| >> I compiled my code with -fdicts-strict. | > | > What is this actually supposed to do? It seems the documentation is | missing: | > http://www.haskell.org/ghc/docs/latest/html/users_guide/options- | optimise.html#options-f | | >From reading the source code, it appears to make any dictionary fields | of GADTs strict. So the dictionary for Eq in: | | data EqDict a where | EqDict :: Eq a => EqDict a | | Will be a strict field. dicts-strict is supposed to make any function that takes a dictionary argument strict in that argument. In principle this is a useful optimization, since dictionaries never diverge, but I have never really followed through on it. One reason is that the picture is more cloudy with recursive dictionaries. In any case, I have no looked at it for ages so it might have bit-rotted. If anyone wants to give it a whirl, do have a go, and look at the Core you get. Simon