Anyway, do you think it is feasible to have a flag such as
-fallow-unsafe-type-families for users to use at their own risk? (supposing
we know how to guarantee these constraints).
I speak for my own, there are currently some nice thinks that I can only
accomplish with partially applied type synonyms in type families, otherwise
code starts to get dummier in terms of type contexts and context variables.
Thanks,
hugo
On Sun, Mar 30, 2008 at 4:14 AM, Hugo Pacheco
On Sun, Mar 30, 2008 at 3:54 AM, Manuel M T Chakravarty < chak@cse.unsw.edu.au> wrote:
Hugo Pacheco:
Yes, but doesn't the confluence problem only occur for type synonyms that ignore one or more of the parameters? If so, this could be checked...
You can't check this easily (for the general case).
I was most interested in knowing that this assumption was enough, and it looks like it does.
Given
type family G a b type FList a x = G a x type instance F [a] = FList a
Does FList ignore its second argument? Depends on the type instances of G.
Manuel
I haven't thought of that, thanks for the example.
hugo