TypeFamilies don't seem to play with LIberalTypeSynonyms
I'm trying to do some type level programming and want to use type families, but also LiberalTypeSynonyms to allow passing in a type level identity:
The following works:
{-# LANGUAGE LiberalTypeSynonyms #-}
type Id x = x
type Generic t (i:: * -> *) = i t
foo :: Generic Int Id
foo = undefined
However, replacing Generic with a type family does not work:
{-# LANGUAGE LiberalTypeSynonyms #-}
{-# LANGUAGE TypeFamilies #-}
type Id x = x
type family Generic t (i:: * -> *)
type instance Generic Int i = i Int
foo :: Generic Int Id
foo = undefined
Hopefully I'm not over looking anything, but I can't see why this doesn't work.
Trac metadata
Trac field | Value |
---|---|
Version | 7.0.4 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
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Blocking | |
CC | |
Operating system | |
Architecture |