> I've had to think about the scheme substrate a lot when I hack on arc; arc feels a very leaky abstraction as a compiler. The hard part in programming is switching layers of abstraction; if an abstraction boundary is leaky enough, just taking it out entirely may make things easier. That's the hypothesis, anyway.
Sounds like an accurate assessment of Arc, though I guess I've been itching for the opposite (probably more obvious) outcome: an entirely platform-independent "arc.arc" with only the handful of axioms in "ac.scm" to bootstrap and guide ports of Arc to other substrates.
Absolutely. One benefit of the transformation layer is that it allows you to grow the language. It could eventually be completely self-sufficient, but you can start with the hard/interesting parts, and other stuff can gradually be abstracted away.
As an example, ac.scm has a comment that ar-gensym is a toy implementation. I don't need to do toy implementations because I can just use PLT's gensym directly until I decide to build my own.
