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Diffstat (limited to 'src/third_party/boost-1.69.0/boost/spirit/home/classic/core/composite/alternative.hpp')
-rw-r--r-- | src/third_party/boost-1.69.0/boost/spirit/home/classic/core/composite/alternative.hpp | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/src/third_party/boost-1.69.0/boost/spirit/home/classic/core/composite/alternative.hpp b/src/third_party/boost-1.69.0/boost/spirit/home/classic/core/composite/alternative.hpp new file mode 100644 index 00000000000..5e472a9a640 --- /dev/null +++ b/src/third_party/boost-1.69.0/boost/spirit/home/classic/core/composite/alternative.hpp @@ -0,0 +1,147 @@ +/*============================================================================= + 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_ALTERNATIVE_HPP) +#define BOOST_SPIRIT_ALTERNATIVE_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 + + /////////////////////////////////////////////////////////////////////////// + // + // alternative 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. One (not both) of the operands may + // be a literal char, wchar_t or a primitive string char const*, + // wchar_t const*. + // + // The expression is short circuit evaluated. b is never touched + // when a is returns a successful match. + // + /////////////////////////////////////////////////////////////////////////// + struct alternative_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 alternative + : public binary<A, B, parser<alternative<A, B> > > + { + typedef alternative<A, B> self_t; + typedef binary_parser_category parser_category_t; + typedef alternative_parser_gen parser_generator_t; + typedef binary<A, B, parser<self_t> > base_t; + + alternative(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; + { // scope for save + iterator_t save = scan.first; + if (result_t hit = this->left().parse(scan)) + return hit; + scan.first = save; + } + return this->right().parse(scan); + } + }; + +#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) +#pragma warning(pop) +#endif + + struct alternative_parser_gen + { + template <typename A, typename B> + struct result + { + typedef + alternative< + typename as_parser<A>::type + , typename as_parser<B>::type + > + type; + }; + + template <typename A, typename B> + static alternative< + typename as_parser<A>::type + , typename as_parser<B>::type + > + generate(A const& a, B const& b) + { + return alternative<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> + alternative<A, B> + operator|(parser<A> const& a, parser<B> const& b); + + template <typename A> + alternative<A, chlit<char> > + operator|(parser<A> const& a, char b); + + template <typename B> + alternative<chlit<char>, B> + operator|(char a, parser<B> const& b); + + template <typename A> + alternative<A, strlit<char const*> > + operator|(parser<A> const& a, char const* b); + + template <typename B> + alternative<strlit<char const*>, B> + operator|(char const* a, parser<B> const& b); + + template <typename A> + alternative<A, chlit<wchar_t> > + operator|(parser<A> const& a, wchar_t b); + + template <typename B> + alternative<chlit<wchar_t>, B> + operator|(wchar_t a, parser<B> const& b); + + template <typename A> + alternative<A, strlit<wchar_t const*> > + operator|(parser<A> const& a, wchar_t const* b); + + template <typename B> + alternative<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/alternative.ipp> |