Looping default associated type family without UndecidableInstances
When I say
{-# LANGUAGE TypeFamilies #-}
module Bug where
import Data.Proxy
class C a where
type F a
type F a = F a
instance C Bool
x :: Proxy (F Bool)
x = Proxy
GHC just loops. Setting a low -ftype-function-depth
doesn't help. I actually don't terribly mind the looping (although aborting with an overflow would be better). But I don't like that it's possible without UndecidableInstances
in sight.
Trac metadata
Trac field | Value |
---|---|
Version | 7.10.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |