%%%----- Licensing notice ---------------------------------------------------
%%%
-%%% This file is part of the Sensble Object Design, an object system for C.
+%%% This file is part of the Sensible Object Design, an object system for C.
%%%
%%% SOD is free software; you can redistribute it and/or modify
%%% it under the terms of the GNU General Public License as published by
\ProvidesPackage{sod}
+%%%--------------------------------------------------------------------------
+%%% Basic style things.
+
%% More reference types.
\defxref{p}{part}
+%% A gadget to include in `\xref': call as
+%%
+%% \xref[\instead{THING}]{LABEL}
+%%
+%% to replace the usual `section' or whatever with THING.
+\def\instead#1#2{#1}
+
%% Other languages with special typesetting.
\def\Cplusplus{C\kern-\p@++}
\def\Csharp{C\#}
\let\implies\Rightarrow
\let\epsilon\varepsilon
+%% A table heading cell. Clone and hack \multicolumn.
+\def\thd{\omit\@ifnextchar[\thd@{\thd@[l]}}
+\def\thd@[#1]#2{%
+ \begingroup
+ \tab@multicol \tab@initread \let\tab@looped\tab@err@multi
+ \tab@preamble{}\def\tab@midtext{\bfseries#2}\tab@readpreamble{#1}%
+ \the\tab@preamble
+ \endgroup \ignorespaces
+}
+
%% Unix manpage references.
\def\man#1#2{\textbf{#1}(#2)}
%% Listings don't need to be small.
\let\listingsize\relax
+%% Notes for later.
+\def\fixme#1{\leavevmode\marginpar{FIXME}\index{FIXME}[FIXME: #1]}
+
+%% Diagram settings.
+\tikzset{
+ every picture/.style={>=stealth, thick},
+ lit/.style={font=\sffamily}
+}
+
%% Metavariables are italics without decoration.
\def\syntleft{\normalfont\itshape}
\let\syntright\empty
%% Literal code is in sans face.
-\let\codeface\sffamily
-\def\code#1{\ifmmode\hbox\fi{\normalfont\codeface\/#1\/}}
+\def\codeface{\upshape\sffamily}
+\DeclareRobustCommand\code[1]{%
+ \ifmmode\hbox\else\leavevmode\fi%
+ {\normalfont\codeface\/#1\/}%
+}
\def\ulitleft{\normalfont\codeface}
\let\ulitright\empty
+\def\lit@i#1#2#3{\ifmmode\leavevmode\hbox\fi{#1{#3\/}#2}}
%% Conditionally enter maths mode. Can't use \ensuremath here because we
%% aren't necessarily sure where the maths will actually end.
\atdef <#1>{\synt{#1}\@scripts}
\atdef "#1"{\lit*{#1}\@scripts}
\atdef `#1'{\lit{#1}\@scripts}
-\atdef |#1|{\textsf{#1}\@scripts}
+\atdef |#1|{\lit*{#1}\@scripts}
%% A handy abbreviation; `\\' itself is too good to steal.
\atdef \\{\textbackslash}
%% Intercept grammar typesetting and replace the vertical bar with the
%% maths-font version.
-\let\@@grammar\grammar
-\def\grammar{\def\textbar{\hbox{$|$}}\@@grammar}
+\let\@@syn@shorts\syn@shorts
+\def\syn@shorts{\def\textbar{\hbox{$|$}}\@@syn@shorts}
%% Collect super- and subscripts. (Note that underscores are active for the
%% most part.) When we're done, end maths mode if we entered it
%% conditionally.
\def\@scripts{\futurelet\@ch\@scripts@i}
\begingroup\lccode`\~=`\_\lowercase{\endgroup
-\def\@scripts@i{\if1\ifx\@ch~1\else\ifx\@ch^1\else0\fi\fi%
+\def\@scripts@i{\if1\ifx\@ch~1\else\ifx\@ch_1\else\ifx\@ch^1\else0\fi\fi\fi%
\expandafter\@scripts@ii\else\expandafter\m@maybe@end\fi}}
\def\@scripts@ii#1#2{\m@maybe#1{#2}\@scripts}
\expandafter\@firstoftwo\expandafter\@scripts%
\else\@tempa\expandafter\@scripts\fi}
+%% Lookahead without eating spaces.
