libs/regex/example/snippets/captures_example.cpp
/*
*
* Copyright (c) 2003-2004
* John Maddock
*
* Use, modification and distribution are 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)
*
*/
/*
* LOCATION: see http://www.boost.org for most recent version.
* FILE captures_example.cpp
* VERSION see <boost/version.hpp>
* DESCRIPTION: Demonstrate the behaviour of captures.
*/
#include <boost/regex.hpp>
#include <iostream>
void print_captures(const std::string& regx, const std::string& text)
{
boost::regex e(regx);
boost::smatch what;
std::cout << "Expression: \"" << regx << "\"\n";
std::cout << "Text: \"" << text << "\"\n";
if(boost::regex_match(text, what, e, boost::match_extra))
{
unsigned i, j;
std::cout << "** Match found **\n Sub-Expressions:\n";
for(i = 0; i < what.size(); ++i)
std::cout << " $" << i << " = \"" << what[i] << "\"\n";
std::cout << " Captures:\n";
for(i = 0; i < what.size(); ++i)
{
std::cout << " $" << i << " = {";
for(j = 0; j < what.captures(i).size(); ++j)
{
if(j)
std::cout << ", ";
else
std::cout << " ";
std::cout << "\"" << what.captures(i)[j] << "\"";
}
std::cout << " }\n";
}
}
else
{
std::cout << "** No Match found **\n";
}
}
int main(int , char* [])
{
print_captures("(([[:lower:]]+)|([[:upper:]]+))+", "aBBcccDDDDDeeeeeeee");
print_captures("a(b+|((c)*))+d", "abd");
print_captures("(.*)bar|(.*)bah", "abcbar");
print_captures("(.*)bar|(.*)bah", "abcbah");
print_captures("^(?:(\\w+)|(?>\\W+))*$", "now is the time for all good men to come to the aid of the party");
print_captures("^(?>(\\w+)\\W*)*$", "now is the time for all good men to come to the aid of the party");
print_captures("^(\\w+)\\W+(?>(\\w+)\\W+)*(\\w+)$", "now is the time for all good men to come to the aid of the party");
print_captures("^(\\w+)\\W+(?>(\\w+)\\W+(?:(\\w+)\\W+){0,2})*(\\w+)$", "now is the time for all good men to come to the aid of the party");
return 0;
}