Javascript Iterators

iterators.js

// DEFAULT CLASS ITERATOR
[Symbol.iterator](){
    let n       = this.head;
    let result  = { value:null, done:false };

    return { next:()=>{
        if( !n ) result.done = true;
        else{
            result.value = n.value;
            n            = n.next;
        }
        return result;
    }};
}

// FUNCTION ITERATOR OR EXTRA ITERATORS FOR A CLASS
iter(){
    let n       = this.head;
    let result  = { value:null, done:false };
    let next    = ()=>{
        if( !n ) result.done = true;
        else{
            result.value = n.value;
            n            = n.next;
        }
        return result;
    };

    return { [Symbol.iterator](){ return { next }; } };
}