path: root/Master/texmf-dist/source/fontinst/base/ficommon.dtx

% \CheckSum{2283}
% \iffalse meta-comment
%
% Copyright 1993, 1994, 1995, 1996 Alan Jeffrey,
% hacked and maintained 1997, 1998 Sebastian Rahtz,
% copyright 1998, 1999, 2000, 2001 the fontinst maintenance team and 
% any individual authors listed elsewhere in this file.  
% All rights reserved.
% 
% This file is part of the fontinst system version 1.9.
% -----------------------------------------------------
% 
% It may be distributed under the terms of the LaTeX Project Public
% License, as described in lppl.txt in the base LaTeX distribution.
% Either version 1.2 or, at your option, any later version.
% 
%%% From file: ficommon.dtx
%
%<*driver>
\documentclass{ltxdoc}
\usepackage{fisource}
\title{The \package{fontinst} utility}
\author{Alan Jeffrey, Sebastian Rahtz, Ulrik Vieth, Lars Hellstr\"om}
\begin{document}
\maketitle
\tableofcontents
\DocInput{ficommon.dtx}
\end{document}
%</driver>
% \fi
%
% \StopEventually{}
%
% 
% \section{General commands}
% \changes{1.916}{2000/12/27}{Moved Section \thesection\ to 
%    \texttt{ficommon.dtx}. (LH)}
% 
% \changes{1.916}{2001/01/02}{\emph{Major} overhaul of \package{fontdoc} 
%    mechanisms for integer and string expressions completed. (LH)}
% There are roughly five types of arguments that \package{fontinst} 
% commands can take. These are
% \begin{itemize}
%   \item integer expressions,
%   \item string expressions,
%   \item dimensions,
%   \item commands (i.e., \TeX\ control sequences), and
%   \item other (pretty much ``none of the above'').
% \end{itemize}
% The most common form of an integer expression is simply a \TeX\ 
% \meta{number} and the most common form of a string expression is 
% simply a sequence of character tokens, but there are more complicated 
% forms. Dimensions are simply \TeX\ \meta{dimen}s; their use is rather 
% limited. Common to integer expressions, string expressions, and 
% dimensions is that these argument types get expanded during 
% evaluation (in the case of string expressions, this expansion 
% \emph{is} the evaluation), which means one can use macros in 
% arguments of these types.
% 
% Command arguments do not get expanded---they are mainly used with 
% commands that modify the definitions of other commands. As for the 
% ``other'' arguments one cannot give any rules: they might get 
% expanded, but it could also happen that they won't.
% 
% 
% \subsection{String expressions}
% 
% The first problem with string expressions is to typeset the values. 
% The character strings that appear in ETX and MTX files usually consist 
% only of immediately printable characters, but there are a few 
% characters (such as underscore) which may be used even though they 
% aren't directly printable. This subsection defines commands which deal 
% with this problem by replacing non-printable characters by commands. 
% The implementation is based on the implementation of the 
% |\MakeHarmless| command in the \package{xdoc} package.
% 
% \subsubsection{Typesetting problematic characters}
% 
% \begin{macro}{\PrintChar}
% \begin{macro}{\InvisibleCharPrefix}
% \begin{macro}{\InvisibleCharSuffix}
%   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^_}'. For an argument in the range 32--126, 
%   |\PrintChar| calls |\Print|\-|Visible|\-|Char| which typesets the 
%   corresponding ASCII character (similar to |\char|, but it takes the 
%   path via the \LaTeX\ internal representation so that it works with 
%   non-typewriter \texttt{OT1} fonts); in particular, |\PrintChar{32}| 
%   prints 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}'.
%   The |\PrintChar| command is robust.
%   
%   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 
%   |\PrintChar|).
%    \begin{macrocode}
%<*doc>
\DeclareRobustCommand\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}
% \end{macro}\end{macro}\end{macro}
% 
% \begin{macro}{\PrintVisibleChar}
%   The |\PrintVisibleChar| command should print the visible ASCII 
%   character whose character code is given in the argument. The 
%   definition given here translates every character code to the 
%   corresponding \LaTeX\ internal representation, which is necessary 
%   if the current font is e.g.\ an \texttt{OT1}-encoded non-typewriter 
%   font. If the current font is known to be \texttt{T1}-encoded then 
%   one can do just as well with |\char#1 | as the replacement text.
%    \begin{macrocode}
\newcommand\PrintVisibleChar[1]{%
   \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
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\textvisiblespace}
%   The |\textvisiblespace| command, which is heavily used in names of 
%   coding schemes, unfortunately has a default definition which lacks 
%   leading on the right side. This redefinition attempts to improve 
%   things.
%   \changes{1.921}{2002/03/27}{Redefinition added. (LH)}
%    \begin{macrocode}
\DeclareTextCommandDefault{\textvisiblespace}{%
   \makebox[\fontdimen\tw@\font]{%
      \hfil
      \vrule \@height.3ex%
      \vbox{\hrule \@width .66\fontdimen\tw@\font}%
      \vrule \@height.3ex%
      \hfil
   }%
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\FD@quoted@PrintChar}
%   One sometimes wants to use a printable character string as part of a 
%   control sequence name. If the normal definition of |\PrintChar| is 
%   in force at such times then each |\PrintChar| in the string would 
%   produce lots of errors, which is why |\FD@quoted@PrintChar| has 
%   been defined. This macro is an alternative definition of 
%   |\PrintChar| which expands to |"|\meta{number}|"|, which can be part 
%   of a macro name.
%    \begin{macrocode}
\def\FD@quoted@PrintChar#1{"\number#1"}
%    \end{macrocode}
% \end{macro}
% 
% 
% \subsubsection{Converting character strings}
% 
% Replacing all problematic characters with |\PrintChar| calls certainly 
% makes the strings easier to manage, but actually making those 
% replacements is a rather complicated task. This subsubsection 
% contains the macros necessary for doing these replacements.
% 
% The first problem is how to efficiently recognise the problematic 
% characters. One might think that it is sufficient to look at their 
% |\catcode|, but that will fail for characters like |<| whose normal 
% catcode is 12 but do not appear in the \texttt{OT1} encoding. Because 
% of this, I have chosen a brute strength solution: build a table 
% (indexed by character code) that gives the printable form of 
% every character. This table is stored in the
% \describecsfamily{FD@printable@\meta{code}}^^A
% |\FD@printable@|\meta{code} family of control sequences, where the 
% \meta{code} is in the range |32|--|126|. The printable form of 
% characters outside this range is always the |\PrintChar| form.
%    \begin{macrocode}
\count@=32
\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
      \x@cs\let{FD@printable@\the\count@}=\@tempa
      \advance \count@ \@ne
   \ifnum 127>\count@ \repeat
}
%    \end{macrocode}
% This loop hasn't caught all non-printable characters, so a few 
% entries have to be set explicitly.
%    \begin{macrocode}
\@namedef{FD@printable@34}{\PrintChar{34}} % "
\@namedef{FD@printable@60}{\PrintChar{60}} % <
\@namedef{FD@printable@62}{\PrintChar{62}} % >
%    \end{macrocode}
% 
% 
% \begin{macro}{\MakePrintable}
%   To render a character string harmless, you do
%   \begin{quote}
%     |\MakePrintable|\marg{macro}\marg{flag}\marg{string}
%   \end{quote}
%   This locally assigns to \meta{macro} the printable character string 
%   which corresponds to \meta{string}. Furthermore the control sequence 
%   |\if|\meta{flag} is locally let to |\iftrue| or |\iffalse| 
%   depending on whether the printable string is simple (only consists 
%   of character tokens and |\PrintChar| commands) or not.
%   
%   During the conversion the converted part of the string is stored in 
%   |\toks@| and the |@tempswa| switch keeps track of whether the string 
%   so far is simple (yes when |false|), but those are both local to 
%   |\MakePrintable|.
%    \begin{macrocode}
\def\MakePrintable#1#2#3{%
   \begingroup
      \toks@={}%
      \escapechar=`\\%
      \@tempswafalse
      \FD@printable@#3\protect\FD@printable@
      \toks@=\expandafter{%
         \expandafter\let \csname if#2\expandafter\endcsname
         \csname if\if@tempswa false\else true\fi \expandafter\endcsname
         \expandafter\def \expandafter#1\expandafter{\the\toks@}%
      }%
   \expandafter\endgroup \the\toks@
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\FD@printable@iii}
% \begin{macro}{\FD@printable@iv}
% \begin{macro}{\FD@printable@v}
% \begin{macro}{\FD@printable@vi}
%   What one has to be most careful about when making strings printable
%   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 consists begins 
%   (|\FD@printable@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 (|\FD@printable@iv|) then the character code 
%   is 32 and the actual space can be gobbled (|\FD@printable@v|), and 
%   if it isn't then the next token can be grabbed in a undelimited macro 
%   argument (|\FD@printable@vi|). In either case, the harmless form 
%   is given by the |\FD@printable@|\meta{code} table entry 
%   (in |\FD@printable@v| or |\FD@printable@vi|).
%    \begin{macrocode}  
\def\FD@printable@iii{%
   \expandafter\futurelet \expandafter\@let@token 
   \expandafter\FD@printable@iv \string
}
%    \end{macrocode}
%    \begin{macrocode}
\def\FD@printable@iv{%
   \ifx \@let@token\@sptoken
      \expandafter\FD@printable@v
   \else
      \expandafter\FD@printable@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\FD@printable@v} {%
      \toks@=\expandafter{\the \expandafter\toks@ \FD@printable@32}%
      \FD@printable@
   }
\endgroup
%    \end{macrocode}
%   \endgroup
%    \begin{macrocode}
\def\FD@printable@vi#1{%
   \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
      \toks@=\expandafter{\the\expandafter\expandafter\expandafter\toks@
         \csname FD@printable@\number`#1\endcsname}%
   \fi
   \FD@printable@
}
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
% 
% \begin{macro}{\FD@printable@}
% \begin{macro}{\FD@printable@i}
% \begin{macro}{\FD@printable@ii}
% \begin{macro}{\FD@printable@vii}
%   But that is not all |\MakePrintable| can do. One must also deal 
%   with things in the string that are not simply characters, but more 
%   complex items (for example |\str| and |\strint| constructions). When 
%   control sequences that start such complex items are fed to 
%   |\MakePrintable| they must be preceeded by a |\protect| (they will 
%   be if the original command is defined using \LaTeX's 
%   |\Declare|\-|Robust|\-|Command| command and the string has been fed 
%   through a |\protected@edef|, which happens to be the case); this 
%   |\protect| is taken as a signal that the next token should get 
%   special processing. Control sequences that are not preceeded by a 
%   |\protect| are simply |\string|ed.
