Section: New Results

Undo in Collaborative Editing

Participants : Victorien Elvinger, Claudia-Lavinia Ignat.

In collaborative editors a selective undo allows a user to undo an earlier operation, regardless of when, where and by which user the operation was generated. In most existing collaborative editors such as GoogleDrive, selective undo is not integrated and users can only undo their own operations but not the ones generated by the other users. There is currently no generally applicable undo support as stated in the manifesto on CRDTs [17]. We presented a generic support of selective undo for CRDTs by proposing an abstraction that captures the semantics of concurrent undo and redo operations through equivalence classes. The abstraction is a natural extension of undo and redo in sequential applications and is straightforward to implement in practice [9].