On 06/08/10 15:59, Johan Tibell wrote:
> There are a few functions on Maps that could be implemented on IntMaps

> but aren't: [...]

Isn't it time to seriously think about defining maps as a type family to
avoid this sort of incompatibility once and for all and to enable GHC to
automatically use IntMap wherever appropriate?

class Map k where
data Map k :: * -> *
empty ...
insert ...

instance Map Int where
data Map Int v = Data.IntMap.IntMap v
...

instance (Ord k) => Map k where
data Map k v = Data.Map.Map k v
...

Or something similar?

Definitely worth researching. I think we should pursue this as a separate track and fix what we have in the mean time.