Ticket #2165: regex-bug.cpp

#include <iostream>
#include <string>

#include <boost/regex.hpp>
#include <boost/format.hpp>

// g++ -o regex-bug{,.cpp} -lboost_regex -Wall -pedantic
//  
//  tests case :
//  echo " toto" | regex '[a-z]*' > result_0
//  echo " toto" | regex ' [a-z]*' > result_1
//
//
//

char const * c_decorate_string = "% -12s (%s)" ;
char const * c_decorate_matched = "   [% -3d,% -3d] (%s)" ;

int main(int argc, char * argv[])
{
        using namespace std ;
        using namespace boost ;

        cout << format(c_decorate_string) % "seeked" % argv[1] << endl ;

        regex re(argv[1]) ;
        string extract ;
        getline(cin, extract) ;

        cout << format(c_decorate_string) % "input" % extract << endl ;

        if(extract.length() > 0)
        {
                string const & c_extract = extract ;

                string::const_iterator start = c_extract.begin() ;
                string::const_iterator end = c_extract.end() ;


                smatch matches ;
                match_flag_type flags = match_default ;
                unsigned counter = 0 ;
                while(regex_search(start, end, matches, re, flags))
                {
                        cout << format(c_decorate_string) % "current" % std::string(start, end) << endl ;

                        for(unsigned i = 0 ; i < matches.size() ; i++)
                                cout << format(c_decorate_matched)
                                        % counter % i
                                        % std::string(matches[i].first, matches[i].second) << endl ;

                        cout << format(c_decorate_string)
                                % "suffix"
                                % std::string(matches.suffix().first, matches.suffix().second) << endl ;

                        cout << format(c_decorate_string)
                                % "prefix"
                                % std::string(matches.prefix().first, matches.prefix().second) << endl ;

                        counter++ ;
                        flags |= match_prev_avail ;
                        flags |= match_not_bob ;

                        if(matches[0].first == matches[0].second)
                                throw "If the string is null, it means regex_search has to be false !" ;
                        else
                                start = matches[0].second ;
                }
        }

        return 0 ;
}