There is no 'corruption' happening anywhere. When you register local variables, they are merely defined as register locations and have a default value of nil w

There is no 'corruption' happening anywhere. When you register local variables, they are merely defined as register locations and have a default value of nil which is absence and hence memory saved. They would have to mark nil explicity as a new data structure which is probably wastage as they would have to allocate memory for every variable declaration that may or may not be used. It is just nil, nil at a literal level with the exception being local variables which are handled differently as offsets to register locations than other dynamic languages without such 'local' qualifiers. That should explain why variables can be nil but not ta les. You can hash nils but it would take up memory. I don't think it's logical to use memory for something you are already marking as absent. Why not use false instead?