In this talk we will compare three techniques for meta-programming in Scala: macros, shapeless, and code generation. Through a sequence of simple examples we will attempt to characterise the relative pros and cons of each each technique, where they become appropriate, and when they might turn around and bite you.

We can solve many Scala programming problems using simple tools: algebraic data types, higher order functions, and type classes. Sometimes, however, the code becomes verbose or unwieldy, and we search for ways to make our code cleaner and more maintainable. “Meta-programming” is a broad term describing techniques for generating code using code, but the meta programming techniques listed above could not be more different. Sometimes, being able to identify the correct technique may save hours of frustration attempting to go down blind alleys. This is the problem we are trying to solve in this talk.

The talk is aimed at intermediate Scala developers who have a basic awareness of each technique. You don’t need to know shapeless or macro programming to benefit.