symbol property &optional verbatim
-This function returns the documentation string that is recorded
+This function returns the documentation string that is recorded in
@var{symbol}'s property list under property @var{property}. It
-retrieves the text from a file if necessary, and runs
-@code{substitute-command-keys} to substitute actual key bindings. (This
-substitution is not done if @var{verbatim} is non-@code{nil}.)
+retrieves the text from a file if the value calls for that. If the
+property value isn't @code{nil}, isn't a string, and doesn't refer to
+text in a file, then it is evaluated to obtain a string.
+
+Finally, @code{documentation-property} passes the string through
+@code{substitute-command-keys} to substitute actual key bindings,
+unless @var{verbatim} is non-@code{nil}.
@smallexample
@group
(documentation-property 'command-line-processed
'variable-documentation)
- @result{} "t once command line has been processed"
+ @result{} "Non-nil once command line has been processed"
@end group
@group
(symbol-plist 'command-line-processed)
@end defun
@defun documentation function &optional verbatim
-This function returns the documentation string of @var{function}. It
-reads the text from a file if necessary. Then (unless @var{verbatim} is
-non-@code{nil}) it calls @code{substitute-command-keys}, to return a
-value containing the actual (current) key bindings.
+This function returns the documentation string of @var{function}.
+
+If @var{function} is a symbol, this function first looks for the
+@code{function-documentation} property of that symbol; if that has a
+non-@code{nil} value, the documentation comes from that value (if the
+value is not a string, it is evaluated). If @var{function} is not a
+symbol, or if it has no @code{function-documentation} property, then
+@code{documentation} extracts the documentation string from the actual
+function definition, reading it from a file if called for.
+
+Finally, unless @var{verbatim} is non-@code{nil}, it calls
+@code{substitute-command-keys} so as to return a value containing the
+actual (current) key bindings.
The function @code{documentation} signals a @code{void-function} error
if @var{function} has no function definition. However, it is OK if
@c That makes them incorrect.
@group
-set-goal-column Command: C-x C-n
+set-goal-column Keys: C-x C-n
Set the current horizontal position as a goal for C-n and C-p.
@end group
@c DO NOT put a blank line here! That is factually inaccurate!
@end group
@end smallexample
+The asterisk @samp{*} as the first character of a variable's doc string,
+as shown above for the @code{goal-column} variable, means that it is a
+user option; see the description of @code{defvar} in @ref{Defining
+Variables}.
+
@defun Snarf-documentation filename
This function is used only during Emacs initialization, just before
the runnable Emacs is dumped. It finds the file offsets of the
@code{single-key-description}, below.
@end defun
-@defun single-key-description event
+@defun single-key-description event &optional no-angles
@cindex event printing
@cindex character printing
@cindex control character printing
@cindex meta character printing
This function returns a string describing @var{event} in the standard
-Emacs notation for keyboard input. A normal printing character appears
-as itself, but a control character turns into a string starting with
-@samp{C-}, a meta character turns into a string starting with @samp{M-},
-and space, tab, etc.@: appear as @samp{SPC}, @samp{TAB}, etc. A
-function key symbol appears as itself. An event that is a list appears
-as the name of the symbol in the @sc{car} of the list.
+Emacs notation for keyboard input. A normal printing character
+appears as itself, but a control character turns into a string
+starting with @samp{C-}, a meta character turns into a string starting
+with @samp{M-}, and space, tab, etc.@: appear as @samp{SPC},
+@samp{TAB}, etc. A function key symbol appears inside angle brackets
+@samp{<@dots{}>}. An event that is a list appears as the name of the
+symbol in the @sc{car} of the list, inside angle brackets.
+
+If the optional argument @var{no-angles} is non-@code{nil}, the angle
+brackets around function keys and event symbols are omitted; this is
+for compatibility with old versions of Emacs which didn't use the
+brackets.
@smallexample
@group
@result{} "C-x SPC M-y SPC C-j SPC TAB SPC RET SPC C-l 1 2 3"
@end group
@group
+(single-key-description 'delete)
+ @result{} "<delete>"
+@end group
+@group
(single-key-description 'C-mouse-1)
+ @result{} "<C-mouse-1>"
+@end group
+@group
+(single-key-description 'C-mouse-1 t)
@result{} "C-mouse-1"
@end group
@end smallexample
@code{help-form} is a non-@code{nil} Lisp expression, it evaluates that
expression, and displays the result in a window if it is a string.
-Usually the value of @code{help-form}'s value is @code{nil}. Then the
+Usually the value of @code{help-form} is @code{nil}. Then the
help character has no special meaning at the level of command input, and
it becomes part of a key sequence in the normal way. The standard key
binding of @kbd{C-h} is a prefix key for several general-purpose help
@end defvar
@defvar help-event-list
-@tindex help-event-list
The value of this variable is a list of event types that serve as
alternative ``help characters.'' These events are handled just like the
event specified by @code{help-char}.