+\def\@ifnextchar@preserve#1#2#3{%
+ \let\want@= #1\def\@tempa{#2}\def\@tempb{#3}%
+ \futurelet\nch@\@ifnch@p%
+}
+\def\@ifnch@p{%
+ \ifx\want@\nch@\expandafter\@tempa\else\expandafter\@tempb\fi}
+
%% Extra syntax for Lisp templates. These produce the maths-font versions of
%% characters, which should contrast well against the sans face used for
%% literals.
\atdef ({\m@maybe(\@scripts}
\atdef ){\m@maybe)\@scripts}
\atdef !{\m@maybe|\@scripts}
+
\def\returns{\m@maybe\longrightarrow\m@maybe@end\hspace{0.5em}\ignorespaces}
+\def\nlret{\\\hspace{4em}\returns}
\atdef >{\leavevmode\unskip\hspace{0.5em}\returns}
-%% Comment setting.
-\atdef ;#1\\{\normalfont\itshape;#1\\}
+%% Extra syntax for common tokens.
+\atdef ~{\textasciitilde}
+\atdef -{\leavevmode\hbox\bgroup\futurelet\ch@\@dash}
+\def\@dash{%
+ \ifx\ch@>%
+ --\raisebox{.4pt}{>}%
+ \def\next@{\@firstoftwo{\egroup\penalty200\relax}}%
+ \else\ifx\ch@-%
+ --\,%
+ \def\next@{\@firstoftwo{\futurelet\ch@\@dash}}%
+ \else%
+ --%
+ \let\next@\egroup%
+ \fi\fi
+ \next@%
+}
-%% Environment for setting programs. Newlines are explicit, because
-%% otherwise I need comments in weird places to make the vertical spacing
-%% come out properly. You can write `\obeylines' if you really want to.
-\def\prog{\codeface\quote\tabbing}
-\def\endprog{\endtabbing\endquote}
-\def\ind{\quad\=\+\kill}
+%% Comment setting.
+\def\comment#1{\mbox{\normalfont\itshape\/#1\/}}
+\atdef /*#1*/{/*\comment{#1}*/}
+\def\@semis;{\@ifnextchar@preserve;{;\@semis}\@semicomment}
+\def\@semicomment#1\\{\comment{#1}\\}
+\atdef ;{;\@semis;}
%% Put a chunk of text in a box.
\newenvironment{boxy}[1][\q@]{%
+ \savenotes%
\dimen@\linewidth\advance\dimen@-1.2pt\advance\dimen@-2ex%
\medskip%
\vbox\bgroup\hrule\hbox\bgroup\vrule%
\endminipage\hskip1ex\egroup\vskip1ex\egroup%
\vrule\egroup\hrule\egroup%
\medskip%
+ \spewnotes%
}
-%% Lisp documentation machinery.
-\def\definedescribecategory#1#2{\@namedef{cat!#1}{#2}}
-\def\describecategoryname#1{%
- \expandafter\let\expandafter\@tempa\csname cat!#1\endcsname%
- \ifx\@tempa\relax#1\else\@tempa\fi}
-\definedescribecategory{fun}{function}
-\definedescribecategory{gf}{generic function}
-\definedescribecategory{var}{variable}
-\definedescribecategory{const}{constant}
-\definedescribecategory{meth}{primary method}
-\definedescribecategory{ar-meth}{around-method}
-\definedescribecategory{be-meth}{before-method}
-\definedescribecategory{af-meth}{after-method}
-\definedescribecategory{cls}{class}
-\definedescribecategory{ty}{type}
-\definedescribecategory{mac}{macro}
-\def\nlret{\\\hspace{4em}\returns}
+%%%--------------------------------------------------------------------------
+%%% Environment for setting programs.
+
+%% Save `\kill' so that `longtable' won't clobber it.
+\let\prog@@kill\kill
+
+%% Main guts of `prog' and `nprog'.
+\def\@prog{%
+ \let\prog@@cr\@tabcr%
+ \let\@tabcr\@progcr%
+ \let\kill\prog@@kill%
+ \codeface%
+ \tabbing%
+}
+
+%% Newlines: called by `\\' within a `prog'.