%   
%   To accommodate for this, |\FD@printable@| (which is the first step 
%   in converting a token) always begins by checking (in |\FD@|\-^^A
%   |printable@i|) whether the next token is a control sequence. If it 
%   is and that control sequence is |\protect| then it is checked (in 
%   |\FD@printable@ii|) whether the control sequence 
%   \describecsfamily{FD@printable\PrintChar{`\\}\meta{cs-name}}^^A
%   |\FD@printable\|\meta{cs-name}, where \meta{cs-name} is the name 
%   without |\| (and with any spaces removed) of the control sequence 
%   encountered, is defined. If it is defined then control is handed 
%   over to |\FD@printable\|\meta{cs-name} which should process the 
%   arguments (if any) of |\|\meta{cs-name} and add a suitable 
%   representation to |\toks@|, but if |\FD@printable\|\meta{cs-name} 
%   isn't defined then this is considered to be an error.
%   
%   If the next token isn't a control sequence then control is handed 
%   over to |\FD@printable@ii|. If the next token is a control sequence 
%   but not |\protect| then that token is |\string|ed (in 
%   |\FD@printable@vii|) and control is handed over to 
%   |\FD@printable@vi|.
%    \begin{macrocode}
\def\FD@printable@{\futurelet\@let@token \FD@printable@i}
%    \end{macrocode}
%    \begin{macrocode}
\def\FD@printable@i{%
   \csname FD@printable@%
      \ifcat \noexpand\@let@token \noexpand\FD@printable@
         \ifx \@let@token\protect ii\else vii\fi
      \else iii\fi
   \endcsname
}
%    \end{macrocode}
%    \begin{macrocode}
\def\FD@printable@ii\protect#1{%
   \@ifundefined{FD@printable\expandafter\zap@space\string#1 \@empty}{%
      \PackageError{fontdoc}{Command \protect#1 not allowed in string}%
         \@eha
   }{\csname FD@printable\expandafter\zap@space\string#1 \@empty
     \endcsname}%
}
%    \end{macrocode}
%    \begin{macrocode}
\def\FD@printable@vii{\expandafter\FD@printable@vi \string}
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
% 
% \begin{macro}{\FD@printable\FD@printable@}
%   A control sequence |\FD@printable\|\meta{cs-name} is responsible for 
%   interpreting the string item that begins with the control sequence 
%   |\|\meta{cs-name} and appending a printable representation of it to 
%   |\toks@|. Normal |\FD@printable\|\meta{cs-name} control sequences 
%   must also end by inserting |\FD@printable@| 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 made printable. The only 
%   such control sequence which does not insert |\FD@printable@| is 
%   |\FD@printable\FD@printable@|, but that is as it should be since 
%   |\MakePrintable| itself appends a |\FD@printable@| to every character 
%   string it should convert to mark the end of it.
%    \begin{macrocode}
\expandafter\let 
   \csname FD@printable\string\FD@printable@\endcsname \@empty
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\FD@printable\PrintChar}
%   It is occasionally convenient to use a |\PrintChar| command as part 
%   of a string that is to be made harmless instead of using the raw 
%   character. The definition is very similar to that of 
%   |\FD@printable@vi|.
%    \begin{macrocode}
\@namedef{FD@printable\string\PrintChar}#1{%
   \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
      \toks@=\expandafter{\the\expandafter\expandafter\expandafter\toks@
         \csname FD@printable@\number#1\endcsname}%
   \fi
   \FD@printable@
}
%    \end{macrocode}
% \end{macro}
% 
% 
% \begin{macro}{\ExpandAndMakePrintable}
%   The |\ExpandAndMakePrintable| command is an abbreviation for a 
%   common use of |\MakePrintable|, namely to first feed the string 
%   through a |\protected@edef| to get rid of all the simple macros.
%    \begin{macrocode}
\newcommand*\ExpandAndMakePrintable[3]{%
   \protected@edef\@tempa{{#2}{#3}}%
   \expandafter\MakePrintable \expandafter#1\@tempa
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% 
% \subsubsection{Evaluating string expressions}
% 
% In string expressions, the only available operation is juxtaposition 
% (fancy name for putting things next to each other) and thus the 
% syntax for a string expression is
% \begin{quote}
%   \meta{string expression} \(\longrightarrow\) $\emptyset \mid$ 
%   \meta{string atom}\meta{string expression}
% \end{quote}
% where $\emptyset$ denotes the empty string. A \meta{string atom} is 
% one of
% \begin{quote}
%   \meta{character token}\\
%   |\str|\marg{string expression}\\
%   |\strint|\marg{string expression}
% \end{quote}
% The meaning of a \meta{character token} is explained 
% in~\cite{TeXbook}. The |\str| and |\strint| forms of 
% \marg{string atom} refer to the respective values of the string and 
% integer variables (see Subsection~\ref{Ssec:Variables}) whose names 
% are given in the argument of |\str| or |\strint| respectively. Since 
% the names of variables are themselves string expressions, |\str| and 
% |\strint| may themselves be used in names of variables.
% 
% It should be noted that most of \package{fontinst}'s string 
% expressions sooner or later end up between a |\csname| and the 
% corresponding |\endcsname|. This places significant restrictions on 
% what may occur in string expressions.
% 
% \begin{macro}{\str}
% \begin{macro}{\strint}
%   \changes{1.909}{1999/10/19}{Change to stop it from gobbling a 
%      following space if the integer is stored in a macro. (LH)}
%   In \package{fontinst} the only macros needed for dealing with string 
%   expressions are |\str| and |\strint|.
%    \begin{macrocode}
%<*pkg>
\def\str#1{\csname~s-#1\endcsname}
\def\strint#1{\expandafter\identity_one\expandafter{\number\int{#1}}}
%</pkg>
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% \package{fontdoc} mainly uses \TeX's text mode for typesetting string 
% expressions because not all characters are available in math mode; 
% it's easier to switch to text mode than to augment the math setup. One 
% kind of material is however typeset in math mode, namely 
% ``string-valued functions'': the name and functional parenthesis of 
% such material is typeset in math mode to get a mathematical look.
% 
% \begin{macro}{\FD@string@func}
%   The |\FD@string@func| macro has the syntax
%   \begin{quote}
%     |\FD@string@func|\marg{name}\marg{argument}
%   \end{quote}
%   It is used for typesetting the \meta{name}$($\meta{argument}$)$ of a 
%   string-valued function (e.g.\ the value-of-string-variable function 
%   $\mathrm{s}$). It should only be used in horizontal mode.
%   
%   |\FD@string@func| includes a bit of extra spacing around the typeset 
%   text, but not at the beginning or end of a string and neither 
%   between two string-valued functions. As a flag for this is used 
%   that the value of |\spacefactor| is 1; when it is one should proceed 
%   as if this extra spacing is already present.
%    \begin{macrocode}
%<*doc>
\def\FD@string@func#1#2{%
   \relax
   \ifnum \spacefactor=\@ne $\mkern1mu\else$\fi
   \mathrm{#1}($%
   #2%
   \ifnum \spacefactor=\@ne $\mkern-1mu\else $\fi)\mkern1mu$%
   \spacefactor=\@ne
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\TypesetStringExpression}
% \begin{macro}{\FD@typeset@string}
% \begin{macro}{\ifFD@swa}
%   In \package{fontdoc} the string expressions must be typeset, and 
%   that is not trivial due to that (i) not all character tokens have 
%   catcode 11 or 12 and (ii) not all characters are available in all 
%   fonts. Furthermore the non-character string atoms should be given 
%   special treatment in character strings!
%   
%   Because of this, string expressions that are to be typeset are 
%   handed to a special command |\TypesetStringExpression|, which takes 
%   the string to typeset as its only argument. This string may contain 
%   user-defined macros.
%    \begin{macrocode}
\newcommand\TypesetStringExpression[1]{%
   \protected@edef\@tempa{%
      \noexpand\MakePrintable \noexpand\@tempa {FD@swa}{#1}%
   }%
   \@tempa
   \FD@typeset@string{\@tempa}%
}
%    \end{macrocode}
%   Actually typesetting the string is handled in |\FD@typeset@string|, 
%   but strings handed to this macro must be preprocessed by a full 
%   protected expansion and a |\MakeHarmless|.
%    \begin{macrocode}
\def\FD@typeset@string#1{%
   \mbox{%
      \normalfont\ttfamily
      \spacefactor=\@ne
      #1%
      \ifnum \spacefactor=\@ne $\mkern-1mu\m@th$\fi
   }%
}
%    \end{macrocode}
%   The |\ifFD@swa| control sequence is often |\let| to |\iftrue| or 
%   |\iffalse| by |\Make|\-|Printable|, and then it is used as a 
%   conditional. Since that assignment sometimes takes place in 
%   conditional text however, one must make sure that |\ifFD@swa| 
%   always is some conditional.
%    \begin{macrocode}
\let\ifFD@swa\iffalse
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}
% 
% \begin{macro}{\str}
% \begin{macro}{\FD@printable\str}
%   The processing of the |\str| macro in \package{fontdoc} is far from 
%   straightforward. |\str| has to be robust, but apart from that its 
%   defintion has no effect on how its argument is processed. That is 
%   instead controlled by |\FD@printable\str|, which happens to use 
%   |\str| as an auxiliary formatting macro.
%   
%   Most of the complexity below is however due to the processing 
%   needed to determine whether the string variable accessed has been 
%   assigned a value. See |\Set|\-|String|\-|Variable| for more 
%   information. 
%    \begin{macrocode}
\DeclareRobustCommand\str[1]{\FD@string@func{s}{#1}}
\@namedef{FD@printable\string\str}#1{%
   \MakePrintable\@tempa{FD@swa}{#1}%
   \begingroup
      \let\PrintChar=\FD@quoted@PrintChar
   \if \ifFD@swa \@ifundefined{FD@s-\@tempa}{0}{1}\else 0\fi 1%
      \expandafter
   \endgroup
      \csname FD@s-\@tempa\endcsname
   \else
   \endgroup
      \toks@=\expandafter{\the\expandafter\toks@
         \expandafter\str \expandafter{\@tempa}}%
      \@tempswatrue
   \fi
   \FD@printable@
}
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% 
% \begin{macro}{\strint}
% \begin{macro}{\FD@printable\strint}
%   |\strint| is handled similarly to |\str|.
%    \begin{macrocode}
\DeclareRobustCommand\strint[1]{\FD@string@func{int}{#1}}
\@namedef{FD@printable\string\strint}#1{%
   \MakePrintable\@tempa{FD@swa}{#1}%
   \protected@edef\@tempa{%
      \ifFD@swa \protect\FD@simple@int \else \strint \fi{\@tempa}%
   }
   \toks@=\expandafter{\the\expandafter\toks@ \@tempa}%
   \@tempswatrue
   \FD@printable@
}
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% \begin{macro}{\macroparameter}
%   \changes{1.916}{2001/01/06}{Command added. (LH)}
% \begin{macro}{\FD@printable\macroparameter}
%   The |\macroparameter| command can be used in string and integer 
%   expressions as a sort of ``macro parameter placeholder''. It is not 
%   defined in \package{fontinst}, but in \package{fontdoc} one 
%   occationally writes comments which say things like ``XXX is short 
%   for ASDFSKADN'', and in those cases one can use |\macroparameter| 
%   as a placeholder for an argument. The syntax is
%   \begin{quote}
%     |\macroparameter|\marg{digit}
%   \end{quote}
%   where \meta{digit} should be a decimal digit between |1| and |9| 
%   inclusive.
%   
%   The definition in |\macroparameter| handles uses of the command in 
%   integer expressions, whereas |\FD@printable\macroparameter| takes 
%   care of uses in string expressions.
%    \begin{macrocode}
\DeclareRobustCommand\macroparameter[1]{%
   \gdef\FD@expression{\text{\normalfont\itshape\##1}}%
   \global\chardef\FD@priority=5%
   \global\FD@bracket@level=\z@
   \FD@evaluate@false
}
\@namedef{FD@printable\string\macroparameter}#1{%
   \toks@=\expandafter{\the\toks@\textrm{\emph{\##1}}}%
   \@tempswatrue
   \FD@printable@
}
%</doc>
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% 
% 
% \subsection{Integer expressions}
% 
% An \meta{integer expression} is one of the following:
% \begin{quote}
%   \meta{number}\\
%   |\int|\marg{string expression}\\
%   |\neg|\marg{integer expression}\\
%   |\add|\marg{integer expression}\marg{integer expression}\\
%   |\sub|\marg{integer expression}\marg{integer expression}\\
%   |\max|\marg{integer expression}\marg{integer expression}\\
%   |\min|\marg{integer expression}\marg{integer expression}\\
%   |\mul|\marg{integer expression}\marg{integer expression}\\
%   |\div|\marg{integer expression}\marg{integer expression}\\
%   |\half|\marg{integer expression}\\
%   |\otherhalf|\marg{integer expression}\\
%   |\scale|\marg{integer expression}\marg{integer expression}\\
%   |\width|\marg{string expression}\\
%   |\height|\marg{string expression}\\
%   |\depth|\marg{string expression}\\
%   |\italic|\marg{string expression}\\
%   |\kerning|\marg{string expression}\marg{string expression}
% \end{quote}
% \meta{number} is any \TeX\ number, as defined in~\cite{TeXbook}. The 
% \meta{string expression} in the argument of |\int| must be the name of 
% an integer variable which is currently set, i.e., the condition
% \begin{quote}
%   |\ifisint|\marg{string expression}|\then|
% \end{quote}
% must evaluate to true. Likewise the \meta{string expression} in the 
% argument of |\width|, |\height|, |\depth|, and |\italic| must be the 
% name of a glyph which is currently set, i.e., the condition
% \begin{quote}
%   |\ifisglyph|\marg{string expression}|\then|
% \end{quote}
% must evaluate to true.
% 
% \begin{macro}{\eval_expr}
% \begin{macro}{\eval_expr_to}
% \begin{macro}{\g_eval_expr_to}
% \begin{macro}{\result}
%   The only thing \package{fontinst} does with integer expressions is 
%   evaluating them. The macro
%   \begin{quote}
%     |\eval_expr|\marg{integer expression}
%   \end{quote}
%   globally assigns |\result| to the value of 
%   \meta{integer expression}, and changes the value of no other 
%   counters.
%   
%   The macro
%   \begin{quote}
%     |\eval_expr_to|\marg{\TeX\ integer variable}^^A
%        \marg{integer expression}
%   \end{quote}
%   locally assigns the value of \meta{integer expression} to 
%   \meta{\TeX\ integer variable} (which is an integer variable as 
%   defined in~\cite{TeXbook}).
%   |\g_eval_expr_to| does the same globally.
%   
%    \begin{macrocode}
%<*pkg>
\newcount\result
\def\eval_expr#1{\global\result=#1\x_relax}
\def\eval_expr_to#1#2{\eval_expr{#2}#1=\result}
\def\g_eval_expr_to#1#2{\eval_expr{#2}\global#1=\result}
%</pkg>
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
% 
% 
% \begin{macro}{\TypesetIntegerExpression}
%   In \package{fontdoc} the main task is instead to typeset the 
%   expression as a mathematical formula, but in some cases one wants to 
%   know its value as well (if possible). Therefore things get a bit 
%   more complex in that context. The top-level command there is
%   \begin{quote}
%     |\TypesetIntegerExpression|\marg{integer expression}
%   \end{quote}
%   which typesets the \meta{integer expression} by first forming (in the 
%   |\FD@expression| macro) code for typesetting the integer expression.
%   |\Typeset|\-|Integer|\-|Expression| should be only be used in math 
%   mode.
%   
%   Most of the work in |\TypesetIntegerExpression| is carried out by 
%   the |\FD@eval@expr| macro and hence |\TypesetIntegerExpression| sets 
%   a couple of other variables as explained below. Apart from the fact 
%   that |\FD@eval@expr| doesn't actually typeset anything, the main 
%   difference between it and |\Typeset|\-|Integer|\-|Expression| is that 
%   the latter also accepts code that after expansion will become integer 
%   expressions, whereas the former requires that all such macros have 
%   first been expanded.
%    \begin{macrocode}
%<*doc>
\newcommand\TypesetIntegerExpression[1]{%
   \protected@edef\@tempa{#1}%
   \expandafter\FD@eval@expr \expandafter{\@tempa}%
   \FD@expression
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\FD@expression}
% \begin{macro}{\FD@result}
% \begin{macro}{\FD@priority}
% \begin{macro}{\FD@bracket@level}
% \begin{switch}{FD@evaluate@}
%   The |\FD@expression| macro, |\FD@result| and |\FD@bracket@level| 
%   count registers, the |\FD@priority| chardef token, and the 
%   |FD@evaluate@| switch are used by \package{fontdoc} when formatting 
%   and evaluating an integer expression. They are all assigned globally.
%   
%   The |\FD@expression| macro contains code for typesetting an 
%   expression. |\FD@priority| is a chardef token whose numerical value 
%   specifies the priority of the outermost operation in 
%   |\FD@expression| according to the following table:
%   \begin{enumerate}
%     \item[0]
%       Outermost operation is $+$ or $-$.
%     \item[1]
%       Outermost operation is explicit multiplication ($\cdot$) or 
%       division $/$. If it is one of the factors in a product then 
%       that multiplication must be explicit.
%     \item[2]
%       Outermost operation is explicit multiplication. If it is to be 
%       the right factor in a product, then the multiplication must be 
%       made explicit too.
%     \item[3]
%       Outermost operation is explicit multiplication. It 
%       does not need to be explicitly multiplied.
%     \item[4]
%       Outermost operation is implicit multiplication (juxtaposition), 
%       unary prefix (unary $-$) or something which is bracketed anyway. 
%       If it is to be the right factor in a product, then that 
%       multiplication should be made explicit too. A typical example 
%       of this kind of thing is an explicit negative number.
%     \item[5]
%       Outermost operation is implicit multiplication (juxtaposition) 
%       or something which is bracketed anyway. It does not need to be 
%       explicitly multiplied.
%     \item[6]
%       The expression is an explicit non-negative number. If it is to 
%       be the right factor in a product, then the multiplication 
%       should be made explicit. 
%   \end{enumerate}
%   |\FD@bracket@level| keeps track of what parenthesis size one must 
%   use to cover the expression in |\FD@expression|: 0 is the normal 
%   size, 1 is |\big| size, 2 is |\Big| size, etc. The |FD@evaluate@| 
%   switch specifies whether |\FD@eval@expr| should try to (upon entry) 
%   or managed to (after it is completed) evaluate the integer 
%   expression (true is evaluate, false is don't bother). When the value 
%   has been evaluated, it is returned in |\FD@result|.
%    \begin{macrocode}
\newcount\FD@result
\newcount\FD@bracket@level
\def\FD@evaluate@true{\global\let\ifFD@evaluate@\iftrue}
\def\FD@evaluate@false{\global\let\ifFD@evaluate@\iffalse}
\FD@evaluate@false
%    \end{macrocode}
% \end{switch}\end{macro}\end{macro}\end{macro}\end{macro}
% 
% \begin{macro}{\FD@eval@expr}
%   The |\FD@eval@expr| macro has the syntax
%   \begin{quote}
%     |\FD@eval@expr|\marg{integer expression}
%   \end{quote}
%   It puts code for typesetting the \meta{integer expression} in the 
%   |\FD@expression| macro, sets |\FD@bracket@level| to the 
%   corresponding value, and if |FD@evaluate@| is true it also tries to 
%   evaluate the expression and put the result in |\FD@result|.
%   
%   More precisely, |\FD@eval@expr| only handles the \meta{\TeX~number} 
%   cases of integer expression. In the other cases the first token in 
%   the integer expression is a robust command which should take care of 
%   building the expression as needed.
%    \begin{macrocode}
\def\FD@eval@expr#1{%
   \expandafter\expandafter \expandafter\ifx 
         \expandafter\@car#1\x@relax\@nil \protect 
      #1%
   \else\ifcat \expandafter\noexpand \@car#1\x@relax\@nil 0%
      \global\FD@result=#1\x@relax
      \xdef\FD@expression{\the\FD@result}%
      \global\chardef\FD@priority=\ifnum \FD@result<\z@ 4\else 6\fi
      \global\FD@bracket@level=\z@
   \else
      \begingroup
      \MakePrintable\@tempa{FD@swa}{#1}%
      \global\FD@bracket@level=\ifFD@swa\z@\else\@ne\fi
      \protected@xdef\FD@expression{\protect\mbox{\texttt{\@tempa}}}%
      \endgroup
      \global\chardef\FD@priority=5%
      \FD@evaluate@false
   \fi\fi
}
%</doc>
%    \end{macrocode}
%   Note: It is important that all groups that are started or ended 
%   during the evaluation of an integer expression are of |\begingroup| 
%   type, since |\bgroup| groups affect spacing in math mode.
% \end{macro}
% 
% \begin{macro}{\add}
%   The |\add| command has the syntax
%   \begin{quote}
%     |\add|\marg{integer expression}\marg{integer expression}
%   \end{quote}
%   It represents the sum of the two \meta{integer expression}s.
%    \begin{macrocode}
%<*pkg>
\def\add#1#2{
   #1
   \bgroup
      \a_count=\result
      \eval_expr{#2}
      \global\advance \result \a_count
   \egroup
}
%</pkg>
%<*doc>
\DeclareRobustCommand\add[2]{%
   \begingroup
   \FD@eval@expr{#1}%
   \let\@tempa=\FD@expression
   \ifFD@evaluate@ \a@count=\FD@result \fi
   \b@count=\FD@bracket@level
   \FD@eval@expr{#2}%
   \protected@xdef\FD@expression{\@tempa+\FD@expression}%
   \ifFD@evaluate@ \global\advance \FD@result \a@count \fi
   \ifnum \FD@bracket@level<\b@count
      \global\FD@bracket@level=\b@count
   \fi
   \global\chardef\FD@priority=\z@
   \endgroup
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\sub}
%   The |\sub| command has the syntax
%   \begin{quote}
%     |\sub|\marg{integer expression}\marg{integer expression}
%   \end{quote}
%   It represents the difference between the two \meta{integer 
%   expression}s.
%    \begin{macrocode}
%<*pkg>
\def\sub#1#2{
   #1
   \bgroup
      \a_count=\result
      \eval_expr{#2}
      \advance \a_count -\result
      \global\result=\a_count
   \egroup
}
%</pkg>
%<*doc>
\DeclareRobustCommand\sub[2]{%
   \begingroup
   \FD@eval@expr{#1}%
   \let\@tempa=\FD@expression
   \ifFD@evaluate@ \a@count=\FD@result \fi
   \b@count=\FD@bracket@level
   \FD@eval@expr{#2}%
   \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
   \protected@xdef\FD@expression{\@tempa-\FD@expression}%
   \ifFD@evaluate@ 
      \advance \a@count -\FD@result
      \global\FD@result=\a@count 
   \fi
   \ifnum \FD@bracket@level<\b@count
      \global\FD@bracket@level=\b@count
   \fi
   \global\chardef\FD@priority=\z@
   \endgroup
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\FD@subexpression}
% \begin{macro}{\FD@commapenalty}
%   The |\FD@subexpression| macro has the syntax
%   \begin{quote}
%     |\FD@subexpression|\marg{math mode material}
%   \end{quote}
%   It should only be used in math mode and produces results very 
%   similar to \meta{math mode material}, but it locally increases all 
%   the math-related penalties by |\FD@commapenalty| for when the math 
%   mode material is converted to a horizontal list. This allows 
%   linebreaking to take notice of logical nesting in expressions.
%   
%   |\FD@commapenalty| is used as a companion of |\relpenalty| and 
%   |\binoppenalty|, but which is used after commas (where \TeX\ doesn't 
%   insert penalties automatically).
%    \begin{macrocode}
\def\FD@subexpression#1{${%
   \advance \binoppenalty \FD@commapenalty
   \advance \relpenalty \FD@commapenalty
   \advance \FD@commapenalty \FD@commapenalty
   $#1$}$%
}
\newcount\FD@commapenalty
\FD@commapenalty=\binoppenalty
\advance \FD@commapenalty \relpenalty
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% \begin{macro}{\FD@bracket@expression}
%   The |\FD@bracket@expression| brackets the expression currently in 
%   |\FD@expression| by the suitable size of parentheses and updates 
%   |\FD@bracket@level| and |\FD@priority| accordingly.
%    \begin{macrocode}
\def\FD@bracket@expression{%
   \protected@xdef\FD@expression{%
      \ifcase\FD@bracket@level \or \protect\bigl \or \protect\Bigl \or 
         \protect\biggl \else \protect\Biggl \fi (%
      \protect\FD@subexpression{\FD@expression}%
      \ifcase\FD@bracket@level \or \protect\bigr \or \protect\Bigr \or 
         \protect\biggr \else \protect\Biggr \fi )%
   }%
   \global\chardef\FD@priority=5%
   \global\advance \FD@bracket@level \@ne
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% 
% \begin{macro}{\int}
%   \changes{1.909}{1999/10/19}{\package{fontdoc} implementation 
%      changed to using \cs{typeset@integer}. (LH)}
% \begin{macro}{\FD@simple@int}
%   The |\int| command has the syntax
%   \begin{quote}
%     |\int|\marg{string expression}
%   \end{quote}
%   It is used to represent the value of the \package{fontinst} integer 
%   whose name is the value of the \meta{string expression} in integer 
%   expressions.
%   
%   The |\FD@simple@int| macro take the printable string form of the 
%   name of an integer variable as its argument and typesets the 
%   printed representation of this integer, but it should only be used 
%   when the argument is a simple string expression. When the argument 
%   is not a simple string expression, |\FD@integer@func| should be 
%   used instead. |\FD@simple@int| should only be called in horizontal 
%   mode.
%    \begin{macrocode}
%<pkg>\def\int#1{\csname i-#1 \endcsname}
%<*doc>
\DeclareRobustCommand\int[1]{%
   \begingroup
   \MakePrintable\@tempa{FD@swa}{#1}%
   \protected@xdef\FD@expression{%
      \ifFD@swa
         \text{\protect\FD@simple@int{\@tempa}}%
      \else
         \protect\FD@integer@func{int}{\@tempa}%
      \fi
   }%
   \global\chardef\FD@priority=5%
   \global\FD@bracket@level=\ifFD@swa\z@\else\@ne\fi
   \FD@evaluate@false
   \endgroup
}
\def\FD@simple@int#1{{\normalfont\itshape #1\/}}
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% \begin{macro}{\FD@integer@func}
%   The |\FD@integer@func| macro has the syntax
%   \begin{quote}
%     |\FD@integer@func|\marg{name}\marg{argument}
%   \end{quote}
%   It is used for typesetting the \meta{name}$($\meta{argument}$)$ 
%   of an integer-valued function which takes a string expression as 
%   argument (e.g.\ the width-of-glyph function $\mathrm{w}$). It 
%   should only be used in math mode. 
%   
%   The empty group in the argument of |\mathop| is there to ensure 
%   that the nucleus of the mathop atom isn't simply a symbol, since 
%   \TeX\ in that case centers it vertically.
%    \begin{macrocode}
\def\FD@integer@func#1#2{%
   \mathop{\mathrm{#1}{}}(\text{\FD@typeset@string{#2}})%
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% 
% \begin{macro}{\neg}
%   The |\neg| command has the syntax
%   \begin{quote}
%     |\neg|\marg{integer expression}
%   \end{quote}
%   It represents the negative of the \meta{integer expression}.
%    \begin{macrocode}
%<pkg>\def\neg#1{#1 \global\result=-\result}
%<*doc>
\DeclareRobustCommand\neg[1]{%
   \FD@eval@expr{#1}%
   \ifnum 5>\FD@priority \FD@bracket@expression \fi
   \protected@xdef\FD@expression{-\FD@expression}%
   \global\chardef\FD@priority=4%
   \ifFD@evaluate@ \global\FD@result=-\FD@result \fi
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\mul}
%   The |\mul| command has the syntax
%   \begin{quote}
%     |\mul|\marg{integer expression}\marg{integer expression}
%   \end{quote}
%   It represents the product of the two \meta{integer expression}s.
%    \begin{macrocode}
%<*pkg>
\def\mul#1#2{
   #1
   \bgroup
      \a_count=\result
      \eval_expr{#2}
      \global\multiply \result \a_count
   \egroup
}
%</pkg>
%    \end{macrocode}
%   
%   The main problem in the \package{fontdoc} definition of |\mul| is 
%   to determine whether the multiplication should be made explicit or 
%   not, and what priority code the resulting expression should be 
%   given. It turns out that if the right factor has priority 1 (it is 
%   a quotient or a product that ends with a quotient) then the 
%   combined expression will be too, whereas if it isn't but the left 
%   factor has priority 1 then the combined expression will get 
%   priority 2. The remaining cases will be explicit or implicit 
%   depending on the parity of the priority of the right expression, and 
%   priority will be odd or even depending on the parity of the priority 
%   of the left expression.
%    \begin{macrocode}
%<*doc>
\DeclareRobustCommand\mul[2]{%
   \begingroup
   \FD@eval@expr{#1}%
   \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
   \let\@tempa=\FD@expression
   \ifFD@evaluate@ \a@count=\FD@result \fi
   \b@count=\FD@bracket@level
   \let\FD@left@priority=\FD@priority
   \FD@eval@expr{#2}%
   \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
   \protected@xdef\FD@expression{%
      \@tempa
      \if \ifnum \FD@left@priority=\@ne e%
          \else\ifnum \FD@priority<\thr@@ e%
          \else\ifodd \FD@priority i\else e\fi\fi\fi e%
         \cdot
      \fi
      \FD@expression
   }%
   \ifFD@evaluate@ \global\multiply \FD@result \a@count \fi
   \ifnum \FD@bracket@level<\b@count
      \global\FD@bracket@level=\b@count
   \fi
   \a@count=%
      \ifnum \FD@priority=\@ne 1%
      \else\ifnum \FD@left@priority=\@ne 2%
      \else\ifodd\FD@left@priority
         \ifodd\FD@priority 5\else 3\fi
      \else
         \ifodd\FD@priority 4\else 2\fi
      \fi\fi\fi
   \global\chardef\FD@priority=\a@count
   \endgroup
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\div}
%   The |\div| command has the syntax
%   \begin{quote}
%     |\div|\marg{integer expression}\marg{integer expression}
%   \end{quote}
%   It represents the quotient of the two \meta{integer expression}s, as 
%   computed by \TeX's |\divide| command: non-integer quotients are 
%   rounded towards zero.
%    \begin{macrocode}
%<*pkg>
\def\div#1#2{
   #1
   \bgroup
      \a_count=\result
      \eval_expr{#2}
      \divide \a_count \result
      \global\result=\a_count
   \egroup
}
%</pkg>
%<*doc>
\DeclareRobustCommand\div[2]{%
   \begingroup
   \FD@eval@expr{#1}%
   \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
   \let\@tempa=\FD@expression
   \ifFD@evaluate@ \a@count=\FD@result \fi
   \b@count=\FD@bracket@level
   \FD@eval@expr{#2}%
   \ifnum 4>\FD@priority \FD@bracket@expression \fi
   \ifnum \FD@bracket@level<\b@count
      \global\FD@bracket@level=\b@count
   \fi
   \protected@xdef\FD@expression{%
      \@tempa
      \ifcase\FD@bracket@level \or \protect\big \or \protect\Big \or
         \protect\bigg \else \protect\Bigg \fi /%
      \FD@expression
   }%
   \ifFD@evaluate@ 
      \divide \a@count \FD@result
      \global\FD@result=\a@count 
   \fi
   \global\chardef\FD@priority=\@ne
   \endgroup
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\FD@eval@spec@expr}
%   The |\FD@eval@spec@expr| macro has the syntax
%   \begin{isyntax}
%     |\FD@eval@spec@expr|\marg{integer expression}^^A
%        \discretionary{}{}{}\marg{spec-command}^^A
%        \discretionary{}{}{}\marg{rep-command}
%   \end{isyntax}
%   It does pretty much the same thing as |\FD@eval@expr|, but if the 
%   first token in the \meta{integer expression} is the 
%   \meta{spec-command} then it will do
%   \begin{quote}
%     \meta{rep-command}\meta{integer expression}
%   \end{quote}
%   instead of the normal activities. This is useful for operations that 
%   are normally denoted as $n$-ary operations rather that binary ones, 
%   i.e., for |\max| and |\min|.
%    \begin{macrocode}
\def\FD@eval@spec@expr#1#2#3{%
   \expandafter\ifx \@car#1\x@relax\@nil #2%
      #3#1%
   \else
      \FD@eval@expr{#1}%
   \fi
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\max}
%   The |\max| command has the syntax
%   \begin{quote}
%     |\max|\marg{integer expression}\marg{integer expression}
%   \end{quote}
%   It represents the maximum of the two \meta{integer expression}s.
