Module selection 

Cursors and selections, and how they survive somebody else’s edit.

A cursor is just a zero-width Range. V1 ships a single cursor (ARCHITECTURE.md §10’s ship discipline), but the model is multi-range from the start so multi-cursor is additive rather than a rewrite.

Structs

Range

A selection with a fixed anchor and a moving head, in char offsets.

Selection

The set of ranges owned by a buffer. Always non-empty.