+%%
+%% \\ newline without following break
+%% \\[SKIP] newline /with/ break and vertical glue
+%% \\*[SKIP] newline without break, with optional glue
+%% \\+ newline with break and a vertical gap
+%% \\- newline without break, with a tiny gap
+\def\@progcr{\futurelet\@tempa\@progcr@i}
+\def\@progcr@i{%
+ \ifx\@tempa\@sptoken\let\next@\@progcr@sp\else
+ \if1\ifx\@tempa[1\else
+ \ifx\@tempa*1\else
+ 0\fi\fi
+ \let\next@\prog@@cr\else
+ \if1\ifx\@tempa+1\else
+ \ifx\@tempa-1\else
+ 0\fi\fi
+ \let\next@\@progcr@ii\else
+ \let\next@\@progcr@a\fi\fi\fi
+ \next@}
+\def\@progcr@a{\prog@@cr*{}\ignorespaces}
+\def\@progcr@ii#1{\csname @progcr@#1\endcsname\ignorespaces}
+\@namedef{@progcr@+}{\prog@@cr[\medskipamount]}
+\@namedef{@progcr@-}{\prog@@cr*[\jot]}
+{\def\:{\gdef\@progcr@sp}\: {\@progcr}} % \@progcr@sp eats space and recurses
+
+%% Set a program in `codeface', with implicit tabbing and other toys.
+%% Newlines are explicit, because otherwise I need comments in weird places
+%% to make the vertical spacing come out properly. You can write
+%% `\obeylines' if you really want to.
+\def\prog{\quote\@prog}
+\def\endprog{\endtabbing\endquote}
+
+%% Like `prog', but without indenting the code. Use this within environments
+%% which already set their contents out from the body text in some
+%% distinctive way.
+\let\nprog\@prog
+\let\endnprog\endtabbing
+
+%% Indent the following material. Cancel using `\-'.
+\def\ind{\quad\=\+\kill}
+
+%% Show a backslash by the right-hand margin; for multiline macros etc.
+\def\macsl{\`\textbackslash\hskip\leftmargin}
+
+%% \maplist{THING}{{ITEM}...}: Invoke THING{ITEM} for each ITEM in turn.
+\def\maplist#1#2{\map@i{#1}#2\q@}
+\def\map@i#1{\def\next@{\map@ii{#1}}\futurelet\ch@\next@}
+\def\map@ii#1{\ifx\ch@\q@\expandafter\@gobble%
+ \else\def\next@{\map@iii{#1}}\expandafter\next@\fi}
+\def\map@iii#1#2{#1{#2}\map@i{#1}}
+
+%% \crossproduct{THING}{{LIST}...} where each LIST is {ITEM}...
+%% For each possible way of selecting one ITEM from each LIST, in order,
+%% invoke THING{{ITEM}...}
+\toksdef\cprod@new=0
+\toksdef\cprod@old=2
+\toksdef\cprod@head=4
+\toksdef\cprod@tail=6
+\def\crossproduct#1#2{%
+ \cprod@new{{}}%
+ \maplist{\cprod@f{#1}}{#2}%
+ \cprod@head{#1}%
+ \edef\next@{\noexpand\maplist{\the\cprod@head}{\the\cprod@new}}
+ \next@%
+}
+\def\cprod@f#1#2{%
+ \cprod@old\cprod@new\cprod@new{}%
+ \maplist\cprod@g{#2}%
+}
+\def\cprod@g#1{%
+ \cprod@head{#1}%
+ \expandafter\maplist\expandafter\cprod@h\expandafter{\the\cprod@old}%
+}
+\def\cprod@h#1{%
+ \cprod@tail{#1}%
+ \cprod@new\expandafter{\the\expandafter\cprod@new\expandafter{%
+ \the\expandafter\cprod@tail\the\cprod@head}}%
+}
+%%%--------------------------------------------------------------------------
+%%% Machinery for describing functions, etc.
+
+%% \definedescribecategory{CAT}[KIND]{NAME}
+%%
+%% Define a category of things to document. CAT is a short label identifying
+%% the category to `\describe', `\descref', and friends. The NAME is the
+%% text to show in the description headline; it is a macro body which is
+%% passed an argument `#1' that applies a modifier to some portion of the
+%% text.
+%%
+%% The KIND allows additional arguments to be collected, included in label
+%% strings, and mentioned in the index. The default is `plain'.
+\def\definedescribecategory#1{%
+ \@ifnextchar[{\def@desc{#1}}{\def@desc{#1}[plain]}}
+\def\def@desc#1[#2]#3{\@namedef{cat!#1}##1{#3}\@namedef{catsw!#1}{#2}}
+
+%% \describecategoryname[MOD]{CAT}
+%%
+%% Typeset the category name for CAT, modified by MOD.
+\def\describecategoryname{\@ifnextchar[\@descname@i{\@descname@i[]}}
+\def\@descname@i[#1]#2{%
+ \expandafter\let\expandafter\@tempa\csname cat!#2\endcsname%
+ \expandafter\let\expandafter\@tempb\csname modcat/#1\endcsname%
+ \ifx\@tempa\relax\@tempb{#2}\else\@tempa\@tempb\fi}
+
+%% Call a modifier method.
+\def\@mod@dispatch#1#2{\csname #1/#2\endcsname}
+
+%% Call a description method given the category.
+\def\@desc@dispatch#1#2{%
+ \csname #1/%
+ \expandafter\ifx\csname catsw!#2\endcsname\relax plain%
+ \else \csname catsw!#2\endcsname \fi%
+ \endcsname%
+}
+
+%% Modifier methods for the default `plain' modifier.
+\@namedef{modcat/plain}#1{#1}
+\@namedef{modlabel/plain}#1{#1}
+\@namedef{modindex/plain}#1{#1@\noexpand\code{#1}}
+
+%% Modifier methods for `setf'. The name text prefixes the relevant word
+%% with `setf-'.
+\@namedef{modcat/setf}#1{\code{setf}-#1}
+\@namedef{modlabel/setf}#1{setf/#1}
+\@namedef{modindex/setf}#1{#1@\noexpand\code{#1}}
+
+%% Modifier methods for words with *earmuffs*. Sort into the index without
+%% the earmuffs.
+\@namedef{modcat/muffs}#1{#1}
+\@namedef{modlabel/muffs}#1{#1}
+\@namedef{modindex/muffs}#1{\@unmuff#1@\noexpand\code{#1}}
+\def\@unmuff*#1*{#1}
+
+%% Modifier methods for :keywords. Sort into the index without the `:'.
+\@namedef{modcat/kwd}#1{#1}
+\@namedef{modlabel/kwd}#1{#1}
+\@namedef{modindex/kwd}#1{\@gobble#1@\noexpand\code{#1}}
+
+%% Category-kind methods for plain categories.
+\@namedef{descargs/plain}#1{#1{}}
+\@namedef{desclabel/plain}#1#2#3{#2:\@mod@dispatch{modlabel}{#1}{#3}}
+\@namedef{descindex/plain}#1#2#3{%
+ \@mod@dispatch{modindex}{#1}{#3}!%
+ \protect\describecategoryname[#1]{#2}%
+}
+
+%% Category-kind methods for `method' categories. Collect an extra argument
+%% listing the specializers: include them in the label, and typeset them in
+%% the index.
+\def\fmtspecs#1#2{%
+ \if!#2!\else\count@\z@\toks@{}#1\fmtspecs@i#2,\q@,\fi}
+\def\fmtspecs@i#1,{%
+ \def\@tempa{#1}%
+ \ifx\@tempa\q@%
+ \ifcase\count@(no args?!)%
+ \or% nothin' doin
+ \or \space and %
+ \else, and %
+ \fi%
+ \the\toks@%
+ \else%
+ \ifnum\count@>\@ne, \fi%
+ \the\toks@%
+ \toks@{\code{#1}}\advance\count@\@ne%
+ \expandafter\fmtspecs@i%
+ \fi%
+}
+\@namedef{descargs/method}#1#2{#1{{#2}}}
+\@namedef{desclabel/method}#1#2#3#4%
+ {#2:\@mod@dispatch{modlabel}{#1}{#4}(#3)}
+\@namedef{descindex/method}#1#2#3#4{%
+ \@mod@dispatch{modindex}{#1}{#4}!%
+ \protect\describecategoryname[#1]{#2}%
+ \protect\fmtspecs{ specialized at }{#3}%
+}
+
+%% Some magic strings.
