🚀 Haskell Types Overview

Welcome to the ultimate guide to Haskell types! This document covers Sum Types and all other major types in Haskell, with detailed explanations and practical examples. Let’s dive in! 🚀

📖 1. Sum Types

Sum types represent values that can be one of many alternatives. They’re perfect for modeling the data with multiple “cases.”

Example of a Sum Type

data Shape = Circle Float | Rectangle Float Float | Triangle Float Float Float
Example of a Product Type

data Point = Point Int Int
Example of a Record Type

data Employee = Employee { name :: String, age :: Int }
Example of a Newtype

newtype UserId = UserId Int
Example of a Polymorphic Type

data Box a = Box a
Example of an Enum Type

data Color = Red | Green | Blue
Example of a Recursive Type

data List a = Empty | Cons a (List a)
Example of a Phantom Type

data Phantom a = Phantom
Example of an Existential Type

data Showable = forall a. Show a => MkShowable a
Example of a GADT

data Expr a where
IntLit :: Int -> Expr Int
BoolLit :: Bool -> Expr Bool
Add :: Expr Int -> Expr Int -> Expr Int
If :: Expr Bool -> Expr a -> Expr a -> Expr a
Example of a Type Synonym

type StringAlias = String
Example of a Tuple

pair = (1, “Hello”)
Example of a List

numbers = [1, 2, 3, 4]
Example of Maybe Type

data Maybe a = Nothing | Just a
Example of Either Type

data Either a b = Left a | Right b
Example of Unit Type

unit = ()
Example of a Function Type

add :: Int -> Int -> Int
add x y = x + y

🔑 Conclusion

Haskell offers a wide variety of types to model > data with precision, flexibility, and safety. From simple Sum Types to powerful GADTs, you can choose the best tool for the job. Explore these types to write robust and expressive Haskell programs! 🛠️✨