lex/qi/plain_tokenid_mask.hpp

0001 //  Copyright (c) 2001-2011 Hartmut Kaiser
0002 //
0003 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005
0006 #if !defined(BOOST_SPIRIT_LEX_PLAIN_TOKENID_MASK_JUN_03_2011_0929PM)
0007 #define BOOST_SPIRIT_LEX_PLAIN_TOKENID_MASK_JUN_03_2011_0929PM
0008
0009 #if defined(_MSC_VER)
0010 #pragma once
0011 #endif
0012
0013 #include <boost/spirit/home/support/info.hpp>
0014 #include <boost/spirit/home/qi/detail/attributes.hpp>
0015 #include <boost/spirit/home/support/common_terminals.hpp>
0016 #include <boost/spirit/home/support/handles_container.hpp>
0017 #include <boost/spirit/home/qi/skip_over.hpp>
0018 #include <boost/spirit/home/qi/domain.hpp>
0019 #include <boost/spirit/home/qi/parser.hpp>
0020 #include <boost/spirit/home/qi/meta_compiler.hpp>
0021 #include <boost/spirit/home/qi/detail/assign_to.hpp>
0022
0023 #include <boost/fusion/include/vector.hpp>
0024 #include <boost/fusion/include/at.hpp>
0025 #include <boost/mpl/or.hpp>
0026 #include <boost/range/iterator_range_core.hpp>
0027 #include <boost/type_traits/is_integral.hpp>
0028 #include <boost/type_traits/is_enum.hpp>
0029 #include <iterator> // for std::iterator_traits
0030 #include <sstream>
0031
0032 namespace boost { namespace spirit
0033 {
0034     ///////////////////////////////////////////////////////////////////////////
0035     // Enablers
0036     ///////////////////////////////////////////////////////////////////////////
0037
0038     // enables tokenid_mask(id)
0039     template <typename A0>
0040     struct use_terminal<qi::domain
0041       , terminal_ex<tag::tokenid_mask, fusion::vector1<A0> >
0042     > : mpl::or_<is_integral<A0>, is_enum<A0> > {};
0043
0044     // enables *lazy* tokenid_mask(id)
0045     template <>
0046     struct use_lazy_terminal<
0047         qi::domain, tag::tokenid_mask, 1
0048     > : mpl::true_ {};
0049 }}
0050
0051 namespace boost { namespace spirit { namespace qi
0052 {
0053 #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
0054     using spirit::tokenid_mask;
0055 #endif
0056     using spirit::tokenid_mask_type;
0057
0058     ///////////////////////////////////////////////////////////////////////////
0059     // The plain_tokenid represents a simple token defined by the lexer inside
0060     // a Qi grammar. The difference to plain_token is that it exposes the
0061     // matched token id instead of the iterator_range of the matched input.
0062     // Additionally it applies the given mask to the matched token id.
0063     template <typename Mask>
0064     struct plain_tokenid_mask
0065       : primitive_parser<plain_tokenid_mask<Mask> >
0066     {
0067         template <typename Context, typename Iterator>
0068         struct attribute
0069         {
0070             typedef Mask type;
0071         };
0072
0073         plain_tokenid_mask(Mask const& mask)
0074           : mask(mask) {}
0075
0076         template <typename Iterator, typename Context
0077           , typename Skipper, typename Attribute>
0078         bool parse(Iterator& first, Iterator const& last
0079           , Context& /*context*/, Skipper const& skipper
0080           , Attribute& attr) const
0081         {
0082             qi::skip_over(first, last, skipper);   // always do a pre-skip
0083
0084             if (first != last) {
0085                 // simply match the token id with the mask this component has
0086                 // been initialized with
0087
0088                 typedef typename
0089                     std::iterator_traits<Iterator>::value_type
0090                 token_type;
0091                 typedef typename token_type::id_type id_type;
0092
0093                 token_type const& t = *first;
0094                 if ((t.id() & mask) == id_type(mask))
0095                 {
0096                     spirit::traits::assign_to(t.id(), attr);
0097                     ++first;
0098                     return true;
0099                 }
0100             }
0101             return false;
0102         }
0103
0104         template <typename Context>
0105         info what(Context& /*context*/) const
0106         {
0107             std::stringstream ss;
0108             ss << "tokenid_mask(" << mask << ")";
0109             return info("tokenid_mask", ss.str());
0110         }
0111
0112         Mask mask;
0113     };
0114
0115     ///////////////////////////////////////////////////////////////////////////
0116     // Parser generators: make_xxx function (objects)
0117     ///////////////////////////////////////////////////////////////////////////
0118     template <typename Modifiers, typename Mask>
0119     struct make_primitive<terminal_ex<tag::tokenid_mask, fusion::vector1<Mask> >
0120       , Modifiers>
0121     {
0122         typedef plain_tokenid_mask<Mask> result_type;
0123
0124         template <typename Terminal>
0125         result_type operator()(Terminal const& term, unused_type) const
0126         {
0127             return result_type(fusion::at_c<0>(term.args));
0128         }
0129     };
0130 }}}
0131
0132 namespace boost { namespace spirit { namespace traits
0133 {
0134     ///////////////////////////////////////////////////////////////////////////
0135     template<typename Mask, typename Attr, typename Context, typename Iterator>
0136     struct handles_container<qi::plain_tokenid_mask<Mask>, Attr, Context, Iterator>
0137       : mpl::true_
0138     {};
0139 }}}
0140
0141 #endif