| 1 | /*============================================================================= |
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| 2 | Copyright (c) 2001-2003 Daniel Nuffer |
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| 3 | http://spirit.sourceforge.net/ |
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| 4 | |
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| 5 | Use, modification and distribution is subject to the Boost Software |
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| 6 | License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
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| 7 | http://www.boost.org/LICENSE_1_0.txt) |
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| 8 | =============================================================================*/ |
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| 9 | #ifndef BOOST_SPIRIT_FLUSH_MULTI_PASS_HPP |
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| 10 | #define BOOST_SPIRIT_FLUSH_MULTI_PASS_HPP |
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| 11 | |
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| 12 | /////////////////////////////////////////////////////////////////////////////// |
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| 13 | #include <boost/spirit/core.hpp> |
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| 14 | #include <boost/spirit/iterator/multi_pass.hpp> |
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| 15 | |
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| 16 | /////////////////////////////////////////////////////////////////////////////// |
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| 17 | namespace boost { namespace spirit { |
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| 18 | |
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| 19 | namespace impl { |
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| 20 | |
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| 21 | template <typename T> |
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| 22 | void flush_iterator(T &) {} |
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| 23 | |
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| 24 | template <typename T1, typename T2, typename T3, typename T4> |
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| 25 | void flush_iterator(boost::spirit::multi_pass< |
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| 26 | T1, T2, T3, T4, boost::spirit::multi_pass_policies::std_deque> &i) |
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| 27 | { |
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| 28 | i.clear_queue(); |
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| 29 | } |
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| 30 | |
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| 31 | } // namespace impl |
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| 32 | |
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| 33 | /////////////////////////////////////////////////////////////////////////// |
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| 34 | // |
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| 35 | // flush_multi_pass_parser |
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| 36 | // |
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| 37 | // The flush_multi_pass_parser flushes an underlying |
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| 38 | // multi_pass_iterator during the normal parsing process. This may |
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| 39 | // be used at certain points during the parsing process, when it is |
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| 40 | // clear, that no backtracking is needed anymore and the input |
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| 41 | // gathered so far may be discarded. |
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| 42 | // |
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| 43 | /////////////////////////////////////////////////////////////////////////// |
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| 44 | class flush_multi_pass_parser |
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| 45 | : public parser<flush_multi_pass_parser> |
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| 46 | { |
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| 47 | public: |
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| 48 | typedef flush_multi_pass_parser this_t; |
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| 49 | |
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| 50 | template <typename ScannerT> |
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| 51 | typename parser_result<this_t, ScannerT>::type |
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| 52 | parse(ScannerT const& scan) const |
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| 53 | { |
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| 54 | impl::flush_iterator(scan.first); |
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| 55 | return scan.empty_match(); |
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| 56 | } |
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| 57 | }; |
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| 58 | |
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| 59 | /////////////////////////////////////////////////////////////////////////// |
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| 60 | // |
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| 61 | // predefined flush_multi_pass_p object |
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| 62 | // |
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| 63 | // This object should may used to flush a multi_pass_iterator along |
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| 64 | // the way during the normal parsing process. |
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| 65 | // |
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| 66 | /////////////////////////////////////////////////////////////////////////// |
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| 67 | |
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| 68 | flush_multi_pass_parser const |
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| 69 | flush_multi_pass_p = flush_multi_pass_parser(); |
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| 70 | |
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| 71 | }} // namespace boost::spirit |
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| 72 | |
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| 73 | #endif // BOOST_SPIRIT_FLUSH_MULTI_PASS_HPP |
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