Accessing members of a custom data type in Haskell

Question

Say I have the following custom data type and function in Haskell: ``` data Person = Person { first_name :: String, last_name :: String, age :: Int } deriving (Eq, Ord, Show) ``` If I want to create a function `print_age` to print a Person's age, like so: `print_age (Person "John" "Smith" 21)` , how would I write `print_age` to access the age parameter? I'm an Object Oriented guy, so I'm out of my element here. I'm basically looking for the equivalent of Person.age.

Accepted Answer

Function application is prefix, so `age person` would correspond to the `person.age()` common in OOP languages. The `print_age` function could be defined pointfree by function composition

```
print_age = print . age
```

or point-full

```
print_age person = print (age person)
```

Accessing members of a custom data type in Haskell

Solution

Problem