Difference between revisions of "Solution2.html"

From HaskellWiki
Jump to: navigation, search
m
m (Contents transferred to single solutions page)
 
Line 16: Line 16:
 
grandparent s = parent s >>= parent
 
grandparent s = parent s >>= parent
 
</haskell>
 
</haskell>
  +
  +
[[Category:Pages to be removed]]

Latest revision as of 08:43, 9 April 2021

parent :: Sheep -> Maybe Sheep
parent s = father s `mplus` mother s

grandparent :: Sheep -> Maybe Sheep
grandparent s = paternalGrandfather s `mplus` 
                paternalGrandmother s `mplus` 
                maternalGrandfather s `mplus` 
                maternalGrandmother s


This next solution will not work. If the sheep has a father and only a maternal grandparent, this function will return Nothing:

grandparent :: Sheep -> Maybe Sheep
grandparent s = parent s >>= parent