Repeated property writes to one object made member-mutation collection
cubic. Each write evaluated its target binding to rule out a primitive,
and every evaluation folded all earlier mutation paths, copying every
slot once per path. 2,000 writes to one object took 27 s and 4,000 took
203 s.
- A recorded write always leaves a non-primitive binding value, so only
the first write to a binding needs the primitive check.
- Apply mutation paths per slot in one pass with the same ordering
semantics instead of one full slot copy per path.
Co-authored-by: Claude Opus 5.5 <[email protected]>
Co-authored-by: N0zoM1z0 <[email protected]>
