ghc panics on accessing a labeled field
GHC panics about a following code:
class Bar a where
bar :: Foo a -> Foo a
bar x = x { foo = [] }
data Foo a = Bar a => Foo { foo :: [a] }
GHC says:
Chasing modules from: Main.hs Compiling Main ( Main.hs, Main.o ) ghc: panic! (the `impossible' happened, GHC version 6.4.2): types/Type.lhs:(1107,0)-(1108,77): Non-exhaustive patterns in function zip_ty_env
Trac metadata
Trac field | Value |
---|---|
Version | 6.4.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |