At Sun, 23 Oct 2011 12:03:23 -0300, Eric Tanter wrote: > However, of course, this does not work if the return type is compatible with > Void: > > (: f ((U String Integer) -> Any)) > (define (f x) > (cond > [(string? x) (string=? x "hi")] > [(exact-nonnegative-integer? x) (= x 7)])) > > typechecks.
Using `Any' as a return type is something I only do as a quick and dirty solution. I assume that if you care enough to want case exhaustiveness checking, you probably care enough to nail down your return types precisely. If you actually _need_ to use `Any' as a return type, this is something that really should stick out and be documented. > I guess you could include a type Invalid, which is NOT a subtype of Any. That sounds like a bad idea. Vincent _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
