Data instance for Data.Map is incomplete
There's no dataCast1 defined for Data.Map. This makes the ext1
family unusable with Maps, since ext
is built on dataCast rather than gcast.
Observe:
Prelude Data.Data Data.Generics Data.Map> gcast1 (Just empty :: forall d. (Data d) => Maybe (Map Int d)) :: Maybe (Maybe (Map Int Int))
Just (Just (fromList []))
Prelude Data.Data Data.Generics Data.Map> dataCast1 (Just empty :: forall d. (Data d) => Maybe (Map Int d)) :: Maybe (Maybe (Map Int Int))
Nothing
Trac metadata
Trac field | Value |
---|---|
Version | 7.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries/base |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |