TailRec.ts

class TailRec<T> {
    private next: () => TailRec<T>;
    private done: boolean;
    private result: T;

    constructor(next: () => TailRec<T>, done: boolean, result: T) {
        this.next = next;
        this.done = done;
        this.result = result;
    }

    get(): T {
        let t: TailRec<T> = this;
        while (true) {
            if (t.done) {
                return t.result;
            }
            t = t.next();
        }
    }

    static call<T>(next: () => TailRec<T>): TailRec<T> {
        return new TailRec<T>(next, false, null);
    }

    static done<T>(result: T): TailRec<T> {
        return new TailRec<T>(() => null, true, result);
    }
}