foo.elm

{- a function that calculates the length of a rope -}
length :: Rope -> Int
length (Leaf s) = length s
length (Node l r) = length l + length r

{- a function that calculates the height of a rope -}
height :: Rope -> Int
height (Leaf s) = 1
height (Node l r) = 1 + max (height l) (height r)

{- a function that calculates the weight of a rope -}
weight :: Rope -> Int
weight (Leaf s) = 1
weight (Node l r) = weight l + weight r

{- a function that calculates the depth of a rope -}
depth :: Rope -> Int
depth (Leaf s) = 0
  
{- a function that calculates the balance of a rope -}
balance :: Rope -> Int
balance (Leaf s) = 0
balance (Node l r) = weight l - weight r

{- a function that calculates the balance factor of a rope -}
balanceFactor :: Rope -> Int
balanceFactor (Leaf s) = 0
balanceFactor (Node l r) = abs (balance l) + abs (balance r)

{- a function that calculates the average depth of a rope -}
averageDepth :: Rope -> Int
averageDepth (Leaf s) = 0
averageDepth (Node l r) = (depth l + depth r) `div` 2

{- a function that calculates the average balance factor of a rope -}
averageBalanceFactor :: Rope -> Int
averageBalanceFactor (Leaf s) = 0
averageBalanceFactor (Node l r) = (balanceFactor l + balanceFactor r) `div` 2