patClean :: Pattern -> Pairs Pattern (EndoKleisli' Maybe Expression)
patClean p@PWildCard = return (p, \_ -> return LitUnit)
patClean :: Pattern -> Pairs Pattern (EndoKleisli' Maybe Expression)
patClean p@PWildCard = return (p, \_ -> return LitUnit)
patClean p@PWildCard = return (p, \_ -> return LitUnit)