On Mon, May 30, 2011 at 9:01 AM, John Ky <newho...@gmail.com> wrote: > instance Monoid (Stream a) where > mempty = Chunks mempty > mappend (Chunks xs) (Chunks ys) = Chunks (xs ++ ys) > mappend _ _ = EOF > > I guess, it shows my lack of experience in Haskell, but my question is, why > is writing the code this way preferred over say writing it like this:
I don't care for the inconsistency in this example, using both mempty and (++). Your version is at least consistent, but I'd actually prefer to use mappend instead of (++) here, because it makes it clear that this isn't actually defining a "new" Monoid instance, just translating an existing instance for the constructor parameter to work for the surrounding data type. - C. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
