Derived functor instance for void types handles errors badly
If we have
data V a deriving (Functor)
and we evaluate
f <$> (error "Boo!" :: Void)
we should really get a "Boo" error, rather than a useless "Void fmap" one. The offending code is in compiler/typecheck/TcGenFunctor.hs
.
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1 |
Type | FeatureRequest |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |