[Haskell-cafe] Strong version of 'local' for reader monad

Hi all, Today I wanted this function strongLocal :: (MonadReader r1 m1, MonadReader r2 m2) => (r2 -> r1) -> m1 a -> m2 a Of course, after staring at this type for ten seconds I realized that it cannot be implemented. But I wondered whether anyone has any pointers to anything related, or if anyone has good ideas for a reasonable interface that would allow this. -Brent