% \CheckSum{2952}
%
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%
% This file may be distributed and/or modified under the conditions
% of the LaTeX Project Public License, either version 1.2 of this
% license or (at your option) any later version. The latest version
% of this license is in
% http://www.latex-project.org/lppl.txt
% and version 1.2 or later is part of all distributions of LaTeX
% version 1999/12/01 or later.
%
% Copyright 2000 2001 2002 Lars Hellstr\"om
%
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%</driver>
% \fi
%
% \title{The \package{xdoc} package --- experimental reimplementations
% of features from \package{doc}, second~prototype}
% \author{Lars Hellstr\"om^^A
% \thanks{E-mail: \texttt{Lars.Hellstrom@math.umu.se}}}
% \date{2003/07/07}
% \maketitle
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%
% \changes{prot1}{2000/06/15}{Started writing first prototype. (LH)}
% \changes{prot2}{2000/07/13}{Began work on the second prototype. (LH)}
%
% \begin{abstract}
% The \package{xdoc} package contains reimplementations of some of
% the features found in the standard \LaTeX\ \package{doc}
% package~\cite{doc} by Mittelbach \emph{et~al. }The ultimate goals
% for these reimplementations are that the commands should be better,
% easily configurable, and be easy to extend, but this is only a
% second prototype implementation and nothing in it is guaranteed to
% be the same in the third prototype.\footnote{But there are no
% guarantees there will ever be a third prototype either.}
% \end{abstract}
%
% \tableofcontents
%
%
% \section{Usage}
%
% When I began working on this package I thought that there would be no
% need for a usage section (at least on the prototype stage)---either you
% are interested in using the new features and then you might just as
% well read the descriptions of the commands in the implementation part
% of this document (they are written as specifications of what the
% commands do), or else you can simply insert a |\usepackage|\B|{xdoc2}|
% in the preamble and see how things work a little better than when you
% simply use \package{doc}---but with some features it became natural
% to introduce incompatible changes and some new features ought to be
% mentioned. Hence I wrote a short section on usage after all.
%
% It is my intention that this document will eventually evolve into the
% source for a package \package{xdoc}\footnote{The name \package{doc2}
% has also been discussed; we'll see when we get there.} which will
% either build on the \package{doc} package and provide better
% implementations of many of its features, or replace it completely,
% but this document is still only the source for a prototype for that
% package. As I believe that the need for some improvement in this area
% is rather large however, I have decided to release this prototype so
% that other people can use it in their documents or create packages that
% are based on it. In doing so, one must of course bear in mind that this
% prototype needs not be compatible with the final \package{xdoc}
% package, and to overcome most incompatibility problems I therefore
% release it under the variant name \package{xdoc2}. This way, documents
% based on this prototype can still be typeset using the package they
% were written for long after the next \package{xdoc} prototype (or final
% version) is released.
%
% Thus although this document frequently speaks of \package{xdoc}, you
% might just as well read it as \package{xdoc2}.
%
%
% \subsection{Changes to old features}
%
% Whereas \package{doc} more or less assumes that all pages have the
% same layout, \package{xdoc} takes measures to ensure that the
% \package{doc} features support two-sided document designs. If the
% left margin has been widened to better accommodate long macro names
% however (like for example the \package{ltxdoc} document class does),
% then you may find that the outer margin on right (odd) pages is too
% narrow for printing macro names in. The remedy for this is the
% \GenericDescribePrint{\MacroFont dolayout \normalfont option}^^A
% \SortIndex{dolayout}{\texttt{dolayout} option\encapchar
% usage}\texttt{dolayout} option; in two-sided mode it causes
% \package{xdoc} to recompute the |\oddsidemargin| so that the outer
% margin has the same size on right pages as it previously did on left
% pages. In documents which are not processed in two-sided mode the
% \texttt{dolayout} option has no effect.
%
% |\DocInput| has been changed to not make percent a comment character
% upon return unless it was before the |\DocInput|. This makes |\DocInput|
% nestable and I recommend that \texttt{.dtx} files which input other
% \texttt{.dtx} files use |\DocInput| for this.
%
% The |\DocInclude| command, which is defined by the \package{ltxdoc}
% document class rather than \package{doc}, is also by default
% redefined in an incompatible manner by \package{xdoc}, but you can
% stop \package{xdoc} from making incompatible changes if you pass it the
% option \GenericDescribePrint{\MacroFont olddocinclude \normalfont
% option}\SortIndex{olddocinclude}{\texttt{olddocinclude} option^^A
% \encapchar usage}\texttt{olddocinclude}. The main incompatibility
% lies in that the default redefinition of |\DocInclude| behaves purely
% as an |\include| command which |\DocInput|s a \texttt{.dtx} file rather
% than merely |\input|ting a \texttt{.tex} file---you must pass the
% \GenericDescribePrint{\MacroFont fileispart \normalfont option}^^A
% \SortIndex{fileispart}{\texttt{fileispart} option\encapchar
% usage}\texttt{fileispart} option to \package{xdoc} to get the |\part|
% headings etc.\ for each new file---but there are also minor changes
% in the appearance of these headings, in how page styles are set, and
% in how the information presented in the page footer is obtained.
%
% Other changes are as far as I can tell minor and within the bounds of
% expected behaviour, but code that relies on the implementation of some
% feature in \package{doc} may of course behave differently or break
% completely. Note in particular that the formats of the internal
% \package{doc} variables |\saved@macroname|, |\macro@namepart|, and
% |\index@excludelist| have changed completely (see
% Section~\ref{Sec:Changes}, Subsection~\ref{Ssec:Scanning macrocode},
% and Subsection~\ref{Ssec:Index-exclude} respectively)---hence any hack
% involving one of these must be revised before it is used with
% \package{xdoc}. These are however exceptions; in my experience the most
% noticeable changes not listed above are that the index exclude
% mechanism actually works for control sequences whose names consist of
% a single non-letter and that symbols get sorted in a different order.
%
%
% \subsection{Some notable new features}
%
% The main new feature is the \DescribeMacro\NewMacroEnvironment
% |\NewMacroEnvironment| command, which defines a new \texttt{macro}-like
% environment. The command offers complete control of the argument
% structure, the formatting of the marginal heading, the code for making
% index entries, and the change entry sorting and formatting, but the
% syntax is too complex to explain here. Those who are interested in
% using it should read Section~\ref{Sec:Macro-environments}. In
% particular, Subsections~\ref{Ssec:Macro&environment}--^^A
% \ref{Ssec:More macros} contain several examples of how it can be
% used. In addition to using |\New|\-|Macro|\-|Environment| for
% redefining the \DescribeEnv{macro}\texttt{macro} and
% \DescribeEnv{environment}\texttt{environment} environments,
% \package{xdoc} also defines an \DescribeEnv{option}\texttt{option}
% environment (which is intended for document class and package
% options) and a \DescribeEnv{switch}\texttt{switch} environment (which
% is intended for switches defined using |\newif|; the argument should
% not include the |\if|).
%
% There is also a companion command \DescribeMacro\NewDescribeCommand
% |\NewDescribeCommand| which defines new commands similar to
% |\Describe|\-|Macro| and |\Describe|\-|Env|. The syntax of
% |\New|\-|Describe|\-|Command| is also too complex to explain here, so
% I have to refer readers who want to use it to Section~^^A
% \ref{Sec:Describing}. Two more commands which are defined in that
% section are \DescribeMacro\describeoption|\describe|\-|option|, which
% is the \texttt{describe}\dots\ companion of the \texttt{option}
% environment, and \DescribeMacro\describecsfamily
% |\describe|\-|cs|\-|family| which is meant for describing control
% sequence families (see the table on page~\pageref{Tab:CS-families} for
% examples of what I mean). The argument of this latter command is simply
% the material you would put between |\csname| and |\endcsname|. Variant
% parts are written as |\meta|\B\marg{text} and print as one would expect
% them to (but notice that the \meta{text} is a moving argument) whereas
% most other characters can be written verbatim without any special
% quoting (but |\|, |{|, |}|, and |%| need quoting; see the comments to
% the definition of |\describe|\-|cs|\-|family| for information on how
% to do that).
%
% The \DescribeMacro\DoNotIndexBy|\DoNotIndexBy| command tells the
% commands that make index entries for macros to ignore a certain
% character sequence when the index entries are sorted. The
% |\DoNotIndexBy| command takes one argument: the character sequence to
% ignore. If |\DoNotIndexBy| is used more than once then the indexing
% commands will look for, and if it finds it ignore, each of the
% character sequences given to it, starting with the one specified last.
%
% It has already been mentioned that the |\DocInclude| command has been
% changed. What has not been mentioned is its companion
% \DescribeMacro\setfileinfo|\setfileinfo|,
% which the partfiles should use for setting the date and version
% information presented in the page footer, but that is explained in
% detail in Subsection~\ref{Ssec:New DocInclude}.
%
% Finally there is a new variant of the |\changes| command which is
% intended for changes that, although not limited to a single macro and
% thus being ``general'' changes in the \package{doc} terminology, affect
% only a few (probably widely dispersed) macros (or whatever). The basic
% idea is that you can define a change with a specific version, date,
% and text using the \DescribeMacro{\definechange}|\definechange| command
% and then recall those parameters later using the
% \DescribeMacro{\usechange}|\usechange| command. Primarily this ensures
% that the entry texts are identical so that \package{makeindex} will
% combine them into one entry, but it is also specified which macro
% was changed at which page. See Section~\ref{Sec:Changes} for more
% details. Another new feature concerning |\changes| is that there is
% now support for sorting version numbers according to mathematical
% order rather than ASCII order. Traditionally the version numbers
% \texttt{2}, \texttt{11}, and \texttt{100} would have been sorted so
% that \texttt{100}${}<{}$\texttt{11}${}<{}$\texttt{2}, but if they are
% entered as \DescribeMacro{\uintver}|\uintver{2}|, |\uintver{11}|, and
% |\uintver{100}| then they will be sorted as
% \texttt{2}${}<{}$\texttt{11}${}<{}$\texttt{100}. The argument of
% |\uintver| must be a \TeX\ \meta{number}.
%
% \medskip
%
% \package{xdoc} also contains several features which are of little use
% as direct user commands, but which can simplify the definitions of other
% commands. The foremost of these are the `harmless character strings',
% which can be seen as a datatype for (short pieces of) verbatim text.
% \TeX\ typesets a harmless character string in pretty much the same way
% as the corresponding string of `other' tokens, but the harmless
% character string can also be written to file and read back arbitrarily
% many times without getting garbled, it doesn't make \package{makeindex}
% choke, and it survives being fed to a |\protected@edef|. The most
% important commands related to harmless character strings are
% \DescribeMacro\PrintChar|\PrintChar|, which is used for representing
% problematic characters, and \DescribeMacro\MakeHarmless|\MakeHarmless|,
% which converts arbitrary \TeX\ code to the corresponding harmless
% character string.
%
% The superfluity of indexing commands in \package{doc} has been
% replaced by the single command \DescribeMacro\IndexEntry|\IndexEntry|,
% which has been designed with the intention that it should provide a
% clear interface between the user level macros and the index sorting
% program. It takes three arguments: the index entry specification, the
% name of the encapsulation scheme that should be used, and the number to
% put in the index. The index entry specification is a sequence of
% |\LevelSame| and\slash or |\LevelSorted| commands, which have the
% respective syntaxes
% \begin{quote}
% \DescribeMacro\LevelSame|\LevelSame|\marg{text}\\
% \DescribeMacro\LevelSorted|\LevelSorted|\marg{sort key}\marg{text}
% \end{quote}
% Each such command specifies one level of the index entry. In the case of
% |\LevelSorted|, the \meta{text} is what will be written in the sorted
% index at that level and \meta{sort key} is what the index-sorting
% program should look at when sorting the entry (at that level). In the
% case of |\LevelSame|, the \meta{text} is used both as sort key and
% contents of entry in the sorted index. The first command is for the
% topmost level and each subsequent command is for the next sublevel.
% The complete description appears in Subsection~\ref{Ssec:IndexEntry}.
%
% \package{xdoc} also contains support for external cross-referencing
% programs (see Subsection~\ref{Ssec:XXR} for details) and a system for
% determining whether a piece of text falls on an even or an odd page
% (see Section~\ref{Sec:Twoside} for details). I expect that the latter
% system will eventually migrate out of \package{xdoc}, either to a
% package of its own, or into oblivion because the \LaTeXplus\ output
% routine makes it obsolete.
%
%
% \subsection{The \package{docindex} package}
%
% As of prototype version 2.2, the \package{xdoc} package has a companion
% package \package{docindex}~\cite{docindex} which provides improved
% formatting of the index and list of changes. \package{xdoc} works fine
% without \package{docindex}, however.
%
%
% \subsection{A note on command names}
%
% The \package{doc} package defines several commands with mixed-case
% names which (IMHO) should really have all-lower-case names (according
% to the rule of thumb spelled out in \cite[Ssec.~2.4]{clsguide}) since
% people use them in the capacity of being the author of a \texttt{.dtx}
% file rather than in the capacity of being the writer of a class or
% package. The names in question are
% \begin{longtable}{ll}
% \textbf{Name in \package{doc}}& \textbf{Better (?) name}\endhead
% \cs{AlsoImplementation}& \cs{alsoimplementation}\\
% \cs{CharacterTable}& \cs{charactertable}\\
% \cs{CharTableChanges}& \cs{chartablechanges}\\
% \cs{CheckModules}& \cs{checkmodules}\\
% \cs{CheckSum}& \cs{checksum}\\
% \cs{CodelineIndex}& \cs{codelineindex}\\
% \texttt{CodelineNo} (counter)& \texttt{codelineno}\\
% \cs{CodelineNumbered}& \cs{codelinenumbered}\\
% \cs{DeleteShortVerb}& \cs{deleteshortverb}\\
% \cs{DescribeEnv}& \cs{describeenv}\\
% \cs{DescribeMacro}& \cs{describemacro}\\
% \cs{DisableCrossrefs}& \cs{disablecrossrefs}\\
% \cs{DocInput}& \cs{docinput}\\
% \cs{DoNotIndex}& \cs{donotindex}\\
% \cs{DontCheckModules}& \cs{dontcheckmodules}\\
% \cs{EnableCrossrefs}& \cs{enablecrossrefs}\\
% \cs{Finale}& \cs{finale}\\
% \texttt{GlossaryColumns} (counter)& \texttt{glossarycolumns}\\
% \cs{GlossaryPrologue}& \cs{glossaryprologue}\\
% \texttt{IndexColumns} (counter)& \texttt{indexcolumns}\\
% \cs{IndexInput}& \cs{indexinput}\\
% \cs{IndexPrologue}& \cs{indexprologue}\\
% \cs{MakePrivateLetters}& \cs{makeprivateletters}\\
% \cs{MakeShortVerb}& \cs{makeshortverb}\\
% \cs{OnlyDescription}& \cs{onlydescription}\\
% \cs{PageIndex}& \cs{pageindex}\\
% \cs{PrintChanges}& \cs{printchanges}\\
% \cs{PrintIndex}& \cs{printindex}\\
% \cs{RecordChanges}& \cs{recordchanges}\\
% \cs{SortIndex}& \cs{sortindex}\\
% \cs{SpecialEscapechar}& \cs{specialescapechar}\\
% \texttt{StandardModuleDepth} (counter)& \texttt{standardmoduledepth}\\
% \cs{StopEventually}& \cs{stopeventually}
% \end{longtable}
% \noindent With the exception for \texttt{CodelineNo},\footnote{Where I
% recommend using \texttt{codelineno} instead of \texttt{CodelineNo},
% \cs{PrintCodelineNo} instead of \cs{theCodelineNo}, and
% \cs{thecodelineno} instead of \cs{number}\cs{c@CodelineNo}; see
% Subsection~\ref{Ssec:CodelineNo}.} I haven't changed any of the
% \package{doc} names in this \package{xdoc} prototype, nor introduced any
% of the ``better names'' as alternatives, but I think the matter should
% be given a bit of thought during the future development of
% \package{doc}\slash \package{xdoc}.
%
% For completeness, I should also remark that there are several macros
% that \package{doc} gives mixed-case names which I haven't listed above.
% The logo command names have special capitalizing rules by tradition.
% Some macros and named registers---for example |\Docstyle|\-|Parms|,
% |\Index|\-|Parms|, |\Macro|\-|Font|, |\Macro|\-|Topsep|,
% |\Make|\-|Percent|\-|Ignore|, and |\Print|\-|Macro|\-|Name|---are part
% of the package or document class writer's interface to \package{doc},
% although I cannot claim it to be obvious that for example
% |\Index|\-|Parms| and the \texttt{IndexColumns} counter should belong
% to different classes here (but several of these control sequences will
% probably disappear from the interface in \LaTeXplus\ anyway, so the
% problem isn't that important). The |\Special|\dots\B|Index| commands
% (and their even more special variants, such as
% |\Left|\-|Brace|\-|Index|) are internal commands rather than user level
% commands. Finally there is the |\Get|\-|File|\-|Info| command, which I
% doubt there is any point in having.
%
%
% \StopEventually{}
%
%
% \subsection{\package{docstrip} modules}
%
% The \package{docstrip} modules in \texttt{xdoc2.dtx} are:
% \begin{description}
% \item[\textsf{pkg}]
% This module directive surrounds the code for the \package{xdoc}
% package.
% \item[\textsf{driver}]
% The driver.
% \item[\textsf{internals}]
% This module contains an alternative replacement text for the
% |\Print|\-|Visible|\-|Char| command that uses ``\LaTeX\ internal
% character representation'' (i.e., as much as possible
% encoding-specific commands---|\text|\textellipsis\ commands and
% the like) rather than the primitive |\char| command for
% typesetting visible characters.
% It is provided as a separate module mainly for compability with
% prototype version~2.0, as this alternative definition can (as of
% prot.\,2.1) be chosen by passing the option
% \describeoption{notrawchar}\texttt{notrawchar} to \package{xdoc}.
% \item[\textsf{economical}]
% There is little point in storing the harmless representations of
% the 161 non-visible-ASCII characters as these representations are
% always the same and can be formed on the fly whenever they are
% needed. The \textsf{economical} modules contain some alternative
% code which makes use of this fact to reduce the number of control
% sequences used for storing the table of harmless representations.
% The \Module{economical} module appears inside the \Module{pkg}
% module.
% \item[\textsf{xdoc2}]
% This module contains code for compability with previous releases
% of \package{xdoc2}. It will not be included in \package{xdoc3}
% or \package{xdoc} (whichever is the next major version).
% \item[\textsf{enccmds}]
% This module contains the code for defining two \texttt{macro}-like
% environments for encoding-specific commands. These are not included
% in the \package{xdoc} package since so few \texttt{.dtx} files
% define encoding-specific commands.
% \item[\textsf{rsrccmd}]
% Similar to the \textsf{enccmds} module, but demonstrates the
% |\New|\-|Describe|\-|Command| command instead.
% \item[\textsf{example}]
% This surrounds some code which to \package{docstrip} looks like it
% should be copied, but isn't meant to.
% \end{description}
%
%
%
% \section{Initial stuff}
%
% First there's the usual |\NeedsTeXFormat| and |\ProvidesPackage|.
% \begin{macrocode}
%<*pkg>
\NeedsTeXFormat{LaTeX2e}[1995/12/01]
\ProvidesPackage{xdoc2}[2003/07/06 prot2.5 doc reimplementation package]
% \end{macrocode}
%
% \subsection*{Options}
%
% The first option has to do with the page layout.
% Although \package{doc} itself doesn't modify any of the main layout
% parameters, it is well known that using it does tend to restrict
% one's choices in terms of document layout. In particular the
% \texttt{macro} and \texttt{environment} environments require a rather
% large left margin since they will otherwise print long macro names
% partially outside the paper. It is furthermore hard to decrease the
% |\textwidth| as it should be wide enough to contain about 70 columns of
% |\MacroFont| text. Thus the only solution is to do as the
% \package{ltxdoc}~\cite{ltxdoc} document class and enlarge the left
% margin at the expense of the right.
%
% The resulting layout has a left--right asymmetry with the main galley
% (the text rectangle) on the right and a very wide left margin (in
% which marginal headings and marginal notes appears). Although this
% layout is not uncommon in technical manuals, it is inappropriate for
% two-sided designs since the vertical line at which the two pages of a
% spread meet becomes the natural vertical symmetry axis for the entire
% spread and it breaks this symmetry to let the left margin be the
% widest on all pages. It would look better to always let the outer
% margin be the largest.
%
% \begin{option}{dolayout}
% \begin{macro}{\oddsidemargin}
% The \texttt{dolayout} option modifies |\oddsidemargin| so that
% spreads are symmetric around the center in two-sided mode. As size
% of the outer margin is taken the size of the left margin on left
% (even) pages, i.e., |\evensidemargin|${}+1\,\mathrm{in}$.
%
% In one-sided mode, the \texttt{dolayout} option does nothing.
% \begin{macrocode}
\DeclareOption{dolayout}{%
\if@twoside
\setlength\oddsidemargin{\paperwidth}
\addtolength\oddsidemargin{-\textwidth}
\addtolength\oddsidemargin{-\evensidemargin}
\addtolength\oddsidemargin{-2in}
\fi
}
% \end{macrocode}
% \end{macro}\end{option}
%
% \begin{option}{olddocinclude}
% \begin{option}{fileispart}
% The \texttt{olddocinclude} and \texttt{fileispart} options are
% related to the |\DocInclude| command defined by the \package{ltxdoc}
% document class. Some of the code related to that command relies on
% modifying the \package{doc} internal macro |\codeline@wrindex|, but
% that has no effect with \package{xdoc} so in order to get the
% expected results one has to reimplement the |\DocInclude| command as
% well. The \texttt{olddocinclude} and \texttt{fileispart} options
% control how this should be done.
%
% If the \texttt{olddocinclude} option is passed to \package{xdoc}
% then only the parts of the implementation of |\DocInclude| which
% must be altered to make the command work with the \package{xdoc}
% implementation of indexing and cross-referencing are changed. These
% redefinitions will furthermore only be made if the \package{ltxdoc}
% document class has been loaded; nothing is done if the
% \texttt{olddocinclude} option is passed and \package{ltxdoc} hasn't
% been loaded. Passing the \texttt{olddocinclude} option can be
% considered as requesting a ``compatibility mode'' for |\DocInclude|.
%
% If the \texttt{olddocinclude} option is not passed then the
% |\DocInclude| command is reimplemented from scratch, regardless of
% whether some definition of it has already been given or not. The
% basis of this reimplementation is the observation that the
% |\DocInclude| command of \package{ltxdoc} really does two quite
% distinct things at once---it is an |\include| command which
% |\DocInput|s files rather than |\input|ting them, but it also starts
% a new |\part|, sets the pagestyle, and changes how the values of
% some counters are typeset. This latter function is by default
% disabled in the \package{xdoc} implementation of |\DocInclude|, but
% passing the \texttt{fileispart} option enables it.
%
% There is no code for these two options here, as it is rather long;
% instead that code appears in Section~\ref{Sec:DocInclude}. The
% |\Pass|\-|Options|\-|To|\-|Package| commands make sure that these
% options are registered as local options for \package{xdoc}, so that
% one can test for them using |\@if|\-|package|\-|with| below.
% \begin{macrocode}
\DeclareOption{olddocinclude}{%
\PassOptionsToPackage{\CurrentOption}{xdoc2}%
}
\DeclareOption{fileispart}{%
\PassOptionsToPackage{\CurrentOption}{xdoc2}%
}
% \end{macrocode}
% \end{option}\end{option}
%
% \changes{prot2.5}{2003/07/06}{Reregeristing options in case
% they were global. (LH)}
%
% \begin{option}{notrawchar}
% The \texttt{notrawchar} option controls how the |\PrintVisibleChar|
% command is defined, and thereby what method is used for typesetting
% visible characters in e.g.\ macro names. The default is to use the
% |\char| primitive (which is better for \texttt{T1}-encoded fonts and
% non-italic \texttt{OT1}-encoded typewriter fonts), but the
% \texttt{notrawchar} option causes things to go via the ``\LaTeX\
% internal character representation'' instead (which is necessary
% for e.g.\ \texttt{OT1}-encoded non-typewriter fonts).
%
% There is no code for this option here; instead that code is found
% in the definition of |\Print|\-|Visible|\-|Char|.
% \begin{macrocode}
\DeclareOption{notrawchar}{%
\PassOptionsToPackage{\CurrentOption}{xdoc2}%
}
% \end{macrocode}
% \end{option}
%
%
% Then options are processed.
% \begin{macrocode}
\ProcessOptions\relax
% \end{macrocode}
% And finally the \package{doc} package is loaded.
% \begin{macrocode}
\RequirePackage{doc}
% \end{macrocode}
%
%
% \section{Character strings}
%
% A source of much of the complexity in \package{doc} is that it has to
% be able to deal with rather arbitrary strings of characters (mainly
% the names of control sequences). Once the initial problems with
% characters having troublesome catcodes have been overcome however, it
% is usually no problem to manage such things in \TeX. \package{doc}
% does however complicate things considerably by also putting these
% things in the index and list of changes. Not only must they then be
% formatted so that the \package{makeindex} program doesn't choke on
% them, but they must also be wrapped up in code that allows \TeX\ to
% make sense of them when they are read back. \package{doc} manages the
% \package{makeindex} problems mainly by allowing the user to change what
% characters are used as \package{makeindex} metacharacters and the
% reading back problem by making abundant use of |\verb|.
%
% All this relies on that the author of a document is making sure that
% the metacharacters aren't used for anything else. If for example the
% |\verbatimchar| (by default |+|) is one of the ``private letters''
% then names of control sequences containing that character will be
% typeset incorrectly because the |\verb| used to typeset it is
% terminated prematurely---control sequence names such as `|\lost+found|'
% will be typeset as `|\lost|found+'. On top of that, one also has to
% make sure that the font used for typesetting these |\verb| sections
% contains all the characters needed.
