The expression problem

[joroKr21]

Like any more involved AST, the comprehension model is suffering from the infamous expression problem. It's easy to add operations, but hard to add combinators (would involve modifying all operations). I can't think of a reason to add more combinators right now, but still...

There is however, a neat solution by Oliviera and Cook (2012), utilizing object algebras. I think it's a worthwhile read at this point.

[aalexandrov]

Will read this carefully through. Thanks 👍.

[joroKr21]

I'm closing this since we're sticking to the Scala AST. More details in #147.