functors.hs

{-# LANGUAGE OverloadedStrings #-}

tupleFromInputString :: String -> Maybe (String, String, Integer)
tupleFromInputString input = 
    if length stringComponents /= 3
    then Nothing
    else Just (stringComponents !! 0, stringComponents !! 1, age)
    where
        stringComponents = words input
        age = (read (stringComponents !! 2) :: Integer)

data Person = Person {
    firstName :: String,
    lastName :: String,
    age :: Integer
} deriving (Show)

personFromTuple :: (String, String, Integer) -> Person
personFromTuple (fName, lName, age) = Person fName lName age

convertTuple :: Maybe (String, String, Integer) -> Maybe Person
convertTuple Nothing = Nothing
convertTuple (Just t) = Just (personFromTuple t)