This book is for developers who are interested in learning about the advanced features of the Scala language. Basic knowledge of the Scala programming language is required to follow the instructions in this book.

Chapter 1, Setting up the Development Environment, shows you how to set up your development environment. You'll learn the basics of Scala, such as what the simple Scala program looks like and what a typical developer flow is. It'll also cover some aspects of testing your Scala program by using unit testing.

Chapter 2, Basic Language Features, covers classes and objects, traits, pattern matching, case class, and so on. You'll also implement your chatbot application by applying the object oriented concepts.

Chapter 3, Functions, covers functional programming with Scala and how object- oriented and functional approaches complete each other. You'll identify generic classes and also identify how to create user-defined pattern matching and why is it useful.

Chapter 4, Scala Collections, teaches you how to work with lists. Then, it covers some more relevant data structures. Finally, you'll look at how collections relate to monads and how you can use that knowledge to make some powerful abstractions in your code.

Chapter 5, Scala Type System, covers the type system and polymorphism. It'll also enable you to identify the different types of variance, which provides a way to constrain parameterized types. Then, you'll cover some advanced types such as abstract type members and option.

Chapter 6, Implicits, covers implicit parameters and implicit conversions. You'll be learning about how they work, how to use them, and what kind of benefits and perils they provide.

Chapter 7, Functional Idioms, covers the core concepts of functional programming like Pure functions, immutability, and higher-order functions. It'll also cover two popular functional programming libraries called Cats and Doobie, and use them to write some interesting programs.

Chapter 8, Domain Specifc Languages, covers how Scala makes it possible to write powerful DSLs by providing a few interesting language features. Then, it'll cover a DSL that you'll very likely be using if you're going to work with Scala professionally.

Finally, you'll implement your own DSL.

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows:

Here, we define an immutable value with the name name, which keeps the user's  stdin.

The main method is an essential part of any Scala program.

A block of code is set as follows:

package com.packt.courseware
import scala.io.StdIn
object Chatbot1
{
   def main(args: Array[String]):Unit =  {
     // do something
   }
}

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: " Select Run sbt-test."

Important new programming terms are shown in bold. Conceptual terms are shown in italics.

Before we start this book, we'll install IntelliJ IDE.

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