When you use a JavaScript array or hash table, you have so many ways to get utility functions at your disposal through libraries like Underscore, Zepto, jQuery, or natively in ECMAScript5. Why can't we have these same utility functions just as easily for other data structures that can be iterated over? Say, a linked list, or a tree, or a graph, or that newest thing that your monkey came up with?

This library is heavily inspired by Ruby's Enumerable module, and borrows great deal of its functionality.

Note: This is not meant to be a standalone library, but to be used in conjunction with another data type that has a defineable .each method.

Annotated source

As an NPM module npm install enumerable-js

As a bower package bower install enumerable-js

From Github git clone git@github.com:bioball/Enumerable.js.git

// contrived example
var LinkedList = function(){
  this.head = null;
  this.tail = null;
};

LinkedList.prototype.add = function(value){
  var node = {
    value: value,
    next: null
  };
  if(!this.head){
    this.head = this.tail = node;
  } else {
    this.tail.next = node;
    this.tail = node;
  }
};

// option 1: use enumerable.extend
enumerable.extend(LinkedList.prototype);

// option 2: use Object#create. NOTE: In this case, doing so will will completely 
// reassign what LinkedList.prototype is. Here, we would need to define 
// LinkedList#add again after this.

LinkedList.prototype = Object.create(enumerable);

LinkedList.prototype.each = function(callback, context){
  var node = this.head;
  while(node){
    callback.call(context, node);
    node = node.next;
  }
};

var list = new LinkedList();
list.add(5);
list.add(9);
list.add(15);

var sum = list.reduce(function(sum, node){ return sum + node.value; }, 0);
console.log(sum);
// => 27   ¯\_(ツ)_/¯

Returns as specified

• reduce / inject / foldl
• first

Returns an array

• filter / select / findAll
• mapToArray
• toArray
• sort
• partition

Returns the collection

• mapInPlace
• eachCons
• eachSlice
• eachUntilN
• reverseEach
• cycle

Returns an item in the collection

• find
• max
• min
• detect

Returns a boolean

• all
• any
• none
• hasN

Returns an integer

• count

*Want to contribute? Please send in pull requests! However, please also have test coverage in your pull requests.