%% %% This is file `simplebnf.sty'. %% %% --------------------------------------------------------------------------- %% The simplebnf package --- A simple package to format Backus-Naur form %% Maintained by Jay Lee %% E-mail: jaeho.lee@snu.ac.kr %% Released under the MIT License. %% --------------------------------------------------------------------------- %% \RequirePackage{expl3,xparse} % mathtools is needed for the \Coloneqq simbol \RequirePackage{mathtools} \ProvidesExplPackage {simplebnf} {2020/09/01} {0.2.0} {A simple package to format Backus–Naur form} \cs_generate_variant:Nn \seq_set_split:Nnn {NVn} \tl_new:N \g__simplebnf_defeq_tl \tl_gset:Nn \g__simplebnf_defeq_tl { \ensuremath{\Coloneqq} } \tl_new:N \g__simplebnf_defor_tl \tl_gset:Nn \g__simplebnf_defor_tl { \ensuremath{|} } \seq_new:N \l__input_seq \seq_new:N \l__term_seq \tl_new:N \l__term_tl \tl_new:N \l__keypairs_tl \tl_new:N \l__table_tl \seq_new:N \l__keypairs_seq \bool_new:N \l__first_rhs %% Typeset a single rhs of a production. %% \l__first_rhs = true => `::=' already typeset %% \l__first_rhs = false => move to a newline and typeset `|' %% #1 - rhs : annot or rhs \cs_new:Nn \simplebnf_typeset_rhs:n { \bool_if:NTF \l__first_rhs { \bool_set_false:N \l__first_rhs } { \tl_put_right:Nn \l__table_tl { \\ & \g__simplebnf_defor_tl & } } \regex_split:nnNTF { : } { #1 } \l_tmpa_seq { \seq_pop_left:NNT \l_tmpa_seq \l_tmpa_tl { \tl_set:Nx \l_tmpa_tl { \bnfexpr { \l_tmpa_tl } } \tl_put_right:NV \l__table_tl \l_tmpa_tl } \tl_put_right:Nn \l__table_tl { & } \seq_pop_left:NNT \l_tmpa_seq \l_tmpb_tl { \tl_set:Nx \l_tmpb_tl { \bnfannot { \l_tmpb_tl } } \tl_put_right:NV \l__table_tl \l_tmpb_tl } } { \tl_put_right:Nn \l__table_tl { \bnfexpr { #1 } &} } } \NewDocumentCommand \bnfexpr { m } { \texttt { #1 } } \NewDocumentCommand \bnfannot { m } { \textit{ #1 } } \NewDocumentEnvironment { bnfgrammar } { +b } { %% \l__input_seq is a list of term definitions. \regex_split:nnN { ;; } { #1 } \l__input_seq \begin{center} \tl_set:Nn \l__table_tl { \begin{tabular}{lcll} } \bool_set_true:N \l_tmp_first_term % Is this the first term in this grammar? \seq_map_inline:Nn \l__input_seq { %% \l__term_seq - (term, rhses)... %% \l__term_tl - term %% \l__keypairs_tl - rhses \regex_split:nnN { ::= } { ##1 } \l__term_seq \seq_pop_left:NN \l__term_seq \l__term_tl \seq_pop_left:NN \l__term_seq \l__keypairs_tl \regex_replace_once:nnN { ^\s+ } {} \l__term_tl \bool_if:NTF \l_tmp_first_term { \bool_set_false:N \l_tmp_first_term } { \tl_put_right:Nn \l__table_tl { \\ } } \tl_put_right:Nx \l__table_tl { \bnfexpr { \l__term_tl } & \g__simplebnf_defeq_tl & } %% \l__keypairs_seq - (rhs:annot | rhs)... \seq_set_split:NnV \l__keypairs_seq { | } \l__keypairs_tl \bool_set_true:N \l__first_rhs \seq_map_function:NN \l__keypairs_seq \simplebnf_typeset_rhs:n } \tl_put_right:Nn \l__table_tl { \end{tabular} } \tl_use:N \l__table_tl \end{center} } { } %% The MIT License (MIT) %% %% Copyright © 2019-2020 Jay Lee %% %% Permission is hereby granted, free of charge, to any person obtaining %% a copy of this software and associated documentation files (the "Software"), %% to deal in the Software without restriction, including without limitation %% the rights to use, copy, modify, merge, publish, distribute, sublicense, %% and/or sell copies of the Software, and to permit persons to whom the %% Software is furnished to do so, subject to the following conditions: %% %% The above copyright notice and this permission notice shall be included %% in all copies or substantial portions of the Software. %% %% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, %% EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES %% OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. %% IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, %% DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, %% TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE %% OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. %% %% End of file `simplebnf.sty'.