PolyKinds is more permissive in GHC 8
The docs claim that the definition in section 9.11.10
data G (a :: k) where
GInt :: G Int
GMaybe :: G Maybe
"requires that -XTypeInType
be in effect", but this isn't the case.
The following compiles with GHC-8.0.2:
{-# LANGUAGE PolyKinds, GADTs #-}
data G (a :: k) where
GInt :: G Int
GMaybe :: G Maybe
The example does *not* compile with 7.10.3, so this seems to be a case where -XPolyKinds
has become more permissive in GHC 8 (as outlined in section 9.11.1).
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
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Blocking | |
CC | |
Operating system | |
Architecture |