Semi-structured cursor movements in MUPE-2

Cursor movements on a textual representation of a program present some problems when the movements are based on an underlying abstract syntax tree in a programming system. Approaches taken in many systems use structured or textual cursor movements, but both have some drawbacks. The paper presents a new approach, semi-structured movements, based on the idea of cursor movement paths, or streams, that the cursor can follow in a program. The key benefits of this approach are that it eliminates the treeness of structured movements and the flatness of textual movements, while providing inherent support for program editing and browsing. Semi-structured cursor movements have been successfully implemented in the MUPE-2 programming environment, and the paper provides several scenarios illustrating example cursor movements