Ruby's instance_eval equivalent in Scala for building DSLs

Question

In Ruby, when you design an embedded DSL a very useful trick is to leverage instance_eval . That way one can offer special statements within a certain block by implementing them as private methods on a special object. This is very nice for contextual stuff.

For an example see: https://robots.thoughtbot.com/writing-a-domain-specific-language-in-ruby

I was wondering what the closest equivalent would be in a Scala EDSL? More specifically how would I offer parts of the syntax only within a certain context that is delimited by a block?

Answer 1

If anybody's wondering: It looks like this is gonna be solve by so-called implicit function types. Here's a good write-up of the idea by Martin Odersky himself: https://www.scala-lang.org/blog/2016/12/07/implicit-function-types.html