3 Nov
2011
3 Nov
'11
10:43 a.m.
On 3 November 2011 14:56, Ryan Newton
Aside: The problem with collections is that we don't have the programming language means to do this well yet (although soon!). The issue is that we want to declare a type class where the context of the methods depends on the instance e.g. class MapLike m where type Ctx :: Context -- Can't do this today! insert Ctx => k -> v -> m -> m Java et all cheats in their container hierarchy by doing unsafe casts (i.e. they never solved this problem)!
Ah, interesting. Is there a proposal to do this?
Even better: it's already implemented by Max Bolingbroke and will be in ghc-7.4! See: http://hackage.haskell.org/trac/ghc/wiki/Status/Oct11 So be patient and wait for your Christmas present ;-) Bas