%
% For \package{xdoc}, I have chosen a completely different approach.
% Instead of allowing the strings (after they have converted to the
% internal format) to contain \TeX\ character tokens with arbitrary
% character codes, they may only contain \TeX\ character tokens which
% are unproblematic---the normal catcode should be 11 (letter) or 12
% (other), they should not be outside visible ASCII, and they may not
% be one of the \package{makeindex} metacharacters. All other characters
% are represented using a robust command which takes the character code
% (in decimal) as the argument. This takes care of all ``moving
% argument'' type problems that may occur.
%
% An important observation about these character strings is that
% they are strings of \emph{input} characters. This means that rather
% than using the characters in some special font for typesetting
% control sequences like |\^^M| (recall that the |^^| substitutions
% take place before tokenization), one should typeset them using only
% visible ASCII characters. (After all, that's the only way they are
% written in \TeX\ code.) The default definition is to typeset
% invisible characters as precisely the |^^|-sequences that \TeX\
% normally uses for these characters when they are written to a file.
%
%
% \subsection{Typesetting problematic characters}
%
% \begin{macro}{\PrintChar}
% \begin{macro}{\XD@threedignum}
% The |\PrintChar| command has the syntax
% \begin{quote}
% |\PrintChar|\marg{8-bit number}
% \end{quote}
% where \meta{8-bit number} is a \TeX\ number in the range 0--255.
% For arguments in the range 0--31, |\PrintChar| prints
% `\textit{\ttfamily\string^\string^@}'--`\textit{\ttfamily
% \string^\string^\string_}'. For an argument in the range 32--126,
% |\PrintChar| calls |\Print|\-|Visible|\-|Char| which by default
% simply does |\char| on that argument (but which can be redefined
% if the font set-up requires it); in particular, |\PrintChar{32}|
% should print a ``visible space'' character. |\PrintChar{127}| prints
% `\textit{\ttfamily\string^\string^?}'. For arguments in the range
% 128--255, |\PrintChar| prints
% `\textit{\ttfamily\string^\string^80}'--`\textit{\ttfamily
% \string^\string^ff}'.
%
% |\PrintChar| is robust. |\PrintChar| also has a special behaviour
% when it is written to a file (when |\protect| is |\noexpand|): it
% makes sure that the argument consists of three decimal digits, to
% ensure external sorting gets it right.
% \begin{macrocode}
\@ifundefined{PrintChar}{}{%
\PackageInfo{xdoc2}{Redefining \protect\PrintChar}%
}
\def\PrintChar{%
\ifx \protect\@typeset@protect
\expandafter\XD@PrintChar
\else\ifx \protect\noexpand
\string\PrintChar
\expandafter\expandafter \expandafter\XD@threedignum
\else
\noexpand\PrintChar
\fi\fi
}
% \end{macrocode}
%
% |\XD@threedignum| does a |\number| on its argument, possibly prepends
% a |0| or two, and wraps it all up in a ``group'' (the braces have
% category other, not beginning and end of group).
% \changes{prot2.1}{2000/11/15}{Braces inserted by
% \cs{XD@threedignum} are given catcode other. (LH)}
% \begin{macrocode}
\edef\XD@threedignum#1{%
\string{%
\noexpand\ifnum #1<100 %
\noexpand\ifnum #1<10 0\noexpand\fi
0%
\noexpand\fi
\noexpand\number#1%
\string}%
}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\XD@PrintChar}
% \begin{macro}{\InvisibleCharPrefix}
% \begin{macro}{\InvisibleCharSuffix}
% |\XD@PrintChar| manages the typesetting for |\PrintChar|. It
% distinguishes between visible characters (code 32--126) and
% invisible characters. The visible characters are typeset directly
% using |\PrintVisibleChar|, whereas the invisible characters are
% typeset as |^^|-sequences.
%
% The macros |\InvisibleCharPrefix| and |\InvisibleCharSuffix| begin
% and end a |^^|-sequence. |\InvisibleCharPrefix| should print the
% actual |^^|, but it may also for example select a new font for
% the |^^|-sequence (such font changes are restored at the end of
% |\XD@PrintChar|).
% \begin{macrocode}
\def\XD@PrintChar#1{%
\leavevmode
\begingroup
\count@=#1\relax
\ifnum \@xxxii>\count@
\advance \count@ 64%
\InvisibleCharPrefix
\PrintVisibleChar\count@
\InvisibleCharSuffix
\else\ifnum 127>\count@
\PrintVisibleChar\count@
\else
\InvisibleCharPrefix
\ifnum 127=\count@ \PrintVisibleChar{63}\else
\@tempcnta=\count@
\divide \count@ \sixt@@n
\@tempcntb=\count@
\multiply \count@ \sixt@@n
\advance \@tempcnta -\count@
\advance \@tempcntb \ifnum 9<\@tempcntb 87\else 48\fi
\advance \@tempcnta \ifnum 9<\@tempcnta 87\else 48\fi
\char\@tempcntb \char\@tempcnta
\fi
\InvisibleCharSuffix
\fi\fi
\endgroup
}
% \end{macrocode}
% \begin{macrocode}
\newcommand\InvisibleCharPrefix{%
\/\em
\PrintVisibleChar{`\^}\PrintVisibleChar{`\^}%
}
\newcommand\InvisibleCharSuffix{\/}
% \end{macrocode}
% There are some alternative methods for making hexadecimal numbers
% which should perhaps be mentioned. The \LaTeX\ kernel contains a
% macro |\hexnumber@| which uses |\ifcase| to produce one hexadecimal
% digit, but that uses upper case letters, and things like `8E' look
% extremely silly if the upper case letters doesn't line with the
% digits. Applying |\meaning| to a \meta{chardef token} or
% \meta{mathchardef token} expands to |\char"|\meta{hex} and
% |\mathchar"|\meta{hex} respectively, where \meta{hex} is the
% corresponding number in hexadecimal, but that too has upper case A--F
% and leading zeros are removed.
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\PrintVisibleChar}
% \changes{prot2.1}{2000/12/18}{Made it possible to select the
% alternative defintion of \cs{PrintVisibleChar} through an
% \package{xdoc} package option. (LH)}
% The |\PrintVisibleChar| command should print the visible ASCII
% character whose character code is given in the argument. There are
% currently two definitions of this command: one which uses the \TeX\
% primitive |\char| and one which goes via the ``\LaTeX\ internal
% character representation'' for the character. By default
% \package{xdoc} uses the former definition, but if \package{xdoc}
% is passed the
% \SortIndex{notrawchar}{\texttt{notrawchar} option\encapchar usage}
% \texttt{notrawchar} option then it will use the latter.
%
% The reason there are two definitions is a deficiency in how the NFSS
% encoding attribute has been assigned to fonts; even though the
% encodings of Computer Modern Roman and Computer Modern Typewriter
% are quite different, \LaTeXe\ uses the \texttt{OT1} encoding for
% both. As a result of this, the \LaTeX\ internal representation will
% in some important cases use characters from non-typewriter fonts
% despite the fact that typewriter forms are immediately available.
% Since the cases in which the |\char| primitive produces results as
% least as good as those made through the \LaTeX\ internal
% character representation includes those that the current font is
% \texttt{T1}-encoded or an \texttt{OT1}-encoded nonitalic typewriter
% font, the shorter |\char| primitive defintion has been made the
% default.
%
% For compability with prototype version~2.0 of \package{xdoc}, the
% replacement text for |\Print|\-|Visible|\-|Char| that uses \LaTeX\
% internal character representation can alternatively be extracted by
% \package{docstrip}ping \texttt{xdoc2.dtx} with the option
% \Module{internals}.
% \begin{macrocode}
\@ifpackagewith{xdoc2}{notrawchar}{%
\newcommand\PrintVisibleChar[1]{%
%</pkg>
%<*pkg|internals>
\ifcase #1%
\or\or\or\or\or\or\or\or \or\or\or\or\or\or\or\or
\or\or\or\or\or\or\or\or \or\or\or\or\or\or\or\or
% "20
\textvisiblespace \or!\or\textquotedbl \or\#\or\textdollar
\or\%\or\&\or\textquoteright\or(\or)\or*\or+\or,\or-\or.\or/%
\or % "30
0\or1\or2\or3\or4\or5\or6\or7\or8\or9\or:\or;\or
\textless\or=\or\textgreater\or?%
\or % "40
@\or A\or B\or C\or D\or E\or F\or G\or
H\or I\or J\or K\or L\or M\or N\or O%
\or % "50
P\or Q\or R\or S\or T\or U\or V\or W\or X\or Y\or Z\or [\or
\textbackslash \or]\or\textasciicircum \or\textunderscore
\or % "60
\textquoteleft \or a\or b\or c\or d\or e\or f\or g\or h\or
i\or j\or k\or l\or m\or n\or o%
\or % "70
p\or q\or r\or s\or t\or u\or v\or w\or x\or y\or z\or
\textbraceleft \or\textbar \or\textbraceright \or
\textasciitilde
\fi
}%
%</pkg|internals>
%<*pkg>
}{%
\newcommand\PrintVisibleChar[1]{\char #1\relax}%
}
% \end{macrocode}
% \end{macro}
%
%
% \begin{macro}{\Bslash}
% It turns out that it is very common to say |\PrintChar{92}|
% (backslash), so a macro which expands to that reduces typing.
% \begin{macrocode}
\newcommand\Bslash{\PrintChar{92}}
% \end{macrocode}
% \end{macro}
%
%
% \subsection{Rendering character strings harmless}
%
% Replacing all problematic characters with |\PrintChar| calls certainly
% makes the strings easier to manage, but actually making those
% replacements is a rather complicated task. Therefore this subsection
% contains the macros necessary for doing these replacements.
%
% The first problem is how to efficiently recognise the problematic
% characters. A first solution which gets rather far is to mainly look
% in the |\catcode| register for that character and keep the character
% as it is if the category found there is 11 or 12, but replace it with
% a |\PrintChar| command if the category is anything else. Two extra
% tests can be performed to take care of invisible ASCII, and the
% \package{makeindex} metacharacters can be cared for by locally
% changing their catcodes for when the string is processed.
% Unfortunately this doesn't work inside \texttt{macrocode}
% environments (where one would like to use it for the macro
% cross-referencing) since that environment changes the catcodes of
% several characters from being problematic to being unproblematic and
% vice versa.\footnote{As the entire \texttt{macrocode} environment is
% tokenized by the expansion of \cs{xmacro@code} one could alternatively
% solve this problem by reimplementing the \texttt{macrocode}
% environment so that normal catcodes are in force when the contents are
% being typeset.} As furthermore harmless character strings should be
% possible to move to completely different parts of the document, the
% test used for determining whether a character is problematic should
% yield the same result throughout the document.
%
% Because of this, I have chosen a brute strength solution: build a
% table (indexed by character code) that gives the harmless form of
% every character. This table is stored in the
% \describecsfamily{XD@harmless@\meta{code}}^^A
% |\XD@harmless@|\meta{code} family of control sequences, where the
% \meta{code} is in the range |0|--|255|. Assignments to this table are
% global. In principle, the table should not change after the preamble,
% but there is a command |\SetHarmState| which can be used at any time
% for setting a single table entry. This could be useful for documents
% which, like for example~\cite{fontinst}, have nonstandard settings of
% |\catcode|s.
%
% \begin{macro}{\SetHarmState}
% The |\SetHarmState| command takes three arguments:
% \begin{quote}
% |\SetHarmState|\marg{type}\marg{char}\marg{harm}
% \end{quote}
% \meta{char} is the character whose entry should be set. \meta{type}
% is a flag which specifies what format \meta{char} is given in. If
% \meta{type} is |\BooleanTrue| then \meta{char} is the \TeX\
% \meta{number} of the table entry to set, and if \meta{type} is
% |\BooleanFalse| then \meta{char} is something which expands to a
% single character token whose entry should be set. The expansion is
% carried out by an |\edef|, so it needs not be only one level.
% \meta{harm} is |\BooleanTrue| if the character is problematic and
% |\BooleanFalse| if it is not.
%
% The \meta{type} and \meta{harm} arguments are currently not subject
% to any expansion. In the future they probably should be, but I
% don't want to make assumptions about the actual definitions of
% |\BooleanTrue| and |\BooleanFalse| at this point.
% \begin{macrocode}
\begingroup
\catcode\z@=12
\@ifdefinable\SetHarmState{
\gdef\SetHarmState#1#2#3{%
\begingroup
\ifx #1\BooleanTrue
\count@=#2\relax
\else
\protected@edef\@tempa{#2}%
\count@=\expandafter`\@tempa\relax
\fi
\ifx #3\BooleanTrue
\edef\@tempa{\noexpand\PrintChar{\the\count@}}%
\else
\uccode\z@=\count@
\uppercase{\def\@tempa{^^@}}%
\fi
\global\expandafter\let
\csname XD@harmless@\the\count@ \endcsname \@tempa
\endgroup
}%
}
\endgroup
% \end{macrocode}
% \end{macro}
%
% \begin{trivlist}\item[]\leavevmode ^^A Just for the look of it
% \GenericDescribePrint{\small\cs{XD@harmless@}\meta{code}}^^A
% ^^A There should have been a "main" index entry here as well,
% ^^A but generating that with \package{doc} commands is more than I
% ^^A bother to do right now.
% Initializing the |\XD@harmless@|\meta{code} table is a
% straightforward exercise of |\loop| \dots\ |\repeat|.
% \begin{macrocode}
%<*!economical>
\count@=\z@
\loop
\expandafter\xdef \csname XD@harmless@\the\count@ \endcsname
{\noexpand\PrintChar{\the\count@}}%
\advance \count@ \@ne
\ifnum 33>\count@ \repeat
%</!economical>
%<economical>\count@=\@xxxii
\begingroup
\catcode\z@=12\relax
\@firstofone{%
\endgroup
\loop
\if \ifnum 11=\catcode\count@ 1\else \ifnum 12=\catcode\count@
1\else 0\fi\fi 1%
\uccode\z@=\count@
\uppercase{\def\@tempa{^^@}}%
\else
\edef\@tempa{\noexpand\PrintChar{\the\count@}}%
\fi
\global\expandafter\let
\csname XD@harmless@\the\count@ \endcsname \@tempa
\advance \count@ \@ne
\ifnum 127>\count@ \repeat
}
%<*!economical>
\loop
\expandafter\xdef \csname XD@harmless@\the\count@ \endcsname
{\noexpand\PrintChar{\the\count@}}%
\ifnum \@cclv>\count@
\advance \count@ \@ne
\repeat
%</!economical>
% \end{macrocode}
% Marking the \package{makeindex} metacharacters as harmful is
% deferred until |\begin|\nolinebreak[2]|{document}|, since it is not
% unreasonable that these are changed in the preamble.
% \begin{macrocode}
\AtBeginDocument{%
\SetHarmState\BooleanFalse\actualchar\BooleanTrue
\SetHarmState\BooleanFalse\encapchar\BooleanTrue
\SetHarmState\BooleanFalse\levelchar\BooleanTrue
\SetHarmState\BooleanFalse\quotechar\BooleanTrue
}
% \end{macrocode}
% \package{doc}'s |\verbatimchar| is not harmful, since it isn't used
% at all in \package{xdoc}.
% \end{trivlist}
%
%
% \begin{macro}{\MakeHarmless}
% To render a character string harmless, you do
% \begin{quote}
% |\MakeHarmless|\marg{macro}\marg{string}
% \end{quote}
% This locally assigns to \meta{macro} the harmless character string
% which corresponds to \meta{string}. During the conversion the converted
% part of the string is stored in |\toks@|, but that is local to
% |\MakeHarmless|.
% \begin{macrocode}
\def\MakeHarmless#1#2{%
\begingroup
\toks@={}%
\escapechar=`\\%
\XD@harmless@#2\XD@harmless@
\expandafter\endgroup \expandafter\def \expandafter#1%
\expandafter{\the\toks@}%
}
% \end{macrocode}
%
% \begin{macro}{\XD@harmless@iii}
% \begin{macro}{\XD@harmless@iv}
% \begin{macro}{\XD@harmless@v}
% \changes{prot2}{2000/07/27}{Moved code for adding to \cs{toks@} here
% and changed it to append the contents of \cs{XD@harmless@32}, not
% necessarily a \cs{PrintChar}. (LH)}
% \begin{macro}{\XD@harmless@vi}
% What one has to be most careful about when rendering strings
% harmless are the space tokens, since many of \TeX's primitives gladly
% snatches an extra space (or more) where you don't want them to in
% this case. Macro parameters can be particularly dangerous, as \TeX\
% will skip any number of spaces while looking for the replacement
% text for an undelimited macro argument. Therefore the algorithm for
% rendering a character token harmless begins
% (|\XD@|\B|harmless@iii|) with |\string|ing the next token in the
% string---this preserves the character code and sets the category to
% 12 for all characters except the ASCII space, which gets category 10
% (space)---and then |\futurelet| is used to peek at the next token. If
% it is a space token (|\XD@|\B|harmless@iv|) then the character code
% is 32 and the actual space can be gobbled (|\XD@|\B|harmless@v|), and
% if it isn't then the next token can be grabbed in an undelimited macro
% argument (|\XD@|\B|harmless@vi|). In either case, the harmless form
% is given by the |\XD@|\B|harmless@|\meta{code} table entry
% (in |\XD@|\B|harmless@v| or |\XD@|\B|harmless@vi|).
% \begin{macrocode}
\def\XD@harmless@iii{%
\expandafter\futurelet \expandafter\@let@token
\expandafter\XD@harmless@iv \string
}
% \end{macrocode}
% \begin{macrocode}
\def\XD@harmless@iv{%
\ifx \@let@token\@sptoken
\expandafter\XD@harmless@v
\else
\expandafter\XD@harmless@vi
\fi
}
% \end{macrocode}
% ^^A Hack:
% \begingroup
% \expandafter\def \expandafter\MakePrivateLetters \expandafter{^^A
% \MakePrivateLetters
% \catcode`3=11
% \catcode`2=11
% }
% \begin{macrocode}
\begingroup
\catcode`3=\catcode`a
\catcode`2=\catcode`a
\@firstofone{\gdef\XD@harmless@v} {%
\toks@=\expandafter{\the \expandafter\toks@ \XD@harmless@32}%
\XD@harmless@
}
\endgroup
% \end{macrocode}
% \endgroup
% In the \Module{economical} (with hash table space) variant
% implementation the |\XD@harmless@|\meta{code} table has entries only
% for the characters in visible ASCII. Thus the harmless forms of
% characters outside visible ASCII must be constructed on the fly.
% \begin{macrocode}
\def\XD@harmless@vi#1{%
%<*economical>
\if \ifnum `#1<\@xxxii 1\else \ifnum `#1>126 1\else 0\fi\fi 1%
\toks@=\expandafter{\the\expandafter\toks@
\expandafter\PrintChar \expandafter{\number`#1}%
}%
\else
%</economical>
\toks@=\expandafter{\the\expandafter\expandafter\expandafter\toks@
\csname XD@harmless@\number`#1\endcsname}%
%<economical> \fi
\XD@harmless@
}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\XD@harmless@}
% \begin{macro}{\XD@harmless@i}
% \begin{macro}{\XD@harmless@ii}
% But that is not all |\MakeHarmless| can do. In some cases (as for
% example when one is describing a family of control sequences) one
% might want to include things in the string that are not simply
% characters, but more complex items---such as for example |\meta|
% constructions like \meta{code}. To accommodate for this,
% |\XD@harmless@| (which is the first step in converting a token)
% always begins by checking whether the next token to render harmless
% is a control sequence. If it is then it is checked (in
% |\XD@harmless@ii|) whether the control sequence
% \describecsfamily{XD@harmless\Bslash\meta{cs-name}}^^A
% |\XD@harmless\|\meta{cs-name}, where \meta{cs-name} is the name
% without |\| of the control sequence encountered, is defined. If it
% isn't then the encountered control sequence is |\string|ed and
% conversion continues as above, but if it is defined then the
% encountered control sequence begins such a more complex item.
% \begin{macrocode}
\def\XD@harmless@{\futurelet\@let@token \XD@harmless@i}
% \end{macrocode}
% \begin{macrocode}
\def\XD@harmless@i{%
\ifcat \noexpand\@let@token \noexpand\XD@harmless@
\expandafter\XD@harmless@ii
\else
\expandafter\XD@harmless@iii
\fi
}
% \end{macrocode}
% \begin{macrocode}
\def\XD@harmless@ii#1{%
\@ifundefined{XD@harmless\string#1}{%
\expandafter\XD@harmless@vi \string#1%
}{\csname XD@harmless\string#1\endcsname}%
}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\XD@harmless\XD@harmless@}
% A control sequence |\XD@harmless\|\meta{cs-name} is responsible for
% interpreting the string item that begins with the control sequence
% |\|\meta{cs-name} and appending a harmless representation of it to
% |\toks@|. Harmless representations should only contain robust
% control sequences and they must not rely on changing any catcodes.
% Normal |\XD@harmless\|\meta{cs-name} control sequences must also
% end by inserting |\XD@harmless@| in front of what remains of the
% string after the complex string item has been removed. This sees to
% that the rest of the string is also rendered harmless. The only such
% control sequence which does not insert |\XD@harmless@| is
% |\XD@harmless\XD@harmless@|, but that is as it should be since
% |\MakeHarmless| itself appends a |\XD@harmless@| to every character
% string it should convert to mark the end of it.
% \begin{macrocode}
\expandafter\let
\csname XD@harmless\string\XD@harmless@\endcsname \@empty
% \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\XD@harmless\PrintChar}
% It is occasionally convenient to use a |\PrintChar| command as part
% of a string that is to be rendered harmless instead of using the raw
% character. The definition is very similar to that of
% |\XD@harmless@vi|.
% \begin{macrocode}
\@namedef{XD@harmless\string\PrintChar}#1{%
%<*economical>
\if \ifnum #1<\@xxxii 1\else \ifnum #1>126 1\else 0\fi\fi 1%
\toks@=\expandafter{\the\expandafter\toks@
\expandafter\PrintChar \expandafter{\number#1}%
}%
\else
%</economical>
\toks@=\expandafter{\the\expandafter\expandafter\expandafter\toks@
\csname XD@harmless@\number#1\endcsname}%
%<economical> \fi
\XD@harmless@
}
% \end{macrocode}
% \end{macro}
%
%
% \subsection{Interaction with mechanisms that make characters
% problematic}
%
% If additional visible characters are made problematic after the
% initial |\XD@harmless@|\meta{code} table is formed then problems may
% indeed arise, because some character which is expected to be
% unproblematic when read from (for example) an \texttt{.ind} file will
% actually not be. In fortunate cases this will only lead to that
% characters will print strangely or not at all, but it can quite
% conceivably lead to errors that prevent further typesetting and it
% should therefore be prevented if possible.
%
% Right now, I can think of two mechanisms that make characters
% problematic, and both do that by making them active. One is the
% shorthand mechanism of \package{babel}, but I think I'll delay
% implementing any interaction with that until some later prototype; I
% don't know it well enough and anyway I don't think it is that likely
% to cause any problems. The other mechanism is the short verb mechanism
% of \package{doc} itself, and this should be taken care of right away.
%
% The main difficulty is that the |\XD@harmless@|\meta{code} table should
% be the same throughout the document body (otherwise you may get more
% than one index entry for the same thing, with index references
% arbitrarily distributed between the two) whereas short verb characters
% can be made and deleted at any time. It would actually be wrong to
% always have the |\XD@harmless@|\meta{code} table entry mirroring the
% current state of the character! Instead a character will be considered
% as problematic even if it is only made problematic temporarily (with
% the exception for characters that are made problematic in
% \texttt{verbatim} environments and the like---the index file isn't
% being read in while those catcodes are active). Since it is impossible
% to know in the beginning of a document whether a character will be made
% a short verb character at some later point, the modifications to the
% |\XD@harmless@|\meta{code} table that will be made because of short verb
% characters will (at least partially) be based on which characters were
% made short verbs on the previous run.
%
% \begin{macro}{\SetCharProblematic}
% \changes{prot2}{2000/07/26}{Command added. (LH)}
% The |\SetCharProblematic| command should be called by commands which
% make a character problematic (e.g.\ makes it active) in the general
% context (commands which make some character problematic only in some
% very special context, such as the \texttt{verbatim} environment,
% need not call |\Set|\-|Char|\-|Problematic|). The syntax is
% \begin{quote}
% |\SetCharProblematic|\marg{code}
% \end{quote}
% and it sets the ``harm state'' of the character whose code is
% \meta{code} to problematic.
%
% When |\SetCharProblematic| is called in the preamble, it sets the
% harm state on the current run. When it is called in the document
% body however, it sets the harm state on the next run by writing a
% |\SetHarmState| command to the \texttt{.aux} file. This is done to
% ensure that the contents of the |\XD@harmless@|\meta{code} table
% doesn't change during the body of a document.
% \begin{macrocode}
\newcommand\SetCharProblematic[1]{%
\SetHarmState\BooleanTrue{#1}\BooleanTrue
}
\AtBeginDocument{%
\gdef\SetCharProblematic#1{%
\if@filesw
\immediate\write\@auxout{\string\SetHarmState
\string\BooleanTrue {\number#1}\string\BooleanTrue}%
\fi
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\add@specials}
% \changes{prot2}{2000/07/26}{Redefinition added. (LH)}
% |\MakeShortVerb|'s call to |\SetCharProblematic| is put in the
% |\add@|\B|specials| macro, which anyway already adds the character
% to the |\dospecials| and |\@sanitize| lists. Only familiar
% definitions of |\add@special| are changed.
