Chapter 8 - Making Our Own Types and Typeclasses

Chapter 8 - Making Our Own Types and Typeclasses

1. Algebraic data types intro

   • For the creation of a type is the word "data"
     • For example, the bool type is defined the following way:
       • data Bool = False | True

2. Record syntax

   • Similar to the creation of a POO object
     • data Person = Person String String Int Float String String deriving (Show)

3. Type parameters

   • Data builders and type they can take parameters and produce a new value.

4. Type synonyms

   • They are a way of defining that 2 types are equal and interchangeable, for example:
     • type String = [Char]

5. A yes-no typeclass

   • Define a function
     • This function takes a value of any kind that can express some truth value and tells us if it is true or not.

6. Kinds and some type-foo

   • We talk about type constructors take other types as parameters and end up producing specific types
     • Like the functions that take values ​​as parameters and return value