pub fn next_step<'a>(flow: &'a Flow, evidence: &[StageEvidence]) -> Step<'a>Expand description
The pure decision at the heart of a flow: given the flow and the
evidence recorded so far, what runs next. Linear and halt-on-fail, with
no notion of loops, branches, or retries (see sloop-flows.md §4).
Because this only reads persisted evidence rows and never a clock or a
process, resuming after a crash with the same rows yields the same
Step: the walk is idempotent by construction.