use Test; my Str() @vowels = <a e i o u>; multi split-string(Str() @string) { so @string>>.lc.grep(@vowels.one) %% 2 } multi split-string(Str() $string) { $string.lc.comb(/@vowels/) %% 2 } for [ "perl", False, "book", True, "good morning", True, ] -> $string, $is { is $string.&split-string, $is, "$string -> $is"; is $string.comb.&split-string, $is, "$string.comb() -> $is"; }