On Mon, 2009-01-12 at 20:24 -0200, rodrigo.bonifacio wrote: > Hi all, > > I'm trying to build a library that has the following code: > > hasTypeOf (TermRep (dx,_,_)) (x::t) > = ((fromDynamic dx)::Maybe t) > Could you do something like this?
Enforce the types with a signature: hasTypeOf :: (Typeable t) => Dynamic -> t -> Maybe t hasTypeOf x _ = fromDynamic x > hasTypeOf (toDyn (2::Int)) (undefined::Integer) Nothing > hasTypeOf (toDyn (2::Int)) (undefined::Int) Just 2 Or if you just want boolean result: hasTypeOf x y = typeOf y == dynTypeRep x
rcmAttmntN3MDzg
Description: micalg/pgp-sha1
_______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
