Bulat Ziganshin wrote:
i like O'Haskell because it's very close to traditional OO languages
in its ways to extend the types. why O'Haskell is not really
implemented as extension to GHC/Hugs? because it is not compatible
with System F?
O'Haskell *is* implemented as an extension of Hugs. Google
Daniel Brown <[EMAIL PROTECTED]> wrote:
> Jonathan Cast wrote:
> > Lennart Augustsson <[EMAIL PROTECTED]> wrote:
> >>
> >>foo :: Either a b -> Either () b
> >>foo (Left _) = Left ()
> >>foo x@(Right _) = x
> >>
> >>Since Haskell type checking doesn't use the information gained by
> >>pattern mat
Lennart Augustsson <[EMAIL PROTECTED]> wrote:
> There are, of course, type systems where my program works fine.
> O'Haskell is an example of a language with such a type system. In
> O'Haskell the Either type is defined like this:
>
>data Left a = Left a
>data Right a = Right a
On Sun, 26 Jun 2005, Daniel Fischer wrote:
> >m x y = if x==0 then 0 else x*y
>
> Plain
>
> foldr m 1
>
> does fine, in fact much better than
>
> foldl' (*) 1 . upTo (== 0),
>
> both in hugs and ghc, regarding speed and memory usage.
E.g.
foldr m 1 [a,b,c]
means
m a (m b (m c 1)))
That
Am Sonntag, 26. Juni 2005 06:06 schrieb Scott Turner:
> On 2005 June 25 Saturday 17:49, [EMAIL PROTECTED] wrote:
> >Simplified:
> >prodList xs = foldl (*) 1 xs
> >
> > But my original at least made some provision for short circuiting the
> > whole operation if the list contained a 0. As fa
On Sun, 26 Jun 2005, Daniel Fischer wrote:
> Am Samstag, 25. Juni 2005 21:22 schrieb Josh Hoyt:
> > Hello,
> >
> > I'm a new Haskeller, and I'm running into a problem attempting to
> > declare certain types as instances. I was attempting something that's
> >
> > effectively equivalent to:
> > > c
Scott Turner wrote:
> It's still possible to use fold and get short circuiting with good memory
> usage.
> upTo pred = foldr (\a -> \xs -> if pred a then [a] else a:xs) []
> prodList = foldl' (*) 1 . upTo (== 0)
> It might be considered cheating, but AFAICT the test for ==0 needs to be
> se
Am Samstag, 25. Juni 2005 21:22 schrieb Josh Hoyt:
> Hello,
>
> I'm a new Haskeller, and I'm running into a problem attempting to
> declare certain types as instances. I was attempting something that's
>
> effectively equivalent to:
> > class Foo a
> >
> > instance Foo (Either b b)
>
> but GHC comp
