GHC Panic: Visible type application + function type @(_ -> _)
$ ghci -XTypeApplications -ignore-dot-ghci
GHCi, version 8.3.20170605: http://www.haskell.org/ghc/ :? for help
Prelude> :t fmap @(_ -> _)
ghc: panic! (the 'impossible' happened)
(GHC version 8.3.20170605 for x86_64-unknown-linux):
repSplitAppTys
w0_a1pF[tau:2]
w0_a1pH[tau:2]
[]
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
Prelude>
Doesn't happen with other types it seems, probably something to do with levity polymorphism.
Trac metadata
Trac field | Value |
---|---|
Version | 8.3 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
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Blocking | |
CC | |
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