%    \begin{macrocode}
%<*pkg>
\def\max#1#2{
   #1
   \bgroup
      \a_count=\result
      \eval_expr{#2}
      \ifnum \a_count>\result \global\result=\a_count \fi
   \egroup
}
%</pkg>
%<*doc>
\DeclareRobustCommand\max[2]{%
   \begingroup
   \toks@={}%
   \a@count=-\maxdimen
   \b@count=\z@
   \FD@eval@spec@expr{\max{#1}{#2}}{\max}{\FD@maxmin@comma}%
   \ifnum \a@count>\FD@bracket@level
      \global\FD@bracket@level=\a@count
   \fi
   \protected@xdef\FD@expression{%
      \protect\plainmax
      \ifcase\FD@bracket@level \protect\@firstofone \or \protect\bigl 
         \or \protect\Bigl \or \protect\biggl \else \protect\Biggl 
      \fi{\{}%
      \the\toks@
      \protect\FD@subexpression{\FD@expression}%
      \ifcase\FD@bracket@level \protect\@firstofone \or \protect\bigl 
         \or \protect\Bigl \or \protect\biggl \else \protect\Biggl 
      \fi{\}}%
   }%
   \ifFD@evaluate@
      \ifnum \a@count>\FD@result \global\FD@result=\a@count \fi
   \fi
   \global\chardef\FD@priority=5%
   \global\advance \FD@bracket@level \@ne
   \endgroup
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\min}
%   The |\min| command has the syntax
%   \begin{quote}
%     |\min|\marg{integer expression}\marg{integer expression}
%   \end{quote}
%   It represents the minimum of the two \meta{integer expression}s.
%    \begin{macrocode}
%<*pkg>
\def\min#1#2{
   #1
   \bgroup
      \a_count=\result
      \eval_expr{#2}
      \ifnum \a_count<\result \global\result=\a_count \fi
   \egroup
}
%</pkg>
%<*doc>
\DeclareRobustCommand\min[2]{%
   \begingroup
   \toks@={}%
   \a@count=\maxdimen
   \b@count=\z@
   \FD@eval@spec@expr{\min{#1}{#2}}{\min}{\FD@maxmin@comma}%
   \ifnum \a@count>\FD@bracket@level
      \global\FD@bracket@level=\a@count
   \fi
   \protected@xdef\FD@expression{%
      \protect\plainmin
      \ifcase\FD@bracket@level \protect\@firstofone \or \protect\bigl 
         \or \protect\Bigl \or \protect\biggl \else \protect\Biggl 
      \fi{\{}%
      \the\toks@
      \protect\FD@subexpression{\FD@expression}%
      \ifcase\FD@bracket@level \protect\@firstofone \or \protect\bigl 
         \or \protect\Bigl \or \protect\biggl \else \protect\Biggl 
      \fi{\}}%
   }%
   \ifFD@evaluate@
      \ifnum \a@count<\FD@result \global\FD@result=\a@count \fi
   \fi
   \global\chardef\FD@priority=5%
   \global\advance \FD@bracket@level \@ne
   \endgroup
}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\FD@maxmin@comma}
%   The |\FD@maxmin@comma| macro does most of the work for |\max| and 
%   |\min| in \package{fontdoc}. In some sense it inserts the commas 
%   between the operands, but it also takes care of evaluating the 
%   maximum\slash minimum and determining the proper bracketing level.
%   
%   The sequence of arguments (separated by commas) is compiled in 
%   |\toks@|. The greatest\slash least value of an argument found so 
%   far is kept in |\a@count|, and the greatest bracketing level found 
%   is kept in |\b@count|.
%    \begin{macrocode}
\def\FD@maxmin@comma#1#2#3{%
   \FD@eval@spec@expr{#2}{#1}{\FD@maxmin@comma}%
   \toks@=\expandafter{\the\expandafter\toks@
      \expandafter\protect \expandafter\FD@subexpression
      \expandafter{\FD@expression}%
      ,\penalty\FD@commapenalty\,%
   }
   \ifFD@evaluate@
      \ifnum \a@count \ifx\max#1<\else>\fi \FD@result 
         \a@count=\FD@result 
      \fi
   \fi
   \ifnum \b@count<\FD@bracket@level \b@count=\FD@bracket@level \fi
   \FD@eval@spec@expr{#3}{#1}{\FD@maxmin@comma}%
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\half}
% \begin{macro}{\otherhalf}
%   \multchanges{\cs{half}\cs{otherhalf}}{1.916}{2000/12/31}{Macros 
%      added. (LH)}
%   The |\half| and |\otherhalf| macros have the syntaxes
%   \begin{quote}
%     |\half|\marg{integer expression}\\
%     |\otherhalf|\marg{integer expression}
%   \end{quote}
%   They both represent one half of the \meta{integer expression}, but 
%   they don't round it the same way. |\half| does rounding as 
%   specified in~\cite[p.~237]{TAOCP2} (towards even integers) whereas 
%   |\otherhalf| does it the other way (towards odd integers). This 
%   means that
%   \begin{quote}
%     |\add{\half{|\meta{IE}|}}{\otherhalf{|\meta{IE}|}}|
%   \end{quote}
%   will always sum up to precisely the same as the \meta{IE} integer 
%   expression.
%    \begin{macrocode}
%<*pkg>
\def\half#1{
   #1\x_relax
   \ifodd\result
      \global\advance \result \@ne
      \global\divide \result \tw@
      \ifodd\result \global\advance \result \m@ne \fi
   \else
      \global\divide \result \tw@
   \fi
}
\def\otherhalf#1{
   #1\x_relax
   \ifodd\result
      \global\advance \result \@ne
      \global\divide \result \tw@
      \ifodd\result \else \global\advance \result \m@ne \fi
   \else
      \global\divide \result \tw@
   \fi
}
%</pkg>
%<*doc>
\DeclareRobustCommand\half[1]{%
   \begingroup
   \FD@eval@expr{#1}%
   \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
   \a@count=%
      \ifnum \FD@priority=\@ne 1%
      \else\ifodd\FD@priority 5%
      \else 3\fi\fi
   \global\chardef\FD@priority=\a@count
   \protected@xdef\FD@expression{%
      \protect\frac{1}{2}%
      \ifnum \FD@priority>\thr@@ \else \cdot \fi
      \FD@expression
   }%
   \ifFD@evaluate@
      \ifodd \FD@result
         \global\advance \FD@result \@ne
         \global\divide \FD@result \tw@
         \ifodd\FD@result \global\advance \FD@result \m@ne \fi
      \else
         \global\divide \FD@result \tw@
      \fi
   \fi
   \endgroup
}
\DeclareRobustCommand\otherhalf[1]{%
   \begingroup
   \FD@eval@expr{#1}%
   \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
   \a@count=%
      \ifnum \FD@priority=\@ne 1%
      \else\ifodd\FD@priority 5%
      \else 3\fi\fi
   \global\chardef\FD@priority=\a@count
   \protected@xdef\FD@expression{%
      \protect\frac{1}{2}%
      \ifnum \FD@priority>\thr@@ \else \cdot \fi
      \FD@expression
   }%
   \ifFD@evaluate@
      \ifodd \FD@result
         \global\advance \FD@result \@ne
         \global\divide \FD@result \tw@
         \ifodd\FD@result\else \global\advance \FD@result \m@ne \fi
      \else
         \global\divide \FD@result \tw@
      \fi
   \fi
   \endgroup
}
%</doc>
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% \begin{macro}{\scale}
%   The |\scale| command has the syntax
%   \begin{quote}
%     |\scale|\marg{integer expression}\marg{integer expression}
%   \end{quote}
%   It represents the result of multiplying the first \meta{integer 
%   expression} by as many thousands as is specified by the second 
%   \meta{integer expression}. In practice, |\scale|\marg{ie1}\marg{ie2} 
%   is very similar to
%   \begin{quote}
%     |\div{\mul|\marg{ie1}\marg{ie2}|}{1000}|
%   \end{quote}
%   but |\scale| also tries to do proper rounding (note however that 
%   |\scale|ing by 500 is not rounded properly; use |\half| instead).
%    \begin{macrocode}
%<*pkg>
\def\scale#1#2{
   #1
   \bgroup
      \a_count=\result
      \eval_expr{#2}
      \global\multiply \result \a_count
      \rounded_thousandths
   \egroup
}
%</pkg>
%    \end{macrocode}
%   
%   The second (scaling factor) argument of |\scale| is usually very 
%   simple, and in that case the |\scale| will be formatted as a 
%   fraction (containing the second argument) multiplied by the first 
%   argument. 
%    \begin{macrocode}
%<*doc>
\DeclareRobustCommand\scale[2]{%
   \begingroup
   \FD@eval@expr{#1}%
   \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
   \let\@tempa=\FD@expression
   \ifFD@evaluate@ \a@count=\FD@result \fi
   \b@count=\FD@bracket@level
   \let\FD@left@priority=\FD@priority
   \FD@eval@expr{#2}%
   \if \ifnum \FD@bracket@level<\@ne \ifnum \FD@priority>\thr@@
         1\else 0\fi\else 0\fi 1%
      \protected@xdef\FD@expression{%
         \protect\frac{\FD@expression}{1000}%
         \if \ifnum \FD@left@priority<\thr@@ e\else
             \ifodd \FD@left@priority i\else e\fi\fi e%
            \cdot
         \fi
         \@tempa
      }
      \global\chardef\FD@priority=%
         \ifnum \FD@left@priority=\@ne 1\else
         \ifodd\FD@left@priority 5\else 3\fi\fi
      \global\FD@bracket@level=\b@count
   \else
      \ifnum \FD@priority<\@ne \FD@bracket@expression \fi
      \protected@xdef\FD@expression{%
         \@tempa
         \if \ifnum \FD@left@priority=\@ne e%
             \else\ifnum \FD@priority<\thr@@ e%
             \else\ifodd \FD@priority i\else e\fi\fi\fi e%
            \cdot
         \fi
         \FD@expression
         \ifcase\FD@bracket@level \or \protect\big \or \protect\Big 
            \or \protect\bigg \else \protect\Bigg \fi /1000%
      }%
      \ifnum \FD@bracket@level<\b@count
         \global\FD@bracket@level=\b@count
      \fi
      \global\chardef\FD@priority=\@ne
   \fi
   \ifFD@evaluate@ 
      \global\multiply \FD@result \a@count 
      \global\divide \FD@result 500
      \ifodd \FD@result
         \global\advance \FD@result \ifnum 0>\FD@result - \fi \@ne
      \fi
      \global\divide \FD@result \tw@
   \fi
   \endgroup
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\rounded_thousandths}
%   \changes{1.901}{1999/03/06}{Macro added. \cs{scale} changed to 
%      use it. (LH)}
% \begin{macro}{\l_rounded_thousandths}
%   The |\rounded_thousandths| macro divides |\result| 
%   by 1000 and rounds the result to the nearest integer. This is 
%   different from
%   \begin{quote}
%     |\global\divide \result \one_thousand|
%   \end{quote}
%   since the latter always rounds positive numbers downwards and 
%   negative numbers upwards.
