There are basically two options here: 1. If you just use `cond' with no `else', you get a type error when your cases are not exhaustive. For example:
(: f ((U String Integer) -> Boolean)) (define (f x) [(string? x) (string=? x "hi")] [(exact-nonnegative-integer? x) (= x 7)]) This program will fail to typecheck. 2. For the particular case of the PLAI `cases' form, Eli and I have built something for his class which uses Typed Racket, but the exhaustiveness checking is done by `cases' itself. Lots more about that is available from Eli's class web page [1], and I'm sure he'd be happy to give you the code. [1] http://pl.barzilay.org/ On Thu, Oct 20, 2011 at 10:48 AM, Eric Tanter <etan...@dcc.uchile.cl> wrote: > Hi again, > > Is there a mechanism to do an exhaustive type case? > > I know I can use (cond [(type-pred? v) ...] > [...]) > > but of course I have no guarantee that I am exhaustive (and of course, doing > pattern matching to destruct the value would be even nicer). > > Basically, I guess I'm after the typed version of PLAI's type-case. > > Thanks, > > -- Éric > > > > _________________________________________________ > For list-related administrative tasks: > http://lists.racket-lang.org/listinfo/users > -- sam th sa...@ccs.neu.edu _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
