52 lines
1.8 KiB
C++
52 lines
1.8 KiB
C++
/*=============================================================================
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Copyright (c) 2003 Vaclav Vesely
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http://spirit.sourceforge.net/
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Use, modification and distribution is subject to the Boost Software
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License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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//
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// This example demonstrates usage of the parser_context template with
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// an explicit argument to declare rules with match results different from
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// nil_t. For better understanding, you should read the chapter "In-depth:
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// The Parser Context" in the documentation.
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//
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// The default context of non-terminals is the parser_context.
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// The parser_context is a template with one argument AttrT, which is the type
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// of match attribute.
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//
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// In this example int_rule is declared as rule with int match attribute's
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// type, so in int_rule variable we can hold any parser, which returns int
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// value. For example int_p or bin_p. And the most important is that we can
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// use returned value in the semantic action binded to the int_rule.
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//
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//-----------------------------------------------------------------------------
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#include <iostream>
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#include <boost/cstdlib.hpp>
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#include <boost/spirit/include/phoenix1.hpp>
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#include <boost/spirit/include/classic_core.hpp>
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using namespace std;
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using namespace boost;
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using namespace phoenix;
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using namespace BOOST_SPIRIT_CLASSIC_NS;
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//-----------------------------------------------------------------------------
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int main()
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{
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rule<parser_context<int> > int_rule = int_p;
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parse(
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"123",
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// Using a returned value in the semantic action
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int_rule[cout << arg1 << endl]
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);
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return exit_success;
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}
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//-----------------------------------------------------------------------------
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