fn next_in_sequence(cursor: i64, start: i64, interval: i64) -> Result<i64>Expand description
The smallest start + k * interval value that is strictly after cursor
(start itself lies on the anchor + k * interval lattice, so every
result is phase-consistent with the anchor). All arithmetic happens in
i128: cursor - start cannot overflow and the result is either exactly
on the lattice or an explicit error.