Iterators (TypeScript) forked from https://basarat.gitbooks.io/typescript/docs/iterators.html#

iterator.ts

interface Iterator<T> {
next(value?: any): IteratorResult<T>;
return?(value?: any): IteratorResult<T>;
throw?(e?: any): IteratorResult<T>;
}

interface IteratorResult<T> {
done: boolean;
value?: T;
}

class Component {
  constructor (public name: string) {}
}

class Data implements Iterator<Component> {

  private pointer = 0;

  constructor(public name: string, public components: Component[]) {}

  public next(): IteratorResult<Component> {
    if (this.pointer < this.components.length) {
      return {
        done: false,
        value: this.components[this.pointer++]
      }
    } else {
      return {
        done: true
      }
    }
  }
}

let data = new Data("ABCD", [new Component("first"), new Component("second"), new Component("third"), new Component("fourth")]);
let iteratorResult1 = data.next(); //{ done: false, value: Component { name: 'first' } }
let iteratorResult2 = data.next(); //{ done: false, value: Component { name: 'second' } }
let iteratorResult3 = data.next(); //{ done: false, value: Component { name: 'third' } }
let iteratorResult4 = data.next(); //{ done: false, value: Component { name: 'fourth' } }
let iteratorResult5 = data.next(); //{ done: true }
let component = iteratorResult1.value; //Component { name: 'first' }