Teaching Domain Specific Languages in Scala

Abstract

In 2017, I was asked to teach a small, 3 credits master course on engineering domain specific languages. At the time I was already a Scala enthusiast, and I had no doubt that it would have been the best language to teach this course. While learning about DSL, students are introduced to the basics like functional domain modeling, parser combinators, extension and symbolic-named methods, but also advanced topics like metaprogramming, and how to implement programming language features in Visual Studio Code (using Scala.js).

After a brief introduction on DSLs and the context where I teach them, the talk will focus on two main areas:

• Why Scala is suitable for internal and external DSL development, i.e., what are the characteristics of the language, the platforms, and the libraries in the community that make it amazing to teach (and engineer) DSLs.
• How to structure a course and what are the possible topics and areas to cover, including how to design compelling assignments where students build software inspired by real DSLs.

The talk will include examples of what the best students were able to achieve. Furthermore, I will pinpoint controversial aspects concerning the actual state of the language, libraries, and tools that are connected to DSL development, and debunk a few misconceptions around DSLs that made them a little unpopular in the Scala world.

Recording