#include "word_count.h"

#include <algorithm>


namespace word_count {

using namespace std;


Words words(const string &str, const locale &loc)
{
    Words result;

    string::const_iterator begin, end, i;
    i = end = str.begin();
    begin = str.end();

    for (; i != str.end(); ++i) {

        bool is_alpha_or_digit = isalpha(*i, loc) || isdigit(*i, loc);
        bool is_word_char = is_alpha_or_digit || *i == '\'';

        if (is_alpha_or_digit) {

            if (begin > end)
                begin = i;

            end = next(i);
        }

        if (!is_word_char || next(i) == str.end()) {

            if (begin < end) {

                string word;
                word.reserve(distance(begin, end));
                transform(begin, end, back_inserter(word),
                            [=](char c){return tolower(c, loc);});

                result[word]++;

                begin = str.end();
            }
        }
    }

    return result;
}

}