export class Queue<T> {
    /**
     * The elements in the queue
     */
    private elements: T[] = []
    /**
     * The head (index) of the queue.
     * For performance, this is not always zero, as would be expected.
     */
    private head = 0
    /**
     *
     */
    get length(): number {
        return this.elements.length - this.head
    };
    empty(): boolean {
        return this.elements.length === 0
    };
    put(element: T): void {
        this.elements.push(element)
    };
    get(): T {
        if (0 !== this.elements.length) {
            const c = this.elements[this.head]
            this.head++
            // If over half of the elements towards the front of the queue are no longer needed,
            // re-allocated the elements.
            if (2 * this.head >= this.elements.length) {
                this.elements = this.elements.slice(this.head)
                this.head = 0
            }
            return c
        }
        else {
            throw new Error("")
        }
    }
    peek(): T | undefined {
        return this.elements.length > 0 ? this.elements[this.head] : void 0
    }
}