My YAML loader[0] is a condensed example of the architecture and techniques I'm thinking of. It's a couple years old, so the code is dirty by my current standards, but the couple of times I've gone back to read it, I have found the YAML-specific concerns to be quite salient.

That said, it's specifically written for an audience that is familiar with YAML detail in particular, parsing more generally, and of course APL expressions of ideas. In fact, that is a big part of what makes the code readable and maintainable: it is optimized for communicating to the expert worker not for on-boarding new developers. The latter is more appropriately handled via other means IMHO.

The poster child for this style of APL is Co-dfns[0]. It's a production APL compiler and a much larger example of the code I'm talking about. The entrypoint to read is cmp/PS.apl.

If you're interested, I'm willing to have a chat and talk more about what makes this kind of APL imminently workable, in which case there are also some personal private examples I could share as well. Feel free to reach out to the contact info on my profile here.

[0]:https://github.com/xelxebar/dayaml/blob/master/Y.apln.

[1]:https://github.com/Co-dfns/Co-dfns