sophisticated problem

[gal064]

hi,

I came across with sophisticated problem.

I need to build pattern to string that built like this "1-2,3,4-5,6-7,8-11,12..."

Namely, collection of ranges that seperated with comma (,)
every range can be displayed by two varied numbers or by single number (range in size 1).

Note that range in size 1 display like this: 3 - not like this: 3-3.

I want to use in tr1::regex and get array string: ["1-2","3","4-5"...].

The real problem it is unlown how many ranges have (it's user input)
help me please solve this with regex.


thanks

[Cubbi]

Since you don't know how many ranges there are, you have to populate a data structure that can grow as needed, not an array. I'll use a vector of strings:

#include <string>
#include <iostream>
#include <vector>
#include <regex>

int main()
{
    std::string in = "1-2,3,4-5,6-7,8-11,12,100-123";
    std::regex re("(\\d+(-\\d+)?),?");

    std::vector<std::string> out( std::sregex_token_iterator(in.begin(), in.end(), re, 1),
                                  std::sregex_token_iterator() );
    for(auto& s: out)
        std::cout << "\"" << s << "\"\n";
}

Tested with Visual Studio 2012 and Clang++ 3.1/libc++-svn.

If you #include <boost/regex.hpp> and use boost::regex/boost::sregex_token_iterator, this will work with GCC as well.