Infinite context reduction stack overflow
The contrived example below gets a Context reduction stack overflow error no matter how big you make the context reduction stack. I'm not sure whether this constitutes a fixable bug or not.
{-# LANGUAGE FunctionalDependencies, MultiParamTypeClasses #-}
import Control.Monad.State (StateT)
class C1 a b c | a -> b
class C2 a b c
data T b = T
f1 :: (Monad m, C1 a b c) => a -> StateT (T b) m a
f1 f = undefined
f2 :: (Monad m, C1 a1 b1 c1, C2 a2 b2 c2) => a1 -> StateT (T b2) m a2
f2 fm = f1 fm >>= return . undefined
Trac metadata
Trac field | Value |
---|---|
Version | 7.0.3 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
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Blocking | |
CC | |
Operating system | |
Architecture |