Compiler crash on invalid type class instance
If you try compiling the following code, the compiler crashes
class Foo a where
foo :: a -> ()
class Bar a where
bar :: a -> ()
instance (Foo a) => (Bar a -> ()) where
bar = undefined
*** Exception: compiler/rename/RnSource.lhs:430:14-81: Irrefutable pattern failed for pattern Data.Maybe.Just (inst_tyvars,
_,
SrcLoc.L _ cls,
_)
Trac metadata
Trac field | Value |
---|---|
Version | 7.4.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |