Book Image

Kotlin Standard Library Cookbook

By : Samuel Urbanowicz
Book Image

Kotlin Standard Library Cookbook

By: Samuel Urbanowicz

Overview of this book

For developers who prefer a more simplistic approach to coding, Kotlin has emerged as a valuable solution for effective software development. The Kotlin standard library provides vital tools that make day-to-day Kotlin programming easier. This library features core attributes of the language, such as algorithmic problems, design patterns, data processing, and working with files and data streams. With a recipe-based approach, this book features coding solutions that you can readily execute. Through the book, you’ll encounter a variety of interesting topics related to data processing, I/O operations, and collections transformation. You’ll get started by exploring the most effective design patterns in Kotlin and understand how coroutines add new features to JavaScript. As you progress, you'll learn how to implement clean, reusable functions and scalable interfaces containing default implementations. Toward the concluding chapters, you’ll discover recipes on functional programming concepts, such as lambdas, monads, functors, and Kotlin scoping functions, which will help you tackle a range of real-life coding problems. By the end of this book, you'll be equipped with the expertise you need to address a range of challenges that Kotlin developers face by implementing easy-to-follow solutions.
Table of Contents (11 chapters)

Restricting property updates with the Vetoable delegate

In this recipe, we are going to explore the usage of the Vetoable delegate offered by the standard library. Similar to the Observable, the Vetoable tracks the changes applied to the delegated property. However, the Vetoable delegate is able to refuse to update the delegated property if a predefined update condition is not met. We are going to declare a variable of the Int type and specify the update condition, allowing us to update the variable only if the absolute value of change is greater than or equal to 10.

How to do it...

  1. Let's start by defining an initial value for the temperature variable:
val initialValue = 1
  1. Define the update condition for the observed...