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Opening a door towards Spirit: a parser framework

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23 Mar 20037 min read 200.6K   942   69  
A quick introduction to Spirit, a parser generator framework based
// CmdLineParser.cpp : d�finit le point d'entr�e pour l'application console.
//

#include "stdafx.h"


#include <iostream>

#include "CmdLine.h"
using namespace std;
using namespace boost;
using namespace spirit;


////////////////////////////////////////////////////////////////////////////
//
//  Main program
//
////////////////////////////////////////////////////////////////////////////
int
main()
{
	using namespace boost::spirit;

    cout << "/////////////////////////////////////////////////////////\n\n";
    cout << "\t\tCommand line parser \n\n";
    cout << "/////////////////////////////////////////////////////////\n\n";
    cout << "Type a command line parameter like nested tag input...or [q or Q] to quit\n\n";
    cout << "Example: cmd -key=value -key2=\"value2\" -key3='value3'\n\n";

	command_line_parser cmdline;

    string str;
    while (getline(cin, str))
    {
        if (str[0] == 'q' || str[0] == 'Q')
            break;

		
		if (cmdline.parse(str))
        {
            cout << "-------------------------\n";
			cout << "Parsing succeeded\nCommand: "<<cmdline.get_command()<<"\n";
			command_line_parser::keyvalue_container::const_iterator it = cmdline.get_keyvalues().begin();
			while (it != cmdline.get_keyvalues().end())
			{
				cout<<it->first<<" -> "<<it->second<<"\n";
				++it;
			}
            cout << "-------------------------\n";
        }
        else
        {
            cout << "-------------------------\n";
            cout << "Parsing failed\n";
            cout << "stopped at: \": " << cmdline.stop() << "\"\n";
            cout << "-------------------------\n";
        }
    }

    cout << "Bye... :-) \n\n";
    return 0;
}

/*
////////////////////////////////////////////////////////////////////////////
//
//  Plain calculator example.
//
//  [ JDG 5/10/2002 ]
//
////////////////////////////////////////////////////////////////////////////
#include "boost/spirit/core.hpp"
#include <iostream>
#include <string>

////////////////////////////////////////////////////////////////////////////
using namespace std;
using namespace boost::spirit;

////////////////////////////////////////////////////////////////////////////
//
//  Semantic actions
//
////////////////////////////////////////////////////////////////////////////
namespace {

    void    do_int(char const* str, char const* end)
    {
        string  s(str, end);
        cout << "PUSH(" << s << ')' << endl;
    }

    void    do_add(char const*, char const*)    { cout << "ADD\n"; }
    void    do_subt(char const*, char const*)   { cout << "SUBTRACT\n"; }
    void    do_mult(char const*, char const*)   { cout << "MULTIPLY\n"; }
    void    do_div(char const*, char const*)    { cout << "DIVIDE\n"; }
    void    do_neg(char const*, char const*)    { cout << "NEGATE\n"; }
}

////////////////////////////////////////////////////////////////////////////
//
//  Our calculator grammar
//
////////////////////////////////////////////////////////////////////////////
struct calculator : public grammar<calculator>
{
    template <typename ScannerT>
    struct definition
    {
        definition(calculator const& self)
        {
            expression
                =   term
                    >> *(   ('+' >> term)[&do_add]
                        |   ('-' >> term)[&do_subt]
                        )
                ;

            term
                =   factor
                    >> *(   ('*' >> factor)[&do_mult]
                        |   ('/' >> factor)[&do_div]
                        )
                ;

            factor
                =   lexeme_d[(+digit_p)[&do_int]]
                |   '(' >> expression >> ')'
                |   ('-' >> factor)[&do_neg]
                |   ('+' >> factor)
                ;
        }

        rule<ScannerT> expression, term, factor;

        rule<ScannerT> const&
        start() const { return expression; }
    };
};

////////////////////////////////////////////////////////////////////////////
//
//  Main program
//
////////////////////////////////////////////////////////////////////////////
int
main()
{
    cout << "/////////////////////////////////////////////////////////\n\n";
    cout << "\t\tExpression parser...\n\n";
    cout << "/////////////////////////////////////////////////////////\n\n";
    cout << "Type an expression...or [q or Q] to quit\n\n";

    calculator calc;    //  Our parser

    for (;;)
    {
        char str[256];
        cin.getline(str, 256);
        if (str[0] == 'q' || str[0] == 'Q')
            break;

        parse_info<> info = parse(str, calc, space_p);

        if (info.full)
        {
            cout << "-------------------------\n";
            cout << "Parsing succeeded\n";
            cout << "-------------------------\n";
        }
        else
        {
            cout << "-------------------------\n";
            cout << "Parsing failed\n";
            cout << "stopped at: \": " << info.stop << "\"\n";
            cout << "-------------------------\n";
        }
    }

    cout << "Bye... :-) \n\n";
    return 0;
}
*/

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Written By
Engineer
United States United States
Jonathan de Halleux is Civil Engineer in Applied Mathematics. He finished his PhD in 2004 in the rainy country of Belgium. After 2 years in the Common Language Runtime (i.e. .net), he is now working at Microsoft Research on Pex (http://research.microsoft.com/pex).

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