> On Wed, Mar 07, 2007 at 10:54:55PM +0000, Dave(a)haskell.org wrote:
> > io f = interact (unlines . f . lines)
> > showln = (++ "\n") . show
> >
> > -- Compute a simple cksum of a file
> >
> > main = interact $ showln . foldl' k 5381
> > where k h c = h * 33 + ord c
> >
> > ========
> >
> > Hugs> :load chksum.hs
> > ERROR "chksum.hs":15 - Unresolved top-level overloading
> > *** Binding : showln
> > *** Outstanding context : Show b
> >
> > Text.Printf>
> >
> > This error has been around for a while.
>
> Yes, it's a documented divergence from Haskell 98 in the handling of
> the Monomorphism Restriction.
>
> Workarounds are to give an explicit signature for showln, or to tweak
> the definition so it's a function:
>
> showln x = show x ++ "\n"
>
> (or, better)
>
> showln x = shows x "\n"
That Works.
Thanks,
Dave
