Virtual base class for backend-aware matrices

aMatrix is the abstract base from which all concrete amatrix classes inherit. It carries backend-dispatch metadata that controls which compute backend (CPU, GPU, etc.) is used for operations on the matrix.

Slots

preferred_backend

Single string naming the preferred compute backend; one of "cpu", "mlx", "metal", or "arrayfire".

policy

Single string controlling dispatch policy; one of "auto", "cpu", "mlx", "metal", or "arrayfire".

precision

Single string; either "strict" (double precision, exact results) or "fast" (backend may use lower precision).

object_id

Non-empty string uniquely identifying this object within the session; used for caching and residency tracking.

src_id

String recording the object_id of the object this was derived from, or "" for originals.

finalizer_env

Environment used to manage GPU-resident memory and deferred host-copy state.