There already is a "lambda-case" syntax. "fact(match) = ..." is sugar for "fact = match -> ...". If one works, then so does the other. Personally I much prefer

There already is a "lambda-case" syntax. "fact(match) = ..." is sugar for "fact = match -> ...". If one works, then so does the other. Personally I much prefer the way I do it, because it is more powerful, works in more places, and requires no new syntactic forms.