In the last chapter, we looked at functions, recursions, and higher order functions. In this chapter, we will look at another important aspect of the Haskell language. The data types in Haskell are very expressive and are used to express very intuitive data structures. We have seen that Haskell works by reducing or computing the values from expressions (which are formed by applying functions to values and so on). For each value, there is some type associated with it. In fact, we can also say that each type represents a collection or a set of values.
In this chapter, we will look at basic algebraic types. The term algebraic type came from the association between the values of a type and algebraic operations such as sum and product. We will also look at recursively defined types, where the type is included in the definition of the type itself. We will also look at...