Building maps with parsnip

To further demonstrate the brevity and power of Parsnip, here is the code for a simple grammar which accepts strings of the format "key1 = value1; key2 = value2;". The return value of the parser is an std::map of the key-value pairs.

Parser<string, Tuple2<string, string>>::type single_pair = letters >> skip(token_ch('=')) >>  letters >> skip_ch(';');

Parser<string, std::map<string, string>>::type pair_parser = many< BuildMap<string, string> >(token(single_pair));

That's it!