Achim Schneider <[EMAIL PROTECTED]> wrote: > zeroIf :: MonadPlus m => (a -> Bool) -> m a -> m a > zeroIf f m = m >>= (\nz -> if f nz then mzero else m) > > zeroZero :: (MonadPlus m, Num a) => m a -> m a > zeroZero = zeroIf (==0) > > makes it interesting again as you can't construct a Just value with > it.
d'oh. return nz. /me hides under a monad. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
