Book Image

Professional Scala

By : Mads Hartmann, Ruslan Shevchenko
Book Image

Professional Scala

By: Mads Hartmann, Ruslan Shevchenko

Overview of this book

This book teaches you how to build and contribute to Scala programs, recognizing common patterns and techniques used with the language. You’ll learn how to write concise, functional code with Scala. After an introduction to core concepts, syntax, and writing example applications with scalac, you’ll learn about the Scala Collections API and how the language handles type safety via static types out-of-the-box. You’ll then learn about advanced functional programming patterns, and how you can write your own Domain Specific Languages (DSLs). By the end of the book, you’ll be equipped with the skills you need to successfully build smart, efficient applications in Scala that can be compiled to the JVM.
Table of Contents (12 chapters)

Partial Functions in Practice

Now that we have learned a lot about functions and pattern matching, let's apply our theoretical knowledge to practical programming.

Let's get our chatbot, which we developed during the previous chapter, and change the modes to partial functions instead of classes.


Open /Lesson 3/5-project in the supplement materials and import the project into the IDE.

Representing ChatbotMode as a Partial Function

Let's navigate to the scala file package in com.packt.courseware.l4:

package com.packt.courseware.l4

package object modes {
  type ChatbotMode = PartialFunction[(String,EffectsProvider),Processed]


Here, we see the package object, which was not mentioned previously in our chapters.

The package object is an object which is associated with a package. When you import a package with a wildcard, then you import the current scope content of the package object if one exists.

So, the package object is a good way to store some utility definitions and functions...