| /*============================================================================= |
| 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_EXCLUSIVE_OR_HPP) |
| #define BOOST_SPIRIT_EXCLUSIVE_OR_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 |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // |
| // exclusive_or class |
| // |
| // Handles expressions of the form: |
| // |
| // a ^ b |
| // |
| // where a and b are parsers. The expression returns a composite |
| // parser that matches a or b but not both. One (not both) of the |
| // operands may be a literal char, wchar_t or a primitive string |
| // char const*, wchar_t const*. |
| // |
| /////////////////////////////////////////////////////////////////////////// |
| struct exclusive_or_parser_gen; |
| |
| template <typename A, typename B> |
| struct exclusive_or |
| : public binary<A, B, parser<exclusive_or<A, B> > > |
| { |
| typedef exclusive_or<A, B> self_t; |
| typedef binary_parser_category parser_category_t; |
| typedef exclusive_or_parser_gen parser_generator_t; |
| typedef binary<A, B, parser<self_t> > base_t; |
| |
| exclusive_or(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; |
| result_t l = this->left().parse(scan); |
| std::swap(save, scan.first); |
| result_t r = this->right().parse(scan); |
| |
| if (l ? !bool(r) : bool(r)) |
| { |
| if (l) |
| scan.first = save; |
| return l ? l : r; |
| } |
| |
| return scan.no_match(); |
| } |
| }; |
| |
| struct exclusive_or_parser_gen |
| { |
| template <typename A, typename B> |
| struct result |
| { |
| typedef |
| exclusive_or< |
| typename as_parser<A>::type |
| , typename as_parser<B>::type |
| > |
| type; |
| }; |
| |
| template <typename A, typename B> |
| static exclusive_or< |
| typename as_parser<A>::type |
| , typename as_parser<B>::type |
| > |
| generate(A const& a, B const& b) |
| { |
| return exclusive_or<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> |
| exclusive_or<A, B> |
| operator^(parser<A> const& a, parser<B> const& b); |
| |
| template <typename A> |
| exclusive_or<A, chlit<char> > |
| operator^(parser<A> const& a, char b); |
| |
| template <typename B> |
| exclusive_or<chlit<char>, B> |
| operator^(char a, parser<B> const& b); |
| |
| template <typename A> |
| exclusive_or<A, strlit<char const*> > |
| operator^(parser<A> const& a, char const* b); |
| |
| template <typename B> |
| exclusive_or<strlit<char const*>, B> |
| operator^(char const* a, parser<B> const& b); |
| |
| template <typename A> |
| exclusive_or<A, chlit<wchar_t> > |
| operator^(parser<A> const& a, wchar_t b); |
| |
| template <typename B> |
| exclusive_or<chlit<wchar_t>, B> |
| operator^(wchar_t a, parser<B> const& b); |
| |
| template <typename A> |
| exclusive_or<A, strlit<wchar_t const*> > |
| operator^(parser<A> const& a, wchar_t const* b); |
| |
| template <typename B> |
| exclusive_or<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/exclusive_or.ipp> |