%
% Syntax typesetting package for LaTeX 2e
%
-% (c) 1996 Mark Wooding
+% (c) 2003 Mark Wooding
%
% \end{meta-comment}
%
% \begin{meta-comment} <general public licence>
%%
%% syntax package -- typesetting syntax descriptions
-%% Copyright (c) 1996 Mark Wooding
+%% Copyright (c) 2003 Mark Wooding
%%
%% This program is free software; you can redistribute it and/or modify
%% it under the terms of the GNU General Public License as published by
% \begin{meta-comment} <Package preamble>
%<+package>\NeedsTeXFormat{LaTeX2e}
%<+package>\ProvidesPackage{syntax}
-%<+package> [1996/05/17 1.07 Syntax typesetting (MDW)]
+%<+package> [2003/08/25 1.08 Syntax typesetting (MDW)]
% \end{meta-comment}
%
-% ^^A \CheckSum{1504}
+% \CheckSum{1627}
%% \CharacterTable
%% {Upper-case \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%% Lower-case \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
% \begin{listing}
%\def\<#1>{\synt{#1}}
% \end{listing}
-% to allow you to type "\\<"<text>">" as an alternative to
+% to allow you to type "\\<"<text>">" as an alternative to
% "\\synt{"<text>"}".
%
% \DescribeMacro\lit
% blank lines. You can use the normal |\\| command to perform line-breaking
% of a production rule. Note that a production rule must begin with a
% nonterminal name enclosed in angle brackets (|<| \dots |>|), followed by
-% whitespace, then some kind of production operator (usually `::=') and then
-% some more whitespace. You can control how this text is actually typeset,
-% however.
+% any decorative material, whitespace, some kind of production operator
+% (usually `::=') and then some more whitespace. You can control how this
+% text is actually typeset, however.
%
% \DescribeMacro{\[[}
% \DescribeMacro{\]]}
% You can use syntax diagrams (see below) instead of a straight piece of BNF
-% by enclosing it in a |\[[| \dots |\]]| pair. Note that you can't mix
+% by enclosing it in a |\[[| \dots |\]]| pair. Note that you can't mix
% syntax diagrams and BNF in a production rule, and you will get something
% which looks very strange if you try.
%
%
% \end{description}
%
-% \DescribeMacro\grammarlabel
+% \DescribeMacro\grammarlabelx
% You can also control how the `label' is typeset by redefining the
-% |\grammarlabel| command. The command is given two arguments: the name of
-% the nonterminal (which was enclosed in angle brackets), and the `production
-% operator'. The command is expected to produce the label. By default, it
-% typesets the nonterminal name using |\synt| and the operator at opposite
-% ends of the label, separated by an |\hfill|.
+% |\grammarlabelx| command. The command is given three arguments: the name
+% of the nonterminal (which was enclosed in angle brackets), the following
+% decorative material, and the `production operator'. The command is
+% expected to produce the label. By default, it typesets the nonterminal
+% name using |\synt| followed by the decoration, and the operator, at
+% opposite ends of the label, separated by an |\hfill|.
+%
+% \DescribeMacro\grammarlabel
+% For compatibility, if there is no decorative material, the macro
+% |\grammarlabel| is called instead, with just two arguments: the nonterminal
+% name and the operator. The default implementation of |\grammarlabel| just
+% calls |\grammarlabelx| with empty decoration.
%
% \subsection{Syntax diagrams}
%
% ^^A took to get the table below to look right: __6. Hmm... not as bad
% ^^A as I expected. Most of them were fine-tuning things.
%
-% \medskip ^^A Leave a vertical gap
-% \hbox to\columnwidth{\hfil\vbox{\tabskip=0pt ^^A Centre it horizontally
-% \sdsize \csname sd@setsize\endcsname ^^A Position syntdiag arrows
-% \halign to .5\columnwidth{ ^^A Set the table width
+% \medskip ^^A Leave a vertical gap
+% \hbox to\columnwidth{\hfil\vbox{\tabskip=0pt ^^A Centre it horizontally
+% \sdsize \csname sd@setsize\endcsname ^^A Position syntdiag arrows
+% \halign to .5\columnwidth{ ^^A Set the table width
% &\ttfamily\ignorespaces#\unskip\hfil\tabskip=0pt ^^A Typeset the name
-% &\quad\csname sd@arr@#\endcsname\hfil ^^A Typeset the arrow
-% &\setbox0=\hbox{#}\tabskip=0pt plus 1fil\cr ^^A Stretch between columns
+% &\quad\csname sd@arr@#\endcsname\hfil ^^A Typeset the arrow
+% &\setbox0=\hbox{#}\tabskip=0pt plus 1fil\cr ^^A Stretch between columns
% >>-&>>-& &>-&>-& &->&->\cr
% -><&-><& &...&...& &-&-\cr
-% }}\hfil} ^^A Close the boxing
-% \medskip ^^A And leave another gap
+% }}\hfil} ^^A Close the boxing
+% \medskip ^^A And leave another gap
%
% These declarations should be used only in the optional argument to the
% \env{syntdiag$*$} command. The second optional argument to the
%
% \DescribeMacro\tok
% You can also include text using the |\tok| command. The argument of this
-% command is typeset in \LaTeX's LR~mode and inserted into the diagram.
+% command is typeset in \LaTeX's LR~mode and inserted into the diagram.
% Syntax abbreviations are allowed within the argument, so you can, for
% example, include textual descriptions like
% \begin{listing}
%
% Note that items on the backwards arrow of a \env{rep} construction should
% be displayed \emph{backwards}. You must put the individual items in
-% reverse order when building this part of your diagrams. \syn\ will
+% reverse order when building this part of your diagrams. \syn\ will
% correctly reverse the arrows on \env{rep} structures, but apart from
% this, you must cope on your own. You are recommended to keep these parts
% of your diagrams as simple as possible to avoid confusing readers.
