orc.trace
Interface EventCursor

All Known Implementing Classes:

BackwardEventCursor, InputStreamEventCursor, WeakBackwardEventCursor

public interface EventCursor

Functional cursor in a stream of trace events. You'd probably implement this as a Zipper.

Author:

quark

Nested Class Summary

static class

EventCursor.EndOfStream

Method Summary

EventCursor	backward() Return a cursor to the previous event in the stream.
Event	current() Return the current event in the stream.
EventCursor	forward() Return a cursor to the next event in the stream.

Method Detail

current

Event current()

Return the current event in the stream.

forward

EventCursor forward()
                    throws EventCursor.EndOfStream

Return a cursor to the next event in the stream. Why "forward" instead of "next"? To avoid confusion with the temporal logic "next" operator which evaluates a predicate at the next location. Also because I prefer the symmetry of forward/backward to next/previous.

Throws:

EventCursor.EndOfStream

backward

EventCursor backward()
                     throws EventCursor.EndOfStream

Return a cursor to the previous event in the stream.

Throws:

EventCursor.EndOfStream