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#ifndef META_HS_GRAMMAR_HPP
#define META_HS_GRAMMAR_HPP
// Copyright Abel Sinkovics (abel@sinkovics.hu) 2012.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#include <token.hpp>
#include <semantic.hpp>
#include <boost/metaparse/middle_of.hpp>
#include <boost/metaparse/transform.hpp>
#include <boost/metaparse/sequence.hpp>
#include <boost/metaparse/last_of.hpp>
#include <boost/metaparse/one_of.hpp>
#include <boost/metaparse/foldl_reject_incomplete_start_with_parser.hpp>
#include <boost/metaparse/foldr_start_with_parser.hpp>
#include <boost/metaparse/entire_input.hpp>
#include <boost/metaparse/build_parser.hpp>
namespace grammar
{
/*
* The grammar
*
* definition ::= token::name+ token::define expression
* expression ::= cmp_exp
* cmp_exp ::= plus_exp (token::cmp plus_exp)*
* plus_exp ::= mult_exp ((token::plus | token::minus) mult_exp)*
* mult_exp ::= application ((token::mult | token::div) application)*
* application ::= single_exp+
* single_exp ::= if_exp | token::name | token::int_ | bracket_exp
* if_exp ::= token::if_ expression token::then expression token::else_ expression
* bracket_exp ::= token::open_bracket expression token::close_bracket
*/
struct expression;
typedef
boost::metaparse::middle_of<
token::open_bracket,
expression,
token::close_bracket
>
bracket_exp;
typedef
boost::metaparse::transform<
boost::metaparse::sequence<
boost::metaparse::last_of<token::if_, expression>,
boost::metaparse::last_of<token::then, expression>,
boost::metaparse::last_of<token::else_, expression>
>,
semantic::if_
>
if_exp;
typedef
boost::metaparse::one_of<
if_exp,
boost::metaparse::transform<token::name, semantic::ref>,
boost::metaparse::transform<token::int_, semantic::value>,
bracket_exp
>
single_exp;
typedef
boost::metaparse::foldl_reject_incomplete_start_with_parser<
single_exp,
single_exp,
semantic::application
>
application;
typedef
boost::metaparse::foldl_reject_incomplete_start_with_parser<
boost::metaparse::sequence<
boost::metaparse::one_of<token::mult, token::div>,
application
>,
application,
semantic::binary_op
>
mult_exp;
typedef
boost::metaparse::foldl_reject_incomplete_start_with_parser<
boost::metaparse::sequence<
boost::metaparse::one_of<token::plus, token::minus>,
mult_exp
>,
mult_exp,
semantic::binary_op
>
plus_exp;
typedef
boost::metaparse::foldl_reject_incomplete_start_with_parser<
boost::metaparse::sequence<token::cmp, plus_exp>,
plus_exp,
semantic::binary_op
>
cmp_exp;
struct expression : cmp_exp {};
typedef
boost::metaparse::transform<
boost::metaparse::sequence<
token::name,
boost::metaparse::foldr_start_with_parser<
token::name,
boost::metaparse::last_of<token::define, expression>,
semantic::lambda
>
>,
semantic::pair
>
definition;
typedef
boost::metaparse::build_parser<
boost::metaparse::entire_input<definition>
>
def_parser;
}
#endif
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