\def\q@{\q@}
-\newenvironment{describe}[3][\q@]{%
+\def\@setf{setf}
+\def\@starstar{**}
+
+%% \parse@dhd{NEXT}[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%%
+%% Parse the arguments for a description header, and call
+%%
+%% NEXT{MOD}{CAT}{{...}...}{NAME}{SYNOPSIS}
+%%
+%% Here, {...}... represents the additional category-kind arguments. See
+%% `describe' for what all of this means.
+\def\parse@dhd#1{% {NEXT}
+ \@ifnextchar[{\parse@dhd@a{#1}}{\parse@dhd@c{#1}}}
+\def\parse@dhd@a#1[#2]#3{% {NEXT}[MOD]{CAT}
+ \@desc@dispatch{descargs}{#3}{\parse@dhd@ab{#1}{#2}{#3}}}
+\def\parse@dhd@ab#1#2#3#4{% {NEXT}{MOD}{CAT}{{...}...}
+ \@ifnextchar[{\parse@dhd@ac{#1}{#2}{#3}{#4}}{\parse@dhd@ad{#1}{#2}{#3}{#4}}}
+\def\parse@dhd@ac#1#2#3#4[#5]#6{% {NEXT}{MOD}{CAT}{{...}...}[NAME]{SYNOPSIS}
+ #1{#2}{#3}{#4}{#5}{#6}}
+\def\parse@dhd@ad#1#2#3#4#5{% {NEXT}{MOD}{CAT}{{...}...}{NAME [ARGS...]}
+ \parse@dhd@ae{#1}{#2}{#3}{#4}{#5}#5 \q@}
+\def\parse@dhd@ae#1#2#3#4#5#6 #7\q@{%
+ % {NEXT}{MOD}{CAT}{{...}...}{SYNSOPSIS}NAME [ARGS...]\q@
+ #1{#2}{#3}{#4}{#6}{#5}}
+
+\def\parse@dhd@c#1#2{% {NEXT}{CAT}
+ \@desc@dispatch{descargs}{#2}{\parse@dhd@cb{#1}{#2}}}
+\def\parse@dhd@cb#1#2#3{% {NEXT}{CAT}{{...}...}
+ \@ifnextchar[{\parse@dhd@cc{#1}{#2}{#3}}{\parse@dhd@cd{#1}{#2}{#3}}}
+\def\parse@dhd@cc#1#2#3[#4]#5{% {NEXT}{CAT}{{...}...}[NAME]{SYNOPSIS}
+ #1{plain}{#2}{#3}{#4}{#5}}
+\def\parse@dhd@cd#1#2#3#4{% {NEXT}{CAT}{{...}...}{SYNOPSIS}
+ \parse@dhd@ce{#1}{#2}{#3}{#4}#4 \q@}
+\def\parse@dhd@ce#1#2#3#4#5 #6\q@{%
+ % {NEXT}{CAT}{{...}...}{SYNOPSIS}NAME [ARGS...]\q@
+ \def\temp@{#5}%
+ \ifx\@setf\temp@\def\next@{\parse@dhd@csetf{#1}{#2}{#3}{#4}#6 \q@}%
+ \else\def\temp@##1##2*##3\q@{\def\temp@{##1##3}}\temp@#5*\q@%
+ \ifx\temp@\@starstar\def\next@{#1{muffs}{#2}{#3}{#5}{#4}}%
+ \else\def\temp@##1##2\q@{\def\temp@{##1}}\temp@#5\q@%
+ \if:\temp@\def\next@{#1{kwd}{#2}{#3}{#5}{#4}}%
+ \else\def\next@{#1{plain}{#2}{#3}{#5}{#4}}\fi\fi\fi%
+ \next@%
+}
+\def\parse@dhd@csetf#1#2#3#4(#5 #6\q@{%
+ % {NEXT}{CAT}{{...}...}{SYNOPSIS}(NAME [ARGS...])\q@
+ #1{setf}{#2}{#3}{#5}{#4}}
+
+%% \dhead[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%% \dhead*[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%%
+%% Typeset a description head. Use this within the first argument of
+%% `describe*'; see `describe' for the details.