% \begin{macrocode}
\def\@tempa#1{%
\rem@special{#1}%
\expandafter\gdef\expandafter\dospecials\expandafter
{\dospecials \do #1}%
\expandafter\gdef\expandafter\@sanitize\expandafter
{\@sanitize \@makeother #1}}
\ifx \@tempa\add@special
\def\add@special#1{%
\rem@special{#1}%
\expandafter\gdef\expandafter\dospecials\expandafter
{\dospecials \do #1}%
\expandafter\gdef\expandafter\@sanitize\expandafter
{\@sanitize \@makeother #1}%
\SetCharProblematic{`#1}%
}
\else
\PackageWarningNoLine{xdoc2}{Unfamiliar definition of
\protect\add@special;\MessageBreak the macro was not patched}
\fi
% \end{macrocode}
% \end{macro}
%
%
%
% \section{Indexing}
% \label{Sec:Indexing}
%
% Each type of index entry \package{doc} produces is implemented through
% a different indexing command.\footnote{Sometimes there are
% even more than one command per entry type---the \cs{SpecialIndex},
% \cs{LeftBraceIndex}, \cs{RightBraceIndex}, and \cs{PercentIndex}
% commands all generate entries of the same type.} This might be
% manageable when there are only \texttt{macro}s and
% \texttt{environment}s to distinguish between, but it soon gets
% unmanageable if more environments of this type are added. Therefore
% all \package{xdoc} index entries are made with a single
% command---|\IndexEntry|.
%
%
% \subsection{New basic indexing commands}
% \label{Ssec:IndexEntry}
%
% \begin{macro}{\IndexEntry}
% \begin{macro}{\LevelSame}
% \changes{prot2.1}{2000/11/18}{New name for \cs{levelsame}. (LH)}
% \begin{macro}{\LevelSorted}
% \changes{prot2.1}{2000/11/18}{New name for \cs{levelsorted}. (LH)}
% \begin{macro}{\XD@if@index}
% The |\IndexEntry| command writes one index entry to the \texttt{.idx}
% file. It takes three arguments:
% \begin{quote}
% |\IndexEntry|\marg{entry text}\marg{encap}\marg{thenumber}
% \end{quote}
% The \meta{entry text} contains the text for the entry. It is a
% nonempty sequence of commands in which each item is one of
% \begin{quote}
% |\LevelSame|\marg{text}\\
% |\LevelSorted|\marg{sort key}\marg{text}
% \end{quote}
% Each such item specifies one level of the entry that is to be
% written. In the case of |\LevelSorted|, the \meta{text} is what will
% be written in the sorted index at that level and \meta{sort key} is
% a key which the index-sorting program should use for sorting that
% entry at that level. In the case of |\LevelSame|, the \meta{text} is
% used both as sort key and contents of entry in the sorted index.
% The first item is for the topmost level and each subsequent item is
% for the next sublevel. The \meta{entry text} will be fully expanded
% by the |\IndexEntry| command.
%
% \meta{thenumber} is the number (if any) that the index entry refers
% to. It can consist of explicit characters, but it can also be a
% |\the|\meta{counter} control sequence or a macro containing such
% control sequences. \meta{thenumber} is fully expanded by the
% |\IndexEntry| command, with the exception for occurrences of
% |\thepage|---expansion of |\thepage| will instead be delayed until
% the page is shipped out, so that the page numbers will be right.
% \textbf{Note:} \meta{thenumber} must not contain any formatting that
% will upset the index-sorting program. \package{doc}'s default
% definition of |\theCodelineNo| contains such formatting, so one
% must instead use |\thecodelineno| as \meta{thenumber} in that case.
%
% \meta{encap} is the name of the encapsulation scheme that should be
% applied to \meta{thenumber}. All encapsulation schemes that have been
% implemented instruct the index sorting program to wrap up
% \meta{thenumber} in some code that gives it special formatting when
% the sorted index is written, but one could also use the \meta{encap}
% to specify `beginning of range' and `end of range' index entries.
% Use \GenericDescribePrint{\small\texttt{none}}^^A
% \SortIndex{none}{\texttt{none}\encapchar usage}\texttt{none} as
% \meta{encap} if you don't want any special formatting.
%
% \textbf{Note:} |\IndexEntry| uses |\@tempa| internally, so you
% cannot use that in argument \#2 or \#3. Using it in argument \#1
% presents no problems, though.
% \begin{macrocode}
\newcommand\IndexEntry[3]{%
\@bsphack
\begingroup
\def\LevelSame##1{\levelchar##1}%
\def\LevelSorted##1##2{\levelchar##1\actualchar##2}%
\protected@edef\@tempa{#1}%
\protected@edef\@tempa{\expandafter\@gobble\@tempa\@empty}%
\@ifundefined{XD@idxencap@#2}{%
\PackageError{xdoc2}{Index entry encap `#2' unknown}\@eha
}{%
\XD@if@index{%
\csname XD@idxencap@#2\endcsname\@tempa{#3}%
}{}%
}%
\endgroup
\@esphack
}
% \end{macrocode}
% |\IndexEntry| does (like |\index|) not contribute any material to the
% current list if indices aren't being made.
%
% |\XD@if@index| is |\@firstoftwo| if index entries are being written
% and |\@second|\-|of|\-|two| if they are not.
% \begin{macrocode}
\let\XD@if@index=\@secondoftwo
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
%
% In \LaTeXplus, the \cs{IndexEntry} command should probably be
% implemented using templates, e.g. the \meta{encap}s could be names of
% instances.
%
% \begin{macro}{\levelsame}
% \begin{macro}{\levelsorted}
% These names were used for |\LevelSame| and |\LevelSorted|
% respectively in prototype version~2.0, but the macros should belong
% to the same capitalization class as |\IndexEntry| so their names
% were changed in prototype version~2.1. The old names |\levelsame|
% and |\levelsorted| will continue to work in \package{xdoc2}, though.
% \begin{macrocode}
%<*xdoc2>
\newcommand*\levelsame{\LevelSame}
\newcommand*\levelsorted{\LevelSorted}
%</xdoc2>
% \end{macrocode}
% \end{macro}\end{macro}
%
% \describecsfamily{XD@idxencap@\meta{encap}}^^A
% Macros in the family |\XD@idxencap@|\meta{encap} takes two
% arguments as follows
% \begin{quote}
% |\XD@idxencap@|\meta{encap}\,\marg{entry}\,\marg{thenumber}
% \end{quote}
% They should write an entry with the \meta{encap} encapsulation of the
% \meta{thenumber} to the index file. They need not check whether index
% generation is on or not, but they must be subject to the \LaTeX\ kernel
% \texttt{@filesw} switch. They must expand both arguments fully at the
% time of the command, with the exception for the control sequence
% |\thepage|, which should not be expanded until the page on which the
% write appears is output. Both these conditions are met if the macro
% is implemented using |\protected@write|.
%
% \begin{macro}{\XD@idxencap@none}
% \begin{macro}{\XD@idxencap@main}
% \begin{macro}{\XD@idxencap@usage}
% These macros implement the encapsulation schemes that are used in
% \package{doc}.
% \begin{macrocode}
\def\XD@idxencap@none#1#2{%
\protected@write\@indexfile{}{\XD@index@keyword{#1}{#2}}%
}
% \end{macrocode}
% \begin{macrocode}
\def\XD@idxencap@main#1#2{%
\protected@write\@indexfile{}%
{\XD@index@keyword{#1\encapchar main}{#2}}%
}
% \end{macrocode}
% \begin{macrocode}
\def\XD@idxencap@usage#1#2{%
\protected@write\@indexfile{}%
{\XD@index@keyword{#1\encapchar usage}{#2}}%
}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\XD@index@keyword}
% \changes{prot2.2}{2001/02/13}{Macro added and \meta{encap} macros
% changed to use it. (LH)}
% The |\XD@index@keyword| is a hook for changing the index entry
% keyword (the text that is put in front of every index entry in the
% \texttt{.idx} file). It is changed by e.g.\ the \package{docindex}
% package~\cite{docindex}.
% \begin{macrocode}
\@ifundefined{XD@index@keyword}{%
\edef\XD@index@keyword{\@backslashchar indexentry}%
}{}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\CodelineIndex}
% \changes{prot2.1}{2000/10/08}{Using \cs{thecodelineno}. (LH)}
% \begin{macro}{\PageIndex}
% \begin{macro}{\TheXDIndexNumber}
% The |\CodelineIndex| and |\PageIndex| commands do the same things as
% in \package{doc}, but work with the \package{xdoc} internals instead
% of the \package{doc} ones. |\TheXDIndexNumber| is used as
% \meta{thenumber} argument to |\IndexEntry| by all indexing commands
% that would have used |\special@index| in \package{doc}.
% \begin{macrocode}
\renewcommand\CodelineIndex{%
\makeindex
\let\XD@if@index=\@firstoftwo
\codeline@indextrue
\def\TheXDIndexNumber{\thecodelineno}%
}
% \end{macrocode}
% \begin{macrocode}
\renewcommand\PageIndex{%
\makeindex
\let\XD@if@index=\@firstoftwo
\codeline@indexfalse
\def\TheXDIndexNumber{\thepage}%
}
% \end{macrocode}
% \begin{macrocode}
\def\TheXDIndexNumber{??}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
%
% \subsection{Making good sort keys}
%
% \changes{prot2.1}{2000/11/15}{Sort key making commands added. (LH)}
% A common nuisance in \package{doc} indices is that many macros are
% sorted by parts of the name that do not carry any interesting
% information. In the \LaTeX\ kernel many macro names begin with a
% silent |@|, whereas the names of private macros in many packages
% (including this one) begin with some fixed abbreviation of the
% package name. Since such prefixes usually are harder to remember than
% the rest of the macro name, it is not uncommon that the index position
% one thinks of first isn't the one where the macro actually is put.
% Hence a mechanism for removing such annoying prefixes from the macro
% names might be useful, and that is presicely what is defined below.
%
% The actual mechanism is based on having a set of macros called
% \emph{operators} which operate on the harmless character string that
% is to become the sort key. Each operator has a specific prefix string
% which it tries to match against the beginning of the to-be sort key,
% and if they match then the prefix is moved to the end of the sort key.
% Automatically constructed operators (see below) have names of the form
% \describecsfamily{XD@operatorA@\meta{prefix}}|\XD@operatorA@|^^A
% \meta{prefix}, but operators can be given arbitrary names.
%
% \begin{macro}{\XD@operators@list}
% The |\XD@operators@list| macro contains the list of all currently
% active operators.
% \begin{macrocode}
\let\XD@operators@list\@empty
% \end{macrocode}
% \end{macro}
%
% The operators do all their work at expand-time. When an operator
% macro is expanded, it is in the context
% \begin{quote}
% \meta{operator} \meta{subsequent operators} |\@firstofone|
% \meta{sort key text} |\@empty|
% \end{quote}
% There may not be any |\@empty|s or |\@firstofone|s amongst the
% \meta{subsequent operators} or in the \meta{sort key text}. This should
% expand to
% \begin{quote}
% \meta{subsequent operators} |\@firstofone| \meta{operated-on sort
% key text} |\@empty|
% \end{quote}
% The purpose of the |\@firstofone| after the \meta{subsequent
% operators} is to remove any spaces that some operator might have put
% in front of the sort key. This happens if the entire sort key text has
% been ignored by some operator.
%
% \begin{macro}{\MakeSortKey}
% The |\MakeSortKey| command is called to make the acutal sort key.
% The syntax of this command is
% \begin{quote}
% |\MakeSortKey|\marg{macro}\marg{text}\marg{extras}
% \end{quote}
% This locally defines \meta{macro} to be the sort key that the
% currently active operators manufacture from \meta{text}. The
% \meta{extras} argument can contain additional assignments needed for
% handling macros with special harmless forms, such as |\meta|.
% \begin{macrocode}
\newcommand\MakeSortKey[3]{%
\begingroup
\def\PrintChar{\string\PrintChar\XD@threedignum}%
#3%
\unrestored@protected@xdef\@gtempa{#2}%
\endgroup
\protected@edef#1{%
\expandafter\XD@operators@list \expandafter\@firstofone
\@gtempa\@empty
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\XD@make@operator}
% The |\XD@make@operator| macro takes a harmless character sequence as
% argument, constructs the corresponding operator, and returns the
% operator control sequence in the |\toks@| token list register.
%
% More precisely, given a harmless character string \meta{string},
% |\XD@make@operator| will construct a sequence of other tokens
% \meta{text} from \meta{string} by replacing all |\PrintChar|
% commands in the same way as |\MakeSortKey| does. Then it defines the
% macro |\XD@operatorA@|\meta{text} to be
% \begin{quote}
% \raggedright \spaceskip=0.16666em
% \#1\,|\@firstofone|\,\#2\,|\@empty| \ $\rightarrow$ \ %
% |\XD@operatorB@|\meta{text} |\@firstofone| \#2
% |\@firstofone| \meta{text} |\@firstofone| |\relax| \#1 |\@empty|
% \end{quote}
% and the macro |\XD@operatorB@|\meta{text} to do
% \begin{quote}
% \raggedright
% \#1\,|\@firstofone|\,\meta{text}\,\#2\,|\@firstofone|\,\#3\,^^A
% |\relax|\,\#4\,|\@empty| $\rightarrow$
% \#4\,\( \left\{ \begin{array}{ll}
% \mbox{\cs{@firstofone}\,\#2\,\textvisiblespace\,\meta{text}\,^^A
% \cs{@empty}}& \mbox{if \#1 is empty}\\
% \mbox{\#1\,\cs{@empty}}& \mbox{otherwise}
% \end{array} \right.\)
% \end{quote}
%
% \begin{macrocode}
\def\XD@make@operator#1{%
\begingroup
\def\PrintChar{\string\PrintChar\XD@threedignum}%
\let\protect\@gobble
\xdef\@gtempa{#1}%
\endgroup
\expandafter\edef \csname XD@operatorA@\@gtempa\endcsname
##1\@firstofone##2\@empty{%
\expandafter\noexpand \csname XD@operatorB@\@gtempa\endcsname
\noexpand\@firstofone ##2\noexpand\@firstofone \@gtempa
\noexpand\@firstofone \relax##1\noexpand\@empty
}%
\expandafter\edef \csname XD@operatorB@\@gtempa \expandafter\endcsname
\expandafter##\expandafter1\expandafter\@firstofone \@gtempa
##2\@firstofone##3\relax##4\@empty{%
\noexpand\ifx $##1$%
\noexpand\expandafter \noexpand\@firstoftwo
\noexpand\else
\noexpand\expandafter \noexpand\@secondoftwo
\noexpand\fi{%
##4\noexpand\@firstofone ##2 \@gtempa
}{##4##1}%
\noexpand\@empty
}%
\toks@=\expandafter{\csname XD@operatorA@\@gtempa\endcsname}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\DoNotIndexBy}
% The |\DoNotIndexBy| command has the syntax
% \begin{quote}
% |\DoNotIndexBy|\marg{morpheme}
% \end{quote}
% It causes the \meta{morpheme} to be put \emph{last} in the index
% sort key for each macro name which begins by \meta{morpheme}. This
% can be used to ignore e.g.\ ``silent'' |@|s at the beginning of a
% macro name.
% \begin{macrocode}
\newcommand\DoNotIndexBy[1]{%
\MakeHarmless\@tempa{#1}%
\XD@make@operator\@tempa
\expandafter\def \expandafter\XD@operators@list \expandafter{%
\the\expandafter\toks@ \XD@operators@list
}%
}
% \end{macrocode}
% \end{macro}
%
%
%
%
% \subsection{Reimplementations of \package{doc} indexing commands}
%
% The \package{doc} indexing commands aren't that interesting in
% \package{xdoc}, since they take `raw' control sequences as
% arguments rather than the harmless strings that the \package{xdoc}
% commands will want to put in the index. But it can be instructive to
% see how they would be implemented in this context.
%
% \begin{macro}{\SortIndex}
% \changes{prot2.2}{2001/02/13}{Redefinition added. (LH)}
% The |\SortIndex| takes a sort key and an entry text as argument, and
% writes a one-level index entry for that.
% \begin{macrocode}
\renewcommand*\SortIndex[2]{%
\IndexEntry{\LevelSorted{#1}{#2}}{none}{\thepage}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\SpecialIndex}
% \begin{macro}{\SpecialMainIndex}
% \begin{macro}{\SpecialUsageIndex}
% The |\SpecialIndex|, |\SpecialMainIndex|, and |\SpecialUsageIndex|
% commands take a control sequence (or more often something which looks
% like a |\string|ed control sequence) as their only argument. The
% entry text is that item verbatim, and the initial backslash is
% ignored in sorting (|\Special|\-|Index| always ignores the first
% character regardless of whether it is a backslash or not, the other
% two checks first). |\Special|\-|Index| has \texttt{none} formatting,
% |\Special|\-|Main|\-|Index| has \texttt{main} formatting, and
% |\Special|\-|Usage|\-|Index| has \texttt{usage} formatting of the
% index number.
%
% Although these definitions will (or at least are supposed to) yield
% the same typeset results as the \package{doc} definitions in the
% mainstream cases, I doubt that they will do so in all cases. At any
% rate, they shouldn't perform worse.
% \begin{macrocode}
\renewcommand\SpecialIndex[1]{%
\expandafter\MakeHarmless \expandafter\@tempa
\expandafter{\string#1}%
\IndexEntry{%
\LevelSorted{%
\expandafter\XD@unbackslash \@tempa\@empty
}{\texttt{\@tempa}}%
}{none}{\TheXDIndexNumber}%
}
% \end{macrocode}
% \begin{macrocode}
\renewcommand\SpecialMainIndex[1]{%
\expandafter\MakeHarmless \expandafter\@tempa
\expandafter{\string#1}%
\IndexEntry{%
\LevelSorted{%
\expandafter\XD@unbackslash \@tempa\@empty
}{\texttt{\@tempa}}%
}{main}{\TheXDIndexNumber}%
}
% \end{macrocode}
% \begin{macrocode}
\renewcommand\SpecialUsageIndex[1]{%
\expandafter\MakeHarmless \expandafter\@tempa
\expandafter{\string#1}%
\IndexEntry{%
\LevelSorted{%
\expandafter\XD@unbackslash \@tempa\@empty
}{\texttt{\@tempa}}%
}{usage}{\thepage}%
}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\XD@unbackslash}
% \begin{macro}{\XD@unbackslash@}
% |\XD@unbackslash| is a utility macro which removes the first
% character from a harmless character string if that character is a
% backslash (i.e., if it is |\PrintChar{92}|). The \package{doc}
% commands have traditionally used |\@gobble| for doing this, but the
% \cs{@SpecialIndexHelper@} macro that was comparatively recently added
% tries to do better.
% \begin{macrocode}
\def\XD@unbackslash#1{%
\ifx \PrintChar#1%
\expandafter\XD@unbackslash@
\else
\expandafter#1%
\fi
}
\def\XD@unbackslash@#1{\ifnum #1=92 \else \PrintChar{#1}\fi}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\SpecialMainEnvIndex}
% \begin{macro}{\SpecialEnvIndex}
% These are similar to the above, but \package{doc} thinks that the
% arguments don't need any special care, and it produces two index
% entries per command. |\Special|\-|Env|\-|Index| should really have
% been called |\Special|\-|Usage|\-|Env|\-|Index|.
% \begin{macrocode}
\renewcommand\SpecialMainEnvIndex[1]{%
\IndexEntry{\LevelSorted{#1}{\texttt{#1} (environment)}}{main}%
{\TheXDIndexNumber}%
\IndexEntry{\LevelSame{environments:}\LevelSorted{#1}{\texttt{#1}}}%
{main}{\TheXDIndexNumber}%
}
% \end{macrocode}
% \begin{macrocode}
\renewcommand\SpecialEnvIndex[1]{%
\IndexEntry{\LevelSorted{#1}{\texttt{#1} (environment)}}{usage}%
{\thepage}%
\IndexEntry{\LevelSame{environments:}\LevelSorted{#1}{\texttt{#1}}}%
{usage}{\thepage}%
}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\it@is@a}
% \begin{macro}{\XD@special@index}
% The |\it@is@a| macro is a specialized version of |\SpecialIndex|,
% but the format of its argument is quite different. After full
% expansion the argument will become a single category 12 token
% (\meta{t}, say), and the control sequence for which an entry should
% be made is |\|\meta{t}. \package{doc} uses |\it@is@a| for control
% sequences with one-character names. Note: The following
% definition should really have special code for the \Module{economical}
% \package{docstrip} module, but I don't think that is necessary
% since the \package{doc} macros which used |\it@is@a| will be
% redefined so that they don't.
%
% |\XD@special@index| does the same thing as |\SpecialIndex|, but it
% does it with \package{xdoc} datatypes---the argument must be a
% harmless character string that does not include the initial escape
% (backslash).
% \changes{prot2.1}{2000/11/15}{Using \cs{MakeSortKey} to make the
% sort key. (LH)}
% \begin{macrocode}
\def\it@is@a#1{%
\edef\@tempa{#1}%
\XD@special@index{\csname XD@harmless@\number
\expandafter`\@tempa\endcsname}%
}
% \end{macrocode}
% \begin{macrocode}
\def\XD@special@index#1{%
\MakeSortKey\@tempa{#1}{}%
\IndexEntry{\LevelSorted{\@tempa}{\texttt{\Bslash#1}}}{none}%
{\TheXDIndexNumber}%
}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\LeftBraceIndex}
% \begin{macro}{\RightBraceIndex}
% \begin{macro}{\PercentIndex}
% \begin{macro}{\OldMakeIndex}
% More specialised forms of |\SpecialIndex|. The |\OldMakeIndex|
% command can safely be made a no-op.
% \begin{macrocode}
\renewcommand\LeftBraceIndex{\XD@special@index{\PrintChar{123}}}
\renewcommand\RightBraceIndex{\XD@special@index{\PrintChar{125}}}
\renewcommand\PercentIndex{\XD@special@index{\PrintChar{37}}}
\let\OldMakeIndex\relax
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\@wrindex}
% \changes{prot2.2}{2001/02/13}{Redefinition added. (LH)}
% Finally, while we're at redefining indexing commands, let's redefine
% |\@wrindex| as well to ensure that the index entry keyword is the
% same for all indexing commands.
% \begin{macrocode}
\def\@wrindex#1{%
\protected@write\@indexfile{}{\XD@index@keyword{#1}{\thepage}}%
\endgroup
\@esphack
}
% \end{macrocode}
% \end{macro}
%
%
% \section{Cross-referencing}
%
% \subsection{Scanning \texttt{macrocode} for \TeX\ control sequences}
% \label{Ssec:Scanning macrocode}
%
% The cross-referencing mechanism in \package{doc} isn't problematic in
% the same way as the indexing mechanism is, so one could pretty much
% leave it as it is, but there are things that are better done
% differently when the basic indexing commands are based on harmless
% character strings. Rather than storing control sequence names (without
% escape character) as sequences of category 11 tokens, they will be
% stored as the equivalent harmless character strings.
%
% \begin{macro}{\macro@switch}
% As in \package{doc}, |\macro@switch| determines whether the control
% sequence name that follows consists of letters (call |\macro@name|)
% or a single non-letter (call |\short@macro|). Unlike \package{doc},
% \package{xdoc} accumulates the characters from a multiple-letter
% control sequence name in a token register (|\@toks|), which is why
% that is cleared here.
% \begin{macrocode}
\def\macro@switch{%
\ifcat\noexpand\next a%
\toks@={}%
\expandafter\macro@name
\else
\expandafter\short@macro
\fi
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\scan@macro}
% Since |\macro@namepart| isn't used as in \package{doc}, I might as
% well remove the command that cleared it from |\scan@macro|.
% \begin{macrocode}
\def\scan@macro{%
\special@escape@char
\step@checksum
\ifscan@allowed
\def\next{\futurelet\next\macro@switch}%
\else \let\next\@empty \fi
\next}
% \end{macrocode}
% \end{macro}
%
%
%
% \begin{macro}{\short@macro}
% This macro will be invoked (with a single character as parameter)
% when a single-character macro name has been spotted whilst
% scanning within the \texttt{macrocode} environment. It will produce
% an index entry for that macro, unless that macro has been excluded
% from indexing, and it will also typeset the character that
% constitutes the name of the macro.
% \begin{macrocode}
\def\short@macro#1{%
\protected@edef\macro@namepart{%
%<*economical>
\ifnum `#1<\@xxxii
\noexpand\PrintChar{\number`#1}%
\else\ifnum `#1>126
\noexpand\PrintChar{\number`#1}%
\else
%</economical>
\csname XD@harmless@\number`#1\endcsname
%<economical> \fi\fi
}%
\ifnot@excluded \XD@special@index{\macro@namepart}\fi
% \end{macrocode}
% The cross-referencing mechanism is disabled for when the actual
% character is printed, as it could be the escape character. The index
% entry must be generated before the character is printed to ensure
% that no page break intervenes (recall that a |^^M| will start a new
% line).
% \begin{macrocode}
\scan@allowedfalse #1\scan@allowedtrue
}
% \end{macrocode}
% \end{macro}
%
% There is one mechanism in |\TeX|'s control sequence tokenization that
% |\short@|\B|macro| doesn't cover, and that is the |^^| sequence
% substitution---|\^^M| is (with default catcodes) seen as the three
% tokens |\^|, |^|, and |M|, not as the single control
% sequence token that \TeX\ will make out of it. But this is the way it
% is done in \package{doc}.
%
%
% \begin{macro}{\macro@name}
% \begin{macro}{\more@macroname}
% \begin{macro}{\macro@finish}
% Then there's the macros for assembling a control sequence name which
% consists of one or more letters (category 11 tokens). (This includes
% both the characters which are normally letters in the document and
% those that are made letters by |\MakePrivateLetters|.) They're
% pretty straightforward.
