strings and bytes and unpack, oh my!

    # Performs URI escaping so that you can construct proper
    # query strings faster.
    sub escape($s) is export {
        # RAKUDO: Need 'H2' in Rakudo's unpack before this works
        # RAKUDO: Also need to turn the string into bytes before letting
        #         the substitution loose on it.
        return (~$s).subst(/<-[ a..zA..Z0..9_.\-]>+/,
            { '%' ~ unpack(~$/, "H2" x $/.chars).join('%').uc },
            :global).trans(' ' => '+');
    }