On Thu, Jul 3, 2008 at 10:14 PM, Claus Reinke
actually, GHC gives me "could not deduce Blah f a from Blah f1 a"
first. It seems that desugaring type function notation into an additional constraint helps, so there's something odd going on:
Silly me, I didn't paste the whole type error. Yes, GHC gives both. I should add that I tested this under GHC 6.8.2. But this is known not to work with a (one/two months old) GHC head.
yes, I tested with 6.9.20080514. And just in case my phrasing was unclear: desugaring the type function application makes the error go away, so you have a workaround.
Thanks for highlighting this. Indeed I missed it, and it makes my example work. Cheers, Alexey
It is just confusing that this example shows that the "desugaring" is not a desugaring, in the current implementation..
Claus