Scala infrastructure

First, let's have a look at the infrastructure developed for Scala. Let's have a look at the Scala interpreter first.

Scala interpreter

Although Scala is a compiled language, it has its own interpreter. It comes as part of the standard language distribution, and if you install Scala, you will have access to it. Please consult https://www.scala-lang.org/ on the instructions to install Scala.

You can access the interpreter from the command line by simply typing scala.

 

In this interpreter, you can run Scala expressions and get evaluations of them in real time. Besides ordinary expressions, you can run interpreter-specific expressions to tune it up. This kind of expression usually starts with a colon followed by a keyword. To access the list of all the relevant Scala interpreter expressions, type the following command:

:help

The output of the preceding command looks as follows:

SBT build tool

SBT is a build tool for Scala. It is a dedicated build tool developed specifically for Scala. It is possible to integrate Scala with Gradle or Maven, and in fact, this is an option that many teams prefer to do. SBT is supposed to be simple, but in fact, it is the precise opposite of simple. If you decide to use SBT as your Scala build tool, be advised that it possesses a complex infrastructure and is not well documented.

 

However, it is rather powerful. It allows you to write build descriptions in a subset of the Scala language. This means that your build scripts are Scala programs in themselves. This is not something you get with build tools, such as Gradle or Maven.

For this book, we do not need to be familiar with SBT. The GitHub repository with the examples for this books uses SBT, so you will need some basic familiarity with this software to run the examples. However, in this book, we do not feature SBT in parts that are crucial to functional programming. If you want to become more familiar with this tool, please see the official documentation of SBT.