NewCompositeSignaler creates a new composite signaler.

Sig will send the Completed or Failed event to s depending on err being set if s is not nil.

SigAll send the Completed or Failed event to all given signalers depending on err being set.

SigCompleted sends the Completed event to s if s is not nil.

SigFailed sends the Failed event to s if s is not nil.

NewSplitSignaler creates a new splitSignal if s is not nil.

SignalCallback converts a function accepting SignalResponse into a Signaler.