Design requirements for more flexible structured editors from a study of programmers' text editing.

A detailed study of Java programmers' text editing found that the full flexibility of unstructured text was not utilized for the vast majority of programmers' character-level edits. Rather, programmers used a small set of editing patterns to achieve their modifications, which accounted for all of the edits observed in the study. About two-thirds of the edits were of name and list structures and most edits preserved structure except for temporary omissions of delimiters. These findings inform the design of a new class of more flexible structured program editors that may avoid well-known usability problems of traditional structured editors, while providing more sophisticated support such as more universal code completion and smarter copy and paste.