% \begin{macrocode}
\def\macro@name#1{%
%<*economical>
\if \ifnum `#1<\@xxxii 1\else \ifnum `#1>126 1\else 0\fi\fi 1%
\toks@=\expandafter{\the\expandafter\toks@
\expandafter\PrintChar \expandafter{\number`#1}%
}%
\else
%</economical>
\toks@=\expandafter{\the\expandafter\expandafter\expandafter\toks@
\csname XD@harmless@\number`#1\endcsname}%
%<economical> \fi
\futurelet\next\more@macroname}
% \end{macrocode}
% \begin{macrocode}
\def\more@macroname{%
\ifcat\noexpand\next a%
\expandafter\macro@name
\else
\macro@finish
\fi
}
% \end{macrocode}
% \begin{macrocode}
\def\macro@finish{%
\edef\macro@namepart{\the\toks@}%
\ifnot@excluded \XD@special@index{\macro@namepart}\fi
\macro@namepart
}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
%
%
% \subsection{The index exclude list}
% \label{Ssec:Index-exclude}
%
% The index exclude list mechanisms are not quite as simple to convert
% for use with harmless character strings as the construction of macro
% names are. This is because the trick used for searching the exclude
% list for a certain string doesn't work if the string one is looking
% for contains tokens with category 1 or 2 (beginning and end of group),
% as the \meta{parameter text} of a |\def| cannot contain such tokens.
% On the other hand the only groups that can appear in the harmless
% character strings one will be looking for are the ones around the
% argument of some |\PrintChar|, and these can easily be converted to
% something else. Therefore an item in the index exclude list of
% \package{xdoc} will have the format
% \begin{quote}
% |\do|\,\meta{string}
% \end{quote}
% where the \meta{string} is different from a harmless character string
% only in that all |\PrintChar|\marg{num} have been replaced by
% |\PrintChar|\parg{num}. The \meta{string} does not include an escape
% character. The |\do| serves only to separate the item from the one
% before, but it could in principle be used for other purposes as well
% (such as in typesetting the entire exclude list).
%
% \begin{macro}{\XD@paren@PrintChar}
% |\XD@paren@PrintChar| is a definition of |\PrintChar| which, when it
% is used in an |\edef|, merely replaces the group around the argument
% by a parenthesis and normalizes the number in the argument.
% \changes{prot2.1}{2000/09/16}{\cs{number} added. (LH)}
% \begin{macrocode}
\def\XD@paren@PrintChar#1{\noexpand\PrintChar(\number#1)}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\DoNotIndex}
% \changes{prot2.1}{2000/09/16}{Also changing catcode of \%. (LH)}
% \begin{macro}{\do@not@index}
% \begin{macro}{\XD@do@not@index}
% These are the macros which add elements to the index exclude list.
% |\DoNotIndex| is pretty much as in \package{doc}, but I have added
% resetting of the catcodes of `|,|' (since |\XD@do@not@index| relies
% on it) and `|#|' (since it can otherwise mess things up for the
% |\def\@tempa| in |\do@not@index|).
% \begin{macrocode}
\renewcommand\DoNotIndex{%
\begingroup
\MakePrivateLetters
\catcode`\#=12\catcode`\\=12\catcode`,=12\catcode`\%=12
\expandafter\endgroup \do@not@index
}
% \end{macrocode}
%
% |\do@not@index|, on the other hand, is quite different, as it more
% or less has to convert the argument from the format used in
% \package{doc} to that of \package{xdoc}. The bulk of the work is
% done by |\XD@do@not@index|, which grabs one of the elements in the
% argument of |\do@not@index| and converts it (minus the initial
% backslash) to a harmless character string. That harmless character
% string is then converted by |\XD@paren@PrintChar|, so that the
% string can be searched for using |\expanded@notin|.
%
% The reason for using a special loop structure here, as opposed to
% using for example |\@for|, is that one cannot use either of |\|
% or |,| alone as item separators, as they may both be part of control
% sequence names (consider for example |\DoNotIndex{\a,\\,\b,\,,\c}|),
% but they should be sufficient when combined.
%
% The reason for storing new elements in |\toks@| until the end of
% the loop and only then inserting them into the index exclude list
% is speed; the index exclude list can get rather large, so you don't
% want to expand it more often than you have to. I don't know if the
% difference is noticeable, though.
% \begin{macrocode}
\begingroup
\catcode`\|=0
\catcode`\,=12
\catcode`\\=12
% \end{macrocode}
% \SpecialEscapechar{\|}
% \begin{macrocode}
|gdef|do@not@index#1{%
|def|@tempa{#1}%
|ifx |@empty|@tempa |else
|toks@={}%
|expandafter|XD@do@not@index |@gobble #1,\|XD@do@not@index,\%
|fi
}
|gdef|XD@do@not@index#1,\{%
|ifx |XD@do@not@index#1%
|index@excludelist=|expandafter{%
|the|expandafter|index@excludelist |the|toks@
}%
|expandafter|@gobble
|else
|MakeHarmless|@tempa{#1}%
|begingroup
|let|PrintChar|XD@paren@PrintChar
|unrestored@protected@xdef|@gtempa{|noexpand|do|@tempa}%
|endgroup
|toks@=|expandafter{|the|expandafter|toks@ |@gtempa}%
|fi
|XD@do@not@index
}
|endgroup
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\DoNotIndexHarmless}
% The |\DoNotIndexHarmless| command takes a harmless character string
% as argument and locally adds the control sequence whose name is that
% character string to the index exclude list.
% \begin{macrocode}
\newcommand\DoNotIndexHarmless[1]{%
\begingroup
\let\PrintChar\XD@paren@PrintChar
\unrestored@protected@xdef\@gtempa{\noexpand\do#1}%
\endgroup
\index@excludelist=\expandafter{%
\the\expandafter\index@excludelist \@gtempa
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\index@excludelist}
% In case the index exclude list is not empty, its contents are
% converted to \package{xdoc} format.
% \begin{macrocode}
\edef\@tempa{\the\index@excludelist}
\index@excludelist{}
\ifx \@tempa\@empty \else
\def\@tempb#1,\@nil{\do@not@index{#1}}
\expandafter\@tempb \@tempa \@nil
\let\@tempa\@empty
\let\@tempb\@empty
\fi
% \end{macrocode}
% The fact that the |\XD@|\B|harmless@|\B\meta{code} table has not
% yet reached its final form means that some of these control sequences
% listed in the exclude list might get a different form here than they
% actually should, but there isn't much that can be done about that. It
% is furthermore unusual that control sequence are given such names
% that they would be affected by this.
% \end{macro}
%
% \begin{macro}{\ifnot@excluded}
% The |\ifnot@excluded| macro ultimately boils down to an
% \texttt{if}, which evaluates to true if and only if the string in
% |\macro@namepart| is not one of the items in the index exclude
% list. Before |\expanded@notin| gets to carry out the actual test,
% the |\PrintChar| calls in |\macro@namepart| are converted by
% |\XD@paren@PrintChar| (it's OK to use an unprotected |\edef| for
% this, since |\PrintChar| is the only control sequence that can
% appear in |\macro@namepart|) so that |\expanded@notin| can be used
% to test for its presence.
% \begin{macrocode}
\def\ifnot@excluded{%
\begingroup
\let\PrintChar\XD@paren@PrintChar
\edef\@tempa{\macro@namepart}%
\expandafter\endgroup \expandafter\expanded@notin
\expandafter{\expandafter\do \@tempa\do}%
{\the\index@excludelist}%
}
% \end{macrocode}
% \end{macro}
%
%
% \subsection{External cross-referencing}
% \label{Ssec:XXR}
%
% (This subsection is a bit speculatory, but I think the structures it
% describes may come in handy.)
%
% \changes{prot2}{2000/07/31}{I finally decided that it would be better
% to make the XXR-commands look like comments to \TeX. (LH)}
%
% It's rather easy to write macros for scanning \TeX\ code for the names
% of control sequences---just look for the escape (category 0)
% character, and whatever follows is the name of a control sequence.
% Doing the same thing for other languages may lay anywhere between
% ``a~tricky exercise in advanced \TeX\ programming'' and ``possible in
% theory'',\footnote{I.e., you know it can be implemented as a computer
% program (in some language), you know that any computer program can be
% translated to a Turing machine (or if you prefer that, expressed in
% lambda calculus), and you know that a Turing machine can be emulated
% by \TeX, but that's the closest thing to a solution you've managed to
% come up with.} but in most cases the available solutions turn out to be
% too complicated and\slash or slow to be of practical use. When that
% happens, one might instead want to use some external piece of software
% for doing the cross-referencing.
%
% The commands in this subsection implement basic support for such an
% external cross-referencing program (or XXR,\footnote{Maybe not the
% most logical name, but it looks much cooler than ECR.} for short). The
% idea is that an XXR should communicate with \LaTeX\ like \BibTeX\
% does---scan the \texttt{.aux} file (or files, if we're |\include|ing
% things) for certain ``commands'' and use them to locate the files to
% cross-reference, get parameter settings (like for example entries for
% the index exclude list), and so on. It should then cross-reference the
% file(s) and write the index entries in a suitable format to some file
% (appending them to the \texttt{.idx} file is probably the easiest
% solution). This way, it is (almost) as simple to use as the built-in
% cross-referencing and the extra work for supporting it is (in
% comparison to not supporting it) negligible.
%
% \begin{xrefcmd}{ExternalXRefMsg}
% \begin{macro}{\SendExternalXRefMsg}
% \changes{prot2}{2000/07/28}{Added \cs{if@filesw} test. (LH)}
% It's hardly possible to predict all kinds of information that one
% might want to give to an XXR, and neither can one assume that
% there is only one XXR program that will read the \texttt{.aux}
% file. A complicated project might involve code in several languages,
% and each language might have its own XXR.
% Therefore the general XXR-command (text in an \texttt{.aux} file which
% is used for communicating information to an XXR) simply has the syntax
% \begin{quote}
% \verb*|%%ExternalXRefMsg |\marg{who}\verb*| |\marg{what}
% \end{quote}
% \meta{who} identifies the XXR this message is meant for. It must be
% balanced text to \TeX\ and may not contain any whitespace, but can
% otherwise be rather arbitrary. \meta{what} is the actual message. It
% too must be balanced text to \TeX\ and it may not contain any
% newlines, but it is otherwise arbitrary.
% \index{whitespace restrictions}^^A
% The reason for these restrictions on the contents of \meta{who} and
% \meta{what} is that many (maybe even most) scripting languages
% (which is what at least the \texttt{.aux}-scanning part of an
% XXR will probably be written in) are much better at recognising
% words on a line than they are at recognising a brace-delimited group.
% By accepting these restrictions, one can make sure that all XXRs can
% correctly determine whether a message is for them, even if they see
% the \texttt{.aux} file as a sequence of lines composed of
% whitespace-delimited words.
%
% |\SendExternalXRefMsg| is the basic command for writing
% |ExternalXRefMsg|s to the \texttt{.aux} file, but it might be
% recommendable that XXR writers provide users with a set of commands
% that have more specific purposes. The syntax of the
% |\Send|\-|External|\-|XRef|\-|Msg| command is (hardly surprising)
% \begin{quote}
% |\SendExternalXRefMsg|\marg{who}\marg{what}
% \end{quote}
% |\SendExternalXRefMsg| does a protected full expansion (like
% |\protected@edef|) of its arguments at the time it is called.
% \begin{macrocode}
\newcommand\SendExternalXRefMsg[2]{%
\begingroup
\if@filesw
\let\protect\@unexpandable@protect
\immediate\write\@auxout{\@percentchar\@percentchar
ExternalXRefMsg {#1} {#2}}%
\fi
\endgroup
}
% \end{macrocode}
% \end{macro}\end{xrefcmd}
%
% The remaining commands in this subsection address complications that
% exist because of how \texttt{.dtx} files are generally written, and
% thus constitutes difficulties that all XXRs will have to face.
%
% \begin{xrefcmd}{ExternalXRefFile}
% The usual way to write \texttt{.dtx} files is to include a
% driver---a~short piece of uncommented \LaTeX\ code which contains
% the necessary preamble material and a document body which mainly
% contains a |\DocInput| for the \texttt{.dtx} file itself---but it
% is also usually understood that this driver may be copied to another
% file if necessary and larger projects usually have a completely
% separate driver file. Therefore an XXR cannot be expected to be
% able to find the file(s) to cross-reference simply by changing
% suffix on the name of the \texttt{.aux} file it reads its commands
% from. A more intricate method must be used.
%
% To tell the XXR that ``here I input the file \dots'', one includes
% an |External|\-|XRef|\-|File| XXR-command in the \texttt{.aux} file.
% Its syntax is
% \begin{quote}
% \verb*|%%ExternalXRefFile |\marg{cmd}\verb*| |\marg{file}^^A
% \verb*| |\marg{what}
% \end{quote}
% \meta{file} is the name (as given to |\input| or the like) of the
% file to input. \meta{cmd} is either \texttt{begin} (begin of
% \meta{file}) or \texttt{end} (end of \meta{file}). \meta{what} is a
% declaration of what is in the file; XXRs should use it to determine
% whether they should process this file or not. \meta{what} is empty
% if all XXRs should process the file, but for example |\IndexInput|
% will put \texttt{TeX} here to declare that the contents of this file
% are \TeX\ code and only XXRs that cross-reference \TeX\ code need to
% process this file.
%
% In connection to this, it should be mentioned that XXRs must also look
% for (and act on) |\@input|\penalty\hyphenpenalty\marg{auxfile} commands
% that |\include| or |\DocInclude| has written to the \texttt{.aux} file,
% since these \meta{auxfile}s can also contain commands for the XXR
% that should result in output to the same \texttt{.idx} file. In
% particular, the |ExternalXRefFile| XXR-commands that are written
% because of a |\DocInclude| will be written to such an \meta{auxfile}.
% \end{xrefcmd}
%
% \begin{xrefcmd}{ExternalXRefSync}
% Most XXRs will probably find it an unreasonable task to keep exact
% track of all codelines in all documents, i.e., they will sometimes
% think that a piece of code contains more or fewer numbered
% codelines than it actually does. If for example a document contains
% code such as\iffalse
%<*example>
% \fi
%\begin{verbatim}
%% \iffalse
%% \begin{macrocode}
%Etaoin Shrldu
%% \end{macrocode}
%% \fi
%\end{verbatim}\iffalse
%</example>
%\fi
% then all reasonable XXRs will probably be fooled into thinking that
% the \texttt{Etaoin Shrldu} line is a numbered codeline. This would
% of course be very bad if an XXR thought it should cross-reference
% the contents of this line, but that shouldn't usually be a problem
% since the specifications\footnote{I imagine these specifications
% will consist of a list of \package{docstrip} options (modules),
% possibly used in combination with restrictions on the names of
% surrounding environments.} of what code should be cross-referenced
% will probably make it clear that the above line should not be
% cross-referenced. Code such as the above will still be problematic
% however, as it will cause the XXR to believe that the
% \texttt{codelineno} counter has another value on any following
% line that is indexed than it actually has in the typeset
% document. This will cause index entries to refer to another line
% than it actually should.
%
% To overcome this, the |ExternalXRefSync| XXR-command can be used to
% tell the XXR what the corresponding values of |\inputlineno| and
% \texttt{codelineno} are. Its syntax is
% \begin{quote}
% \verb*|%%ExternalXRefSync |\marg{inputlineno}\verb*| |^^A
% \marg{codelineno}
% \end{quote}
% where \meta{inputlineno} is the expansion of |\the\inputlineno| and
% \meta{codelineno} is the expansion of |\thecodelineno|, both
% expanded at the same point in the program. Note here that the first
% line of a file is line number 1, that line number 0 is used to
% denote ``just before the first line'', and that \texttt{codelineno}
% gets increased immediately before the number is typeset (i.e.,
% \texttt{codelineno} contains the number of the last numbered
% codeline).
% \end{xrefcmd}
%
% This doesn't support external cross-referencing by pages, since doing
% that requires that the document outputs a lot more information to the
% \texttt{.aux} file. In principle, one could put a |\mark|\penalty0
% |{\thecodelineno}| in |\PrintCodelineNo| and a |\write| in the page
% header which outputs to the \texttt{.aux} file which range of
% codelines correspond to a given page, but the \LaTeXe\ sectioning
% commands' use of marks tends to interfere with this. The \LaTeXplus\
% package \package{xmarks} will probably solve that problem, though.
%
% \begin{macro}{\syncexternalxref}
% \changes{prot2}{2000/07/28}{New name for \cs{SendExternalXRefSync}.
% Also added \cs{if@filesw} test. (LH)}
% ^^A Johann Sebastian Bach: 1685/03/21--1750/07/28
% The |\syncexternalxref| command writes an |ExternalXRefSync|
% XXR-command for the current line number and value of the
% \texttt{codelineno} counter to \texttt{.aux} file. It is used for
% synchronizing the numbered codeline counter that an XXR maintains with
% the \texttt{codelineno} counter that is used for numbering codelines
% in the typeset document after a piece of code in the document that
% some XXR is likely to misinterpret. |\sync|\-|external|\-|xref|
% shouldn't be used inside \texttt{macrocode} environments (or the
% like) as they tend to read ahead in the file---instead it is best
% placed shortly after such an environment. |\sync|\-|external|\-|xref|
% has no arguments.
% \begin{macrocode}
\newcommand\syncexternalxref{%
\if@filesw
\immediate\write\@auxout{\@percentchar\@percentchar
ExternalXRefSync {\the\inputlineno} {\thecodelineno}%
}%
\fi
}
% \end{macrocode}
% \end{macro}
%
% \begin{xrefcmd}{ExternalXRefWrap}
% The |\DocInclude| command complicates matters for XXRs by redefining
% things so that the \texttt{codelineno} counter only makes up a part
% of the line numbers appearing in the index. The purpose of the
% |External|\-|XRef|\-|Wrap| XXR-command is to inform XXRs about such
% changes. The command
% \begin{quote}
% \verb*|%%ExternalXRefWrap {|\meta{prefix}\verb*|} {|^^A
% \meta{suffix}|}|
% \end{quote}
% means that codeline numbers written to the index should have the form
% \begin{quote}
% \meta{prefix}\meta{codelineno}\meta{suffix}
% \end{quote}
% This setting takes effect from the next |External|\-|XRef|\-|Sync|
% and stays in effect until the end of the document or until another
% |External|\-|XRef|\-|Wrap| overrides it. The state at the beginning
% of the document is to have both \meta{prefix} and \meta{suffix}
% empty.
% \end{xrefcmd}
%
%
% \begin{macro}{\XD@input}
% The |\XD@input| command is a version of |\input| which takes care
% to inform XXRs that another file is being |\input|ted. Its syntax is
% \begin{quote}
% |\XD@input|\marg{file}\marg{what}
% \end{quote}
% where \meta{file} is the name of the file to |\input| and \meta{what}
% is the contents of the file, as specified in
% |External|\-|XRef|\-|File| commands.
% \begin{macrocode}
\def\XD@input#1#2{%
\if@filesw
\immediate\write\@auxout{\@percentchar\@percentchar
ExternalXRefFile {begin} {#1} {#2}%
}%
\immediate\write\@auxout{\@percentchar\@percentchar
ExternalXRefSync {0} {\thecodelineno}%
}%
\fi
\input{#1}%
\if@filesw
\immediate\write\@auxout{\@percentchar\@percentchar
ExternalXRefFile {end} {#1} {#2}%
}%
\immediate\write\@auxout{\@percentchar\@percentchar
ExternalXRefSync {\the\inputlineno} {\thecodelineno}%
}%
\fi
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\DocInput}
% The |\DocInput| command is redefined so that it writes
% |External|\-|XRef|\-|File| and |External|\-|XRef|\-|Sync| XXR-commands
% to the \texttt{.aux} file. Furthermore, with \package{xdoc} one
% should always use the |\DocInput| command (or some command based on
% it, like |\DocInclude|) for inputting a file where percent is an
% `ignore' character---even when one such file inputs another. (Doing
% that didn't work with the \package{doc} definition, as it always
% called |\MakePercentComment| upon return, but the \package{xdoc}
% definition contains code for dealing with that.)
% \begin{macrocode}
\renewcommand\DocInput[1]{%
\relax
\ifnum \catcode`\%=14
\expandafter\@firstoftwo
\else
\expandafter\@secondoftwo
\fi{%
\MakePercentIgnore\XD@input{#1}{}\MakePercentComment
}{\XD@input{#1}{}}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\IndexInput}
% The |\IndexInput| command also needs to be redefined to write
% XXR-commands to the \texttt{.aux} file. It would
% probably be enough here to write an |External|\-|XRef|\-|Sync|
% after the file has been |\input| since no external
% cross-referencing of |\IndexInput|ted files is needed, but I do the
% more verbose variant here just to exemplify how these things would
% look for other languages.
% \begin{macrocode}
\renewcommand\IndexInput[1]{%
\begingroup
\macro@code
\frenchspacing
\@vobeyspaces
\XD@input{#1}{TeX}%
\endmacrocode
\endgroup
}
% \end{macrocode}
% \end{macro}
%
%
%
% \section{Two-sided printing}
% \label{Sec:Twoside}
%
% The main problem one faces when reimplementing \package{doc} so that
% the marginal material always appears in the outer margin in two-sided
% documents is that the justification of \package{doc}'s marginal
% material is asymmetric; it always extends outwards. This means that
% the justification to use when typesetting the marginal material must
% depend on whether it is to be put on a left or a right
% page---something which cannot be determined for sure when the
% material is typeset! This is a minor difficulty if the marginal material
% is put in place using \LaTeX's |\marginpar| command, as that allows the
% user to supply different versions of the marginal paragraph for left and
% right margin placements. It is however a major difficulty if the
% marginal material is displaced out into the margin from within the main
% galley (like the \texttt{macro} environment of \package{doc} does),
% since the output routine is never involved.
%
% Even though this difficulty provides arguments for using a |\marginpar|
% mechanism for all text that is put in the margin, that will not be
% done in \package{xdoc} (but maybe it will in some successor).
% Instead \package{xdoc} contains a general mechanism which uses data
% written to the \texttt{.aux} file for determining whether a piece of
% text was put on an odd or even numbered page the \emph{last} time the
% document was typeset. By the usual convergence of page breaks in a
% \LaTeX\ document, this will eventually produce a typeset document
% with the marginal material consistently in the outer margin.
%
% The mechanism works as follows. The places in the document (the
% document source) at which it is necessary to determine whether
% something is going to appear on an even (left) or an odd (right) page
% are called ``page situations''\footnote{I know it's not a particularly
% good name. Suggestions for better names are gracefully accepted.} or
% just ``situations''. In each situation, a relatively simple test (is
% the \texttt{page} counter currently even or odd?) which is right more
% often than not is used as a first guess, and both the guess, the
% placement actually used, and the correct answer (determined from the
% value of \texttt{page} when the piece of text is shipped out) are
% recorded in the \texttt{.aux} file. If the guess (for the current
% situation) coincided with the correct answer the last time the
% document was typeset then the guess determined now is used, otherwise
% the opposite of the guess determined now is used. Finally, when at
% |\end{document}| the \texttt{.aux} file is inputted to check for
% changed labels, the placements used are also checked and the user is
% given a suitable warning if there was an incorrect one.
%
% \begin{macro}{\IfOddPageSituation}
% The |\IfOddPageSituation| macro is the user level test for whether
% the current page situation appears on an odd or an even page. It
% has the syntax
% \begin{quote}
% |\IfOddPageSituation|\marg{odd}\marg{even}
% \end{quote}
% and this will expand to \meta{odd} if the current situation is
% expected to end up on an odd page (based on how correct it was to
% look at the value of \texttt{page} last time) and to \meta{even}
% otherwise. In single-sided mode, it always expands to \meta{even}.
% In two-sided mode, |\IfOddPageSituation| is redefined for the new
% situation each time |\StepPageSituation| is called.
% \begin{macrocode}
\let\IfOddPageSituation=\@secondoftwo
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\StepPageSituation}
% \changes{prot2.1}{2000/12/19}{Now also setting
% \cs{IfOddPageSituation}, instead of having that macro performing
% the test each time it is used. This fixes a rarely occuring bug
% which occurs when a page is shipped out between
% \cs{StepPageSituation} and a corresponding
% \cs{IfOddPageSituation}. (LH)}
% \begin{macro}{\macro@cnt}
% \begin{macro}{\XD@next@wrong}
% \begin{macro}{\XD@wrongs@list}
% The |\StepPageSituation| command is called to inform the page
% situation mechanism that a new situation has begun. The rule for
% when you need to use |\Step|\-|Page|\-|Situation| is simple: if you
% use |\IfOdd|\-|Page|\-|Situation| in two places which may end up on
% different pages, then there must be a |\Step|\-|Page|\-|Situation|
% between them. There is no code which automatically calls
% |\Step|\-|Page|\-|Situation|---not even |\clearpage| or other
% macros which force page breaks do this---hence macros which use
% the page situation mechanism must always call |\Step|\-|Page|\-^^A
% |Situation| explicitly when a new situation begins.
%
% Since the |\macro@cnt| count register isn't used for stacking
% marginal headings (``macro'' names) anymore (see below), it is
% employed for enumerating page situation. |\XD@next@wrong| is a macro
% which contains the number of the next situation in which the guess
% was wrong last time. Unless |\XD@next@wrong|${}={}$|\macro@cnt|, the
% guess was right last time. All assignments to |\macro@cnt| and
% |\XD@next@wrong| are global.
%
% |\XD@wrongs@list| is a list of all the wrong guesses. It has the
% syntax
% \begin{quote}
% |\@elt|\marg{guess no.}|\@elt|\marg{guess no.}\dots
% |\@elt|\marg{guess no.}
% \end{quote}
% where the \meta{guess no.}s are the numbers of the wrong guesses, in
% increasing order. The contents of |\XD@wrongs@list| are collected
% when the \texttt{.aux} file is inputted at |\begin|\B|{document}|,
% and they are removed again as \TeX\ passes the situation in the
% document that they apply to. All assignments to |\XD@wrong@list| are
% global.
%
% Calling |\StepPageSituation| increases |\macro@cnt| by one,
% updates |\XD@|\B|next@|\B|wrong| and |\XD@|\B|wrong@|\B|list|
% appropriately, and sets |\IfOdd|\B|Page|\B|Situation| to
% |\@firstoftwo| or |\@secondoftwo| (whichever is correct for this
% situation). |\@next| is a list management macro from the \LaTeX\
% kernel.
