I haven't tried to run the code, but my first bet is that, due to the rank-2 polymorphism of ST, you should use parenthesis instead of $ in the case of runST.
On Sun, Aug 24, 2008 at 3:25 PM, Andrew Coppin <[EMAIL PROTECTED]> wrote: > colour_grid :: (Particle -> IO ()) -> Grid ph -> IO () > colour_grid fn g = sequence_ $ runST $ do > ps <- grid_coords g > > mapM > (\pix -> do > particle <- read_grid g pix > return $ fn particle > ) > ps > > When I attempt to run this, GHCi just gives me a very cryptic type checker > error. I can't figure out what's wrong here. As far as I can tell, this > should run... > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
