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f44479bcd3
It is better to manage warnings on our side to know what warnings we need to fix or suppress, and the only thing that header does is disabling deprecation warnings on MSVC and ICC which we would prefer to not show to users.
98 lines
3.1 KiB
C++
98 lines
3.1 KiB
C++
/*=============================================================================
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Copyright (c) 2002-2015 Joel de Guzman
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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///////////////////////////////////////////////////////////////////////////////
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//
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// A complex number micro parser.
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//
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// [ JDG May 10, 2002 ] spirit1
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// [ JDG May 9, 2007 ] spirit2
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// [ JDG May 12, 2015 ] spirit X3
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//
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///////////////////////////////////////////////////////////////////////////////
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#include <boost/spirit/home/x3.hpp>
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#include <iostream>
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#include <string>
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#include <complex>
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///////////////////////////////////////////////////////////////////////////////
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// Our complex number parser/compiler
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///////////////////////////////////////////////////////////////////////////////
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namespace client
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{
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template <typename Iterator>
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bool parse_complex(Iterator first, Iterator last, std::complex<double>& c)
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{
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using boost::spirit::x3::double_;
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using boost::spirit::x3::_attr;
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using boost::spirit::x3::phrase_parse;
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using boost::spirit::x3::ascii::space;
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double rN = 0.0;
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double iN = 0.0;
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auto fr = [&](auto& ctx){ rN = _attr(ctx); };
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auto fi = [&](auto& ctx){ iN = _attr(ctx); };
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bool r = phrase_parse(first, last,
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// Begin grammar
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(
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'(' >> double_[fr]
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>> -(',' >> double_[fi]) >> ')'
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| double_[fr]
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),
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// End grammar
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space);
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if (!r || first != last) // fail if we did not get a full match
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return false;
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c = std::complex<double>(rN, iN);
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return r;
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}
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}
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////////////////////////////////////////////////////////////////////////////
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// Main program
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////////////////////////////////////////////////////////////////////////////
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int
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main()
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{
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std::cout << "/////////////////////////////////////////////////////////\n\n";
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std::cout << "\t\tA complex number micro parser for Spirit...\n\n";
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std::cout << "/////////////////////////////////////////////////////////\n\n";
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std::cout << "Give me a complex number of the form r or (r) or (r,i) \n";
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std::cout << "Type [q or Q] to quit\n\n";
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std::string str;
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while (getline(std::cin, str))
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{
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if (str.empty() || str[0] == 'q' || str[0] == 'Q')
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break;
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std::complex<double> c;
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if (client::parse_complex(str.begin(), str.end(), c))
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{
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std::cout << "-------------------------\n";
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std::cout << "Parsing succeeded\n";
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std::cout << "got: " << c << std::endl;
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std::cout << "\n-------------------------\n";
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}
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else
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{
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std::cout << "-------------------------\n";
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std::cout << "Parsing failed\n";
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std::cout << "-------------------------\n";
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}
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}
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std::cout << "Bye... :-) \n\n";
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return 0;
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}
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