+%%
+%% With `*', don't set labels or add items to the index.
+\newif\if@dheadfirst
+\newif\if@dheadindex
+\def\dhead{\@ifstar%
+ {\parse@dhd{\global\@dheadindexfalse\dhead@}}%
+ {\parse@dhd{\global\@dheadindextrue\dhead@}}}
+\def\dhead@#1#2#3#4#5{% {MOD}{CAT}{{...}...}{NAME}{SYNOPSIS}
+ \if@dheadfirst\global\@dheadfirstfalse\else\relax\\*[\smallskipamount]\fi%
+ \if@dheadindex%
+ \phantomsection%
+ {\let\protect\@empty\let\@uscore\relax%
+ \edef\temp@{\@desc@dispatch{desclabel}{#2}{#1}{#2}#3{#4}}%
+ \def\@uscore{_\@gobble}\expandafter\message\expandafter{\temp@}%
+ \def\@uscore{-\@gobble}\expandafter\label\expandafter{\temp@}}%
+ {\begingroup\lccode`\~=`\_\lowercase{\endgroup\def~{_}}%
+ \protected@edef\@tempa##1{%
+ \noexpand\index{\@desc@dispatch{descindex}{#2}{#1}{#2}#3{#4}##1}}%
+ \toks@\expandafter{\@tempa{|)}}%
+ \toks\tw@\expandafter{\after@desc}%
+ \xdef\after@desc{\the\toks\tw@\the\toks@}%
+ \@tempa{|(}}%
+ \fi%
+ \rlap{\hb@xt@\linewidth{\hfil\normalfont\bfseries
+ [\describecategoryname[#1]{#2}]}}%
+ #5%
+}
+
+%% Main guts of a description environment. The argument here typesets the
+%% header line(s).
+\def\desc@begin#1{%
+ \let\saved@after@desc\after@desc%
+ \gdef\after@desc{}%
\normalfont%
- \par\goodbreak%
- \vspace{\bigskipamount}%
- \setbox\z@\hbox{\bfseries[\describecategoryname{#2}]}%
- \dimen@\linewidth\advance\dimen@-\wd\z@%
- \def\@temp##1 ##2\q@{\message{#2:##1}\label{#2:##1}}%
- \def\@tempa{#1}\ifx\@tempa\q@\@temp#3 \q@\else\@temp{#1} \q@\fi%
- \edef\@temp{{\the\linewidth}{@{}p{\the\dimen@}%
- @{\extracolsep{\fill}}l@{\extracolsep{0pt}}}}%
- \noindent\csname tabular*\expandafter\endcsname\@temp%
- \tabbing\codeface#3\endtabbing&\unhbox\z@\\\endtabular%
-% \@afterheading%
- \list{}{\rightmargin\z@}\item%
-}{%
- \endlist%
+ \if@nobreak\else\par\goodbreak\fi%
+ \global\@dheadfirsttrue%
+ \begingroup%
+ \let\@endparenv\relax%
+ \clubpenalty\@M \widowpenalty\@M \interlinepenalty50%
+ \@prog#1\endtabbing%
+ \endgroup%
+ \penalty\@M\@afterheading%
+ \list{}{\rightmargin\z@\topsep\z@}\item%
+}
+\def\desc@end{\endlist\after@desc\global\let\after@desc\saved@after@desc}
+
+%% \begin{describe}[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%% ...
+%% \end{describe}
+%%
+%% Describe some kind of program object. The CAT names the category of thing
+%% being described -- this will be shown in the header, and index. The
+%% SYNOPSIS is an implicit `prog' environment in which invoking the thing can
+%% be summarized.
+%%
+%% The {...}... are any additional arguments required by the category's kind
+%% (e.g., method specializers).
+%%
+%% The NAME is the name of the thing, which ends up in the index and
+%% cross-reference label. If omitted, it defaults to the first word of the
+%% SYNOPSIS, except that there are some special cases.
+%%
+%% The MOD is the modifier to apply. If omitted, it will usually default to
+%% `plain', but in the absence of a NAME, some kinds of synopses are
+%% recognized specially:
+%%
+%% * `setf (NAME ...) ...': selects NAME, and defaults MOD to `setf'.
