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/*==============================================================================
Copyright (c) 2001-2011 Joel de Guzman
Copyright (c) 2010-2011 Bryce Lelbach
Distributed under the Boost Software License, Version 1.0. (See accompanying
file BOOST_LICENSE_1_0.rst or copy at http://www.boost.org/LICENSE_1_0.txt)
==============================================================================*/
#if !defined(BOOST_SPIRIT_UTREE_EXAMPLE_SEXPR_PARSER_HPP)
#define BOOST_SPIRIT_UTREE_EXAMPLE_SEXPR_PARSER_HPP
#include "utf8_parser.hpp"
#include "error_handler.hpp"
namespace boost {
namespace spirit {
namespace traits {
template<>
struct transform_attribute<utree::nil_type, unused_type, qi::domain> {
typedef unused_type type;
static unused_type pre (utree::nil_type&) { return unused_type(); }
static void post (utree::nil_type&, unused_type) { }
static void fail (utree::nil_type&) { }
};
} // traits
} // spirit
} // boost
namespace sexpr
{
namespace qi = boost::spirit::qi;
namespace px = boost::phoenix;
namespace standard = boost::spirit::standard;
using boost::spirit::utree;
using boost::spirit::utf8_symbol_type;
using boost::spirit::utf8_string_type;
using boost::spirit::binary_string_type;
struct bool_input_policies
{
template <typename Iterator, typename Attribute>
static bool
parse_true(Iterator& first, Iterator const& last, Attribute& attr)
{
using boost::spirit::qi::detail::string_parse;
using boost::spirit::qi::bool_policies;
using boost::spirit::qi::unused;
using boost::spirit::traits::assign_to;
if (string_parse("#t", first, last, unused))
{
assign_to(true, attr); // result is true
return true;
}
return bool_policies<bool>::parse_true(first, last, attr);
}
template <typename Iterator, typename Attribute>
static bool
parse_false(Iterator& first, Iterator const& last, Attribute& attr)
{
using boost::spirit::qi::detail::string_parse;
using boost::spirit::qi::bool_policies;
using boost::spirit::qi::unused;
using boost::spirit::traits::assign_to;
if (string_parse("#f", first, last, unused))
{
assign_to(false, attr); // result is false
return true;
}
return bool_policies<bool>::parse_false(first, last, attr);
}
};
struct save_line_pos
{
template <typename, typename>
struct result
{
typedef void type;
};
template <typename Range>
void operator()(utree& ast, Range const& rng) const
{
using boost::spirit::get_line;
std::size_t n = get_line(rng.begin());
if (n != -1)
{
BOOST_ASSERT(n <= (std::numeric_limits<short>::max)());
ast.tag(n);
}
else
ast.tag(-1);
}
};
template <typename Iterator, typename F>
struct tagger : qi::grammar<Iterator, void(utree&, char)>
{
qi::rule<Iterator, void(utree&, char)>
start;
qi::rule<Iterator, void(utree&)>
epsilon;
px::function<F>
f;
tagger(F f_ = F()) : tagger::base_type(start), f(f_)
{
using qi::omit;
using qi::raw;
using qi::eps;
using qi::lit;
using qi::_1;
using qi::_r1;
using qi::_r2;
start = omit[raw[lit(_r2)] [f(_r1, _1)]];
epsilon = omit[raw[eps] [f(_r1, _1)]];
}
};
template <typename Iterator>
struct whitespace : qi::grammar<Iterator> {
qi::rule<Iterator>
start;
whitespace() : whitespace::base_type(start)
{
using standard::space;
using standard::char_;
using qi::eol;
start = space | (';' >> *(char_ - eol) >> eol);
}
};
} // sexpr
//[utree_sexpr_parser
namespace sexpr
{
template <typename Iterator, typename ErrorHandler = error_handler<Iterator> >
struct parser : qi::grammar<Iterator, utree(), whitespace<Iterator> >
{
qi::rule<Iterator, utree(), whitespace<Iterator> >
start, element, list;
qi::rule<Iterator, utree()>
atom;
qi::rule<Iterator, int()>
integer;
qi::rule<Iterator, utf8_symbol_type()>
symbol;
qi::rule<Iterator, utree::nil_type()>
nil_;
qi::rule<Iterator, binary_string_type()>
binary;
utf8::parser<Iterator>
string;
px::function<ErrorHandler> const
error;
tagger<Iterator, save_line_pos>
pos;
parser(std::string const& source_file = "<string>"):
parser::base_type(start), error(ErrorHandler(source_file))
{
using standard::char_;
using qi::unused_type;
using qi::lexeme;
using qi::hex;
using qi::oct;
using qi::no_case;
using qi::real_parser;
using qi::strict_real_policies;
using qi::uint_parser;
using qi::bool_parser;
using qi::on_error;
using qi::fail;
using qi::int_;
using qi::lit;
using qi::_val;
using qi::_1;
using qi::_2;
using qi::_3;
using qi::_4;
real_parser<double, strict_real_policies<double> > strict_double;
uint_parser<unsigned char, 16, 2, 2> hex2;
bool_parser<bool, sexpr::bool_input_policies> boolean;
start = element.alias();
element = atom | list;
list = pos(_val, '(') > *element > ')';
atom = nil_
| strict_double
| integer
| boolean
| string
| symbol
| binary;
nil_ = qi::attr_cast(lit("nil"));
integer = lexeme[ no_case["#x"] > hex]
| lexeme[ no_case["#o"] >> oct]
| lexeme[-no_case["#d"] >> int_];
std::string exclude = std::string(" ();\"\x01-\x1f\x7f") + '\0';
symbol = lexeme[+(~char_(exclude))];
binary = lexeme['#' > *hex2 > '#'];
start.name("sexpr");
element.name("element");
list.name("list");
atom.name("atom");
nil_.name("nil");
integer.name("integer");
symbol.name("symbol");
binary.name("binary");
on_error<fail>(start, error(_1, _2, _3, _4));
}
};
} // sexpr
//]
#endif // BOOST_SPIRIT_UTREE_EXAMPLE_SEXPR_PARSER_HPP
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