HASKELL - Write a function called prob1, that parses a String and returns a PExp. Input strings for this function are tokens that are either numbers or operators separated by whitespace. Numbers can be an arbitrarily long strings of digits.

data Op = Val Int | Plus | Minus | Mul | IntDiv deriving (Show, Eq)

type PExp = [Op]

Homework3*> prob1 "200 + -* /" Val 200,Plus,Minus ,Mul, IntDiv] Homework3*> probi"+ -* 200" [Plus,Minus,Mul,IntDiv,Val 200] Homework3*> prob1 "200 + -* /" Val 200,Plus,Minus ,Mul, IntDiv] Homework3*> probi"+ -* 200" [Plus,Minus,Mul,IntDiv,Val 200]