| /*============================================================================= |
| Copyright (c) 1998-2003 Joel de Guzman |
| Copyright (c) 2001 Daniel Nuffer |
| Copyright (c) 2002 Hartmut Kaiser |
| http://spirit.sourceforge.net/ |
| |
| 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) |
| =============================================================================*/ |
| #if !defined(BOOST_SPIRIT_DIFFERENCE_HPP) |
| #define BOOST_SPIRIT_DIFFERENCE_HPP |
| |
| #include <boost/spirit/home/classic/namespace.hpp> |
| #include <boost/spirit/home/classic/core/parser.hpp> |
| #include <boost/spirit/home/classic/core/primitives/primitives.hpp> |
| #include <boost/spirit/home/classic/core/composite/composite.hpp> |
| #include <boost/spirit/home/classic/meta/as_parser.hpp> |
| |
| namespace boost { namespace spirit { |
| |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // |
| // difference: a - b; Matches a but not b |
| // |
| // Handles expressions of the form: |
| // |
| // a - b |
| // |
| // where a and b are parsers. The expression returns a composite |
| // parser that matches a but not b. One (not both) of the operands |
| // may be a literal char, wchar_t or a primitive string char const*, |
| // wchar_t const*. |
| // |
| /////////////////////////////////////////////////////////////////////////// |
| struct difference_parser_gen; |
| |
| #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) |
| #pragma warning(push) |
| #pragma warning(disable:4512) //assignment operator could not be generated |
| #endif |
| |
| template <typename A, typename B> |
| struct difference |
| : public binary<A, B, parser<difference<A, B> > > |
| { |
| typedef difference<A, B> self_t; |
| typedef binary_parser_category parser_category_t; |
| typedef difference_parser_gen parser_generator_t; |
| typedef binary<A, B, parser<self_t> > base_t; |
| |
| difference(A const& a, B const& b) |
| : base_t(a, b) {} |
| |
| template <typename ScannerT> |
| typename parser_result<self_t, ScannerT>::type |
| parse(ScannerT const& scan) const |
| { |
| typedef typename parser_result<self_t, ScannerT>::type result_t; |
| typedef typename ScannerT::iterator_t iterator_t; |
| iterator_t save = scan.first; |
| if (result_t hl = this->left().parse(scan)) |
| { |
| std::swap(save, scan.first); |
| result_t hr = this->right().parse(scan); |
| if (!hr || (hr.length() < hl.length())) |
| { |
| scan.first = save; |
| return hl; |
| } |
| } |
| |
| return scan.no_match(); |
| } |
| }; |
| |
| #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) |
| #pragma warning(pop) |
| #endif |
| |
| struct difference_parser_gen |
| { |
| template <typename A, typename B> |
| struct result |
| { |
| typedef |
| difference< |
| typename as_parser<A>::type |
| , typename as_parser<B>::type |
| > |
| type; |
| }; |
| |
| template <typename A, typename B> |
| static difference< |
| typename as_parser<A>::type |
| , typename as_parser<B>::type |
| > |
| generate(A const& a, B const& b) |
| { |
| return difference<BOOST_DEDUCED_TYPENAME as_parser<A>::type, |
| BOOST_DEDUCED_TYPENAME as_parser<B>::type> |
| (as_parser<A>::convert(a), as_parser<B>::convert(b)); |
| } |
| }; |
| |
| template <typename A, typename B> |
| difference<A, B> |
| operator-(parser<A> const& a, parser<B> const& b); |
| |
| template <typename A> |
| difference<A, chlit<char> > |
| operator-(parser<A> const& a, char b); |
| |
| template <typename B> |
| difference<chlit<char>, B> |
| operator-(char a, parser<B> const& b); |
| |
| template <typename A> |
| difference<A, strlit<char const*> > |
| operator-(parser<A> const& a, char const* b); |
| |
| template <typename B> |
| difference<strlit<char const*>, B> |
| operator-(char const* a, parser<B> const& b); |
| |
| template <typename A> |
| difference<A, chlit<wchar_t> > |
| operator-(parser<A> const& a, wchar_t b); |
| |
| template <typename B> |
| difference<chlit<wchar_t>, B> |
| operator-(wchar_t a, parser<B> const& b); |
| |
| template <typename A> |
| difference<A, strlit<wchar_t const*> > |
| operator-(parser<A> const& a, wchar_t const* b); |
| |
| template <typename B> |
| difference<strlit<wchar_t const*>, B> |
| operator-(wchar_t const* a, parser<B> const& b); |
| |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_END |
| |
| }} // namespace BOOST_SPIRIT_CLASSIC_NS |
| |
| #endif |
| |
| #include <boost/spirit/home/classic/core/composite/impl/difference.ipp> |