Book Image

Learn Kotlin Programming - Second Edition

By : Stephen Samuel, Stefan Bocutiu
Book Image

Learn Kotlin Programming - Second Edition

By: Stephen Samuel, Stefan Bocutiu

Overview of this book

Kotlin is a general-purpose programming language used for developing cross-platform applications. Complete with a comprehensive introduction and projects covering the full set of Kotlin programming features, this book will take you through the fundamentals of Kotlin and get you up to speed in no time. Learn Kotlin Programming covers the installation, tools, and how to write basic programs in Kotlin. You'll learn how to implement object-oriented programming in Kotlin and easily reuse your program or parts of it. The book explains DSL construction, serialization, null safety aspects, and type parameterization to help you build robust apps. You'll learn how to destructure expressions and write your own. You'll then get to grips with building scalable apps by exploring advanced topics such as testing, concurrency, microservices, coroutines, and Kotlin DSL builders. Furthermore, you'll be introduced to the kotlinx.serialization framework, which is used to persist objects in JSON, Protobuf, and other formats. By the end of this book, you'll be well versed with all the new features in Kotlin and will be able to build robust applications skillfully.
Table of Contents (21 chapters)
Free Chapter
1
Section 1: Fundamental Concepts in Kotlin
5
Section 2: Practical Concepts in Kotlin
15
Section 3: Advanced Concepts in Kotlin

Type reification

A reifiable type is the name given to a type when its type information can be inspected at runtime. Examples of types that are considered reified are non-generic types, such as String or BigDecimal. On the JVM, primitives such as Boolean or double are also considered to be reified.

A non-reifiable type is one that has suffered the effect of type erasure so that some, or all, of its type information has been lost at runtime. Examples of this are parameterized types, such as List<String> and List<Boolean>, which look the same at runtime.

We've seen how erasure removes types at runtime and the issues this can cause. Now, we will look at a way that we can work around some of those issues. Kotlin has introduced a feature called type reification, which enables type information to be kept at runtime for inline functions.

To use this feature, we add reified...