[cogman10]

IMO, the best way to approach a DSL is simply using existing languages with a fairly flexible syntax. We've done this with groovy and it's worked quiet well. If I were to do it again I'd probably pick something like kotlin or ruby instead just because they both seem to have more industry relevance.

The beauty of picking an existing language as the base is you often get an expansive standard library from the get-go. That means your job as a "DSL" writer is more based on making sure you provide the value adds that make sense for the writers of that DSL.

It's worked particularly well for us because we have a data intake pipeline that has to parse and handle all sorts of random garbage (emails, excel docs, csv files, pdfs, etc).

A language like groovy, ruby, and kotlin all work well because it's trivial to add extensions to the syntax in a way that makes sense for your domain problem. Typescript also wouldn't be a bad choice for similar reasons, the only reason I wouldn't consider it is we run a JVM backend and parsing typescript for the JVM is somewhat of a PITA.