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- /*=============================================================================
- Copyright (c) 2002-2003 Joel de Guzman
- Copyright (c) 2002 Juan Carlos Arevalo-Baeza
- http://spirit.sourceforge.net/
- Use, modification and distribution is subject to 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)
- =============================================================================*/
- #include <boost/spirit/include/classic_core.hpp>
- #include <boost/spirit/include/classic_functor_parser.hpp>
- #include <boost/spirit/include/classic_assign_actor.hpp>
- #include <iostream>
- #include <vector>
- #include <string>
- ///////////////////////////////////////////////////////////////////////////////
- //
- // Demonstrates the functor_parser. This is discussed in the
- // "Functor Parser" chapter in the Spirit User's Guide.
- //
- ///////////////////////////////////////////////////////////////////////////////
- using namespace std;
- using namespace BOOST_SPIRIT_CLASSIC_NS;
- ///////////////////////////////////////////////////////////////////////////////
- //
- // Our parser functor
- //
- ///////////////////////////////////////////////////////////////////////////////
- struct number_parser
- {
- typedef int result_t;
- template <typename ScannerT>
- int
- operator()(ScannerT const& scan, result_t& result) const
- {
- if (scan.at_end())
- return -1;
- char ch = *scan;
- if (ch < '0' || ch > '9')
- return -1;
- result = 0;
- int len = 0;
- do
- {
- result = result*10 + int(ch - '0');
- ++len;
- ++scan;
- } while (!scan.at_end() && (ch = *scan, ch >= '0' && ch <= '9'));
- return len;
- }
- };
- functor_parser<number_parser> number_parser_p;
- ///////////////////////////////////////////////////////////////////////////////
- //
- // Our number parser functions
- //
- ///////////////////////////////////////////////////////////////////////////////
- bool
- parse_number(char const* str, int& n)
- {
- return parse(str, lexeme_d[number_parser_p[assign_a(n)]], space_p).full;
- }
- bool
- parse_numbers(char const* str, std::vector<int>& n)
- {
- return
- parse(
- str,
- lexeme_d[number_parser_p[push_back_a(n)]]
- >> *(',' >> lexeme_d[number_parser_p[push_back_a(n)]]),
- space_p
- ).full;
- }
- ////////////////////////////////////////////////////////////////////////////
- //
- // Main program
- //
- ////////////////////////////////////////////////////////////////////////////
- int
- main()
- {
- cout << "/////////////////////////////////////////////////////////\n\n";
- cout << "\t\tA number parser implemented as a functor for Spirit...\n\n";
- cout << "/////////////////////////////////////////////////////////\n\n";
- cout << "Give me an integer number command\n";
- cout << "Commands:\n";
- cout << " A <num> --> parses a single number\n";
- cout << " B <num>, <num>, ... --> parses a series of numbers ";
- cout << "separated by commas\n";
- cout << " Q --> quit\n\n";
- string str;
- while (getline(cin, str))
- {
- if (str.empty() || str[0] == 'q' || str[0] == 'Q')
- break;
- else if (str[0] == 'a' || str[0] == 'A')
- {
- int n;
- if (parse_number(str.c_str()+1, n))
- {
- cout << "-------------------------\n";
- cout << "Parsing succeeded\n";
- cout << str << " Parses OK: " << n << endl;
- cout << "-------------------------\n";
- }
- else
- {
- cout << "-------------------------\n";
- cout << "Parsing failed\n";
- cout << "-------------------------\n";
- }
- }
- else if (str[0] == 'b' || str[0] == 'B')
- {
- std::vector<int> n;
- if (parse_numbers(str.c_str()+1, n))
- {
- cout << "-------------------------\n";
- cout << "Parsing succeeded\n";
- int size = n.size();
- cout << str << " Parses OK: " << size << " number(s): " << n[0];
- for (int i = 1; i < size; ++i) {
- cout << ", " << n[i];
- }
- cout << endl;
- cout << "-------------------------\n";
- }
- else
- {
- cout << "-------------------------\n";
- cout << "Parsing failed\n";
- cout << "-------------------------\n";
- }
- }
- else
- {
- cout << "-------------------------\n";
- cout << "Unrecognized command!!";
- cout << "-------------------------\n";
- }
- }
- cout << "Bye... :-) \n\n";
- return 0;
- }
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