Method StartWith

observable_operator.go:2241–2287

StartWith emits a specified Iterable before beginning to emit the items from the source Observable.

(iterable Iterable, opts ...Option)

// StartWith emits a specified Iterable before beginning to emit the items from the source Observable.
func (o *ObservableImpl) StartWith(iterable Iterable, opts ...Option) Observable {
	option := parseOptions(opts...)
	next := option.buildChannel()
	ctx := option.buildContext(o.parent)

	go func() {
		defer close(next)
		observe := iterable.Observe(opts...)
	loop1:
		for {
			select {
			case <-ctx.Done():
				break loop1
			case i, ok := <-observe:
				if !ok {
					break loop1
				}
				if i.Error() {
					next <- i
					return
				}
				i.SendContext(ctx, next)
			}
		}
		observe = o.Observe(opts...)
	loop2:
		for {
			select {
			case <-ctx.Done():
				break loop2
			case i, ok := <-observe:
				if !ok {
					break loop2
				}
				if i.Error() {
					i.SendContext(ctx, next)
					return
				}
				i.SendContext(ctx, next)
			}
		}
	}()

	return &ObservableImpl{
		iterable: newChannelIterable(next),
	}
}

// SumFloat32 calculates the average of float32 emitted by an Observable and emits a float32.
func (o *ObservableImpl) SumFloat32(opts ...Option) OptionalSingle {