Book Image

Swift Functional Programming - Second Edition

By : Dr. Fatih Nayebi
Book Image

Swift Functional Programming - Second Edition

By: Dr. Fatih Nayebi

Overview of this book

Swift is a multi-paradigm programming language enabling you to tackle different problems in various ways. Understanding each paradigm and knowing when and how to utilize and combine them can lead to a better code base. Functional programming (FP) is an important paradigm that empowers us with declarative development and makes applications more suitable for testing, as well as performant and elegant. This book aims to simplify the FP paradigms, making them easily understandable and usable, by showing you how to solve many of your day-to-day development problems using Swift FP. It starts with the basics of FP, and you will go through all the core concepts of Swift and the building blocks of FP. You will also go through important aspects, such as function composition and currying, custom operator definition, monads, functors, applicative functors,memoization, lenses, algebraic data types, type erasure, functional data structures, functional reactive programming (FRP), and protocol-oriented programming(POP). You will then learn to combine those techniques to develop a fully functional iOS application from scratch
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface

Semigroups


In computer science, a Semigroup is an algebraic structure that has a set and a binary operation that takes two elements in the set and returns a Semigroup that has an associative operation. An associative operation is a binary operation that has a valid rule of replacement or transformation for expressions.

To start, we need to have a set and a specific binary operation, or we can make this behavior generic and define a protocol as follows:

protocol Semigroup { 
    func operation(_ element: Self) -> Self 
} 

Any type that conforms to this protocol requires us to implement the operation method. Here, self presents the type that is conforming to this protocol. For instance, we can extend Int to conform to the Semigroup protocol and provide a summation on itself:

extension Int: Semigroup { 
    func operation(_ element: Int) -> Int { 
        return self + element 
    } 
} 

We can test this as follows:

let number: Int = 5 
number.operation(3) 

This test does not ensure the associativity...