A simple Queue in go.

Queue.go

type Any interface{}

// Queue is a basic FIFO Queue
type Queue struct {
nodes []Any
size int
head int
tail int
count int
}

// Push adds a item to the Queue.
func (q *Queue) Push(n Any) {
// The queue size is reached it doesn't resize. It just pops the item.
if q.count == q.size {
q.Pop()
}
q.nodes[q.backIndex()] = n
q.count++
}

// Pop removes and returns the item.
func (q *Queue) Pop() Any {
if q.count == 0 {
return nil
}
item := q.nodes[q.head]
q.head = (q.head + 1) % len(q.nodes)
q.count--
return item
}

// queue length
func (q *Queue) Len() int {
return q.count
}

func (q *Queue) backIndex() int {
return (q.head + q.count) % q.size
}

// creates a new instance of the queue
func NewQueue(size int) *Queue {
return &Queue{
nodes: make([]Any, size),
size: size,
}
}