TypeApplications-related GHC panic
{-# LANGUAGE DeriveFunctor, TypeApplications #-}
-- {-# Language ViewPatterns #-}
-- {-# Language InstanceSigs, ViewPatterns, TupleSections, GeneralizedNewtypeDeriving, TemplateHaskell, LambdaCase #-}
module D where
import Data.Coerce
import Control.Applicative
newtype A a = A (IO a)
deriving Functor
instance Applicative A where
pure = pure @(_ -> WrappedMonad A _) @(_ -> A _) pure
instance Monad A where
causes a panic
$ ghci -ignore-dot-ghci /tmp/a.hs
GHCi, version 8.3.20170605: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling D ( /tmp/a.hs, interpreted )
ghc: panic! (the 'impossible' happened)
(GHC version 8.3.20170605 for x86_64-unknown-linux):
repSplitAppTys
w0_a1xc[tau:4]
WrappedMonad A w0_a1xe[tau:4]
[]
Call stack:
CallStack (from HasCallStack):
prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1133:58 in ghc:Outputable
callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable
pprPanic, called at compiler/types/Type.hs:809:9 in ghc:Type
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
>
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |