guide.sty

PL/0源码

\oddsidemargin .25in
\textwidth 6in
\pagestyle{plain}
\topmargin 0in
\headheight 0in
\headsep 0in
\textheight 8.8in

% grammar macros and environment:
\def\code#1{{\tt #1}}
\def\goesto{\hspace{.1em}${\bf\longrightarrow}$\hspace{.2em}}
\def\kstar{\hspace{.1em}{\bf*}\hspace{.1em}}
\def\nothing{\protect\@nothing}
\def\@nothing{\relax\ifmmode\epsilon\else$\m@th\epsilon$\fi}
\def\lit#1{\code{#1}}
\def\lparen{{\bf (%                           ) <match paren for emacs>
    }\hspace{.2em}}
\def\rparen{\hspace{.2em}{\bf %               ( <match paren for emacs>
    )}\hspace{.5em}}
\def\lcurly{{\bf \{%                          } <match paren for emacs>
    }\hspace{.2em}}
\def\rcurly{\hspace{.2em}{\bf %               { <match paren for emacs>
    \}}\hspace{.5em}}
\def\alt{\hspace{.2em}\rule[-.7ex]{.075em}{2.5ex}\hspace{.6em}}
\newdimen\lhs@wid \lhs@wid\z@
\newdimen\lhs@indent
\def\grammar{\trivlist\it%
    \lhs@indent 1.5em
    \parindent\z@\parskip .7ex plus .2ex minus .2ex
    \item[]%    old version; disables 'no item!' error message
    \def\item{\@ifnextchar[%                        ] <match brac for emacs>
        {\gram@item}{\gram@item[]}}}
\def\gram@item[#1]{\par%
    \edef\@lhs{#1}
    \ifx\@lhs\empty
        \def\@lhs{\rule{\lhs@wid}{\z@}}
    \else
        \setbox\@tempboxa\hbox{#1}\lhs@wid\wd\@tempboxa
    \fi
    \setbox\@tempboxa\hbox{\hspace*{\lhs@indent}%
        \@lhs\hspace{.7em}\goesto\hspace*{.8em}}
    \hangindent\wd\@tempboxa\unhbox\@tempboxa\ignorespaces}
\def\endgrammar{\endtrivlist}

\input{epsf}