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)

Sorting data with custom comparators

In this recipe, we are going to explore the support for sorting collections' elements by their properties.

Getting started

Let's assume we are dealing with the two collections of the Message type declared as follows:

data class Message(val text: String,
val sender: String,
val receiver: String,
val time: Instant = Instant.now())

These are provided by the allMessages variable:

val sentMessages = listOf(
Message("I'm programming in Kotlin, of course",
"Samuel",
"Agat",
Instant.parse("2018-12-18T10:13:35Z")),
Message(&quot...