Module sort_merge 

Sort-merge propagation pipeline: scan → bucket → merge. See §5.

Constants

SMALL_SUM_THRESHOLD

Empirical threshold below which a hashmap-based fast path beats sort-merge (§8.3). Subject to benchmarking.

Functions

apply_layer

Apply a single channel to a PauliSum, producing the next layer.

apply_layer_adjoint

Apply a channel’s adjoint to a PauliSum. Used by propagate in Direction::Heisenberg mode; structurally identical to apply_layer but routes through Channel::apply_adjoint.