% \begin{macrocode}
\if@twoside
\def\StepPageSituation{%
\global\advance \macro@cnt \@ne
\ifnum \XD@next@wrong<\macro@cnt
\global\@next\XD@next@wrong\XD@wrongs@list{}{%
\let\XD@next@wrong\maxdimen
}%
\fi
\ifnum \ifodd\c@page -\fi \@ne=%
\ifnum \XD@next@wrong=\macro@cnt -\fi \@ne
\global\let\IfOddPageSituation\@secondoftwo
\else
\global\let\IfOddPageSituation\@firstoftwo
\fi
}
\def\XD@next@wrong{-\maxdimen}
\let\XD@wrongs@list\@empty
\else
\let\StepPageSituation=\relax
\fi
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
%
%
% \begin{macro}{\RecordPageSituation}
% The |\RecordPageSituation| command generates a |\write| whatsit node
% which records the outcome of the current page situation. It is the
% location of this whatsit node that determines on which page a
% certain situation is considered to occur. If you don't execute this
% macro for a certain page situation, the first guess will always be
% used for that situation and no warnings will be given if that guess
% is incorrect. In single-sided mode, this is a no-op (thus you should
% better place it somewhere where it doesn't affect spacing).
% Furthermore you must make sure that \TeX\ does not change the value
% of the \texttt{page} counter between a |\StepPageSituation| and its
% corresponding |\RecordPageSituation|, since the |\ifodd| test must
% yield the same result in both cases.
%
% \begin{macrocode}
\if@twoside
\def\RecordPageSituation{%
\if@filesw
\edef\@tempa{%
\string\XD@situation{\the\macro@cnt}{%
\ifodd\c@page 1\else 0\fi
}{\IfOddPageSituation{1}{0}}%
}%
\write\@auxout\expandafter{\@tempa{\ifodd\c@page 1\else 0\fi}}%
\fi
}%
\else
\let\RecordPageSituation=\relax
\fi
% \end{macrocode}
% \end{macro}
%
%
% \begin{macro}{\XD@situation}
% \changes{prot2}{2000/07/13}{Changed to allow multiple
% \cs{XD@situation} commands for the same situation. This is
% necessary for coping with documents which \cs{include} files. (LH)}
% \changes{prot2}{2000/07/26}{Made redefinition at begin document
% global. (LH)}
% \begin{macro}{\XD@check@situation}
% |\XD@situation| is the command that will be written to the
% \texttt{.aux} file with the data about how the situation turned out.
% Its syntax is
% \begin{quote}
% |\XD@situation|\marg{number}\marg{guess}\marg{did}\marg{correct}
% \end{quote}
% where \meta{number} is the number of the situation, and
% \meta{guess}, \meta{did}, and \meta{correct} describe what the
% guess, the actual action done, and what the correct action to do
% respectively was. \meta{guess}, \meta{did}, and \meta{correct} are
% either |0| (denoting even page) or |1| (denoting odd page).
%
% The definition for |\XD@situation| set here is the one which will
% be in force when the \texttt{.aux} file is inputted at |\begin|\B
% |{document}|; its purpose is to build the |\XD@wrongs@list|.
% |\XD@check@situation| is the definition for |\XD@situation| which
% will be in force when the \texttt{.aux} file is inputted at
% |\end|\B|{document}|; its purpose is to check if anything was
% incorrectly placed.
%
% The main problem |\XD@situation| has to face is that text in the
% \texttt{.dvi} file needs not appear in exactly the same order as it
% was typeset, and it is therefore possible that |\XD@situation|s in
% the \texttt{.aux} file do not appear in increasing \meta{number}
% order. Because of this, |\XD@situation| must sort the
% |\XD@wrongs@list| while constructing it. The only reasonable
% algorithm for this seems to be insertion sort, but as the items to
% insert are almost surely almost sorted, a special check is done in
% the beginning to see if that is the case. |\XD@next@wrong| is used
% in this to store the number of the last item so far inserted into
% the |\XD@wrongs@list|. By only assigning |\XD@next@wrong| locally
% here, one is relieved of having to reset it in |\AtBeginDocument|
% code.
%
% When sorting is actually applied, a new item |\@elt|\marg{insert}
% is inserted through expanding the list. When doing that, the |\@elt|
% macro has the syntax
% \begin{quote}
% |\@elt|\,\meta{flag}\,\marg{number}\,\meta{next}
% \end{quote}
% where \meta{flag} is |\BooleanTrue| or |\BooleanFalse|, \meta{number}
% is the item that the |\@elt| belong to, and \meta{next} is either the
% next |\@elt| or |\@gobble| (if this is the last). The \meta{flag}
% specifies whether the item has been inserted; |\Boolean|\B|True| means
% that it has. The above |\@elt|-sequence will expand to
% \begin{quote}
% |\noexpand|\,|\@elt|\,\marg{number}\,\meta{next}\,|\BooleanTrue|
% \end{quote}
% if \meta{flag} is |\BooleanTrue|, or \meta{flag} is |\BooleanFalse|
% and \meta{number} is equal to \meta{insert}. It will expand to
% \begin{quote}
% |\noexpand|\,|\@elt|\,\marg{number}\,\meta{next}\,|\BooleanFalse|
% \end{quote}
% if \meta{flag} is |\BooleanFalse| and \meta{number} is less than
% \meta{insert}. It expands to
% \begin{quote}
% |\noexpand|\,|\@elt|\,\marg{insert}\,|\noexpand|\,|\@elt|^^A
% \,\marg{number}\\
% \meta{next}\,|\BooleanTrue|
% \end{quote}
% if \meta{flag} is |\BooleanFalse| and \meta{number} is greater than
% \meta{insert}.
%
% \begin{macrocode}
\if@twoside
\def\XD@situation#1#2#3#4{%
\if #2#4\else
\ifnum #1<\XD@next@wrong
\begingroup
\def\@elt##1##2##3{%
\noexpand\@elt
\ifcase
\ifx ##1\BooleanTrue 0%
\else\ifnum ##2<#1 1%
\else\ifnum ##2>#1 2%
\else 0%
\fi\fi\fi
\space
{##2}\expandafter\@secondoftwo
\or
{##2}\expandafter\@firstoftwo
\else
{#1}\noexpand\@elt{##2}\expandafter\@secondoftwo
\fi{##3\BooleanFalse}{##3\BooleanTrue}%
}%
\xdef\XD@wrongs@list{%
\expandafter\expandafter \expandafter\@elt
\expandafter\@firstoftwo \expandafter\BooleanFalse
\XD@wrongs@list \@gobble
}%
\endgroup
\else\ifnum #1>\XD@next@wrong
\def\XD@next@wrong{#1}%
\expandafter\gdef \expandafter\XD@wrongs@list
\expandafter{\XD@wrongs@list \@elt{#1}}%
\fi\fi
\fi
}
\def\XD@check@situation#1#2#3#4{%
\if #3#4\else
\PackageWarningNoLine{xdoc2}{Page breaks may have changed.%
\MessageBreak Rerun to get marginal material right}%
\let\XD@situation\@gobblefour
\fi
}
\AtBeginDocument{\global\let\XD@situation\XD@check@situation}
\else
\let\XD@situation\@gobblefour
\fi
% \end{macrocode}
% \end{macro}\end{macro}
%
%
% \begin{macro}{\XD@set@situation}
% \begin{macro}{\XD@write@situation@ckpt}
% \begin{macro}{\cl@@ckpt}
% The page situation counter |\macro@cnt| is closely related to the
% \texttt{page} counter and it needs to be among the counters whose
% values are recorded in |\include| checkpoints, since the enumeration
% of situations will otherwise change when files are added to or
% removed from the |\@partlist|. It is not sufficient to simply set
% the value of |\macro@cnt| however; one must also advance to the
% correct position in the |\XD@wrongs@list| list and set
% |\XD@next@wrong| accordingly. The |\XD@set@situation| command has
% the syntax
% \begin{quote}
% |\XD@set@situation|\marg{number}
% \end{quote}
% It sets |\macro@cnt| to \meta{number} and updates |\XD@wrongs@list|
% and |\XD@|\B|next@|\B|wrong| accordingly.
% \begin{macrocode}
\if@twoside
\def\XD@set@situation#1{%
\global\macro@cnt=#1\relax
\loop \ifnum \XD@next@wrong<\macro@cnt
\global\@next\XD@next@wrong\XD@wrongs@list{}{%
\let\XD@next@wrong\maxdimen
}%
\repeat
}
\else \let\XD@set@situation=\@gobble \fi
% \end{macrocode}
%
% The |\XD@write@situation@ckpt| macro writes an |\XD@set@situation|
% command to the \texttt{.aux} file in the way that |\@wckptelt|
% writes |\setcounter| commands for normal counters. A problem for
% |\XD@write@situation@ckpt| is that it will have to appear in a
% macro which is regularly subjected to the |\xdef| in |\@cons|. For
% that reason, it will simply expand to itself whenever |\@elt| isn't
% |\@wckptelt|.
% \begin{macrocode}
\if@twoside
\def\XD@write@situation@ckpt{%
\ifx \@elt\@wckptelt
\immediate\write\@partaux{%
\string\XD@set@situation{\the\macro@cnt}%
}%
\else
\noexpand\XD@write@situation@ckpt
\fi
}
\expandafter\def \expandafter\cl@@ckpt
\expandafter{\cl@@ckpt \XD@write@situation@ckpt}
\fi
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
%
%
% \section{The list of changes}
% \label{Sec:Changes}
%
% Reimplementations elsewhere have required a few modifications related
% to the |\changes| command. There are a lot of other things that could
% and perhaps should be done with these mechanisms, though.
%
% \begin{macro}{\saved@macroname}
% The contents of the |\saved@macroname| macro now have the syntax
% \begin{quote}
% \marg{sort key}\marg{text}
% \end{quote}
% i.e., exactly like the argument sequence of |\LevelSorted|. It's not
% fed to that macro right now, but it is not unlikely that it will in
% the future. The default definition corresponds to the default
% definition in \package{doc}.
% \begin{macrocode}
\def\saved@macroname{{ }{\generalname}}
% \end{macrocode}
% Unlike the case in \package{doc}, the formatting of the text in
% |\saved@macroname| must be included.
% \end{macro}
%
% \begin{macro}{\if@version@key@}
% The |@version@key@| switch is used for supporting intelligent
% sorting of version numbers. It is normally false, but at times
% where the version number argument of |\changes| is being expanded
% because it will be used as a sort key then it is true. This is used
% by the |\uintver| macro. Assignments to this switch are as a rule
% global, since it is never true for any longer time.
% \changes{prot2.4}{2002/11/01}{Switch added. (LH)}
% \begin{macrocode}
\newif\if@version@key@
\@version@key@false
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\uintver}
% The |\uintver| command can be used in the \meta{version} argument
% of |\changes| to ensure that (unsigned) integers are sorted in
% mathematical rather than ASCII order by \package{makeindex}. Thus
% if for example version |1.10| is later than version |1.9| then one
% should write this as
% \begin{quote}
% |\changes{1.\uintver{10}}{|\dots
% \end{quote}
% The general syntax is
% \begin{quote}
% |\uintver|\marg{number}
% \end{quote}
% and this expands completely in \TeX's mouth.
% \changes{prot2.4}{2002/11/01}{Command added. (LH)}
%
% The idea is that 0--9 are compared as 0--9, whereas 10--99 are
% compared as A10--A99, 100--999 are compared as B100-B999, and so on.
% The comparisons are correct up to 99999, but it could easily be
% extended further.
% \begin{macrocode}
\newcommand*\uintver[1]{%
\if@version@key@
\ifnum #1>9
\ifnum #1<100
A%
\else\ifnum #1<\@m
B%
\else\ifnum #1<\@M
C%
\else
D%
\fi\fi\fi
\fi
\fi
\expandafter\@firstofone \expandafter{\number#1}%
}
% \end{macrocode}
% \end{macro}
%
%
% \begin{macro}{\changes@}
% This |\changes@| is a simple redefinition of the \package{doc}
% macro with the same name. The main difference is that all
% formatting of the second entry level has been taken out---it is
% supposed to be provided in |\saved@macroname|---but in addition to
% that the date is being used as a third level sort key and |\uintver|
% may be used in the version number to correct the data.
% \changes{prot2.4}{2002/11/01}{Added support for \cs{uintver}. (LH)}
%
% The former makes more sense for projects where the date is
% increased faster than the version number and it doesn't change
% anything relevant in the remaining cases. The latter is necessary
% if version numbers are assigned for example by CVS.
% \begin{macrocode}
\def\changes@#1#2#3{%
\global\@version@key@true
\protected@edef\@tempa{#1}%
\global\@version@key@false
\protected@edef\@tempa{%
\noexpand\glossary{%
\@tempa\actualchar#1\levelchar
\expandafter\@firstoftwo\saved@macroname\actualchar
\expandafter\@secondoftwo\saved@macroname:\levelchar
#2\actualchar#3%
}%
}%
\@tempa
\endgroup
\@esphack
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@wrglossary}
% \changes{prot2.2}{2001/02/13}{Redefinition added. (LH)}
% \begin{macro}{\XD@glossary@keyword}
% \changes{prot2.2}{2001/02/13}{Macro added. (LH)}
% The |\@wrglossary| macro is the one which actually writes entries
% to the \texttt{.glo} file. It is redefined by \package{xdoc} to put
% the contents of |\XD@glossary@keyword|, rather than a hardwired
% |\glossaryentry|, in front of the glossary entry.
% |\XD@glossary@keyword| is redefined by the \package{docindex}
% package~\cite{docindex}.
% \begin{macrocode}
\def\@wrglossary#1{%
\protected@write\@glossaryfile{}%
{\XD@glossary@keyword{#1}{\thepage}}%
\endgroup
\@esphack
}
\@ifundefined{XD@glossary@keyword}{%
\edef\XD@glossary@keyword{\@backslashchar glossaryentry}%
}{}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\definechange}
% \begin{macro}{\XD@definechange}
% The |\definechange| command has the syntax
% \begin{quote}
% |\definechange|\marg{name}\marg{version}\marg{date}\marg{text}
% \end{quote}
% The three last arguments are precisely like the arguments of
% |\changes|, but |\definechange| doesn't write the change to the
% \texttt{.glo} file; instead it stores them away as the ``named
% change'' \meta{name}, for later use in the |\usechange| command.
% \begin{macrocode}
\newcommand\definechange{%
\begingroup\@sanitize
\catcode`\\\z@ \catcode`\ 10 \MakePercentIgnore
\expandafter\endgroup \XD@definechange
}
\def\XD@definechange#1#2#3#4{\@namedef{XD@ch-#1}{{#2}{#3}{#4}}}
% \end{macrocode}
% \end{macro}\end{macro}
%
% The named changes are stored in the
% \describecsfamily{XD@ch-\meta{name}}|\XD@ch-|\meta{name} family of
% control sequences. These are parameterless macros with replacement
% texts of the form
% \begin{quote}
% \marg{version}\marg{date}\marg{text}
% \end{quote}
%
% \begin{macro}{\usechange}
% \begin{macro}{\XD@usechange}
% \changes{prot2.4}{2002/11/01}{Added support for \cs{uintver}. (LH)}
% To use a named change defined earlier, one of course uses the
% command |\usechange|, which has the syntax
% \begin{quote}
% |\usechange|\marg{name}
% \end{quote}
% The effect of this is similar to that of a general |\changes|
% (i.e., it appears outside all \texttt{macro}-like environments) with
% the arguments specified in the |\definechange|, but this also
% includes the macro (or whatever) name with the page number, using
% the encapsulation mechanism in \package{makeindex}.
% \begin{macrocode}
\newcommand*\usechange[1]{%
\@ifundefined{XD@ch-#1}{%
\PackageError{xdoc2}{Named change `#1' undefined}\@eha
}{%
\expandafter\expandafter \expandafter\XD@usechange
\csname XD@ch-#1\endcsname
}%
}
\def\XD@usechange#1#2#3{%
\def\@tempa{{ }{\generalname}}%
\ifx \@tempa\saved@macroname
\let\@tempa\@empty
\else
\protected@edef\@tempa{%
\encapchar labelednumber%
{\expandafter\@secondoftwo\saved@macroname}%
}
\fi
\global\@version@key@true
\protected@edef\@tempb{#1}%
\global\@version@key@false
\glossary{%
\@tempb\actualchar #1\levelchar
\space\actualchar\generalname:\levelchar
#2\actualchar#3\@tempa
}%
}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\labelednumber}
% The |\labelednumber| macro belongs to the same category as the
% |\main| and |\usage| macros, but it takes an extra argument. The
% syntax is
% \begin{quote}
% |\labelednumber|\marg{extra}\marg{number}
% \end{quote}
% which typesets as
% \begin{quote}
% \meta{number} (\meta{extra})
% \end{quote}
% \begin{macrocode}
\newcommand*\labelednumber[2]{#2\nolinebreak[2] (#1)}
% \end{macrocode}
% \end{macro}
%
%
%
% \section{\texttt{macro}-like environments}
% \label{Sec:Macro-environments}
%
% There are several reasons one might want to improve the \texttt{macro}
% and \texttt{environment} environments.
% \begin{itemize}
% \item
% The code in them cannot be reused if you want to define other
% things than \TeX\ macros or \LaTeX\ environments. (During the
% last year or so, I have defined \texttt{macro}-like environments
% for over a dozen different things.)
% \item
% They always put the macro\slash environment name to the left of
% the current column. This is inappropriate for two-sided printing,
% as there should be a symmetry over an entire spread in that case.
% \item
% The vertical extent of a macro\slash environment name must not
% exceed that of the |\strut|, since they will otherwise overprint
% each other when stacked. In particular this makes it impossible to
% make line breaks in macro names---something which would otherwise
% be of interest in projects (such as for example \cite{fontinst})
% where some names are very long and obvious breakpoints are
% available.
% \end{itemize}
% (I'm quite sure there are more things that have annoyed me, but I can't
% remember which they are right now.) The redefinitions below take care
% of the all these problems.
%
%
% \subsection{Grabbing arguments}
%
% A special feature of the \texttt{macro}-like environments is that (at
% least some) of their arguments must be given rather special treatment.
% This special treatment usually consists of making temporary |\catcode|
% changes for the time these arguments are tokenized---since the standard
% |\catcode|s for some important characters tend to be unsatisfactory in
% these cases---but there are other possibilities as well. For that
% reason, the \package{xdoc} package employs a mechanism that is very
% similar to that used in the Mittelbach--Rowley--Carlisle
% \package{xparse} package~\cite{xparse}, although it does not share
% any code with that. I call this mechanism the argument grabber.
%
% The heart of the argument grabber is the macro |\XD@grab@arguments|,
% which has the following syntax:
% \begin{quote}
% |\XD@grab@arguments|\marg{call}\marg{grabber sequence}^^A
% \meta{arguments to grab}
% \end{quote}
% \meta{call} is something which will eventually be placed in front of
% all the arguments grabbed. It can simply be a single macro, but it
% can also contain some arguments for that macro. \meta{grabber sequence}
% is a sequence of grabbers. A \emph{grabber} is typically a macro which
% grabs the next argument and stores it in a token list together with the
% arguments that were grabbed before. A grabber could however be some
% more complex piece of code that performs a similar action.
%
% \begin{table}
% \begin{minipage}{\columnwidth}
% \begin{center}\small
% \begin{tabular}{lll>{\raggedright}p{0.3\linewidth}}
% \textbf{Grabber}& \textbf{Arg.\ type}&
% \textbf{Catcodes\footnote[1]{Catcode settings key:
% --- = no change, PL = changes made by \cs{MakePrivateLetters},
% OB = set the catcode of backslash to ordinary.}}&
% \textbf{Post-processing}\tabularnewline
% |\XD@grab@marg|& Mandatory& ---& None\tabularnewline
% |\XD@grab@oarg|& Optional& ---& None\tabularnewline
% |\XD@grab@sarg|\marg{char}& 1-char optional&
% ---& Returns |\BooleanTrue| if the character was present
% and |\BooleanFalse| otherwise.\tabularnewline
% |\XD@grab@withprivate|& Mandatory& PL& None\tabularnewline
% |\XD@grab@asmacro|\footnote[2]{This grabber is probably obsolete;
% it is included because it grabs the argument in precisely the
% way that the \texttt{macro} environment of \package{doc} does.}&
% Mandatory& OB+PL& None\tabularnewline
% |\XD@grab@harmless|\meta{proc}& Mandatory& ---&
% |\MakeHarmless| followed by \meta{proc}\tabularnewline
% |\XD@grab@harmless@oarg|& Optional& ---&
% |\MakeHarmless|\tabularnewline
% \multicolumn{3}{l}{\cs{XD@grab@harmless@asmacro}}\tabularnewline
% & Mandatory& OB+PL&
% |\MakeHarmless| followed by |\XD@unbackslash|\tabularnewline
% |\XD@grab@harmless@cs|& Mandatory\footnote[3]{The argument is
% normally precisely one control sequence.}& PL&
% |\string| whilst |\escapechar| is set to \textminus1,
% followed by |\MakeHarmless|\tabularnewline
% \multicolumn{3}{l}{^^A
% \cs{XD@grab@harmless@withprivate}\marg{proc}}\\
% & Mandatory& PL& |\MakeHarmless| followed by \meta{proc}
% \end{tabular}
% \end{center}
% \end{minipage}
%
% \caption{Grabbers currently defined by \package{xdoc}}
% \label{Tab:Grabbers}
% \end{table}
%
% When arguments are being grabbed, the \meta{call} is stored in |\toks@|
% and the arguments are appended to |\toks@| as they are grabbed. For
% that reason, a grabber may not itself call |\XD@grab@arguments|, nor
% may it use a command defined through \package{xparse}'s
% |\Declare|\-|Document|\-|Command| or anything else which uses this
% token register in a bad way.
%
% When a grabber is expanded, it is in the context
% \begin{quote}
% \meta{grabber}\,\meta{following grabbers}\,|\XD@endgrab|\penalty0
% \thinspace\meta{ungrabbed arguments}
% \end{quote}
% After it has grabbed its argument, everything of the above should be
% put back except for the \meta{grabber} and the argument it grabbed.
% The argument itself should be wrapped in a group and appended to
% |\toks@|.
%
% \textbf{Note:} In prototype~2 the format in which the argument grabber
% returns the grabbed arguments was changed so that it can now be
% unified with argument grabbing mechanisms of \package{xparse}. I
% think this should be done some time in the future, but for the moment
% it seems best not to rely on \LaTeXplus\ packages like \package{xparse}.
%
% \begin{macro}{\XD@grab@arguments}
% \begin{macro}{\XD@endgrab}
% \changes{prot2}{2000/07/13}{The grabbed arguments are no longer
% returned wrapped up in a group. There is no longer a need for
% storing the base call separately in \cs{toks}\,\texttt{2}. (LH)}
% The |\XD@grab@arguments| and |\XD@endgrab| macros set up and finish
% off argument grabbing.
% \begin{macrocode}
\def\XD@grab@arguments#1#2{%
\toks@={#1}%
#2\XD@endgrab
}
% \end{macrocode}
% \begin{macrocode}
\def\XD@endgrab{\the\toks@}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\XD@grab@marg}
% A grabber for ordinary arguments, like the \texttt{m} arguments of
% \package{xparse}.
% \begin{macrocode}
\long\def\XD@grab@marg#1\XD@endgrab#2{%
\addto@hook\toks@{{#2}}%
#1\XD@endgrab
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\XD@grab@oarg}
% \begin{macro}{\XD@grab@oarg@}
% A grabber for optional arguments (\texttt{o} arguments in
% \package{xparse}). It looks ahead for an optional argument and
% grabs that argument if there was one. If it doesn't find anything
% which looks like an optional argument (i.e., if the next character
% isn't a |[|), then the grabber will not grab anything (although it
% may have tokenized the next argument), but it will still append
% |\NoValue| to |\toks@|.
%
% \begin{macrocode}
\def\XD@grab@oarg#1\XD@endgrab{%
\@ifnextchar[{\XD@grab@oarg@{#1}}{%
\addto@hook\toks@\NoValue
#1\XD@endgrab
}%
}
% \end{macrocode}
% |\XD@grab@oarg@| is a helper to remove the brackets around the
% optional argument.
% \begin{macrocode}
\long\def\XD@grab@oarg@#1[#2]{%
\addto@hook\toks@{{#2}}%
#1\XD@endgrab
}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\XD@grab@sarg}
% A grabber for `star'-type arguments (\texttt{s} arguments in
% \package{xparse}). The syntax is
% \begin{quote}
% |\XD@grab@sarg|\marg{char}
% \end{quote}
% It looks ahead to see if the next character is the \meta{char}. In
% that case it gobbles it and adds a |\BooleanTrue| to the grabbed
% arguments, otherwise it adds a |\BooleanFalse| to the grabbed
% arguments.
% \changes{prot2.3}{2001/11/03}{Macro added. (LH)}
% \begin{macrocode}
\def\XD@grab@sarg#1#2\XD@endgrab{%
\@ifnextchar#1{%
\addto@hook\toks@\BooleanTrue
\@firstoftwo{#2\XD@endgrab}%
}{%
\addto@hook\toks@\BooleanFalse
#2\XD@endgrab
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\XD@grab@withprivate}
% |\XD@grab@withprivate| is like |\XD@grab@marg| but grabs the
% argument when the catcodes are as set by |\MakePrivateLetters|.
% \begin{macrocode}
\def\XD@grab@withprivate{%
\begingroup\MakePrivateLetters\relax\expandafter\endgroup
\XD@grab@marg
}
% \end{macrocode}
% To think about: Perhaps things like |\XD@grab@withprivate| should
% rather be considered a modifier for a grabber? Instead of having
% |\XD@grab@withprivate| be the entire grabber, one could let the
% grabber be something like
% \begin{quote}
% |\XD@grab@withprivate\XD@grab@marg|
% \end{quote}
% where the |\XD@grab@withprivate| should only expand to
% \begin{quote}
% |\begingroup\MakePrivateLetters\relax\expandafter\endgroup|
% \end{quote}
% \end{macro}
%
% \begin{macro}{\XD@grab@asmacro}
% |\XD@grab@asmacro| is very similar to |\XD@grab@withprivate|, but it
% sees to that the catcode settings are exactly those used by
% \package{doc}'s \texttt{macro} environment.
