es6-iterator

Iterator abstraction based on ES6 specification

es6-iterator

$ npm install es6-iterator

To port it to Browser or any other (non CJS) environment, use your favorite CJS bundler. No favorite yet? Try: Browserify, Webmake or Webpack

Abstract Iterator interface. Meant for extensions and not to be used on its own.

Accepts any list object (technically object with numeric length property).

Mind it doesn't iterate strings properly, for that use dedicated StringIterator

var Iterator = require('es6-iterator')
var iterator = new Iterator([1, 2, 3]);
 
iterator.next(); // { value: 1, done: false } 
iterator.next(); // { value: 2, done: false } 
iterator.next(); // { value: 3, done: false } 
iterator.next(); // { value: undefined, done: true } 

Dedicated for arrays and array-likes. Supports three iteration kinds:

  • value (default) - Iterates values
  • key - Iterates indexes
  • key+value - Iterates keys and indexes, each iteration value is in [key, value] form.
var ArrayIterator = require('es6-iterator/array')
var iterator = new ArrayIterator([1, 2, 3], 'key+value');
 
iterator.next(); // { value: [0, 1], done: false } 
iterator.next(); // { value: [1, 2], done: false } 
iterator.next(); // { value: [2, 3], done: false } 
iterator.next(); // { value: undefined, done: true } 

May also be used for arguments objects:

(function () {
  var iterator = new ArrayIterator(arguments);
 
  iterator.next(); // { value: 1, done: false } 
  iterator.next(); // { value: 2, done: false } 
  iterator.next(); // { value: 3, done: false } 
  iterator.next(); // { value: undefined, done: true } 
}(1, 2, 3));

Assures proper iteration over unicode symbols.
See: http://mathiasbynens.be/notes/javascript-unicode

var StringIterator = require('es6-iterator/string');
var iterator = new StringIterator('f🙈o🙉o🙊');
 
iterator.next(); // { value: 'f', done: false } 
iterator.next(); // { value: '🙈', done: false } 
iterator.next(); // { value: 'o', done: false } 
iterator.next(); // { value: '🙉', done: false } 
iterator.next(); // { value: 'o', done: false } 
iterator.next(); // { value: '🙊', done: false } 
iterator.next(); // { value: undefined, done: true } 

Polyfill for ECMAScript 6 for...of statement.

var forOf = require('es6-iterator/for-of');
var result = [];
 
forOf('🙈🙉🙊', function (monkey) { result.push(monkey); });
console.log(result); // ['🙈', '🙉', '🙊'];

Optionally you can break iteration at any point:

var result = [];
 
forOf([1,2,3,4]', function (val, doBreak) {
  result.push(monkey);
  if (val >= 3) doBreak();
});
console.log(result); // [1, 2, 3];

Return iterator for any iterable object.

var getIterator = require('es6-iterator/get');
var iterator = get([1,2,3]);
 
iterator.next(); // { value: 1, done: false } 
iterator.next(); // { value: 2, done: false } 
iterator.next(); // { value: 3, done: false } 
iterator.next(); // { value: undefined, done: true } 

Whether obj is iterable

var isIterable = require('es6-iterator/is-iterable');
 
isIterable(null); // false 
isIterable(true); // false 
isIterable('str'); // true 
isIterable(['a', 'r', 'r']); // true 
isIterable(new ArrayIterator([])); // true 

If obj is an iterable it is returned. Otherwise TypeError is thrown.

Chain multiple iterators into one.

Tests

$ npm test