Book Image

Functional Kotlin

Book Image

Functional Kotlin

Overview of this book

Functional programming makes your application faster, improves performance, and increases your productivity. Kotlin supports many of the popular and advanced functional features of functional languages. This book will cover the A-Z of functional programming in Kotlin. This book bridges the language gap for Kotlin developers by showing you how to create and consume functional constructs in Kotlin. We also bridge the domain gap by showing how functional constructs can be applied in business scenarios. We’ll take you through lambdas, pattern matching, immutability, and help you develop a deep understanding of the concepts and practices of functional programming. If you want learn to address problems using Recursion, Koltin has support for it as well. You’ll also learn how to use the funKtionale library to perform currying and lazy programming and more. Finally, you’ll learn functional design patterns and techniques that will make you a better programmer.By the end of the book, you will be more confident in your functional programming skills and will be able to apply them while programming in Kotlin.
Table of Contents (22 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Index

Local delegates


Delegation is powerful, we've already seen that, but think of a common situation where inside a method we declare and initialize a property, then we apply a logic which will either use the property or will continue without it. For example, the following is such a program:

fun useDelegate(shouldPrint:Boolean) { 
    val localDelegate = "Delegate Used" 
    if(shouldPrint) { 
        println(localDelegate) 
    } 
     
    println("bye bye") 
} 

In this program, we will use the localDelegate property, only if the shouldPrint value is true, else we won't use it. But it would always take space in memory since it is declared and initialized. An option to avoid this memory blockage is to have the property inside the if block, but it's a simple dummy program, and here we can easily afford to move the variable declaration inside the if block, whereas in many real-life scenarios, moving the variable declaration inside the if block is not possible.

So, what's the solution? Yes, using...