%   
%   |\l_rounded_thousandths| does the same thing, but to the register 
%   passed as parameter \#1 and is assigned locally.
%   \changes{1.913}{2000/03/04}{Macro added. (LH)}
%    \begin{macrocode}
%<*pkg>
\def\rounded_thousandths{
   \global\divide \result \five_hundred
   \ifodd \result
      \global\advance \result by \ifnum 0>\result - \fi 1
   \fi
   \global\divide \result \tw@
}
%    \end{macrocode}
%    \begin{macrocode}
\def\l_rounded_thousandths#1{
   \divide #1 \five_hundred
   \ifodd #1
      \advance #1 by \ifnum 0>#1 - \fi\@ne
   \fi
   \divide #1 \tw@
}
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% \begin{macro}{\l_inv_scale}
%   \changes{1.913}{2000/03/11}{Macro added. (LH)}
%   The |\l_inv_scale| takes two arguments: as \#1 a count register, 
%   and as \#2 a \TeX\ number. |\l_inv_scale| scales \#1 by the inverse 
%   of \#2, if the value in \#1 is $n$ and the value in \#2 is $m$ then 
%   |\l_inv_scale| computes
%   $$
%     \left[ \frac{1000n}{m} \right] \mbox{,}
%   $$
%   where the brackets denote rounding to the nearest integer, and 
%   assigns this number to \#1 locally.
%    \begin{macrocode}
\def\l_inv_scale#1#2{
   \multiply #1 \two_thousand
   \divide #1 #2\x_relax
   \ifodd#1 \advance #1 \ifnum 0>#1 - \fi\@ne \fi
   \divide #1 \tw@
}
%    \end{macrocode}
% \end{macro}
% 
% \multchanges{\cs{priority}}{1.909}{1999/10/20}{Changed condition for 
%    \cs{ifnum}, so that expressions with equal priority will not get 
%    bracketed when nested. (LH)}
% \multchanges{\cs{expression}\cs{priority}\cs{identity}^^A
%    \cs{bracket}}{1.916}{2001/01/01}{Macros removed. (LH)}
% 
% \begin{macro}{\ifnumber}
%   \changes{1.900}{1999/02/15}{Command added. (LH)}
%   The call
%   \begin{quote}
%     |\ifnumber|\marg{integer expression}\meta{rel}^^A
%     \marg{integer expression}|\then|
%   \end{quote}
%   can be used to compare the two integer expressions. \meta{rel} may 
%   be |<|, |=|, or |>|.
%    \begin{macrocode}
\def\ifnumber#1#2#3\then{
   \eval_expr_to\a_count{#1}
   \eval_expr{#3}
   \ifnum \a_count#2\result
      \expandafter\if_true
   \else
      \expandafter\if_false
   \fi
}
%</pkg>
%    \end{macrocode}
%   
%   Like the other conditionals, |\ifnumber| is treated as being true by 
%   \package{fontdoc}.
%    \begin{macrocode}
%<*doc>
\def\ifnumber#1#2#3\then{%
   \FD@evaluate@false
   \generic@if{%
      $\TypesetIntegerExpression{#1}#2\TypesetIntegerExpression{#3}$%
   }%
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% 
% 
% \subsection{Setting variables}
% \label{Ssec:Variables}
%
% \meta{int}, \meta{str}, and \meta{dim} below are string expressions. 
% \meta{command} can be any control sequence.
% 
% \DescribeMacro{\setint}
% \DescribeMacro{\setstr}
% \DescribeMacro{\setdim}
% \DescribeMacro{\setcommand}
% The macros:
% \begin{quote}
%    |\setint|\marg{int}\marg{integer expression}\\
%    |\setstr|\marg{str}\marg{string}\\
%    |\setdim|\marg{dim}\marg{dimension}\\
%    |\setcommand|\meta{command}\meta{definition}
% \end{quote}
% define new macros 
% \describecsfamily{i-\meta{int}}|\i-|\meta{int}, 
% \describecsfamily{s-\meta{str}}|\s-|\meta{str}, 
% \describecsfamily{d-\meta{dim}}|\d-|\meta{dim}, or 
% \meta{command}.
%
% \DescribeMacro{\resetint}
% \DescribeMacro{\resetstr}
% \DescribeMacro{\resetdim}
% \DescribeMacro{\resetcommand}
% The macros:
% \begin{quote}
%    |\resetint|\marg{int}\marg{integer expression}\\
%    |\resetstr|\marg{str}\marg{string}\\
%    |\resetdim|\marg{dim}\marg{dimension}\\
%    |\resetcommand|\meta{command}\meta{definition}
% \end{quote}
% redefine the macros |\i-|\meta{int}, |\s-|\meta{str}, |\d-|\meta{dim} or 
% \meta{command}.
%
% \DescribeMacro{\int}
% \DescribeMacro{\str}
% \DescribeMacro{\dim}
% The macros:
% \begin{quote}
%    |\int|\marg{int}\\
%    |\str|\marg{str}\\
%    |\dim|\marg{dim}\\
%    \meta{command}
% \end{quote}
% return the values of |\i-|\meta{int}, |\s-|\meta{str}, |\d-|\meta{dim}, 
% or \meta{command}.
%
% \DescribeMacro{\strint}
% The macro
% \begin{quote}
%   |\strint|\marg{int}
% \end{quote}
% returns the value of |\i-|\meta{int} as a string.
% 
% \DescribeMacro{\ifisint}
% \DescribeMacro{\ifisstr}
% \DescribeMacro{\ifisdim}
% \DescribeMacro{\ifiscommand}
% The macros:
% \begin{quote}
%    |\ifisint|\marg{int}|\then|\\
%    |\ifisstr|\marg{str}|\then|\\
%    |\ifisdim|\marg{dim}|\then|\\
%    |\ifiscommand|\meta{command}|\then|
% \end{quote}
% return |\if_true| if |\i-|\meta{int}, |\s-|\meta{str}, 
% |\d-|\meta{dim}, or \meta{command} respectively have been defined, 
% and |\if_false| otherwise.
%
% \DescribeMacro{\unsetint}
% \DescribeMacro{\unsetstr}
% \DescribeMacro{\unsetdim}
% \DescribeMacro{\unsetcommand}
% The macros:
% \begin{quote}
%    |\unsetint|\marg{int}\\
%    |\unsetstr|\marg{str}\\
%    |\unsetdim|\marg{dim}\\
%    |\unsetcommand|\meta{command}
% \end{quote}
% undefine |\i-|\meta{int}, |\s-|\meta{str}, |\d-|\meta{dim}, or 
% \meta{command}.
%
% \DescribeMacro{\x_setint}
% \DescribeMacro{\x_resetint}
% \DescribeMacro{\x_setstr}
% The macros |\x_setint|, |\x_resetint|, and |\x_setstr| are ``private'' 
% versions of |\setint|, |\resetint|, and |\setstr| respectively. They 
% have been included to reduce the problems in case a user turns off one 
% of these commands and forgets to turn it on again.
% 
% \changes{1.900}{1999/02/07}{Replaced internal \cs{setint}, 
%    \cs{resetint}, and \cs{setstr} by \cs{x_setint}, \cs{x_resetint}, 
%    and \cs{x_setstr} respectively, to make the public versions 
%    possible to turn off. (LH)}
% 
% Integers are kept as |\mathchardef|s if possible; a comparision of 
% doing this versus not doing this appears in 
% Subsection~\ref{Ssec: ASAJ tests}.
%
% \begin{macro}{\setsomething_global}
%   The |\setsomething_global| control sequence should be either 
%   |\relax| or |\global|. It appears before the central assignments in 
%   all the |\set|\textellipsis, |\reset|\textellipsis, and 
%   |\unset|\textellipsis\ commands. The normal value is |\relax|, so 
%   that these assignments are local.
%   
%   When there is counter-intuitive grouping, and it could seem that 
%   \TeX\ should not be inside a group at all---i.e., between 
%   |\installfonts| and |\endinstallfonts|---one can make the basic 
%   assignment commands act more logical by setting 
%   |\setsomething_global| to |\global|.
%   
%   \changes{1.912}{2000/01/15}{Control sequence introduced and added 
%      to all \cs{set}\dots, \cs{reset}\dots, and \cs{unset}\dots\ 
%      commands, as well as \cs{offcommand} and \cs{oncommand}. (LH)}
%    \begin{macrocode}
%<*pkg>
\let\setsomething_global=\x_relax
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\x_setint}
% \begin{macro}{\setint}
% \begin{macro}{\x_setstr}
% \begin{macro}{\setstr}
% \begin{macro}{\setdim}
% \begin{macro}{\setcommand}
%   \changes{1.909}{1999/10/17}{Since \package{fontdoc} adds some 
%      grouping, \cs{setcommand} must set its argument globally there. 
%      (LH)}
%   \changes{1.912}{2000/01/15}{Settings of a command already defined 
%      is diverted to \cs{a_macro}; it used to be \cs{a_command}. Saves 
%      one hash table position. (LH)}
%   
%    \begin{macrocode}
\def\x_setint#1#2{
   \x_cs\ifx{i-#1}\x_relax
      \x_resetint{#1}{#2}
   \fi
}
\let\setint=\x_setint
\def\x_setstr#1#2{
   \x_cs\ifx{s-#1}\x_relax
      \setsomething_global\x_cs\edef{s-#1}{#2}
   \fi
}
\let\setstr=\x_setstr
\def\setdim#1#2{
   \x_cs\ifx{d-#1}\x_relax
      \a_dimen=#2\x_relax
      \setsomething_global\x_cs\edef{d-#1}{\the\a_dimen}
   \fi
}
\def\setcommand#1{
   \ifx#1\undefined_command
      \setsomething_global \expandafter\def \expandafter#1
   \else
      \expandafter\def \expandafter\a_macro
   \fi
}
%</pkg>
%    \end{macrocode}
%   
%   In \package{fontdoc}, |\setint|, |\setstr|, and |\setdim| print 
%   headings. There is no need for the private forms |\x_setint| and 
%   |\x_setstr|. |\setcommand|, finally, does the same thing as in 
%   \package{fontinst}; the assignment is global because of grouping 
%   not present in \package{fontinst}.
