-XPolyKinds causes "*** Exception: Prelude.(!!): index too large"
The following program will compile fine:
{-# OPTIONS_GHC -Wall #-}
{-# Language DeriveFunctor #-}
--{-# Language PolyKinds #-}
module Bug where
data V a = V [a] deriving Functor
data C x a = C (V (P x a)) deriving Functor
data P x a = P (x a) deriving Functor
But when PolyKinds is enabled, GHC crashes with
$ ghc Bug.hs
[1 of 1] Compiling Bug ( Bug.hs, Bug.o )
Bug.hs:9:37:ghc: panic! (the 'impossible' happened)
(GHC version 7.8.0.20140228 for x86_64-unknown-linux):
Prelude.(!!): index too large
Trac metadata
Trac field | Value |
---|---|
Version | 7.8.1-rc2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |