saveAllReturningCanonical

Save multiple propositions and report which stored proposition each one landed on.

save has always returned the stored proposition, and on a deduplicating backend that can be a different proposition with a different id from the one passed in. saveAll returns Unit and drops all of it, so a caller doing a batch save had no way to learn a canonical id short of saving one at a time. This is that batch call with its answer kept.

Same writes, same order, same backend behaviour as saveAll — only the return value differs. saveAll keeps its Unit descriptor rather than growing one, because changing it would break every implementation and every compiled caller.

A backend that overrides saveAll for a batched round trip should override this too, or it loses the batching here: the default goes through save one at a time, never through saveAll.

Parameters