% \begin{macrocode}
\def\XD@grab@asmacro{%
\begingroup
\catcode`\\=12 \MakePrivateLetters\relax
\expandafter\endgroup
\XD@grab@marg
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\XD@grab@harmless}
% \begin{macro}{\XD@grab@harmless@oarg}
% \changes{prot2.1}{2000/09/30}{Macro added. (LH)}
% \begin{macro}{\XD@grab@harmless@oarg@}
% \changes{prot2.1}{2000/09/30}{Macro added. (LH)}
% The |\XD@grab@harmless| grabber grabs one mandatory argument and
% converts it to a harmless character string, which it contributes to
% the list of arguments. The syntax is
% \begin{quote}
% |\XD@grab@harmless|\marg{post-processing}
% \end{quote}
% where \meta{post-processing} are commands that will be performed
% after the grabbed argument has been made harmless, but before it is
% contributed to the list of arguments. Thus the
% \meta{post-processing} can modify the argument some more, but
% \meta{post-processing} can just as well be empty.
% \begin{macrocode}
\def\XD@grab@harmless#1#2\XD@endgrab#3{%
\MakeHarmless\@tempa{#3}%
#1%
\toks@=\expandafter{\the\expandafter\toks@ \expandafter{\@tempa}}%
#2\XD@endgrab
}
% \end{macrocode}
%
% The |\XD@grab@harmless@oarg| grabber grabs one optional argument and
% converts it to a harmless character string. This string is
% contributed to the list of arguments if the optional argument, or
% else the token |\NoValue| is contributed instead.
% \begin{macrocode}
\def\XD@grab@harmless@oarg#1\XD@endgrab{%
\@ifnextchar[{\XD@grab@harmless@oarg@{#1}}{%
\addto@hook\toks@\NoValue
#1\XD@endgrab
}%
}
% \end{macrocode}
% |\XD@grab@harmless@oarg@| is a helper to remove the brackets around
% the optional argument.
% \begin{macrocode}
\long\def\XD@grab@harmless@oarg@#1[#2]{%
\MakeHarmless\@tempa{#2}%
\toks@=\expandafter{\the\expandafter\toks@ \expandafter{\@tempa}}%
#1\XD@endgrab
}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\XD@grab@harmless@asmacro}
% \begin{macro}{\XD@grab@harmless@cs}
% \begin{macro}{\XD@grab@harmless@cs@}
% The |\XD@grab@harmless@asmacro| grabber combines the features of
% |\XD@grab@|\B|asmacro| and |\XD@grab@harmless|, since when the
% argument to grab is tokenized the catcode of |\| is set to 12 and
% the catcode assignments in |\MakePrivateLetters| are made. Then the
% grabbed argument is converted to a harmless character sequence, and
% finally the first character is removed if it is a backslash.
% \begin{macrocode}
\def\XD@grab@harmless@asmacro{%
\begingroup
\catcode`\\=12 \MakePrivateLetters\relax
\expandafter\endgroup
\XD@grab@harmless{%
\protected@edef\@tempa{%
\expandafter\XD@unbackslash\@tempa\@empty
}%
}%
}
% \end{macrocode}
%
% The |\XD@grab@harmless@cs| grabber is for use with commands like
% \package{doc}'s |\Describe|\-|Macro|, which take an actual control
% sequence as the argument. It grabs one argument while having
% catcodes changed as indicated by |\Make|\-|Private|\-|Letters|,
% |\string|s the argument while |\escapechar| is |-1| (so that there
% is no escape character inserted), and continues as
% |\XD@grab@harmless|.
% \begin{macrocode}
\def\XD@grab@harmless@cs{%
\begingroup
\MakePrivateLetters\relax
\expandafter\endgroup \XD@grab@harmless@cs@
}
% \end{macrocode}
% \begin{macrocode}
\long\def\XD@grab@harmless@cs@#1\XD@endgrab#2{%
\begingroup
\escapechar=\m@ne
\expandafter\endgroup
\expandafter\MakeHarmless \expandafter\@tempa
\expandafter{\string#2}%
\toks@=\expandafter{\the\expandafter\toks@ \expandafter{\@tempa}}%
#1\XD@endgrab
}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\XD@grab@harmless@withprivate}
% |\XD@grab@harmless@withprivate| is like |\XD@grab@harmless| but
% grabs the argument when the catcodes are as set by
% |\Make|\-|Private|\-|Letters|.
% Like |\XD@|\B|grab@|\B|harmless|, |\XD@grab@|\B|harmless@|\B
% |withprivate| takes an argument which can contain code that
% modifies the harmless character string after it has been formed.
% \begin{macrocode}
\def\XD@grab@harmless@withprivate{%
\begingroup\MakePrivateLetters\relax\expandafter\endgroup
\XD@grab@harmless
}
% \end{macrocode}
% \end{macro}
%
%
% \subsection{The \cs{XD@m@cro} and \cs{NewMacroEnvironment} commands}
%
% In \package{doc} the macro that contains most of the code for the
% \texttt{macro} and \texttt{environment} environments is called
% |\m@cro@|. In \package{xdoc} the corresponding macro is |\XD@m@cro|.
%
% At this point, it is helpful to recall what |\m@cro@| actually does.
% It can be summarized in the following four points:
% \begin{itemize}
% \item It starts a |\trivlist|.\footnote{Seriously, can someone
% explain to me why it seems just about every non-math \LaTeX\
% environment that doesn't start a \cs{list} starts a \cs{trivlist}?
% What good does all these \cs{trivlist}s do? Is it (a)~that people
% just like the basic design, (b)~that there's some deep technical
% reason, or (c)~that people in general doesn't have a clue but all
% other environments do that so it's best to include it just in
% case?}
% \item It prints the name of the macro\slash environment that is
% about to be defined in the margin.
% \item It writes an index entry (and inhibits cross-referencing of
% the macro inside the environment).
% \item It sets |\saved@macroname| to the name of the macro\slash
% environment (for use by |\changes|).
% \end{itemize}
%
% The first and fourth points are simple, and commands for the third
% were defined in Section~\ref{Sec:Indexing}, but the second point
% needs a few helper macros.
%
%
% \begin{macro}{\XDStackItemLabels}
% \changes{prot2}{2000/07/28}{Made it work like a \cs{vtop} (but hide
% the height) if \cs{XD@macro@dimen} is \texttt{-}\cs{maxdimen}.
% (LH)}
% \begin{macro}{\XD@macro@dimen}
% The |\XDStackItemLabels| macro is a definition of |\makelabel| which
% is used in the \texttt{macro}-like environments for stacking the
% names printed by subsequent environments under each other. It makes
% a box which has zero height and depth (it should have zero width as
% well, but that is left as a restriction on the argument) and the
% printed names will be stacked if the reference points of the
% subsequent boxes generated by |\XD|\-|Stack|\-|Item|\-|Labels|
% coincide.
%
% |\XD@macro@dimen| (always assigned globally) stores the vertical
% distance from the reference point of the box that
% |\XD|\-|Stack|\-|Item|\-|Labels| makes to the (bottommost) baseline
% of the previous printed name. |\XD@macro@dimen| is updated by each
% new |\XD|\-|Stack|\-|Item|\-|Labels|. The baseline of the next printed
% name will be put one |\baselineskip| lower than that of the previous
% printed name, except for when |\XD@macro@dimen| is |-\maxdimen| (see
% below). To avoid that printed names clash into each other, this
% additional |\baselineskip| is generated as normal interline glue
% where the upper box has the same depth as a strut and the new value
% of |\XD@macro@dimen| is measured in such a way that the printed
% name's depth below the nominal baseline will not exceed the depth of
% a strut (that's what the |\boxmaxdepth| assignment is for).
% When |\XD@macro@dimen| is |-\maxdimen| the (topmost) baseline of the
% printed name will instead go through the reference point of the box.
% This case is intended for the first item label in a stack.
%
% The reason |\everypar| is cleared is that that is where the list
% environments put the commands which actually insert the item label
% into the paragraph. If that code gets executed inside |\makelabel|,
% the list environments get seriously confused with not at all nice
% consequences.
% \begin{macrocode}
\def\XDStackItemLabels#1{%
\setbox\z@=\vbox{%
\ifdim \XD@macro@dimen=-\maxdimen
\setbox\z@=\vtop{%
\color@begingroup
\everypar={}%
#1%
\color@endgroup
}%
\kern-\ht\z@
\unvbox\z@
\else
\color@begingroup
\everypar={}%
\kern\XD@macro@dimen
\setbox\z@=\copy\strutbox \ht\z@=\z@ \box\z@
#1%
\color@endgroup
\fi
\boxmaxdepth=\dp\strutbox
}%
\global\XD@macro@dimen=\ht\z@
\vtop to\z@{\unvbox\z@ \vss}%
}
% \end{macrocode}
% \begin{macrocode}
\newdimen\XD@macro@dimen
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\XDToMargin}
% \changes{prot2.1}{2000/11/26}{New name for \cs{XD@to@margin}. (LH)}
% The |\XDToMargin| macro takes one argument, which is assumed to be
% some horizontal material, and puts that material in a |\hbox| of
% width zero, horizontally shifted out into the the outer margin, in
% such a way that longer arguments extend further out. |\marginparsep|
% is used as the distance between the argument and the main galley. All
% these placements assume that the |\hbox| will be put |\labelsep| to
% the left of the beginning of a nonindented paragraph, since that is
% where it will be put by the |\item| of a |\trivlist|.
%
% A question is where the margin should be considered to start if the
% |\@total|\-|left|\-|margin| isn't zero. The corresponding
% \package{doc} action would be to consider the margin as everything
% outside the |\linewidth| width, but I don't think that would be
% appropriate here (especially not since \package{doc} always puts the
% codeline numbers at the edge of the |\textwidth| width).
% \begin{macrocode}
\newcommand\XDToMargin[1]{%
\hb@xt@\z@{%
\IfOddPageSituation{%
\dimen@=-\@totalleftmargin
\advance \dimen@ \labelsep
\advance \dimen@ \textwidth
\advance \dimen@ \marginparsep
\kern\dimen@
}\hss
#1%
\IfOddPageSituation\hss{%
\dimen@=\@totalleftmargin
\advance \dimen@ -\labelsep
\advance \dimen@ \marginparsep
\kern\dimen@
}%
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\XDParToMargin}
% The |\XDParToMargin| command is in syntax and use similar to the
% |\XDToMargin| command, but it will try to linebreak an argument
% that is too long rather than letting it extend outside the paper.
%
% The implementation first tries to break the argument without
% considering justification or positioning, but with a rather high
% |\linepenalty|. If the result of that try is a single line paragraph
% then |\XDToMargin| will be called to actually typeset the argument.
% Otherwise the argument is typeset as a paragraph which gets
% displaced out into the outer margin by giving |\leftskip| and
% |\rightskip| nonzero natural widths. The practical line width in
% the paragraph is the |\marginparwidth|, but the hboxes containing
% the individual lines will have width zero. The first line of the
% paragraph will be set flush outwards, the last line of the paragraph
% will be set flush inwards, and the remaining lines will be centered.
%
% \changes{prot2.1}{2000/11/26}{Command added. (LH)}
% \begin{macrocode}
\newcommand\XDParToMargin[1]{%
\parindent=\z@
\setbox\z@=\vbox{%
\leftskip=\z@skip
\rightskip=\z@\@plus 1fil%
\parfillskip=\z@skip
\hsize=\marginparwidth
\linepenalty=1000%
\color@begingroup
\noindent\ignorespaces #1\@@par
\color@endgroup
\expandafter}%
\expandafter\ifnum \the\prevgraf<\tw@
\XDToMargin{#1}%
\else
\hsize=\z@
\leftskip=\z@ \@plus \marginparwidth
\rightskip=\leftskip
\IfOddPageSituation{%
\dimen@=-\@totalleftmargin
\advance \dimen@ \labelsep
\advance \dimen@ \textwidth
\advance \dimen@ \marginparsep
\advance \leftskip \dimen@
\advance \rightskip -\dimen@ \@minus \p@
\advance \rightskip -\marginparwidth
\parfillskip=\z@ \@plus 1fil%
}{%
\dimen@=\@totalleftmargin
\advance \dimen@ -\labelsep
\advance \dimen@ \marginparsep
\advance \leftskip -\dimen@ \@minus \p@
\advance \leftskip -\marginparwidth
\advance \rightskip \dimen@
\parfillskip=\z@ \@plus -\marginparwidth%
}
\noindent\nobreak\hskip\parfillskip
\ignorespaces #1\@@par
\fi
}
% \end{macrocode}
% \end{macro}
%
%
% In the following I exploit the implementation of the |\item| command
% in a slightly hackish way. Instead of starting a new paragraph with
% the item label (which is what one at first would believe |\item|
% does), |\item| actually puts the label in the box |\@labels| register,
% and stores code in |\everypar| that inserts that box into the new
% paragraph. Therefore I can make sure that various |\write| whatsits
% that need to be as the same page as an |\item| label will be there by
% adding them to the contents of the |\@labels| box. This seems more
% reliable to me than putting them on the vertical list followed by a
% |\nobreak| as \package{doc} does, but that would probably work as
% well.
%
% [A funny thing in that which confused me a while was the question of
% whether the |\box| command that inserts the box into the paragraph and
% simultaneously clears the register acted globally or locally. It turns
% out that the question was ill-posed, as the distinction between local
% and global assignments is determined by what restore items they put
% on \TeX's save stack. The |\box| command doesn't put anything there,
% so the assignment it makes will essentially appear at the same
% grouping level as the |\setbox| command that set the contents of the
% box register. As all |\setbox|es for the |\@labels| box register are
% global, the box register will be globally void after |\box\@labels|.]
%
%
% \begin{macro}{\XD@m@cro}
% \changes{prot2}{2000/07/24}{Put the \meta{changes} argument before
% the \meta{assign} argument. Executing the \meta{assign} code
% after the \meta{changes} \cs{edef}. Changed the descriptions of
% these arguments a little. (LH)}
% \changes{prot2.1}{2000/11/26}{Removed \cs{XDToMargin} from the
% argument of \cs{item}. It should now be included in \#1
% instead. (LH)}
% This is the workhorse of all the \texttt{macro}-like environments.
% It calls |\trivlist| and sets related parameters, prints the
% ``macro'' name in the proper place, updates the representation of
% the ``macro'' name that |\changes| will use, and writes appropriate
% index entries (possibly making temporary changes in
% cross-referencing). Exactly what these tasks consist of can vary
% quite a lot between different \texttt{macro}-like environments, and
% therefore the |\XD@m@cro| macro has the following syntax:
% \begin{quote}
% |\XD@m@cro|\marg{print}\marg{index}\marg{changes}\marg{assign}
% \end{quote}
% \meta{print}, \meta{index}, and \meta{assign} are simply the
% commands for printing the ``macro'' name as it should appear in the
% margin, generating the index entries for this \texttt{macro}-like
% environment, and making whatever additional local assignments that
% are needed for this environment (usually a couple of
% |\Do|\-|Not|\-|Index|\-|Harmless| commands, if anything at all)
% respectively. At the time \meta{index} is executed,
% \texttt{codelineno} holds the number of the \emph{next} codeline.
% \meta{changes}, finally, is code that will be put in the context
% \begin{quote}
% |\protected@edef\saved@macroname{|\meta{changes}|}|
% \end{quote}
% to set the |\saved@macroname| macro (for |\changes|).
% \begin{macrocode}
\def\XD@m@cro#1#2#3#4{%
\topsep\MacroTopsep
\trivlist
\global\setbox\@labels=\hbox{%
\unhbox\@labels
\if@inlabel \else
\global\XD@macro@dimen=-\maxdimen
\StepPageSituation
\RecordPageSituation
\fi
\advance \c@codelineno \@ne
#2%
}%
\let\makelabel\XDStackItemLabels
\item[#1]%
\protected@edef\saved@macroname{#3}%
#4%
\ignorespaces
}
% \end{macrocode}
% \end{macro}
%
% In the first \package{xdoc} prototype, the \texttt{macro}-like
% environments were implemented so that each new environment only used
% two control sequences (|\|\meta{env} and |\end|\meta{env}), which is
% the absolute minimum. This implementation worked fine for
% single argument environments, but the number of helper macros that
% would have to be introduced to deal with multiple argument
% environments exceeded what could be considered reasonable. Therefore
% the second prototype claims a third control sequence for the
% implementation of a \texttt{macro}-like environment \meta{env}, namely
% |\\|\meta{env}, which is also used by normal \LaTeXe\ environments
% which take an optional argument.
%
% It should also be mentioned that the implementation in the first
% prototype required that most of the code in |\|\meta{env} had to be
% written in a very special way. Instead of using the |#|\meta{digit}
% notation for the arguments and write straightforward \LaTeX\ code, one
% had to express everything using macros which operate on arguments ``up
% ahead'' (immediately after the code you can specify). This curious
% coding model made it out of the question to create a class designer
% interface for defining new \texttt{macro}-like environments, but in
% the second \package{xdoc} prototype it is quite simple to do something
% of that sort: the command name is |\New|\-|Macro|\-|Environment|.
%
% \begin{macro}{\NewMacroEnvironment}
% \changes{prot2}{2000/07/13}{Command added. (LH)}
% \changes{prot2}{2000/07/24}{Changed syntax in conformity with the
% syntax change in \cs{XD@m@cro}. (LH)}
% \changes{prot2.1}{2000/11/26}{Introduced star form with different
% semanics for the \meta{print} argument. This uses the helper
% macros \cs{XD@NewMacroEnvironment} and
% \cs{XD@NewMacroEnvironment@}. (LH)}
% \begin{macro}{\XD@NewMacroEnvironment}
% \begin{macro}{\XD@NewMacroEnvironment@}
% The |\NewMacroEnvironment| command is used for defining new
% \texttt{macro}-like environments. It has the syntaxes
% \begin{quote}
% |\NewMacroEnvironment|\marg{name}\marg{grabbers}\marg{numargs}\\
% \vadjust{}\hfill\marg{unjust-print}\marg{index}\marg{changes}^^A
% \marg{assign}\\
% |\NewMacroEnvironment*|\marg{name}\marg{grabbers}\marg{numargs}\\
% \vadjust{}\hfill\marg{print}\marg{index}\marg{changes}\marg{assign}
% \end{quote}
% where \meta{name} is the name of the environment to define,
% \meta{grabbers} is a sequence of argument grabbers, \meta{numargs}
% is the number of arguments that the grabbers will grab, and
% \meta{print}, \meta{index}, \meta{changes}, and \meta{assign} are
% code that will be put in the respective arguments of |\XD@m@cro|.
% In the four last arguments, argument specifiers |#1| to
% |#|\meta{numargs} inclusive can be used do mean the arguments that
% were grabbed by the sequence of grabbers.
%
% The argument grabbers that are currently made available by the
% \package{xdoc} package are listed in Table~\ref{Tab:Grabbers} on
% page~\pageref{Tab:Grabbers}.
%
% The \meta{print} code will be executed while \TeX\ is in internal
% vertical mode and it should put one or several hboxes of width zero
% onto the vertical list. The contents of these boxes should be some
% amount of text which will appear displaced out into the outer margin
% on the page when the reference point of the box appears |\labelsep|
% to the left of the left edge of the line. The easiest way of
% achieveing this is to use a \meta{print} of the form
% \begin{quote}
% |\XDToMargin|\marg{unjust-print}
% \end{quote}
% and this is exactly what the non-star form of |\NewMacroEnvironment|
% does by default.
%
% \begin{macrocode}
\newcommand\NewMacroEnvironment{%
\@ifstar\XD@NewMacroEnvironment\XD@NewMacroEnvironment@
}
\def\XD@NewMacroEnvironment@#1#2#3#4{%
\XD@NewMacroEnvironment{#1}{#2}{#3}{\XDToMargin{#4}}%
}
\def\XD@NewMacroEnvironment#1#2#3#4#5#6#7{%
\expandafter\@ifdefinable\csname#1\endcsname{%
\expandafter\def \csname#1\expandafter\endcsname
\expandafter{\expandafter\XD@grab@arguments
\csname\@backslashchar#1\endcsname{#2}}%
\let\l@ngrel@x\relax
\expandafter\@yargdef \csname\@backslashchar#1\endcsname \@ne
{#3}{\XD@m@cro{#4}{#5}{#6}{#7}}%
\expandafter\let \csname end#1\endcsname \endtrivlist
}%
}
% \end{macrocode}
% The \meta{grabbers} argument---in which one specifies a list of
% internal macros---is not how the interface should really look, but I
% think it will have to do for now. The final interface will probably
% use something like the argument specifications of
% |\Declare|\-|Document|\-|Command|, but there is little point in
% implementing that before \package{xparse} has gotten its final form.
% \end{macro}\end{macro}\end{macro}
%
% The macro |\@yargdef| used above should perhaps be checked so that its
% syntax hasn't changed, but since |\@yargdef| quite recently
% (\texttt{ltdefn.dtx} v\,1.3c, 1999/01/18) was completely reimplemented
% without any change in the syntax (despite the fact that the syntax is
% afterwards rather peculiar), I think it can be assumed that the syntax
% will not change in \LaTeXe.
%
%
%
% \subsection{Reimplementing \texttt{macro} and \texttt{environment}}
% \label{Ssec:Macro&environment}
%
% Well, then how does one reimplement the \texttt{macro} and
% \texttt{environment} environments using |\XD@m@cro|? We shall soon
% see, but first it is convenient to define a utility macro.
%
% \changes{prot2}{2000/07/14}{Lots of utility macros were removed:
% \cs{XDWrapText}, \cs{XDAltWrapText}, \cs{XDSortAndText},
% \cs{MultipleApply}, \cs{ApplicableUsageIndex}, and
% \cs{XD@index@family}. (LH)}
%
% \begin{macro}{\XDMainIndex}
% \changes{prot2}{2000/07/14}{New name and syntax for
% \cs{ApplicableMainIndex}. (LH)}
% The |\XDMainIndex| macro is an abbreviation to save a couple of
% tokens in a very frequent call to |\IndexEntry|. It has the syntax
% \begin{quote}
% |\XDMainIndex|\marg{argument}
% \end{quote}
% and that expands to
% \begin{quote}
% |\IndexEntry|\marg{argument}|{main}{\TheXDIndexNumber}|
% \end{quote}
% \begin{macrocode}
\newcommand\XDMainIndex[1]{\IndexEntry{#1}{main}{\TheXDIndexNumber}}
% \end{macrocode}
% \end{macro}
%
% \begin{environment}{macro}
% \changes{prot2.1}{2000/11/15}{Using \cs{MakeSortKey} to make index
% entry. (LH)}
% \begin{environment}{environment}
% It is very easy to implement \texttt{macro} and \texttt{environment}
% environments which behave pretty much as in \package{doc} using the
% |\New|\-|Macro|\-|Environment| command. The important difference
% is that in \package{doc} everything that distinguished the two
% environments was to be found in various helper macros, but here all
% that code is in the |\\macro| and |\\environment| macros. Thus to
% define one new \texttt{macro}-like environment, one doesn't have to
% define six or so new macros---everything can be handled in one
% definition.
%
% The reason for the |\let| commands below is of course that
% \texttt{macro} and \texttt{environment} are already defined, and
% there is no |\Renew|\-|Macro|\-|Environment| command. It could
% perhaps have been better if |\New|\-|Macro|\-|Environment| had
% behaved like |\Declare|\-|Robust|\-|Command|, but I don't think that
% is an important problem for the moment.
% \begin{macrocode}
\let\macro=\relax
\let\endmacro=\relax
\NewMacroEnvironment{macro}{\XD@grab@harmless@asmacro}{1}
{\MacroFont\Bslash#1}
{\MakeSortKey\@tempa{#1}{}%
\XDMainIndex{\LevelSorted{\@tempa}{\texttt{\Bslash#1}}}}
{{#1}{\texttt{\Bslash#1}}}
{\DoNotIndexHarmless{#1}}
% \end{macrocode}
% \begin{macrocode}
\let\environment=\relax
\let\endenvironment=\relax
\NewMacroEnvironment{environment}{\XD@grab@harmless@asmacro}{1}
{\MacroFont#1}
{\XDMainIndex{\LevelSorted{#1}{\texttt{#1} (environment)}}%
\XDMainIndex{%
\LevelSame{environments:}\LevelSorted{#1}{\texttt{#1}}%
}}%
{{#1}{\texttt{#1}}}
{}%
% \end{macrocode}
% \end{environment}\end{environment}
%
%
% \subsection{Further examples of \texttt{macro}-like environments}
% \label{Ssec:More macros}
%
% \begin{environment}{option}
% The \texttt{option} environment is for class\slash package options.
% IMHO, something like this environment should have been added to
% \package{doc} years ago!
%
% \begin{macrocode}
\NewMacroEnvironment{option}{\XD@grab@harmless\relax}{1}
{\MacroFont#1 \normalfont option}
{\XDMainIndex{\LevelSorted{#1}{\texttt{#1} option}}%
\XDMainIndex{%
\LevelSame{options:}\LevelSorted{#1}{\texttt{#1}}%
}}%
{{#1 option}{\texttt{#1} option}}
{}%
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{switch}
% \changes{prot2.1}{2000/11/18}{Using \cs{MakeSortKey}. (LH)}
% The \texttt{switch} environment is for switches created by
% |\newif| (\PlainTeX\ style).
