core architecture notes, ~2024.7.15

[belisarius222]

We discussed Hoon pattern-matching for most of the time. @joemfb and @Fang- presented their work on the ?# pattern-matching rune. A lot of discussion centered around a new counterproposal from @frodwith that would add a top-level alias to the subject for each face= term in the pattern. This will require further investigation to evaluate in terms of feasibility and desirability.

Aura Renovation:
We should move the more aggressive changes from this into a new proposal and leave the parts that are relatively uncontroversial.

Enforcing sanity in ;; is fine. Cleaning up the aura definitions is fine. What should be taken out of scope is the idea from the motivation section that the compiler should enforce sanity of atoms at compile-time, since that would be too hard to implement without large changes to the type system. All changes to the nesting rules should be taken out of scope.

We also talked about @sigilante's proposed assert-and-print-error rune (urbit/UIPs#40). We have not come to any conclusions on it. While there is general agreement that this pattern could be expressed more ergonomically with a rune, we did not find a digraph we all thought would be suitable, and there was also some discussion of whether it would be better to have a rune with a smaller scope that would just combine ~| and !!, to make crashing with an error a rune, rather than just the assertion. Comments on this subject are welcome.