Scope::upper is a perl module that provides a way for perl programs to defer actions at run-time until the control flow returns to the upper scope. it currently enables developers to:

* hook an upper scope end with "reap"
* localize variables, array/hash values or deletions of elements in
higher contexts with respectively "localize", "localize_elem" and
"localize_delete"
* return values immediately to an upper level with "unwind", and know
which context was in use then with "want_at"