% \begin{macrocode}
\NewMacroEnvironment{switch}{\XD@grab@harmless\relax}{1}
{\MacroFont#1 \normalfont switch}%
% \end{macrocode}
% What makes switches different from the other \texttt{macro}-like
% environments defined here is the large number of index entries it
% makes. For a switch \meta{sw} it first makes one under the `switches:'
% heading:
% \begin{macrocode}
{%
\MakeSortKey\XD@last@key{#1}{}%
\XDMainIndex{%
\LevelSame{switches:}\LevelSorted{\XD@last@key}{\texttt{#1}}%
}%
% \end{macrocode}
% Second it makes a `\meta{sw} switch' entry:
% \begin{macrocode}
\XDMainIndex{\LevelSorted{\XD@last@key}{\texttt{#1} switch}}%
% \end{macrocode}
% Third it makes an entry for the macro |\if|\meta{sw}. The sort key
% for this entry is \emph{not} subjected to |\MakeSortKey| because
% no reasonable operator will act on the |if| prefix (an operator
% which acts on |if| could do rather strange things to e.g. |\ifnum|).
% \begin{macrocode}
\XDMainIndex{\LevelSorted{if#1}{\texttt{\Bslash if#1}}}%
% \end{macrocode}
% Fourth it makes an entry for the macro |\|\meta{sw}|false|:
% \begin{macrocode}
\MakeSortKey\@tempa{#1false}{}%
\XDMainIndex{\LevelSorted{\@tempa}{\texttt{\Bslash#1false}}}%
% \end{macrocode}
% Finally it makes an entry for the macro |\|\meta{sw}|true|:
% \begin{macrocode}
\MakeSortKey\@tempa{#1true}{}%
\XDMainIndex{\LevelSorted{\@tempa}{\texttt{\Bslash#1true}}}%
}%
% \end{macrocode}
% The |\changes| heading, on the other hand, is trivial.
% \begin{macrocode}
{{#1}{\texttt{#1} switch}}
% \end{macrocode}
% Finally, \texttt{switch} should turn off indexing of the three macros
% it makes \texttt{main} entries for, since \package{makeindex} will
% otherwise complain.
% \begin{macrocode}
{\DoNotIndexHarmless{if#1}%
\DoNotIndexHarmless{#1false}%
\DoNotIndexHarmless{#1true}}%
%</pkg>
% \end{macrocode}
% \end{environment}
%
%
% To end this section, there now follows two examples which are not
% part of the package as they are very specific, but which have been
% included here because they illustrate that \texttt{macro}-like
% environments may have several arguments.
%
% \begin{environment}{enccommand}
% \begin{environment}{enccomposite}
% The \texttt{enccommand} and \texttt{enccomposite} environments can
% be used for marking up sources for encoding definition files and the
% like. \texttt{enccommand} is for encoding-specific commands and has
% the syntax
% \begin{quote}
% |\begin{enccommand}|\marg{command}\oarg{encoding}
% \end{quote}
% where \meta{command} is the encoding-specific command and
% \meta{encoding} is the encoding that this definition is for. If the
% \meta{encoding} is omitted then the \texttt{enccommand} is assumed
% to be for the default definition of the command.
%
% \texttt{enccomposite} is for composites of encoding-specific
% commands (defined for example using |\Declare|\-|Text|\-|Composite|).
% It has the syntax
% \begin{quote}
% |\begin{enccomposite}|\marg{command}\marg{encoding}\marg{argument}
% \end{quote}
% where \meta{command} and \meta{encoding} are as for
% \texttt{enccommand} and \meta{argument} is the argument with which
% the command is being composed.
%
% The marginal headings these commands print are the actual control
% sequences in which the definitions are stored.
% \begin{macrocode}
%<*enccmds>
\NewMacroEnvironment{enccommand}{%
\XD@grab@harmless@asmacro \XD@grab@oarg
}{2}{\MacroFont\Bslash \ifx\NoValue#2?\else#2\fi \Bslash #1}{%
\XDMainIndex{%
\LevelSorted{#1}{\texttt{\Bslash#1}}%
\ifx \NoValue#2%
\LevelSame{default}%
\else
\LevelSorted{#2}{\texttt{#2} encoding}%
\fi
}%
}{{#1}{\texttt{\Bslash#1}}}{\DoNotIndexHarmless{#1}}
% \end{macrocode}
% \begin{macrocode}
\NewMacroEnvironment{enccomposite}{%
\XD@grab@harmless@asmacro \XD@grab@marg \XD@grab@harmless\relax
}{3}{\MacroFont\Bslash#2\Bslash#1-#3}{%
\XDMainIndex{%
\LevelSorted{#1}{\texttt{\Bslash#1}}%
\LevelSorted{#2}{\texttt{#2} encoding}%
\LevelSorted{\XD@unbackslash#3\@empty}{\texttt{#3} composite}%
}%
}{{#1}{\texttt{\Bslash#1}}}{\DoNotIndexHarmless{#1}}
%</enccmds>
% \end{macrocode}
% In the file \texttt{cyoutenc.dtx} the definitions of many
% encoding-specific commands are written so that the same line of
% code can work is all four files \texttt{t2aenc.def},
% \texttt{t2benc.def}, \texttt{t2cenc.def}, and \texttt{x2enc.def}.
% Therefore the \meta{encoding} argument of the \texttt{enccommand}
% and \texttt{enccomposite} environments should perhaps rather be a
% comma-separated list of encodings than a single encoding, but that
% would make this example unnecessarily complicated.
% \end{environment}\end{environment}
%
%
%
% \section{Describing macros and the like}
% \label{Sec:Describing}
%
% \begin{macro}{\if@mparswitch}
% \begin{macro}{\if@reversemargin}
% In two-sided mode, marginal notes should appear in the outer
% margin. The following code takes care of that.
% \begin{macrocode}
%<*pkg>
\if@twoside
\@mparswitchtrue
\normalmarginpar
\fi
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\GenericDescribePrint}
% \changes{prot2}{2000/07/14}{\cs{leavevmode} and \cs{ignorespaces}
% moved to \cs{NewDescribeCommand}. (LH)}
% \changes{prot2}{2000/07/20}{Added \cs{strut}. Removed it from
% arguments passed to \cs{GenericDescribePrint}. (LH)}
% \changes{prot2.3}{2001/06/24}{Changed formatting to match that of
% \cs{XDParToMargin}. (LH)}
% The |\GenericDescribePrint| macro is a utility macro for use in
% commands like |\Describe|\-|Macro|. Its syntax is
% \begin{quote}
% |\GenericDescribePrint|\marg{text}
% \end{quote}
% and it puts \meta{text} in a marginal paragraph, giving it the
% appropriate justification for appearing in that margin.
%
% The first part simply tests whether the argument fits on a single
% line.
% \begin{macrocode}
\newcommand\GenericDescribePrint[1]{%
\setbox\z@=\vbox{%
\parindent=\z@
\leftskip=\z@skip
\rightskip=\z@\@plus 1fil%
\parfillskip=\z@skip
\hsize=\marginparwidth
\linepenalty=\@m
\color@begingroup
\noindent\ignorespaces #1\@@par
\color@endgroup
\expandafter}%
\expandafter\ifnum \the\prevgraf<\tw@
% \end{macrocode}
% Then comes the actual typesetting. First the single-line format.
% The braces in the optional argument are there to prevent trouble
% in case |#1| contains a right brace; they will be stripped off when
% the argument is grabbed.
% \begin{macrocode}
\if@twoside
\marginpar[{\raggedleft\strut #1}]{\raggedright\strut #1}%
\else
\marginpar{\raggedleft\strut#1}%
\fi
\else
\if@twoside
\marginpar[{%
\leftskip=\z@ \@plus \marginparwidth
\rightskip=\leftskip
\parfillskip=\z@ \@plus -\marginparwidth
\noindent\nobreak\hskip\parfillskip
\ignorespaces #1%
}]{%
\leftskip=\z@ \@plus \marginparwidth
\rightskip=\leftskip
\parfillskip=\z@ \@plus 1fil%
\noindent\nobreak\hskip\parfillskip
\ignorespaces #1%
}%
\else
\marginpar{%
\leftskip=\z@ \@plus \marginparwidth
\rightskip=\leftskip
\parfillskip=\z@ \@plus -\marginparwidth
\noindent\nobreak\hskip\parfillskip
\ignorespaces #1%
}%
\fi
\fi
}
% \end{macrocode}
% \end{macro}
%
% The \texttt{describe}-commands are supposed to be invisible---only
% leave a single space even when there are spaces both before and after
% them---but there are problems with the mechanisms for this. I get the
% impression that they have never worked perfectly, but that seems to
% be mainly due to that certain macros in the \LaTeX\ kernel never did
% either, and I suspect that the general problem has been thrashed over
% many times before.
%
% \package{doc}'s |\DescribeMacro| and |\DescribeEnv| are wrapped up in
% a |\@bsphack| \dots\ |\@esphack| ``group'' to become invisible, but
% the |\marginpar| and various index commands they are built on are
% themselves already invisible, so one would suspect that there is no
% need for additional invisibility. There are however two factors which
% create this need. One is that it doesn't do the right thing at
% beginning of lines; here it seems like what the
% \texttt{describe}-commands would need is the |\@vbsphack| macro
% (whose definition appears in \texttt{ltspace.dtx}, but which has been
% commented out) since they should start a new paragraph and leave no
% following space if they are used in vertical mode. The other factor is
% that the standard |\@bsphack|--|\@esphack| can only suppress every
% second intermediate space if several invisible commands appear in
% sequence, as is quite common for the
% \texttt{describe}-commands.\footnote{It would seem that a simple fix
% for this is to have \cs{@esphack} insert \cs{nobreak}
% \cs{hskip}\texttt{-}\cs{@savsk} \cs{hskip}\cs{@savsk} before it
% executes \cs{ignorespaces}, but since that fix hasn't been
% incorporated into the kernel or the \package{fixltx2e} package there
% probably is some problem with it.}
%
% Instead the \package{doc} implementations of |\DescribeMacro| and
% |\DescribeEnv| begin with |\leavevmode| and end with |\ignorespaces|,
% which means that they are only ``invisible'' if they appear on on the
% left of visible material, but that's how it has been for over a decade
% now.
%
% \begin{macro}{\NewDescribeCommand}
% \changes{prot2}{2000/07/14}{Command added. (LH)}
% The |\NewDescribeCommand| command is a relative to the
% |\New|\-|Macro|\-|Environment| command which defines commands
% analogous to |\Describe|\-|Macro| rather than \texttt{macro}-like
% environments. Its syntax is
% \begin{quote}
% |\NewDescribeCommand|\marg{command}\marg{grabbers}\B
% \marg{numargs}\B\marg{definition}
% \end{quote}
% \meta{command} is the control sequence to define. \meta{grabbers}
% and \meta{numargs} are as for the |\NewMacroEnvironment| command.
% \meta{definition} is the command definition.
% In addition to the definition given in the \meta{definition}
% argument and the code for grabbing the arguments, the command
% actually defined by |\New|\-|Describe|\-|Command| will contain a
% |\leavevmode| at the start and an |\ignorespaces| at the end.
%
% The |\NewDescribeCommand| command should really just be a call to
% \package{xparse}'s |\Declare|\-|Document|\-|Command|, but that will
% have to wait until \package{xdoc} becomes based on the
% \package{xparse} package.
% \begin{macrocode}
\newcommand\NewDescribeCommand[4]{%
\@ifdefinable#1{%
\expandafter\def \expandafter#1\expandafter{%
\expandafter\XD@grab@arguments \csname\string#1\endcsname{#2}%
}%
\let\l@ngrel@x\relax
\expandafter\@yargdef \csname\string#1\endcsname \@ne {#3}%
{\leavevmode#4\ignorespaces}%
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\DescribeMacro}
% \changes{prot2.1}{2000/11/18}{Using \cs{MakeSortKey}. (LH)}
% \begin{macro}{\DescribeEnv}
% The |\DescribeMacro| and |\DescribeEnv| commands are as in
% \package{doc}. The argument of |\DescribeMacro| is supposed to be
% the actual control sequence to describe (not as with the
% \texttt{macro} environment something which looks like the control
% sequence after being |\string|ed).
% \begin{macrocode}
\let\DescribeMacro=\relax
\NewDescribeCommand\DescribeMacro{\XD@grab@harmless@cs}{1}{%
\GenericDescribePrint{\MacroFont\Bslash#1}%
\MakeSortKey\@tempa{#1}{}%
\IndexEntry{%
\LevelSorted{\@tempa}{\texttt{\Bslash#1}}%
}{usage}{\thepage}%
}
% \end{macrocode}
% The argument of |\DescribeEnv|, on the other hand, is treated like
% that of the \texttt{environment} environment, but backslash isn't
% given catcode 12---only the catcode assignments in
% |\Make|\-|Private|\-|Letters| are made.
% \begin{macrocode}
\let\DescribeEnv=\relax
\NewDescribeCommand\DescribeEnv{%
\XD@grab@harmless@withprivate\relax
}{1}{%
\GenericDescribePrint{\MacroFont#1}%
\IndexEntry{%
\LevelSame{environments:}\LevelSorted{#1}{\texttt{#1}}%
}{usage}{\thepage}%
\IndexEntry{%
\LevelSorted{#1}{\texttt{#1} (environment)}%
}{usage}{\thepage}%
}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\describeoption}
% \changes{prot2}{2000/07/31}{Command added---I realised that the need
% to describe options is probably as large as that to mark out
% their definition. (LH)}
% The |\describeoption| command is the \texttt{describe}-companion to
% the \texttt{option} environment.
% \begin{macrocode}
\NewDescribeCommand\describeoption{\XD@grab@harmless\relax}{1}{%
\GenericDescribePrint{\MacroFont#1 \normalfont option}%
\IndexEntry{%
\LevelSame{options:}\LevelSorted{#1}{\texttt{#1}}%
}{usage}{\thepage}%
\IndexEntry{%
\LevelSorted{#1}{\texttt{#1} option}%
}{usage}{\thepage}%
}
% \end{macrocode}
% \end{macro}
%
%
% \begin{macro}{\describecsfamily}
% \changes{prot2}{2000/07/14}{Renamed \cs{DescribeCSFamily} and
% incorporated the code from \cs{XD@index@family}. (LH)}
% \changes{prot2.1}{2000/11/18}{Using \cs{MakeSortKey}. (LH)}
% The |\describecsfamily| command is for marking out sections in text
% where a particular family of control sequences is described---just
% like |\DescribeMacro| does for individual commands. To clarify what
% I mean by a control sequence family, here are a couple of examples:
% \begin{longtable}{l >{\raggedright}p{0.55\linewidth}}
% |\c@|\meta{counter}\label{Tab:CS-families}&
% countdef token for the |\count| register storing the
% \LaTeX\ counter \meta{counter}\tabularnewline
% |\ps@|\meta{pagestyle}&
% macro storing settings for the pagestyle \meta{pagestyle}^^A
% \tabularnewline
% |\|\meta{enc}|/|\meta{fam}|/|\meta{ser}|/|\meta{sh}|/|\meta{sz}&
% the fontdef token for the font which has encoding \meta{enc},
% family \meta{fam}, series \meta{ser}, shape \meta{sh}, and
% size \meta{sz} under NFSS\tabularnewline
% |\|\meta{enc}|\|\meta{cmd}&
% the macro containing the definition for encoding \meta{enc} of
% the encoding-specific \LaTeX\ command |\|\meta{cmd}^^A
% \tabularnewline
% |\fps@|\meta{type}&
% the default placement specifier for \LaTeX\ floats of type
% \meta{type}\tabularnewline
% |\l@|\meta{name}&
% a macro which formats table of contents entries for items of
% type \meta{name} (\texttt{chapter}, \texttt{section}, etc.)^^A
% \tabularnewline
% |\l@|\meta{language}&
% the |\language| number \package{babel} has allocated for the
% language \meta{language} (\texttt{english}, \texttt{french},
% etc.)\tabularnewline
% |\i-|\meta{int}&
% the control sequence (either a mathchardef token or a macro)
% which stores the value of the \package{fontinst} integer
% \meta{int}
% \end{longtable}
%
% The syntax for |\describecsfamily| is
% \begin{quote}
% |\describecsfamily|\marg{cs-fam specification}
% \end{quote}
% The \meta{cs-fam specification} includes only what would be put
% between |\csname| and |\endcsname|; the |\describecsfamily| command
% will add a backslash when printing the name. No special catcodes
% will be in force in the argument, but the |#|, |$|, |&|, |_|, |^|,
% and |~| characters present no problems even if they have their
% ordinary catcodes. All spaces are seen as ASCII space and \TeX\ is
% skipping spaces as usual. Characters with catcode 0, 1, 2, 5, 9, 14,
% or 15 may however be problematic.
% If you need to specify such a problematic character then you can do
% so by writing |\PrintChar|\marg{code}, where \meta{code} is the
% ASCII code for the character, as a valid \TeX\ number in the range
% 0--255. In case you do not remember the ASCII code for some
% character \meta{c}, there is no harm in specifying it as
% |`\|\meta{c}, e.g. |\PrintChar{`\}}| for a right brace. It is even
% possible to write |\PrintChar| commands for characters outside
% visible ASCII (but those are typeset as |^^|-sequences).
%
% The variant parts in the control sequence names are specified as
% \begin{quote}
% |\meta|\marg{text}
% \end{quote}
% and these will be typeset exactly as in normal text. The arguments
% of |\meta|s appearing in a \meta{cs-fam specification} are moving.
% All control sequences other than |\PrintChar| and |\meta| in a
% \meta{cs-fam specification} (and which do not appear in the argument
% of a |\PrintChar| or |\meta|) are essentially treated as if they
% had been |\string|ed.
%
% Apart from the above differences in treatment of the argument, the
% |\describe|\-|cs|\-|family| command is similar to
% |\DescribeMacro|---it prints the control sequence name in the margin
% and makes a \texttt{usage} index entry.
% \begin{macrocode}
\NewDescribeCommand\describecsfamily{\XD@grab@harmless{}}{1}{%
\GenericDescribePrint{%
\MetaNormalfont\MacroFont\Bslash#1%
}%
\MakeSortKey\@tempa{#1}{\def\meta##1{(##1)}}%
\IndexEntry{%
\LevelSorted{\@tempa}{\texttt{\protect\MetaNormalfont\Bslash#1}}%
}{usage}{\thepage}%
}
%</pkg>
% \end{macrocode}
% \end{macro}
%
%
% As for |\NewMacroEnvironment|, I also give an example of an
% application of |\NewDescribeCommand| which is much too special for
% including in \package{xdoc} in general and therefore the code is
% placed in a special module. I had originally written the code as part
% of another package, but I removed it because I thought it was a bit
% too special even for that context. The commentry below is kept
% unchanged.\changes{prot2.1}{2000/09/16}{Additional
% \cs{NewDescribeCommand} code example added. (LH)}
%
% \begin{quotation}
%
% I believe this feature is primarily of interest for MacOS programs,
% but there might be sufficiently similar structures in other operating
% systems to make it useful even in other contexts. Be as it may, what
% the feature described here does is that it allows the user to put an
% entry in the index for each resource in the code. This gives an easy
% way of checking that no two resources are assigned the same id, even
% though there is no mechanism for especially warning for such
% collisions.
%
% \begin{macro}{\DescribeResource}
% The main command available is
% \begin{quote}
% |\DescribeResource|\marg{type}\marg{id}\marg{text}
% \end{quote}
% \meta{type} is a four-character string. Most special characters are
% treated as ordinary ones (very useful for |#|s), but the visible
% ASCII characters |%|, |{|, |\|, and |}| retain their usual meaning.
% To use such a troublesome character \meta{c} in a resource type,
% write it as |\PrintChar{`\|\meta{c}|}|. \meta{id} is a \TeX\ number;
% it will be used as the number of the resource. \meta{text} is normal
% text that will be put in the index entry to describe the resource; it
% seems a good idea to use the name of the resource for this. \meta{id}
% and \meta{text} are read with normal \LaTeX\ catcodes. Note that
% \meta{text} is a moving argument.
%
% |\DescribeResource| does two things---it prints the \meta{type} and
% \meta{id} of the resource in the margin, and it writes an entry
% \begin{quote}
% \meta{type} resources:\\
% \vadjust{}\qquad\meta{id}\\
% \vadjust{}\qquad\qquad\meta{text}
% \end{quote}
% (plus a lot of formatting not shown here) to the \texttt{.idx} file.
% The reference is for the page.
%
% The idea with advancing |\count@| like that when constructing the
% index entry is to get a sort key for which lexicographic order equals
% the wanted order. This would not be the case if the number was simply
% written down. The current code maps numbers to six-digit positive
% integers, but five-digits integers would be sufficient (a resource
% \meta{id} is a signed 16-bits integer). The construction chosen
% here furthermore puts the negative numbers after the positive ones.
% \begin{macrocode}
%<*rsrccmd>
\NewDescribeCommand\DescribeResource{%
\XD@grab@harmless\relax \XD@grab@marg \XD@grab@marg
}{3}{%
\GenericDescribePrint{#1%
\textnormal{:\ifnum#2<\z@ \textminus\number-\else\number\fi#2}%
}%
\count@=#2\relax
\advance \count@ 100000\ifnum \count@<\z@ 0\fi \relax
\protected@edef\@tempa{%
\noexpand\LevelSorted{\the\count@}{%
\ifnum #2<\z@ \string\textminus \number-\else\number\fi#2%
}%
}%
\IndexEntry{%
\LevelSorted{#1 resources:}{\texttt{#1} resources:}%
\@tempa
\LevelSame{#3}%
}{usage}{\thepage}%
}
%</rsrccmd>
% \end{macrocode}
% \end{macro}
%
% \end{quotation}
%
%
% \section{The \cs{DocInclude} command}
% \label{Sec:DocInclude}
%
% The code in this section is based on code from the \package{ltxdoc}
% document class~\cite{ltxdoc} and it implements a command called
% |\DocInclude|. Two implementations of this command are given: one
% which is essentially that of \package{ltxdoc} (preserving all its
% peculiarities), and one which is a reimplementation from scratch. The
% default is to use the latter, but passing the \texttt{olddocinclude}
% option to \package{xdoc} selects the former.
%
%
% \subsection{Old implementation}
%
% It should be observed that this is not a complete implementation of the
% |\Doc|\-|Include| command---it only redefines the \package{ltxdoc}
% macros that need to be changed if the |\Doc|\-|Include| command is to
% work with \package{xdoc} (it doesn't for example change the definition
% of |\Doc|\-|Include| itself). Furthermore it doesn't define anything if
% the \package{ltxdoc} document class hasn't been loaded, since then the
% details of the definition of |\Doc|\-|Include| (even if it would be
% defined) are unknown.
%
% \begin{macro}{\CodelineIndex}
% \changes{prot2.1}{2000/10/08}{Using \cs{thecodelineno}. (LH)}
% \begin{macro}{\filesep}
% \changes{prot2.2}{2001/02/13}{Redefined to use
% \cs{XD@page@compositor}. (LH)}
% \begin{macro}{\@docinclude}
% \package{ltxdoc} redefines |\codeline@wrindex| so that |\filesep| is
% prepended to each codeline number that is written to the index file.
% That redefinition has no effect unless the |\Codeline|\-|Index|
% command is executed afterwards however, so there is no harm in having
% |\Codeline|\-|Index| itself apply the corresponding change.
% \begin{macrocode}
%<*pkg>
\@ifpackagewith{xdoc2}{olddocinclude}{%
\@ifclassloaded{ltxdoc}{%
\renewcommand\CodelineIndex{%
\makeindex
\let\XD@if@index=\@firstoftwo
\codeline@indextrue
\def\TheXDIndexNumber{\filesep\thecodelineno}%
}%
% \end{macrocode}
% The |\filesep| macro is redefined so that the \package{docindex}
% package~\cite{docindex} can use a |page_compositor| string different
% from the default |-| simply by redefining |\XD@page@compositor|.
% This redefinition has to be put in |\docincludeaux| since that macro
% redefines |\filesep| too.
% \begin{macrocode}
\expandafter\def \expandafter\docincludeaux \expandafter{%
\docincludeaux
\gdef\filesep{\thepart\XD@page@compositor}%
}
% \end{macrocode}
% The change to |\@docinclude| merely consists of inserting code for
% writing an |External|\-|XRef|\-|Wrap| to the \texttt{.aux} file to
% record the new value of the \texttt{part} counter.
% \begin{macrocode}
\def\@docinclude#1 {%
\clearpage
\if@filesw
\immediate\write\@mainaux{\string\@input{#1.aux}}%
\fi
\@tempswatrue
\if@partsw
\@tempswafalse
\edef\@tempb{#1}%
\@for\@tempa:=\@partlist\do{%
\ifx\@tempa\@tempb\@tempswatrue\fi
}%
\fi
\if@tempswa
\let\@auxout\@partaux
\if@filesw
\immediate\openout\@partaux #1.aux
\immediate\write\@partaux{\relax}%
\fi
\part{#1.dtx}%
\if@filesw
\immediate\write\@partaux{\@percentchar\@percentchar
ExternalXRefWrap {\filesep} {}%
}%
\fi
{%
\let\ttfamily\relax
\xdef\filekey{%
\filekey, \thepart={\ttfamily\currentfile}%
}%
}%
\DocInput{#1.dtx}%
\clearpage
\@writeckpt{#1}%
\if@filesw \immediate\closeout\@partaux \fi
\else
\@nameuse{cp@#1}%
\fi
\let\@auxout\@mainaux
}
}{}
}{}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
%
% \subsection{New implementation}
% \label{Ssec:New DocInclude}
%
% The default action of the second implementation is to be precisely an
% |\include| variant of |\DocInput|, but in addition to that it also
% has a (one-argument) hook called |\docincludeaux| which is executed
% before a file is actually |\DocInput|ted, but after it has been
% determined that it should be included, and this hook is only executed
% for the files which should be |\include|d. This hook is normally
% |\@gobble|, but passing the \texttt{fileispart} option to
% \package{xdoc} redefines it to start a new part and set the pagestyle.