%    \begin{macrocode}
%<*doc>
\newcommand\setint[2]{%
   \Bheading{Default} \(\TypesetIntegerExpression{\int{#1}}\) = 
   \(\TypesetIntegerExpression{#2}\)%
}
\newcommand\setstr[2]{%
   \Bheading{Default} \TypesetStringExpression{\str{#1}} = 
   \TypesetStringExpression{#2}%
}
\newcommand\setdim[2]{%
   \a@dimen=#2\relax
   \Bheading{Default} \TypesetStringExpression{#1} dimen = \the\a@dimen
}
\def\setcommand#1{\ifx#1\undefined@command
   \expandafter\gdef\expandafter#1\else
   \expandafter\gdef\expandafter\a@command\fi}
%</doc>
%    \end{macrocode}
% \end{macro} \end{macro} \end{macro} \end{macro} \end{macro}
% \end{macro}
% 
% \begin{macro}{\x_resetint}
% \begin{macro}{\resetint}
% \begin{macro}{\resetstr}
% \begin{macro}{\resetdim}
% \begin{macro}{\resetcommand}
%   \changes{1.909}{1999/10/17}{Since \package{fontdoc} adds some 
%      grouping, \cs{resetcommand} must set its argument globally there. 
%      (LH)}
%    \begin{macrocode}
%<*pkg>
\def\x_resetint#1#2{
   \eval_expr{#2}
   \setsomething_global
   \ifnum\result<\max_mathchardef
      \ifnum 0>\result
         \x_cs\edef{i-#1}{\the\result}
      \else
         \x_cs\mathchardef{i-#1}=\result
      \fi
   \else
      \x_cs\edef{i-#1}{\the\result}
   \fi
}
\let\resetint=\x_resetint
\def\resetstr#1#2{\setsomething_global\x_cs\edef{s-#1}{#2}}
\def\resetdim#1#2{
   \a_dimen=#2
   \setsomething_global\x_cs\edef{d-#1}{\the\a_dimen}
}
\def\resetcommand#1{\setsomething_global\def#1}
%</pkg>
%    \end{macrocode}
% 
%   In \package{fontdoc}, |\resetint|, |\resetstr|, and |\resetdim| 
%   print headings. There is no need for the private form |\x_resetint|. 
%   |\resetcommand|, finally, does the same thing as in 
%   \package{fontinst}.
%   
%    \begin{macrocode}
%<*doc>
\newcommand\resetint[2]{%
   \Bheading{Value} \(\TypesetIntegerExpression{\int{#1}}\) = 
   \(\TypesetIntegerExpression{#2}\)%
}
\newcommand\resetstr[2]{%
   \Bheading{Value} \TypesetStringExpression{\str{#1}} = 
   \TypesetStringExpression{#2}%
}
\newcommand\resetdim[2]{%
   \a@dimen=#2\relax
   \Bheading{Value} \TypesetStringExpression{#1} dimen = \the\a@dimen
}
\def\resetcommand#1{\gdef#1}
%</doc>
%    \end{macrocode}
% \end{macro} \end{macro} \end{macro} \end{macro} \end{macro}
%
%
% \begin{macro}{\dim}
%    \begin{macrocode}
%<pkg>\def\dim#1{\csname~d-#1\endcsname}
%    \end{macrocode}
%   \missing{doc}{\dim}
% \end{macro}
%
% \multchanges{\cs{typeset@integer}\cs{typeset@string}^^A
%    \cs{typeset@dimen}}{1.916}{2000/01/02}{Macros removed. (LH)}
%
% \begin{macro}{\ifisint}
% \begin{macro}{\ifisstr}
% \begin{macro}{\ifisdim}
%   \multchanges{\cs{ifisint}\cs{ifisstr}\cs{ifisdim}}{1.912}
%      {2000/02/10}{Reimplemented using \cs{if_defined}. (LH)}
% \begin{macro}{\ifiscommand}
%    \begin{macrocode}
%<*pkg>
\def\ifisint#1\then{\if_defined i-#1\then}
\def\ifisstr#1\then{\if_defined s-#1\then}
\def\ifisdim#1\then{\if_defined d-#1\then}
\def\ifiscommand#1\then{
   \ifx#1\undefined_command
      \expandafter\if_false
   \else
      \expandafter\if_true
   \fi
}
%</pkg>
%    \end{macrocode}
% 
%   In \package{fontdoc}, all conditionals are handled through 
%   |\generic@if|, which by default expands to |\iftrue|.
%   \changes{1.909}{1999/10/17}{Changed one fontdoc definition of 
%      \cs{ifisglyph} to a definition of \cs{ifiscommand}, which was 
%      missing from fontdoc.}
%    \begin{macrocode}
%<*doc>
\def\ifisint#1\then{%
   \generic@if{integer $\TypesetIntegerExpression{\int{#1}}$ set}%
}
\def\ifisstr#1\then{%
   \generic@if{string \TypesetStringExpression{#1} set}%
}
\def\ifisdim#1\then{%
   \generic@if{dimension \TypesetStringExpression{#1} set}%
}
\def\ifiscommand#1\then{%
   \generic@if{command \normalfont{\ttfamily\string#1} set}%
}
%</doc>
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\unsetint}
% \begin{macro}{\unsetstr}
% \begin{macro}{\unsetdim}
% \begin{macro}{\unsetcommand}
%    \begin{macrocode}
%<*pkg>
\def\unsetint#1{\setsomething_global\x_cs\let{i-#1}\x_relax}
\def\unsetstr#1{\setsomething_global\x_cs\let{s-#1}\x_relax}
\def\unsetdim#1{\setsomething_global\x_cs\let{d-#1}\x_relax}
\def\unsetcommand#1{\setsomething_global\let#1=\undefined_command}
%</pkg>
%    \end{macrocode}
%   \missing{doc}{\unsetint}
%   \missing{doc}{\unsetstr}
%   \missing{doc}{\unsetdim}
%   \missing{doc}{\unsetcommand}
%    \begin{macrocode}
%<*doc>
%</doc>
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}\end{macro}
% 
% \begin{macro}{\offcommand}
% \begin{macro}{\oncommand}
%   \multchanges{\cs{offcommand}\cs{oncommand}}{1.900}{1999/02/07}
%      {Commands added. (LH)}
%   The calls
%   \begin{quote}
%     |\offcommand|\meta{command}\\
%     |\oncommand|\meta{command}
%   \end{quote}
%   can be used to turn a command off (make it simply absorb its 
%   arguments but expand to nothing) or on (return it to normal) 
%   respectively. Their primary use is for ignoring some of the 
%   commands in \texttt{.mtx} files that \package{fontinst} generates 
%   from \texttt{.afm}, \texttt{.pl}, or other \texttt{.mtx} files.
%   
%   \describecsfamily{saved-\meta{\textbackslash command}}
%   The normal definition of a command that has been turned off 
%   is saved as the control sequence |\saved-|\meta{command}. If the 
%   syntax of a command is tricky---not all arguments are read by the 
%   base command or its parameter text contains tokens that are not 
%   parameters---or if simply making it do nothing is not the expected 
%   `off' behaviour, then the automatic off-turning may not work. In such 
%   cases a handtooled off definition of the command \meta{command} 
%   may be provided as the control sequence |\off-|\meta{command}.^^A
%   \describecsfamily{off-\meta{\textbackslash command}}
%   
%   Nothing happens if |\offcommand| is called for a command that is 
%   not on. Nothing happens if |\oncommand| is called for a command 
%   that is not off.
%    \begin{macrocode}
%<*pkg>
\def\offcommand#1{
   \x_cs\ifx{saved-\string#1}\x_relax
      \setsomething_global\x_cs\let{saved-\string#1}#1
      \x_cs\ifx{off-\string#1}\x_relax
         \generate_off_command{#1}
      \else
         \setsomething_global \expandafter\let \expandafter#1 
            \csname off-\string#1\endcsname
      \fi
   \fi
}
%    \end{macrocode}
%    \begin{macrocode}
\def\oncommand#1{
   \x_cs\ifx{saved-\string#1}\x_relax \else
      \setsomething_global \expandafter\let \expandafter#1 
            \csname saved-\string#1\endcsname
      \setsomething_global\x_cs\let{saved-\string#1}\x_relax
   \fi
}
%</pkg>
%    \end{macrocode}
%   \multchanges{\cs{offcommand}\cs{oncommand}}{1.914}{2000/05/28}
%      {\package{fontdoc} definitions added. (LH)}
%    \begin{macrocode}
%<*doc>
\def\offcommand#1{\Bheading{Turn off} \texttt{\string#1}}
\def\oncommand#1{\Bheading{Turn on} \texttt{\string#1}}
%</doc>
%    \end{macrocode}
% \end{macro}\end{macro}
%
% \begin{macro}{\generate_off_command}
% \begin{macro}{\count_hashes}
% \begin{macro}{\gobble_to_xrelax}
%   |\generate_off_command|\meta{command} converts \meta{command} to 
%   an ``off'' version of itself by counting the number of arguments 
%   and defining it to gobble that many arguments. It cannot cope with 
%   commands whose parameter texts are not simply of the type
%   \begin{quote}
%     |#1#2|\textellipsis|#|$n$
%   \end{quote}
%    \begin{macrocode}
%<*pkg>
\def\generate_off_command#1{
   \a_count=0
   \let\next=\count_hashes
   \expandafter\next\meaning#1~->\x_relax
   \b_count=0
   \a_toks={}
   \loop \ifnum \b_count<\a_count
      \advance \b_count 1
      \a_toks=\expandafter{\the\expandafter\a_toks \expandafter####
         \the\b_count}
   \repeat
   \setsomething_global \expandafter\def \expandafter#1 \the\a_toks {}
}
%    \end{macrocode}
%    \begin{macrocode}
\def\count_hashes#1#2{
   \if \hash_char#1
      \advance \a_count 1
   \else
      \if -#1
         \if >#2
            \let\next=\gobble_to_xrelax
      \fi\fi
   \fi
   \next#2
}
\def\gobble_to_xrelax#1\x_relax{}
%</pkg>
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}
% 
% 
% Control sequences of the form
% \begin{quote}
%   \describecsfamily{FD@s-\meta{name}}|\FD@s-|\meta{name}
% \end{quote}
% are used by \package{fontdoc} to store the values of string variables 
% which have been assigned values; \meta{name} is the name of the string 
% variable. Unlike the case in \package{fontinst}, the 
% \package{fontdoc} |\setstr| command does not assign values to string 
% variables, but |\SetStringVariable| does.
% 
% The contents of the |\FD@s-|\meta{name} macros aren't really the 
% string values, but code that will append the printable form of the 
% corresponding string expression to |\toks@| and update other variables 
% used by |\MakePrintable| accordingly. Typically it might look 
% something like
% \begin{quote}
%   |\toks@=\expandafter{\the\toks@ ab}|
% \end{quote}
% when the value of the string is |ab|.
% 
% \begin{macro}{\SetStringVariable}
%   \changes{1.916}{2001/01/24}{Command added. (LH)}
%   The |\SetStringVariable| command has the syntax
%   \begin{quote}
%     |\SetStringVariable|\marg{variable name}\marg{new value}
%   \end{quote}
%   where \meta{variable name} and \meta{new value} are both string 
%   expressions. The \meta{variable name} must furthermore be a simple 
%   string expression. The command globally defines the corresponding 
%   |\FD@s-|\meta{name} control sequence to add the printable form of 
%   the \marg{new value} string to the |\toks@| token list register and, 
%   in case the \meta{new value} string is non-simple, sets the |@tempswa| 
%   switch to true.
