Effective Haskell

Exercises

Planting Trees

Consider a binary tree with a type:

data BinaryTree a = Leaf | Branch (BinaryTree a) a (BinaryTree a)

Write the definition of the binary tree type, and then add the following functions:

-- Turn a binary tree of strings into a pretty-printed string
showStringTree :: BinaryTree String -> String

-- Add a new integer into a binary tree of integers
addElementToIntTree :: BinaryTree Int -> Int -> BinaryTree Int

-- Check to see if an int value exists in a binary tree of ints
doesIntExist :: BinaryTree Int -> Int -> Bool

Eval Division by Zero

Write a new version of your eval function named safeEval that will return an error if the user tries to divide by zero. It should have ...