+%%
+%% * `*NAME*': defaults MOD to `muffs'.
+%%
+%% * `:NAME': defaults MOD to `kwd'.
+\def\describe{\parse@dhd\desc@}
+\def\desc@#1#2#3#4#5{%
+ \global\@dheadindextrue%
+ \desc@begin{\dhead@{#1}{#2}{#3}{#4}{#5}}%
+}
+\let\enddescribe\desc@end
+
+%% \begin{describe*}
+%% {\dhead[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%% ...}
+%% ...
+%% \end{describe*}
+%%
+%% This is the fancy form of `describe' for describing several different
+%% things at once.
+\@namedef{describe*}#1{\desc@begin{#1}}
+\expandafter\let\csname enddescribe*\endcsname\desc@end
+
+%% \parse@dlbl{NEXT}[MOD]{CAT}{...}...{LABEL}
+%%
+%% Parse a description label, and call
+%%
+%% NEXT{MOD}{CAT}{{...}...}{LABEL}
+%%
+%% This handles defaulting the MOD correctly, based on the LABEL text. See
+%% `\descref' for the details.
+\def\parse@dlbl#1{\@ifnextchar[{\parse@dlbl@a{#1}}{\parse@dlbl@c{#1}}}
+\def\parse@dlbl@a#1[#2]#3{\@desc@dispatch{descargs}{#3}{#1{#2}{#3}}}
+\def\parse@dlbl@c#1#2%
+ {\@desc@dispatch{descargs}{#2}{\parse@dlbl@cb{#1}{#2}}}
+\def\parse@dlbl@cb#1#2#3#4{%
+ \def\temp@##1##2*##3\q@{\def\temp@{##1##3}}\temp@#4*\q@%
+ \ifx\temp@\@starstar\def\next@{#1{muffs}{#2}{#3}{#4}}%
+ \else\def\temp@##1##2\q@{\def\temp@{##1}}\temp@#4\q@%
+ \if:\temp@\def\next@{#1{kwd}{#2}{#3}{#4}}
+ \else\def\next@{#1{plain}{#2}{#3}{#4}}\fi\fi%
+ \next@%
+}
+
+%% \descref[MOD]{CAT}{...}...{LABEL}[TEXT]
+%% \descref*[MOD]{CAT}{...}...{LABEL}
+%%
+%% Typesets a cross-reference to a described thing. The CAT names the
+%% category of thing being described, and the LABEL names the specific thing.
+%%
+%% The {...}... are any additional arguments required by the category's kind
+%% (e.g., method specializers).
+%%
+%% The MOD is the modifier to apply, similar (but subtly different from) to
+%% the `describe' environment. If omitted, it will usually default to
+%% `plain', but in the absence of a NAME, some kinds of synopses are
+%% recognized specially:
+%%
+%% * `*NAME*': defaults MOD to `muffs'.
+%%
+%% * `:NAME': defaults MOD to `kwd'.
+%%
+%% (`setf' is /not/ specially detected here. Write an explicit `setf'
+%% modifier if necessary, because it's no more typing.)
+%%
+%% Usually a page-number cross-reference is included, so as to help readers
+%% of a dead-tree copy; this is suppressed by the `*' version.
