List<Type> sigToTypeParams() {
        List<Type> tvars = List.nil();
        if (signature[sigp] == '<') {
            sigp++;
            int start = sigp;
            sigEnterPhase = true;
            while (signature[sigp] != '>')
                tvars = tvars.prepend(sigToTypeParam());
            sigEnterPhase = false;
            sigp = start;
            while (signature[sigp] != '>')
                sigToTypeParam();
            sigp++;
        }
        return tvars.reverse();
    }