ClipEventDuration

Ends each left event when a right event with the same key starts.

For each left event, the first right event with the same key that starts after the left event’s start cuts it short: the left event ends there. Left events with no such right event keep their lifetime.

In the diagram, a:1 [1,5) is clipped by a:10 at 2 and becomes [1,2); b:2 [3,9) is clipped by b:20 at 4 and becomes [3,4); a:3 [6,8) keeps its lifetime, because the next a on the right starts at 10.

The clipped events are emitted as a start edge and an end edge: when the left event starts, Trill cannot yet know whether it will be clipped. See reading the diagrams.

See also: AlterEventDuration, WhereNotExists