USeR: A New Framework for Redoing

Abstract

US~l:t (which stands for Undo, Skip, Redo) is a new interactive approach to user recovery that offers significant advantages over current Undo/Redo packages. In the USS'R package, s SKIP or REDO command may be ambiguous, in which case US~'R enumerates the logical interpretations of the command and prompts the user both textually and graphically for the desired choice. USS'R also allows new commands to be executed during the redo process. With US~I:t, novices can perform recoveries that might be dimcult or impossible to do with other systems; experienced users can take even greater advantage of its functionality. USSfR's data structure organizes the recovery information in a natural tree-like fashion that is easy to implement in a variety of interactive settings, including text editors, graphics layout systems, algorithm simulators, and program development systems.