[Haskell] Should the following program be accepted by ghc?
jonathanccast at fastmail.fm
Wed Jan 16 22:35:49 EST 2008
On 16 Jan 2008, at 5:59 PM, Bruno Oliveira wrote:
> Maybe a more slightly more honest type for "decomp" would be:) :
> decomp :: Injective f => f a :=: f b -> a :=: b
Perhaps. Although you *have* to have an implicit Injective
constraint on all type constructor variables to pull of Haskell's
first-order unification trick, so it's not a constraint that will be
relaxed soon (or, most likely, ever).
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