Struct accept_any_index

• Defined in File eval.hpp

Struct Documentation

struct accept_any_index

Builds a custom evaluator (see CacheManager::custom_evaluator_type) that evaluates a subtree in batches over a contracted index, to bound the peak memory of intermediates that carry that index.

For each node it is consulted on, the returned evaluator chooses a batch axis K via batch_axis(node, accept) (declining if none). It asks the backend to partition K into contiguous element-range batches of about target_batch_size elements each (Result::mode_batches); if that yields at most one batch it declines (so small / unselected indices are left to the standard scheme). Otherwise, for each batch it evaluates the subtree by the standard scheme on a fresh scratch cache, with every leaf carrying K sliced to the batch’s element range, and sums the partial results. This is exact because sum_K = sum_{batches} sum_{K in batch}, and never materializes the whole K extent of any intermediate at once.

Param le:

the leaf evaluator (captured).

Param target_batch_size:

the desired size of each batch in elements (a user knob; no memory model is assumed). Backend-neutral: a tiled backend rounds batch boundaries to tile boundaries, so realized batches are uneven and each covers at least this many elements where possible.

Param accept:

predicate selecting which contracted indices may be batched (e.g. only those in the auxiliary/RI IndexSpace). Defaults to any.

Param make_scope_guard:

factory, called with the batch count, returning an RAII object held for the duration of the batched partial contractions; a backend may use it to relax block-sparse screening (scaled by the batch count) so per-batch screening does not drop small contributions that are significant once summed over the full batch axis. Defaults to a no-op (make_no_scope_guard).

Public Functions

inline bool operator()(Index const&) const noexcept