David Menendez wrote:
instance Functor ((,) a) where
fmap f (x,y) = (x, f y)
If we get rid of '(,)' and redefine '(a,b)' as sugar for 'TCons a (TCons
b HNil)' (or whatever), then there is no way to declare the above instance. I don't think that's a deal-killer, but it is a disadvantage.
You need to swap the arguments to TCons...
data TCons l a = TCons !l a
Then:
instance Functor (TCons (TCons HNil a)) where fmap f (TCons (TCons HNil x) y) = TCons (TCons HNil (f x)) y)
Keean.
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