Ghost Variables (3)
Ghost variables provide greater freedom to choose an incremental revision policy. Two basic types of incremental change are:
- An incremental change to all clients, which swaps original and ghost roles for one variable.
- An incremental change to one client, which swaps original and ghost roles for all variables.
In other words, the sequence of program ‘slices’ selected as revision increments may be data-oriented or function-oriented or a hybrid of both.