> 2) Boilerplate-free generation of various (potentially complex) visitors for these ASTs and IRs. For Haskell, Scrap Your Boilerplate library is the closest th

> 2) Boilerplate-free generation of various (potentially complex) visitors for these ASTs and IRs. For Haskell, Scrap Your Boilerplate library is the closest thing to what I want, but it is still far too clumsy. Have you tried QuickCheck? > 4) Parsing is not very important. But yet, it is necessary. The best Haskell got on offer is Parsec. Sorry, not good enough for my requirements. I've not found much better than (atto-)Parsec, to the point where I miss it in other languages.