+\def\descref{\@ifstar%
+ {\parse@dlbl{\descref@i\relax\@gobble\relax}}%
+ {\parse@dlbl{\descref@i{ (}\autopageref)}}}
+\def\descref@i#1#2#3#4#5#6#7{\@ifnextchar@preserve[%
+ % {PGA}{PGB}{PGC}{MOD}{CAT}{{...}...}{LABEL}
+ {\descref@ii{#1}{#2}{#3}{#4}{#5}{#6}{#7}}%
+ {\descref@iii{#1}{#2}{#3}{#4}{#5}{#6}{#7}{}}}
+\def\descref@ii#1#2#3#4#5#6#7[#8]%
+ % {PGA}{PGB}{PGC}{MOD}{CAT}{{...}...}{LABEL}[AFTER]
+ {\descref@iii{#1}{#2}{#3}{#4}{#5}{#6}{#7}{ #8}}
+\def\descref@iii#1#2#3#4#5#6#7#8{%
+ % {PGA}{PGB}{PGC}{MOD}{CAT}{{...}...}{LABEL}{AFTER}
+ \begingroup%
+ \let\protect\@empty\def\@uscore{-\@gobble}%
+ \edef\temp@{\@desc@dispatch{desclabel}{#5}{#4}{#5}#6{#7}}%
+ \edef\next@##1##2##3{\endgroup%
+ \noexpand\hyperref[\temp@]{##1}##2{\temp@}##3}%
+ \next@{\code{#7}}{#8#1#2}{#3}%
}
-%%% ----- That's all, folks --------------------------------------------------
-\endinput
\ No newline at end of file
+%% \descindex[MOD]{CAT}{...}...{LABEL}[SUFFIX]
+%%
+%% Set a label and index entry here, as if for a description. The CAT names
+%% the category of thing being described, and the LABEL names the specific
+%% thing, as for `\descref'. The {...}... are any additional arguments
+%% required by the category's kind (e.g., method specializers). The MOD is
+%% the modifier to apply; see `\descref' for the details.
+%%
+%% The SUFFIX is appended to the index-entry text; by default it is empty.
+%% Useful values are `|(' and `|)' to set ranges.
+\def\descindex{\parse@dlbl\descindex@i}
+\def\descindex@i#1#2#3#4{\@ifnextchar[%
+ {\descindex@ii{#1}{#2}{#3}{#4}}%
+ {\descindex@ii{#1}{#2}{#3}{#4}[]}}
+\def\descindex@ii#1#2#3#4[#5]{%
+ {\begingroup\lccode`\~=`\_\lowercase{\endgroup\def~{_}}%
+ \protected@edef\@tempa{%
+ \noexpand\index{\@desc@dispatch{descindex}{#2}{#1}{#2}#3{#4}#5}}%
+ \@tempa}%
+}
+
+%% \desclabel[MOD]{CAT}{...}...{LABEL}[INDEX-SUFFIX]
+%%
+%% Set a label and index entry here, as if for a description. The CAT names
+%% the category of thing being described, and the LABEL names the specific
+%% thing, as for `\descref'. The {...}... are any additional arguments
+%% required by the category's kind (e.g., method specializers). The MOD is
+%% the modifier to apply; see `\descref' for the details.
+%%
+%% This will also add an index entry, as for `\descindex'; the INDEX-SUFFIX
+%% argument has the same effect as its SUFFIX argument.
+\def\desclabel{\parse@dlbl\desclabel@i}
+\def\desclabel@i#1#2#3#4{%
+ \begingroup%
+ \let\protect\@empty\def\@uscore{-\@gobble}%
+ \edef\@tempa{\@desc@dispatch{desclabel}{#2}{#1}{#2}#3{#4}}%
+ \phantomsection\label{\@tempa}%
+ \endgroup%
+ \descindex@i{#1}{#2}{#3}{#4}%
+}
+
+%% Description categories.
+\definedescribecategory{sym}{symbol}
+\definedescribecategory{fun}{#1{function}}
+\definedescribecategory{gf}{generic #1{function}}
+\definedescribecategory{msg}{message}
+\definedescribecategory{var}{variable}
+\definedescribecategory{modvar}{module variable}
+\definedescribecategory{const}{constant}
+\definedescribecategory{meth}[method]{primary #1{method}}
+\definedescribecategory{ar-meth}[method]{\code{:around} #1{method}}
+\definedescribecategory{be-meth}[method]{\code{:before} #1{method}}
+\definedescribecategory{af-meth}[method]{\code{:after} #1{method}}
+\definedescribecategory{cls}{class}
+\definedescribecategory{rst}{restart}
+\definedescribecategory{ty}{type}
+\definedescribecategory{mac}{#1{macro}}
+\definedescribecategory{feat}{feature macro}
+\definedescribecategory{lmac}{local #1{macro}}
+\definedescribecategory{parse}{parser spec}
+\definedescribecategory{parseform}{parser form}
+\definedescribecategory{opt}{option handler}
+\definedescribecategory{optmac}{option macro}
+\definedescribecategory{plug}{pluggable parser}
+
+%%%----- That's all, folks --------------------------------------------------
+\endinput