pub fn permutation(index: usize, len: usize) -> Vec<usize>Expand description
2026-09-26: The order a sample set is issued in, as indices into it.
Deterministic and RNG-free, so a failing run can be re-run to reproduce it.
Order 0 is the order dataset::load_shard returns, which is also the
order the BFCL benchmark issues its draw in.
Order 1 is the reverse, which changes what preceded every sample. Further
orders are rotations; for len >= 2 none of them is order 0.