odd panic with [()] >>> ()
While messing around with arrows in GHCi, I was surprised to see the following (ill-typed) code cause a panic:
___ ___ _
/ _ \ /\ /\/ __(_)
/ /_\// /_/ / / | | GHC Interactive, version 6.6, for Haskell 98.
/ /_\\/ __ / /___| | http://www.haskell.org/ghc/
\____/\/ /_/\____/|_| Type :? for help.
Loading package base ... linking ... done.
Prelude> :m Control.Arrow
Prelude Control.Arrow> [1, 2] >>> pure (+1)
ghc-6.6: panic! (the 'impossible' happened)
(GHC version 6.6 for i386-unknown-linux):
nameModule it{v aIS}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Further experimentation revealed that
[] >>> ()
is a type-error as expected, whereas
[()] >>> ()
causes a panic.
Trac metadata
Trac field | Value |
---|---|
Version | 6.6 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |