Suppose I have tables referring to tables (by their field values), or functions referring to upvalues (by closure).
Given a table, I can know what it refers to by iterating over its contents. And given a closure, I can use the debug facilities to find its upvalues. I can do both recursively to obtain all objects or upvalues referenced.
Is it possible to go in the other direction? To find all references to a given value (say a table) in other tables or closures (as upvalues)?
Wouldn't the garbage collector have this information? It's not exposed in any debug facilities, is it?