Simple query interface

[cwgoes]

@ray

The concept of “current” being confusing and problematic, we’ve avoided it. A transaction has a concept of “as of my own execution”, which is a lot more specific and actionable; transactions are serializable and there’s an as-if-serialized correct global system state corresponding to each transaction. No “current”; no one knows what this word means and they start doing nontransactional raw reads into private implementation details.

Agreed, I did not intend “current” to be read as a precise technical descriptor.

@ray

The concept of “synchronous” is more promising, but you don’t want it either. It’s just a simple, normal failure semantic to fail sometimes. (It’s a “soft” fail, which despite being the soft one is the one that fails the whole transaction… a “nontermination” fail, really. The one that admits retries 20 years later.)

By “synchronous” I just means “returns results immediately, from the perspective of the caller” - I think we’re on the same page.

@ray

Moving on to the actual question, broadly speaking, defining it this way is fine at a high level but I note no one’s going to pass physical functions around and analyze them, Yoneda lemma nonwithstanding; you’re looking at either a domain-specific query language or what amounts to some kind of compiler to same. (These are good things, this isn’t a dismissal as impractical!)

The structure required for analysis from the perspective of indexing is probably not entirely dissimilar to a circuit - namely, one wants the data dependencies to be explicit - so I’m not sure that this is entirely infeasible, but we can start with a simple DSL.