Module gc 

Mark-sweep garbage collection.

Spike 3 extends spike 2’s reachability rules with two new edges:

5. From any Value::Object, every property value is reachable.
6. From any Value::Object with Some(prototype), the prototype address is reachable.

Both edges are pure-functional traversals identical in shape to the reference edge: gather addresses into an immutable BTreeSet, then delegate sweeping to Heap::retain.

Functions

collect

Retain only the cells reachable from roots and env.

reachable

Compute the set of addresses reachable from roots and env through heap.