Bencode

#!/usr/bin/env raku

grammar Bencode {
    token TOP         { <elem>  {make $<elem>.made} }
    token elem        {
        | <integer>             {make $<integer>.Int}
        | <list>                {make $<list><elem>.List.map(*.made)}
        | <dictionnary>         {make %($<dictionnary><entry>.map({$_<key>.Str,$_<value>.made}).flat)}
        | <string>              {make $<string>.Str}
    }
    token integer     { i <(\-?\d+)> e }
    token string      { $<len> = \d+ ':' <(. ** {$<len>})> }
    token list        { l <( <elem>* )> e }
    token dictionnary { d <( $<entry> = (<key=string> <value=elem>)* )> e }
}

say Bencode.parse("i33e").made;
say Bencode.parse("i-32e").made;
say Bencode.parse("0:").made;
say Bencode.parse("6:foobar").made;
say Bencode.parse("le").made;
say Bencode.parse("li34ei23ee").made;
say Bencode.parse("de").made;
say Bencode.parse("d3:fooi33e3:bari-2ee").made;