queue

type Queue interface {
	// Append adds the data to the Queue at priority level PriorityNormal.
	Append(data interface{})

	// AppendPriority adds the data to the Queue with respect to priority.
	AppendPriority(data interface{}, priority int)

	// Signal returns the Queue signal channel.
	Signal() <-chan struct{}

	// Next returns the data at the front of the Queue.
	Next() (interface{}, bool)

	// Process will execute the callback parameter for each element on the Queue.
	Process(callback func(interface{}))

	// Empty returns true if the Queue is empty.
	Empty() bool

	// Len returns the current length of the Queue.
	Len() int
}