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

Defining enumerations


In Swift, an enumeration defines a common type for related values and enables us to work with those values in a type-safe way. Values provided for each enumeration member can be a String, Character, Integer, or any floating-point type.

The following example presents a simple definition of an enum:

enum MLSTeam { 
    case montreal 
    case toronto 
    case newYork 
    case columbus 
    case losAngeles 
    case seattle 
} 

let theTeam = MLSTeam.montreal 

enum MLSTeam provides options for MLS teams. We can choose only one of the options each time; in our example, montreal is chosen.

Multiple cases can be defined and separated by a comma on a single line:

enum MLSTeam { 
    case montreal, toronto, newYork, columbus, lA, seattle 
} 
var theTeam = MLSTeam.montreal 

The type of theTeam is inferred when it is initialized with MLSTeam.montreal. As theTeam is already defined, we can change it with a shorter syntax as follows:

theTeam = .newYork 

In Swift, enums are very powerful...