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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
3.0 KiB
C++
98 lines
3.0 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 parser for summing a comma-separated list of numbers using phoenix.
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//
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// [ JDG June 28, 2002 ] spirit1
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// [ JDG March 24, 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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namespace client
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{
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namespace x3 = boost::spirit::x3;
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namespace ascii = boost::spirit::x3::ascii;
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using x3::double_;
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using ascii::space;
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using x3::_attr;
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///////////////////////////////////////////////////////////////////////////
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// Our adder
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///////////////////////////////////////////////////////////////////////////
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template <typename Iterator>
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bool adder(Iterator first, Iterator last, double& n)
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{
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auto assign = [&](auto& ctx){ n = _attr(ctx); };
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auto add = [&](auto& ctx){ n += _attr(ctx); };
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bool r = x3::phrase_parse(first, last,
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// Begin grammar
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(
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double_[assign] >> *(',' >> double_[add])
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)
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,
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// End grammar
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space);
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if (first != last) // fail if we did not get a full match
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return false;
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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 parser for summing a list of numbers...\n\n";
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std::cout << "/////////////////////////////////////////////////////////\n\n";
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std::cout << "Give me a comma separated list of numbers.\n";
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std::cout << "The numbers are added using Phoenix.\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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double n;
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if (client::adder(str.begin(), str.end(), n))
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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 << str << " Parses OK: " << std::endl;
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std::cout << "sum = " << n;
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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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