On Thursday 10 March 2011 17:15:29, Bas van Dijk wrote: > On 10 March 2011 14:47, Daniel Fischer <daniel.is.fisc...@googlemail.com> wrote: > > If memory serves correctly, it's impredicative polymorphism. > > Indeed. For example the following also doesn't type check in GHC-7: > > foo :: (forall s. ST s a) -> a > foo st = ($) runST st > > Surprisingly the following does: > > foo :: (forall s. ST s a) -> a > foo st = runST $ st > > Because GHC contains a special rule for infix $. Also see: > > http://article.gmane.org/gmane.comp.lang.haskell.glasgow.user/19152 > > Bas
Bedankt. I sort of knew there was a special case for ($) because runST $ do ... works, but not exactly what was handled. So until I forget, I now know it's infix ($) and only that. Cheers, Daniel _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
