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\documentclass[a4paper]{article}
\usepackage{simplebnf}
\usepackage{hyperref}
\usepackage{tcolorbox}
\tcbuselibrary{listings,breakable}
\tcbset{listing engine=listings,colframe=black,colback=white,size=small}
\NewDocumentEnvironment {exampleside} {}
{ \tcblisting{listing side text,righthand width=.55\textwidth} }
{ \endtcblisting }
\NewDocumentCommand \cmd { m } {\texttt{\textbackslash#1}}
\NewDocumentEnvironment { presentcommand } { b }
{%
\vspace*{0.5\baselineskip}\noindent\fbox{%
\begin{minipage}{\dimexpr\textwidth-2\fboxsep-2\fboxrule}
#1
\end{minipage}}\vspace*{0.5\baselineskip}
}
{ }
\NewDocumentCommand \env { m m }
{
\texttt{%
\textbackslash begin\{#1\} \textrm{#2}%
\textbackslash end\{#1\}%
}%
}
\title{%
\textsf{simplebnf} --- A simple package to format Backus-Naur form%
\footnote{This file describes v0.3.2.}}
\author{Jay Lee\footnote{E-mail: %
\href{mailto:jaeho.lee@snu.ac.kr}{\texttt{jaeho.lee@snu.ac.kr}}}}
\date{2023/01/07}
\begin{document}
\maketitle
This package provides a simple way to typeset grammars written in Backus-Naur form (BNF).
\begin{presentcommand}
\cmd{SimpleBNFDefEq}
\end{presentcommand}
This command is used to typeset the definition symbol separate a nonterminal from its productions. It defaults to \SimpleBNFDefEq. It can be redefined using \verb|RenewDocumentCommand|.
\begin{presentcommand}
\cmd{SimpleBNFDefOr}
\end{presentcommand}
This command is used to typeset the separator symbol between productions. It defaults to \SimpleBNFDefOr. It can be redefined using \verb|RenewDocumentCommand|.
\begin{presentcommand}
\cmd{SimpleBNFStretch}
\end{presentcommand}
This command is used to control the vertical spacing between consecutive rules.
It defaults to 0.
It can be redefined using \verb/Renewdocumentcommand/.
\begin{presentcommand}
\cmd{bnfexpr}
\end{presentcommand}
This command is used when typesetting the BNF nonterminal and productions. It defaults to a wrappers around \cmd{texttt}. It can be redefined to customized output using \verb|RenewDocumentCommand|.
\begin{presentcommand}
\cmd{bnfannot}
\end{presentcommand}
This command is used when typesetting the annotations on nonterminals and productions. It defaults to a wrappers around \cmd{textit}. It can be redefined to customized output using \verb|RenewDocumentCommand|.
\begin{presentcommand}
\env{bnfgrammar}{text}
\end{presentcommand}
can be used to typeset BNF grammars. The \textit{text} inside the environment should be formatted as:
\begin{verbatim}
term1 ::= rhs1
;;
term2 ::= rhs2
;;
...
termk ::= rhsk
\end{verbatim}
where each of the \textit{rhs} represents alternative syntactic forms of the \textit{term}. An annotation may accompany each alternative in which case the alternative must be separated from its annotation with a colon (\verb/:/). If you don't need annotations, simply omit the colons and annotations altogether. The alternatives themselves are separated using the pipe symbol (\verb/|/).
A sample code and the result is shown below:
\begin{exampleside}
\begin{bnfgrammar}
a \in \textit{Vars}
;;
expr ::=
expr + term : sum
| term : term
;;
term ::=
term * a : product
| a : variable
\end{bnfgrammar}
\end{exampleside}
Annotations can also be provided on left-hand sides, to label the nonterminal instead of a specific production.
\begin{exampleside}
\begin{bnfgrammar}
a : Variables \in \textit{Vars}
;;
expr : Expressions ::=
expr + term
| term
;;
term ::=
term * a
| a
\end{bnfgrammar}
\end{exampleside}
You can also provide an optional specification to the grammar environment, to redefine alignment or spacing.
\begin{tcblisting}{text above listing}
\begin{bnfgrammar}[lr@{\hspace{4pt}}c@{\hspace{2pt}}ll]
a : Variables \in \textit{Vars}
;;
expr ::=
expr + term : sum
| term : term
;;
term ::=
term * a : product
| a : variable
\end{bnfgrammar}
\end{tcblisting}
If you want to typeset multiple productions on a single line, you can use double vertical bars by default.
\begin{exampleside}
\begin{bnfgrammar}
a \in \textit{Vars}
;;
expr ::= expr + term || term
;;
term ::= term * a || a
\end{bnfgrammar}
\end{exampleside}
The second and third optional arguments specify regular expressions for the line-breaking and non-breaking RHS seperators:
\begin{tcblisting}{text above listing}
\begin{bnfgrammar}[llcll][\|\|][\|]
a \in \textit{Vars}
;;
expr ::= expr + term | term
;;
term ::= term * a
|| a
\end{bnfgrammar}
\end{tcblisting}
\end{document}
|