%
% You can also alter the appearance of \env{stack}s and \env{rep}s by using
% their optional positioning arguments. By default, \env{stack}s descend
-% below the main line of the diagram, and \env{rep}s extend above it.
+% below the main line of the diagram, and \env{rep}s extend above it.
% Specifying an optional argument of |[b]| for either environment reverses
% this, putting \env{stack}s above and \env{rep}s below the line.
%
% |\lit| and |\lit*|) has two style commands associated with it, as shown
% in the table below.
%
-% \begin{tab}{lll} \hline
-% \bf Syntax item & \bf Left command & \bf Right command \\ \hline
-% Nonterminals & |\syntleft| & |\syntright| \\
-% Quoted terminals & |\litleft| & |\litright| \\
-% Unquoted terminals & |\ulitleft| & |\ulitright| \\ \hline
+% \begin{tab}{lll} \hline
+% \bf Syntax item & \bf Left command & \bf Right command \\ \hline
+% Nonterminals & |\syntleft| & |\syntright| \\
+% Quoted terminals & |\litleft| & |\litright| \\
+% Unquoted terminals & |\ulitleft| & |\ulitright| \\ \hline
% \end{tab}
%
% It's not too hard to see how this works. For example, if you look at
% commands, in \env{grammar} environments, and in syntax diagrams.
%
%
-% \section{Change history}
-%
-% \subsection*{Version 1.07}
-%
-% \begin{itemize}
-% \item Fixed problem with underscore hacking in a \env{tabbing} environment.
-% \end{itemize}
-%
-% \subsection*{Version 1.06}
-%
-% \begin{itemize}
-% \item Added style hooks for syntax items.
-% \item Improved colour handling in syntax diagrams, thanks to the |\doafter|
-% package.
-% \item Fixed some nasty bugs in the \env{grammar} environment which confused
-% other lists and ruined the spacing. The \env{grammar} handling is
-% now much tidier in general.
-% \end{itemize}
-%
-% \subsection*{Version 1.05}
-%
-% \begin{itemize}
-% \item Fixed `the bug' in the syntax diagram typesetting. It now breaks
-% lines almost psychically, and doesn't break in the wrong places.
-% \item Almost rewrote the \env{grammar} environment. It now does lots of
-% the list handling itself, to allow more versatile typesetting of the
-% left hand sides. There's lots of evil in there now.
-% \item Added some more configurability. In particular, two new settings
-% have been added to control \env{grammar} environments, and a neat
-% way of adding new syntax diagram structures has been introduced.
-% \end{itemize}
-%
-% \subsection*{Version 1.04}
-%
-% \begin{itemize}
-% \item Changed the vertical positioning of the rules, to make all the text
-% line up properly. While the old version was elegant and simple, it
-% had the drawback of looking nasty.
-% \item Allow line breaks at underscores, but don't if there's another one
-% afterwards. Also, prevent losing following space if underscore is
-% written to a file.
-% \end{itemize}
-%
-% \subsection*{Version 1.02}
-%
-% \begin{itemize}
-% \item Added support for rounded corners in syntax diagrams.
-% \item Changed lots of |\hskip| commands to |\kern|s, to prevent possible
-% line breaks.
-% \end{itemize}
-%
-% \subsection*{Version 1.01}
-%
-% \begin{itemize}
-% \item Allowed disabling of underscore active character, to avoid messing
-% up filenames.
-% \item Added |\grammarparsep| and |\grammarindent| length parameters to
-% control the appearance of grammars.
-% \end{itemize}
-%
% \implementation
%
% \section{Implementation of \syn}
% characters through. By default, we re-enable |\|, and make `\verb*" "'
% typeset some space glue, rather than a space character. A macro
% `\verb*"\ "' is defined to actually print a space character, which yield
-% `\verb*" "' in the `|\tt|' font.
+% `\verb*" "' in the `|\tt|' font.
%
% Finally, it defines a |\ch| command, which, given a single-character
% control sequence as its argument, typesets the character. This is useful,
\addspecial\|%
\addspecial\"%
\catcode`\|\active%
- \catcode`\<\active%
+ \catcode`\<\active%
\catcode`\"\active%
\catcode`\`\active%
}
% commands. Well, almost \dots
%
% \begin{macrocode}
-\newcommand{\grammarlabel}[2]{%
- \synt{#1} \hfill#2%
-}
+\newcommand{\grammarlabel}[2]{\grammarlabelx{#1}{}{#2}}
+\newcommand{\grammarlabelx}[3]{\synt{#1}#2 \hfill#3}
% \end{macrocode}
%
% Now for a bit of hacking to make the item stuff work properly. This gets
% strut just makes sure that I know exactly how high the line is.
%
% \begin{macrocode}
-\def\gr@implitem<#1> #2 {%
- \sbox\z@{\hskip\labelsep\grammarlabel{#1}{#2}}%
+\def\gr@implitem<#1>#2 #3 {%
+ \sbox\z@{%
+ \hskip\labelsep%
+ \def\@tempa{#2}%
+ \ifx\@tempa\@empty\grammarlabel{#1}{#3}%
+ \else\grammarlabelx{#1}{#2}{#3}\fi%
+ }%
\strut\@@par%
\vskip-\parskip%
\vskip-\baselineskip%
}
\def\sd@leftarr{%
\bgroup%
- \raise\sd@mid\hbox{\@linefnt\char'33\kern-6\p@}%
+ \setbox\tw@\hbox{\@linefnt\char'33\kern-6\p@}%
\sd@arrow%
}
% \end{macrocode}
~mdw / mdwtools / blobdiff