The IEnumerable parts are mainly enabled by coroutines, which for this case more or less equate to generators. The other parts are pretty much what I've already

The IEnumerable parts are mainly enabled by coroutines, which for this case more or less equate to generators. The other parts are pretty much what I've already seen so much problems with that I wouldn't touch them with a 10 foot pole (see the "black magic" comment by others, that sums it up nicely for me). But those are also more or less just about building ASTs and transforming them, something Lisp has done for decades.