On Tue, Feb 06, 2007 at 09:39:22AM +0000, Duncan Coutts wrote:
> On Mon, 2007-02-05 at 19:26 -0800, Stefan O'Rear wrote:
> > I have a structure:
> >
> > data Attr = Attr { fg :: !Color,
> > bg :: !Color,
> > bold :: !Bool,
> > blink :: !Bool,
> > rv :: !Bool,
> > halfBright :: !Bool,
> > underline :: !Bool
> > } deriving(Eq,Show,Ord)
> >
> > newtype Color = Color Int deriving(Eq,Show,Ord)
>
>
> > (Also, GHC seems unable to unbox strict fields that are newtypes. Can
> > this be done, or should I abandon type safety and use type synonyms?)
>
> You have to tell GHC that you want fields to be unboxed (this is because
> it's not always an optimisation). You can either do it for all strict
> fields in the whole module by using the -funbox-strict-fields flag, or
> on a per field basis with:
>
> data Attr = Attr { fg :: {-# UNPACK #-} !Color,
> bg :: {-# UNPACK #-} !Color,
> ...
I was using -funbox-strict-fields, it was a reporting bug. Sorry.
Stefan
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
