8 Apr
2009
8 Apr
'09
4:21 p.m.
|iterateM 0 _ _ = return [] |iterateM n f i = (i:) <$> (iterateM (n-1) f =<< f i) |iterateM' n f i = sequence . scanl (>>=) (return i) $ replicate n f These function are not the same (sequence of scanl? try using print in f). Also, I seriously hope you are not looking for this line noise:-) iterateM' = (foldr op (const $ return []) .) . replicate where f `op` x = uncurry (<$>) . ((:) &&& ((x =<<) . f)) Because if you do, your penance for using it would involve demonstrating that this is equivalent (+-1), or not (and do not mention my name anywhere near it!-) Claus