9 Jan
2008
9 Jan
'08
7:22 p.m.
On 1/9/08, Jorge Marques Pelizzoni <jpeliz@icmc.usp.br> wrote:
Given two type classes A t and B t, I'd like the typechecker to derive different A t instances depending exactly on whether t is an instance of B.
I think this would require some kind of whole-program analysis. While Haskell provides assertions that t is an instance of B (B t), it does *not* provide assertions that t is not an instance of B. This is because an instance of B can be declared by other modules at a later point (e.g. by someone who imports your module). -- Taral <taralx@gmail.com> "Please let me know if there's any further trouble I can give you." -- Unknown