%   
%   The control sequence |\@tempa| can be used as part of \meta{new 
%   value}, but not in the \meta{variable name}.
%    \begin{macrocode}
%<*doc>
\newcommand\SetStringVariable[2]{%
   \protected@edef\@tempa{\noexpand\MakePrintable \noexpand\@tempa 
      {FD@swa}{#2}}%
   \@tempa
   \protected@edef\@tempa{%
      \toks@=\noexpand\expandafter{\noexpand\the \toks@ \@tempa}%
      \ifFD@swa \noexpand\@tempswatrue \fi
   }%
   \protected@edef\@tempb{\noexpand\MakePrintable \noexpand\@tempb 
      {FD@swa}{#1}}%
   \@tempb
   \ifFD@swa
      \begingroup
         \let\PrintChar=\FD@quoted@PrintChar
         \global\expandafter\let \csname FD@s-\@tempb\endcsname \@tempa
      \endgroup
   \else
      \PackageError{fontdoc}{Names of string variables must be 
         simple\MessageBreak if they are to be assigned values}\@eha
   \fi
}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
%   
% 
%
%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \subsection{For loops}
%
% 
% \begin{macro}{\for}
% \begin{macro}{\endfor}
%   \multchanges{\cs{for}\cs{endfor}}{1.900}{1999/02/16}{Commands 
%      added. (LH)}
%   The command sequence
%   \begin{quote}
%     |\for|\parg{name}\marg{start}\marg{stop}\marg{step}\\
%     \vadjust{}\quad\meta{body code}\\
%     |\endfor|\parg{name}
%   \end{quote}
%   will cause the \meta{body code} to be repeated some number of times. 
%   How many depends on the values of \meta{start}, \meta{stop}, and 
%   \meta{step}, which are integer expressions.
%   
%   As a precaution, the \meta{body code} is not allowed to contain any 
%   empty lines (|\par| tokens). If you want to have the visual 
%   separation (for sakes of legibility or otherwise), put a |%| 
%   somewhere on the line---that makes it nonempty.
%   
%   \meta{name} is used as the name of an integer variable. This 
%   variable gets reset to the value of \meta{start} before the first 
%   repetition of \meta{body code}. After each repetition but the last, 
%   it is incremented by \meta{step}. \meta{body code} gets repeated if 
%   the value of \meta{name} has not gotten past that of \meta{stop}. To 
%   get past means to be bigger if \meta{step} is positive and to be 
%   smaller if \meta{step} is negative. In the case that \meta{step} is 
%   zero, the entire construction above will be equivalent to
%   \begin{quote}
%     |\resetint|\marg{name}\marg{start}\\
%     \meta{body code}
%   \end{quote}
%   
%   |\for| \textellipsis\ |\endfor| constructions can be nested. 
%   \meta{name} is used by |\for| to identify its matching |\endfor|, so 
%   they need to be identical in |\for| and |\endfor|.
%   
%   \multchanges{\cs{for}\cs{for_i}\cs{foreach}}{1.914}{2000/05/21}
%      {\cs{setsomething_global} added to assignments of the 
%       \cs{for-\meta{name}} and \cs{body-\meta{name}} control 
%       sequences. (LH)}
%    \begin{macrocode}
%<*pkg>
\def\for(#1)#2#3#4{
   \eval_expr_to\a_count{#2}
   \x_resetint{#1}{\a_count}
   \eval_expr{#4}
   \ifnum 0=\result \else
      \c_count=\result
      \eval_expr_to\b_count{#3}
      \setsomething_global\x_cs\edef{for-#1}{
         \the\c_count \x_relax
         \noexpand\ifnum \gobble_one\fi
         \the\b_count \ifnum 0>\c_count > \else < \fi
      }
      \def\next##1##2##3\endfor(#1){##2\for_i{##1}{##3}}
      \next{#1}
   \fi
}
%    \end{macrocode}
%   
%   The macro \describecsfamily{for-\meta{name}}|\for-|\meta{name} 
%   will contain
%   \begin{quote}
%     \meta{step}|\x_relax\ifnum|\meta{stop}\meta{rel}
%   \end{quote}
%   \meta{step} is the value of the \meta{step} parameter of |\for|, 
%   computed when the loop was entered and now expressed in digits. 
%   \meta{stop} is likewise for the \meta{stop} parameter. \meta{rel} 
%   is |>| or |<|, depending on whether \meta{step} is positive or 
%   negative respectively. The reason for this curious definition will 
%   be appearent in the light of the definition of |\for_ii|.
%   
%   |\for_i| is expanded in the context
%   \begin{quote}
%     |\for_i|\marg{name}\marg{body code}
%   \end{quote}
%   Also remember, when reading the definition below, that |\ifnum| 
%   keeps on expanding tokens until it has found a 
%   \begin{quote}
%     \meta{number}\meta{relation}\meta{number}
%   \end{quote}
%   structure. It is therefore possible to nest |\ifnum|s like this!
%   
%    \begin{macrocode}
\def\for_i#1#2{
   \setsomething_global\x_cs\def{body-#1}{#2}
   \ifnum \b_count \ifnum0>\c_count >\else<\fi \a_count
      \expandafter\gobble_two
   \else
      \csname body-#1 \expandafter\endcsname
   \fi
   \for_ii{#1}
}
%    \end{macrocode}
%   
%   The macro \describecsfamily{body-\meta{name}}|\body-|\meta{name} 
%   expands to the \meta{body code}.
%   
%   |\for_ii| executes the following code:
%   \begin{quote}
%     |\a_count=\int|\marg{name}\\
%     |\advance \a_count |\meta{step}|\x_relax|\\
%     |\ifnum |\meta{stop}\meta{rel}|\a_count|\\
%     |   \expandafter\gobble_two|\\
%     |\else|\\
%     |   \resetint|\marg{name}|\a_count|\\
%     |   \csname body-|\meta{name}| \expandafter\endcsname|\\
%     |\fi|\\
%     |\for_ii|\marg{name}
%   \end{quote}
%   \meta{step}, \meta{stop}, and \meta{rel} are in |\for-|\meta{name}, 
%   and since there only are two other tokens between \meta{step} and 
%   \meta{rel} in the above, one might as well include them in 
%   |\for-|\meta{name} as well. Doing that requires that a matching 
%   hole---that will be filled in by |\for-|\meta{name}---is made in the 
%   definition of |\for_ii| and that is the reason for its somewhat 
%   curious definition.
%   
%    \begin{macrocode}
\def\for_ii#1{
   \a_count=\int{#1}
   \advance \a_count \csname for-#1\endcsname \a_count
      \expandafter\gobble_two
   \else
      \x_resetint{#1}\a_count
      \csname body-#1 \expandafter\endcsname
   \fi
   \for_ii{#1}
}
%    \end{macrocode}
%   
%   |\endfor| just gobbles its argument, so that the \meta{step}${}=0$ 
%   case will work right.
%   
%    \begin{macrocode}
\def\endfor(#1){}
%</pkg>
%    \end{macrocode}
%   \missing{doc}{\for}
%   \missing{doc}{\endfor}
%    \begin{macrocode}
%<*doc>
%</doc>
%    \end{macrocode}
% \end{macro}\end{macro}
%
% 
% \begin{macro}{\foreach}
%   \changes{1.901}{1999/03/07}{Command added. (LH)}
%   \changes{1.916}{2001/01/24}{\package{fontdoc} definition added. (LH)}
% \begin{macro}{\foreach_i}
%   The command sequence
%   \begin{quote}
%     |\foreach|\parg{name}\marg{csep-list}\\
%     \vadjust{}\quad\meta{body code}\\
%     |\endfor|\parg{name}
%   \end{quote}
%   will cause the \meta{body code} to be repeated one time for each item 
%   in the \meta{csep-list}. \meta{csep-list} is a comma-separated list 
%   of strings.
%   
%   As a precaution, the \meta{body code} is not allowed to contain any 
%   empty lines (|\par| tokens). If you want to have the visual 
%   separation (for sakes of legibility or otherwise), put a |%| 
%   somewhere on the line---that makes it nonempty.
%   
%   \meta{name} is used as the name of a string variable. Before each 
%   repetition of the \meta{body code}, this variable will get reset to 
%   the next item in the \meta{csep-list}.
%   
%   |\foreach|\textellipsis\ |\endfor| constructions can be nested. 
%   \meta{name} is used by |\foreach| to identify its matching |\endfor|, 
%   so they need to be identical in |\foreach| and |\endfor|.
%   
%    \begin{macrocode}
%<*pkg>
\def\foreach(#1)#2{
   \def\next##1\endfor(#1){
      \setsomething_global\x_cs\def{body-#1}{##1}
      \process_csep_list{\foreach_i{#1}}#2,\process_csep_list,
   }
   \next
}
\def\foreach_i#1#2{
   \resetstr{#1}{#2}
   \csname body-#1\endcsname
}
%</pkg>
%<*doc>
\def\foreach(#1)#2{%
   \def\next##1\endfor(#1){%
      \@for\@tempa:=#2\do{%
         \SetStringVariable{#1}{\@tempa}%
         ##1%
      }%
   }%
   \next
}
%</doc>
%    \end{macrocode}
% \end{macro} \end{macro}
% 
%
%
% \subsection{Comments}
% 
% \changes{1.911}{1999/11/30}{Comment commands included in 
%    \texttt{finstmsc.sty}. (LH)}
% 
% \begin{macro}{\comment}
%   In \package{fontinst}, |\comment| simply gobbles its argument.
%    \begin{macrocode}
%<pkg>\let\comment=\gobble_one
%    \end{macrocode}
%   
%   In \package{fontdoc}, |\comment| starts a new text paragraph and 
%   leaves the argument to be typeset. Note that the argument group 
%   thus survives; some commands make use of this fact.
%    \begin{macrocode}
%<*doc>
\def\comment{\par\noindent}
%</doc>
%    \end{macrocode}
% \end{macro}
% 
% 
% \begin{macro}{\begincomment}
%   \changes{1.900}{1999/02/07}{Command added. (LH)}
% \begin{macro}{\endcomment}
%   \changes{1.900}{1999/02/07}{Command added. (LH)}
%   Since |\comment| cannot be used for a comment longer than one 
%   paragraph, we also provide the means of introducing longer comments, 
%   by writing
%   \begin{quote}
%     |\begincomment| \meta{any amount of text} |\endcomment|
%   \end{quote}
%   The names are admittedly not nice from a \LaTeX\ point of view, but 
%   it is hardly worth the cost to implement some kind of environment 
%   processing in \package{fontinst}, just for the sake of this command.
%    \begin{macrocode}
%<pkg>\let\begincomment=\iffalse
%<doc>\let\begincomment=\iftrue
%<pkg|doc>\let\endcomment=\fi
%    \end{macrocode}
% \end{macro} \end{macro}
%
% \Finale
% 
\endinput