Panic with PolyKinds + GADTs
This works:
data TypeRep (a :: k) :: * where
TyApp :: TypeRep a -> TypeRep b -> TypeRep (a b)
Whereas this (removing the obvious return kind of the datatype):
data TypeRep (a :: k) where
TyApp :: TypeRep a -> TypeRep b -> TypeRep (a b)
Gives this panic:
ghc-stage2: panic! (the 'impossible' happened)
(GHC version 7.5 for i386-unknown-linux):
metaTvRef
<<details unavailable>>
(The example is pretty much taken from Weirich, Hsu, and Eisenberg, but I haven't seen it reported here yet.)
Trac metadata
Trac field | Value |
---|---|
Version | 7.5 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |