iterate-javascript

A handy function with a unified interface to iterate Strings, Arrays, TypedArrays, Maps, Sets, (any Iterables) & Objects. The api is oriented on Array.prototype.forEach with the advantage of iterating almost everything and iteration skipping.

Installation

$ yarn add @a-z/iterate-it
# or
$ npm i -S @a-z/iterate-it

Usage

The module @a-z/itarate-it exports a single function that takes to parameters; an iterable and a callback. The iterate function returns a iteration result, that indicates if the iteration was complete of has been skipped.

const iterate = require('@a-z/iterate-it');
const { complete } = iterate(iterable, callback);

Parameters

iterable

The iterable or object to iterate over. Supported types are String, Array, TypedArray, Map, Set, (any Iterable) & Object.

callback

A function to be called with every element or value of the iterable. The iteration will stop if the function returns false.

The function takes 3 parameters:

• value: The current element being processed.
• key: The corresponding key
• iterable: The iterable passed to iterate

Return Value

iterate() returns a status object with the following properties:

• complete: Will be true if all items have been iterated, falthy if the iteration was stoped before.

Examples

Iterating strings

iterate("a1b2c3d4e5", (char, index, str) => {}); 
// => "12345"
iterate(new String("a1b2c3d4e5"), (char, index, str) => {}); 
// => [String: '12345']

Iterating maps

const map = new Map([['a', 1], ['b', 2], ['c', 3]]);

iterate(map, (value, key) => console.log(key, value)); 
// a 1
// b 2
// c 3

Iterating sets

const set = new Set(['a', 1, 'b']);

iterate(set, (value, key) => console.log(key, value)); 
// a a
// 1 1
// b b

Iterating arrays

const arr = ['a', 1, 'b'];

iterate(arr, (value, index) => console.log(index, value)); 
// 0 a
// 1 1
// 2 b

Iterating typed arrays

const typedArr = new Int32Array([1, 2, -3]);

iterate(typedArr, (value, index) => console.log(index, value));
// 0 1
// 1 2
// 2 -3

Iterating plain objects

const obj = { a: 1, b: 2, c: 3 };

iterate(obj, (value, key) => console.log(key, value)); 
// a 1
// b 2
// c 3

Skipping the iteration

const arr = [1, 2, undefined, 3, 4];

const { complete } = iterate(arr, (value) => {
  console.log(value);
  
  // skip iteration as soon as there is an invalid item
  if (typeof value === 'undefined') {
    return false;
  }
});

console.log(complete === true)

// 1
// 2
// false

LICENSE

The files in this archive are released under MIT license. You can find a copy of this license in LICENSE.