[Haskell-cafe] Context for type parameters of type
Keith.Wansbrough at cl.cam.ac.uk
Tue Mar 30 13:05:55 EST 2004
> My question was why he doesn't believe that. My definition
> data (Num a) => VList a = VList [a]
> clearly states that VLists will ever get types of class Num as
Ah. Constraints on datatype declarations are a misfeature of Haskell, and
have no useful effect. You shouldn't use them.
Keith Wansbrough <kw217 at cl.cam.ac.uk>
University of Cambridge Computer Laboratory.
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