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

Copy constructors and lenses


After examining our immutable example implementation, we are not able to say that it covers all the functionalities of the imperative approach. For instance, it does not provide us with a way to change the producer of a product. After all, we cannot change it.

Whenever we need to change any property of the product, we need to go through the following process:

let mexBananas = FunctionalProduct(name: bananas.name, 
                                   price: bananas.price, 
                                   quantity: bananas.quantity, 
                                   producer: Producer(name: "XYZ", 
                                                      address: "New 
                                                      Mexico, Mexico")) 

This solution is verbose and does not look nice. Let's examine how we can improve this process.

Copy constructors

The first solution is to provide a new init method that copies the current instance. This approach is called a copy...