[Haskell-cafe] Re: [Haskell] [ANN] Safe Lazy IO in Haskell

[Ryan Ingram]

Minor addition, optimize >>
(I couldn't help myself!)

  -- ryan

> instance Ord b => ConstrainedBind (S.Set a) (S.Set b) where
>    type BindElem (S.Set a) = a
>    m >>= f = S.unions $ map f $ S.toList m
>    m >> n  = if S.null m then S.empty else n