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At that point aren't you just doing normal Racket pattern matching? (match (list (> x y) (stringp foo) (oddp n)) [(list #t _ #t

• kazinator 9y ago
  There you go. That just needs a very light syntactic sugar and it's there. The elements of the lists are constants, so you want to use a literal, and the quoting of that can all be hidden. The (list ...) around the incoming expressions can be trivially hidden also. The one thing I suspect match probably doesn't do is feature a fall-through mechanism that I alluded to; say we want (other-thing) for its side-effect, and then still evaluate (etc) if (> x y). (Under no circumstances do we want fall-through to be opt-out, like in the C switch statement with its forgotten break bugs, but opt-in.) Also, this mechanism could be optimized. Since the pattern lists must only contain #t, #f and _, they can be validated to contain nothing else. Accordingly, they can be arithmetically encoded (two bits per symbol), and subject to a numeric dispatch. '(#f _ #t) is a six bit number; '(_ #f #f) is another six-bit number and so on. Arguably, match itself could do that, but it's rather specialized.