%
% \begin{macro}{\DocInclude}
% \begin{macro}{\@docinclude}
% Most of the code for the |\DocInclude| command is put in the
% |\@docinclude| macro; |\DocInclude| simply checks that it hasn't
% been nested. The main difference to |\include| is that a nested
% |\DocInclude| becomes an error plus the corresponding |\DocInput|,
% whereas a nested |\include| simply becomes an error. The rationale
% for this is that it is probably closer to what was intended.
%
% The argument of |\@docinclude| is, oddly enough, space-delimited.
% This is inherited from the |\@include| macro in the \LaTeX\ kernel,
% where it is a hack to make sure that the part \texttt{.aux} file
% that is opened for writing really gets the suffix \texttt{.aux} (in
% the worst case, \TeX\ could start overwriting a \texttt{.tex} file
% instead).
% \begin{macrocode}
\@ifpackagewith{xdoc2}{olddocinclude}{}{%
\def\DocInclude#1{%
\ifnum\@auxout=\@partaux
\@latexerr{\string\include\space cannot be nested}{%
Your \protect\DocInclude\space will be reduced to a
\protect\DocInput.%
}%
\DocInput{#1.dtx}%
\else \@docinclude#1 \fi
}%
% \end{macrocode}
% The only things in this |\@docinclude| that are not precisely as in
% |\@include| are the |\docincludeaux| and |\DocInput| commands.
% \begin{macrocode}
\def\@docinclude#1 {%
\clearpage
\if@filesw
\immediate\write\@mainaux{\string\@input{#1.aux}}%
\fi
\@tempswatrue
\if@partsw
\@tempswafalse
\edef\@tempb{#1}%
\@for\@tempa:=\@partlist\do{%
\ifx\@tempa\@tempb \@tempswatrue \fi
}%
\fi
\if@tempswa
\let\@auxout\@partaux
\if@filesw
\immediate\openout\@partaux #1.aux
\immediate\write\@partaux{\relax}%
\fi
\docincludeaux{#1.dtx}%
\DocInput{#1.dtx}%
\clearpage
\@writeckpt{#1}%
\if@filesw \immediate\closeout\@partaux \fi
\else
\deadcycles\z@
\@nameuse{cp@#1}%
\fi
\let\@auxout\@mainaux
}%
}{}
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{option}{fileispart}
% \begin{macro}{\docincludeaux}
% The \texttt{fileispart} option works by (re)defining a couple of
% macros, of which the |\doc|\-|include|\-|aux| macro is the most
% important. Its syntax is
% \begin{quote}
% |\docincludeaux|\marg{filename}
% \end{quote}
% where \meta{filename} is the name of a file that will be inputted.
% The \texttt{fileispart} definition of this is to set |\currentfile|
% to the harmless character string of \meta{filename}, produce a
% |\part| heading whose text is that \meta{filename}, add the
% \meta{filename} to the |\filekey| macro, set the page style to
% \texttt{docpart}, clear the |\filedate|, |\fileversion|, and
% |\fileinfo| macros, and write an |External|\-|XRef|\-|Wrap|
% XXR-command to the \texttt{.aux} file to record the new codeline
% number prefix.
% \begin{macrocode}
\@ifpackagewith{xdoc2}{olddocinclude}{\iffalse}{
\@ifpackagewith{xdoc2}{fileispart}{\iftrue}{
\let\docincludeaux=\@gobble
\iffalse
}
} % If fileispart and not olddocinclude then
\def\docincludeaux#1{%
\MakeHarmless\currentfile{#1}%
\part{\texttt{\currentfile}}%
\pagestyle{docpart}%
\let\filedate\@empty
\let\fileversion\@empty
\let\fileinfo\@empty
\protected@xdef\filekey{%
\filekey, \thepart=\texttt{\currentfile}%
}%
\if@filesw
\immediate\write\@partaux{\@percentchar\@percentchar
ExternalXRefWrap {\thepart\XD@page@compositor} {}%
}%
\fi
}%
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\CodelineIndex}
% \changes{prot2.1}{2000/10/08}{Using \cs{thecodelineno}. (LH)}
% The \texttt{fileispart} option also adds the \texttt{codelineno}
% counter to the reset list for \texttt{part} and changes the format
% of codeline numbers written to the index.
% \begin{macrocode}
\@ifclassloaded{ltxdoc}{}{\@addtoreset{codelineno}{part}}%
\renewcommand\CodelineIndex{%
\makeindex
\let\XD@if@index=\@firstoftwo
\codeline@indextrue
\def\TheXDIndexNumber{\thepart\XD@page@compositor\thecodelineno}%
}%
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\partname}
% \begin{macro}{\thepart}
% \begin{macro}{\IndexParms}
% Finally there are a couple of macros which are redefined for
% aesthetic rather than technical reasons. Passing the
% \texttt{fileispart} option sets |\partname| to \texttt{File}, sets
% |\thepart| to |\aalph{part}|, and adds a setting of pagestyle to
% |\IndexParms|. (The pagestyle setting is added to
% |\index@|\B|prologue| by \package{ltxdoc}, but I think
% |\Index|\-|Parms| is more appropriate.)
% \begin{macrocode}
\def\partname{File}
\def\thepart{\aalph{part}}
\expandafter\def \expandafter\IndexParms
\expandafter{\IndexParms \pagestyle{docindex}}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% In case the index formatting is handled by the \package{docindex}
% package~\cite{docindex} (or its \LaTeXe\ incarnation
% \package{docidx2e}), the above addition to |\Index|\-|Parms| won't
% have any effect. Therefore \package{xdoc} also passes the
% \texttt{use}\-\texttt{doc}\-\texttt{index}\-\texttt{ps} option on
% to these packages.
% \begin{macrocode}
\PassOptionsToPackage{usedocindexps}{docindex}
\PassOptionsToPackage{usedocindexps}{docidx2e}
\fi
% \end{macrocode}
% \end{option}
%
% \begin{macro}{\ps@docpart}
% \begin{macro}{\setfileinfo}
% \begin{macro}{\XD@set@file@info}
% The \texttt{docpart} pagestyle is for pages made from the
% |\DocInclude|d files. The page footers contain the page number, the
% part (file) number, and the current file name. It also contains the
% file date and version if that information is available.
%
% \package{ltxdoc} uses |\GetFileInfo| to get the date and version
% information, but that's a very peculiar practice. The data one wants
% to present are about the file being typeset---typically the version
% of the package that is documented in this file---whereas the
% |\GetFileInfo| command really extracts information about
% \emph{unpacked} classes, packages, and similar files---files that
% contribute to the typesetting by defining commands, not by containing
% text. Such information may be of interest for documents which contain
% alternative code for incompatible versions of for example a package,
% but it is of no use for printing version information as above since
% the version of a package used for typesetting a \texttt{.dtx} file
% need not be the version actually contained in that \texttt{.dtx}
% file. Thus the only way to make this work is by doing as the \LaTeX\
% kernel source and include |\ProvidesFile| commands for the
% \texttt{.dtx} file in each such file, which is a rather peculiar use
% of the |\ProvidesFile| command.
%
% The |\setfileinfo| command provides an equivalent feature in a less
% roundabout way. It has the syntax
% \begin{quote}
% |\setfileinfo[|\meta{date}\verb*+ +\meta{version}\verb*+ +^^A
% \meta{info}|]|
% \end{quote}
% and it sets |\filedate| to \meta{date}, |\fileversion| to
% \meta{version}, and |\fileinfo| to \meta{info} if the optional
% argument is present; if the optional argument is missing or contains
% fewer than three words then the missing fields are set to |?|.
%
% \begin{macrocode}
\@ifpackagewith{xdoc2}{olddocinclude}{}{%
\def\ps@docpart{%
\def\@oddfoot{%
File: \texttt{\currentfile}%
\ifx \filedate\@empty \else \ Date: \filedate\fi
\ifx \fileversion\@empty \else \ Version: \fileversion\fi
\hfill\thepage
}%
\if@twoside
\def\@evenfoot{%
\thepage\hfill
File: \texttt{\currentfile}%
\ifx \filedate\@empty \else \ Date: \filedate\fi
\ifx \fileversion\@empty \else \ Version: \fileversion\fi
}%
\else \let\@evenfoot\@oddfoot \fi
}
% \end{macrocode}
% The corresponding definition in \package{ltxdoc} (there it appears in
% |\docincludeaux|) is peculiar in that the odd page footer is set
% globally but the even page footer only locally.
%
% The definition of |\setfileinfo| follows that of |\GetFileInfo|
% except for the fact that the |\relax|es have been replaced by
% |\@empty|s.
% \begin{macrocode}
\newcommand\setfileinfo[1][]{%
\edef\@tempa{#1}%
\expandafter\XD@set@file@info \@tempa\@empty? ? \@empty\@empty
}
\def\XD@set@file@info#1 #2 #3\@empty#4\@empty{%
\def\filedate{#1}%
\def\fileversion{#2}%
\def\fileinfo{#3}%
}
}{}
% \end{macrocode}
% The reason for making the argument of |\setfileinfo| optional is
% that with the |\Provides|\-|File| practice one can (potentially) put
% all date and version information in one place through tricks like
% \iffalse
%<*example>
% \fi
%\begin{verbatim}
%% \begin{macrocode}
%\ProvidesPackage{foobar}
%% \end{macrocode}
%% \ProvidesFile{foobar.dtx}
% [2000/02/02 v1.0 Silly example package]
%%
%\end{verbatim}\iffalse
%</example>
% \fi
% By making the argument of |\setfileinfo| optional, I make sure that
% people who have used such tricks only have to replace the
% |\ProvidesFile{foobar.dtx}| by |\setfileinfo|.
% \end{macro}\end{macro}\end{macro}
%
%
% \begin{macro}{\ps@docindex}
% \begin{macro}{\filekey}
% The \texttt{docindex} pagestyle is for the index in
% \texttt{fileispart} documents. It prints a file key, which is a
% list of all the included files and their corresponding part letters,
% at the bottom of every page. The file key is stored in the macro
% |\filekey|, which should have been constructed file by file as they
% are included. To add a file to the file key, it is recommended that
% you do
% \begin{quote}
% |\protected@xdef\filekey{\filekey, |\meta{entry for new file}|}|
% \end{quote}
% The \texttt{fileispart} version of |\docincludeaux| already does
% this. The initial value of |\filekey| is |\@gobble| so that the
% comma before the first entry is removed. The |\@empty| below is
% there in case no entry has been inserted.
% \begin{macrocode}
% \@ifpackagewith{xdoc2}{olddocinclude}{}{%
\def\ps@docindex{%
\def\@oddfoot{%
\parbox{\textwidth}{%
\strut\footnotesize\raggedright
\textbf{File Key:} \filekey\@empty
}%
}%
\let\@evenfoot\@oddfoot
}%
\let\filekey\@gobble
% }
% \end{macrocode}
% \end{macro}\end{macro}
%
% It should be observed that since |\ps@docindex| only sets the page
% style locally, the page style will revert to its previous setting at
% the end of the \texttt{theindex} environment. As that previous
% setting is probably that of the \texttt{docpart} page style, you
% might have to set the page style manually.
%
% \begin{macro}{\aalph}
% \begin{macro}{\@aalph}
% |\aalph| is a variant of |\alph| which continues with the upper case
% letters for 27--52. It is defined by \package{ltxdoc}, so it is
% merely provided here.
% \begin{macrocode}
\providecommand*\aalph[1]{\@aalph{\csname c@#1\endcsname}}
\providecommand*\@aalph[1]{%
\ifcase#1\or a\or b\or c\or d\or e\or f\or g\or h\or i\or
j\or k\or l\or m\or n\or o\or p\or q\or r\or s\or
t\or u\or v\or w\or x\or y\or z\or A\or B\or C\or
D\or E\or F\or G\or H\or I\or J\or K\or L\or M\or
N\or O\or P\or Q\or R\or S\or T\or U\or V\or W\or
X\or Y\or Z\else\@ctrerr\fi
}
% \end{macrocode}
% In \texttt{source2e.tex} one can see that \package{doc}'s standard
% \texttt{gind.ist} index style file won't sort the 35th file (part
% \texttt{I}) correctly since it causes \package{makeindex} to read an
% \texttt{I} as ``upper case Roman numeral one'', but I doubt very
% many people encounter that problem in their projects.
% \end{macro}\end{macro}
%
% \begin{macro}{\XD@page@compositor}
% \changes{prot2.2}{2001/02/13}{Macro added, other macros changed to
% use it. (LH)}
% The |\XD@page@compositor| macro contains the string which is put
% between the parts of a composite number in the index; it
% corresponds to the |page_compositor| parameter of
% \package{makeindex}.
% \begin{macrocode}
\providecommand*\XD@page@compositor{-}
% \end{macrocode}
% \end{macro}
%
%
%
% \section{Miscellanea}
%
% \subsection{Some \LaTeXplus\ stuff}
%
% \begin{macro}{\BooleanFalse}
% \begin{macro}{\BooleanTrue}
% \begin{macro}{\NoValue}
% These three macros are borrowed from the \package{xparse}
% package~\cite{xparse}, where they work as the three values
% \emph{boolean false}, \emph{boolean true}, and \emph{absence of
% value} respectively. The definitions are taken from
% \package{xparse} v\,0.17 (1999/09/10).
% \begin{macrocode}
\@ifundefined{BooleanFalse}{\def\BooleanFalse{TF}}{}
\@ifundefined{BooleanTrue}{\def\BooleanTrue{TT}}{}
\@ifundefined{NoValue}{\def\NoValue{-NoValue-}}{}
% \end{macrocode}
% By using these macros (rather than some homegrown set of macros
% or tokens) for denoting these values here I hopefully simplify a
% transition to \LaTeXplus, but I don't want to rely on \LaTeXplus\
% since it hasn't been released yet.
% \end{macro}\end{macro}\end{macro}
%
%
% \subsection{The \cs{meta} command}
%
% A reimplementation which has already (as of v\,2.0k) found its way into
% the \package{doc} package is the one that the |\meta| command is made
% robust, but since some people might still have older
% versions of \package{doc} and since that feature is needed for
% |\describe|\-|cs|\-|family|, I apply it here too. First I check
% whether the definition of |\meta| is the old non-robust definition,
% and only apply the fix if it is.
% \begin{macrocode}
\begingroup
\obeyspaces%
\catcode`\^^M\active%
\gdef\@gtempa{\begingroup\obeyspaces\catcode`\^^M\active%
\let^^M\do@space\let \do@space%
\def\-{\egroup\discretionary{-}{}{}\hbox\bgroup\itshape}%
\m@ta}%
\endgroup
\ifx \meta\@gtempa
% \end{macrocode}
%
% \begin{macro}{\l@nohyphenation}
% The new implementation needs a |\language| without any hyphenation
% patterns. By switching to that language, one can inhibit
% hyphenation in a piece of text regardless of what line-breaking
% parameter settings are in force when the paragraph is actually
% broken. This new language will be called \texttt{nohyphenation} and
% it is only allocated if it isn't already known (since some
% \package{babel} settings files already defines this |\language|).
% \begin{macrocode}
\@ifundefined{l@nohyphenation}{\newlanguage\l@nohyphenation}{}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\meta}
% \begin{macro}{\meta@font@select}
% This is the definition of |\meta| from \package{doc} v\,2.0m. For
% an explanation of the implementation, se a \texttt{doc.dtx} at least
% that new or entry \texttt{latex/3170} in the \LaTeX\ bugs database.
% \begin{macrocode}
\DeclareRobustCommand\meta[1]{%
\ensuremath\langle
\ifmmode \expandafter \nfss@text \fi
{%
\meta@font@select
\edef\meta@hyphen@restore
{\hyphenchar\the\font\the\hyphenchar\font}%
\hyphenchar\font\m@ne
\language\l@nohyphenation
#1\/%
\meta@hyphen@restore
}\ensuremath\rangle
}
% \end{macrocode}
% \begin{macrocode}
\let\meta@font@select=\itshape
\fi
% \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\MetaNormalfont}
% \changes{prot2}{2000/07/24}{Removed robustness; protected it
% explicitly wherever needed instead. (LH)}
% The |\MetaNormalfont| command redefines |\meta@font@select| to do a
% |\normal|\-|font| before the |\itshape|. It is useful if |\meta| is
% going to be used to make |\rmfamily| interjections in |\ttfamily|
% text.
% \begin{macrocode}
\newcommand\MetaNormalfont{\def\meta@font@select{\normalfont\itshape}}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\XD@harmless\meta}
% This macro is needed for making |\meta| behave as described in the
% argument of |\describe|\-|cs|\-|family|, i.e., in text which is
% going to be converted into a harmless character string.
% \begin{macrocode}
\@namedef{XD@harmless\string\meta}#1{%
\toks@=\expandafter{\the\toks@ \meta{#1}}%
\XD@harmless@
}
% \end{macrocode}
% \end{macro}
%
%
% \subsection{The checksum feature}
%
% The checksum mechanism in \package{doc} is a remnant from the times
% when file truncation was a common problem and a mechanism for
% detecting this was a great help.\footnote{Even though I suspect that
% the recommended use of it---to put the checking \cs{Finale} at the
% end of the \texttt{.dtx} file---may have reduced its usefulness
% dramatically, as that \cs{Finale} would have been the one thing that
% surely disappears if the file is truncated.} Today its main usefulness
% seems to lie in that it distinguishes versions of a file that are
% ``being worked on'' (where the checksum probably doesn't match) from
% versions of a file that are ``polished and ready for upload''
% (someone has bothered to fix the checksum), and as it exists it might
% as well stay. There is a problem however with files which do not
% contain \TeX\ code, as simply counting backslashes quite probably
% isn't a good (or even reasonable) way of forming a checksum for these
% files (if the checksum turns out to be zero, \package{doc} will
% complain no matter what you do).
%
% \begin{macro}{\check@checksum}
% \changes{prot2.1}{2000/10/02}{Redefinition added. (LH)}
% For that reason, the |\check@checksum| macro is redefined to only
% write the ``no checksum'' warning to the log file if the checksum
% hasn't been set.
% \begin{macrocode}
\renewcommand\check@checksum{%
\relax
\ifnum \check@sum=\z@
\PackageInfo{doc}{This macro file has no checksum!\MessageBreak
The checksum should be \the\bslash@cnt}%
\else\ifnum \check@sum=\bslash@cnt
\typeout{*******************}%
\typeout{* Checksum passed *}%
\typeout{*******************}%
\else
\PackageError{doc}{Checksum not passed (\the\check@sum
<>\the\bslash@cnt)}{The file currently documented seems
to be wrong.\MessageBreak Try to get a correct version.}%
\fi\fi
\global\check@sum\z@
}
% \end{macrocode}
% \end{macro}
%
%
% \subsection{The \cs{theCodelineNo} situation}
% \label{Ssec:CodelineNo}
%
% \changes{prot2.1}{2000/10/08}{\cs{theCodelineNo} situation cleared
% up. (LH)}
% \package{doc} incorporates formatting of the value of the
% \texttt{CodelineNo} counter in the |\theCodelineNo| macro, which is a
% bit awkward since it prevents using this macro in making e.g.\ index
% entries. To get around this, \package{xdoc} introduces the alternative
% name \texttt{codelineno} for this counter so that |\thecodelineno| can
% produce the value representation without formatting.
%
% \begin{macro}{\c@codelineno}
% \begin{macro}{\cl@codelineno}
% \begin{macro}{\p@codelineno}
% \begin{macro}{\thecodelineno}
% The control sequences connected to the \texttt{codelineno} counter
% are |\let| so that they refer to the same |\count| register as the
% \texttt{CodelineNo} counter. Note that \texttt{CodelineNo} isn't a
% proper \LaTeX\ counter, so the macros |\cl@CodelineNo| and
% |\p@CodelineNo| are undefined. |\thecodelineno| is set to the default
% value for a new counter.
% \begin{macrocode}
\@ifundefined{c@codelineno}{}{%
\PackageInfo{xdoc2}{Overwriting codelineno counter}%
}
\let\c@codelineno=\c@CodelineNo
\let\cl@codelineno=\@empty
\let\p@codelineno=\@empty
\def\thecodelineno{\@arabic\c@codelineno}
% \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\PrintCodelineNo}
% The |\PrintCodelineNo| command is the new recommended command for
% printing the formatted form of the codeline number counter. People
% who write their own \texttt{macrocode}-like environments should use
% |\PrintCodelineNo| instead of \package{doc}'s |\theCodelineNo|.
% \begin{macrocode}
\newcommand\PrintCodelineNo{\reset@font\scriptsize\thecodelineno}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\theCodelineNo}
% Finally |\theCodelineNo| is redefined to reference
% |\PrintCodelineNo|. This is done for the sake of backwards
% compability; I didn't feel like redefining |\macro@code| just for
% the sake of changing the |\theCodelineNo| into a |\PrintCodelineNo|).
% \begin{macrocode}
\def\theCodelineNo{\PrintCodelineNo}
% \end{macrocode}
% \end{macro}
%
% \begin{macrocode}
%</pkg>
% \end{macrocode}
%
%
% \section{Problems and things to do}
%
% This section lists some problems that exist with the current
% implementations of commands in \package{xdoc}. The list is rather
% unstable---items are added as I realize there is a problem and removed
% when I find a solution---an in parts it is rather esoteric since most
% of the problems have only been found theoretically.
%
% \medskip
%
% One of the less well-known features of the |\verb| command is that
% it automatically inhibits the known syntactic ligatures. There is
% no such mechanism implemented for the harmless character strings,
% so some (in \TeX\ \texttt{macrocode} uncommon) character sequences
% (such as |!`|) may produce unwanted results. The quick hack to
% circumvent this is to use the |\SetHarmState| command to mark one
% of the characters involved as problematic, as the |\PrintChar|
% command is implemented so that the character it prints will not be
% involved in ligaturing or kerning. On the other hand, \package{doc}
% does nothing to suppress syntactic ligatures in macro or environment
% names when they are printed in the margin, so for that material the
% \package{xdoc} implementation might actually improve things, although
% it could perform worse for verbatim material in the index and list of
% changes.
%
% \medskip
%
% Things to do and\slash or think about:
% \begin{itemize}
% \item
% Examine how complicated it would be to convert the
% |\PrintChar| commands for visible characters in a harmless
% character string back to explicit characters, for possible use in
% sort keys. (This could be used to ensure that visible characters
% are sorted in strict ASCII order.)
% \item
% Should those ``letters'' which are commonly used as word
% separators---in \LaTeX\ code mainly |@|---be ignored when sort
% keys are being formed (just like the backslash is)? (This would
% require a change in the implementation of the \texttt{macro}
% environment.)
%
% A mechanism for doing this is included as of prototype version~2.1.
% \item
% Examine how much more efficient it would be to put temporary
% additions to the index exclude list in a separate list instead of
% the main list. This could be advantageous for deeply nested
% \texttt{macro} environments, as \TeX\ will otherwise store as many
% (almost identical and often rather long) copies of the exclude list
% as there are nested environments.
%
% When asked about it, Frank Mittelbach didn't think there was
% any gains worth mentioning in this. On the other hand it might be
% worth investigating reimplementations that avoid calling |\trivlist|
% at the beginning of each \texttt{macro}-like environment when they
% are nested, since |\trivlist| does quite a lot of assignments.
%
% \item
% In an automatically generated index one often faces the problem
% that the entries at the innermost level are best formatted in one
% way when there is only one, but in a completely different way when
% there are several of them. To get optimal formatting in both cases,
% one would like to let the |\item|, |\subitem|, |\subsubitem| or
% corresponding macros detect the situation in this respect and
% choose the optimal formatting at each case.
%
% A mechanism for this is implemented by the \package{docindex}
% package.
% \end{itemize}
%
%
% \begin{thebibliography}{9}
% \bibitem{ltxdoc}
% David Carlisle:
% \textit{The file \texttt{ltxdoc.dtx} for use with \LaTeXe},
% The \LaTeX3 Project; ^^A , 1993~ff.
% \textsc{ctan}:\discretionary{}{}{\thinspace}\texttt{macros}\slash
% \texttt{latex}\slash \texttt{base}\slash \texttt{ltxdoc.dtx}.
% \bibitem{docindex}
% Lars Hellstr\"om:
% \textit{The \package{docindex} package}, 2001,
% \textsc{ctan}:\discretionary{}{}{\thinspace}\texttt{macros}\slash
% \texttt{latex}\slash \texttt{exptl}\slash \texttt{xdoc}\slash
% \texttt{docindex.dtx}.
% \bibitem{fontinst}
% Alan Jeffrey, Sebastian Rahtz, Ulrik Vieth (and as of v\,1.9 Lars
% Hellstr\"om): \textit{The \package{fontinst} utility}, v\,1.8~ff.,
% documented source code,
% \textsc{ctan}:\discretionary{}{}{\thinspace}^^A
% \texttt{fonts}\slash \texttt{utilities}\slash
% \texttt{fontinst}\slash \texttt{source}/
% \bibitem{clsguide}
% The \LaTeX3 Project:
% \textit{\LaTeXe~for class and package writers},
% The \LaTeX3 Project; ^^A , 1995~ff.
% \textsc{ctan}:\discretionary{}{}{\thinspace}\texttt{macros}\slash
% \texttt{latex}\slash \texttt{base}\slash \texttt{clsguide.tex}.
% \bibitem{doc}
% Frank Mittelbach, B.~Hamilton Kelly, Andrew Mills, Dave Love, and
% Joachim \mbox{Schrod}: \textit{The \package{doc} and
% \package{shortvrb} Packages}, The \LaTeX3 Project; ^^A , 1993~ff.
% \textsc{ctan}:\discretionary{}{}{\thinspace}\texttt{macros}\slash
% \texttt{latex}\slash \texttt{base}\slash \texttt{doc.dtx}.
% \bibitem{xparse}
% Frank Mittelbach, Chris Rowley, and David Carlisle: \textit{The
% \package{xparse} package}, The \LaTeX3 Project, 1999. Currently
% not available by anonymous FTP, but available by HTTP from
% \texttt{www.latex-project.org} (look for ``experimental code'').
% \end{thebibliography}
%
% \Finale
\endinput