hash-array

A data structure that combines a hash and an array for add, remove and get operations by object keys or index.

Multi-level key paths can be used (e.g. 'name' as well as ['child', 'label'] etc.).

Install

npm install hasharray

Testing

>mocha

START

  ․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․․

  38 passing (24ms)

Example

Basic Usage

var HashArray = require ('hasharray');

// Create new hasharray with two key mappings.
var ha = new HashArray(['name', 'zip']);

// Add 2 objects to the hash.
var item1 = {name: 'Josh', zip: '54321'};
var item2 = {name: 'Josh', zip: '12345'};
ha.add(item1, item2);

if (ha.has('Josh'))
  console.log(ha.get('Josh')); // Will output two objects to the console

// Display the number of unique objects. In this case, 2.
console.log(ha.all.length);

// Remove an element by one of the keys
ha.removeByKey('54321'); // This removes item1

// Remove item2 directly
ha.remove(item2);

** Retreiving Multiples of a Single Key (getAsArray) **

var ha = new HashArray(['firstName', 'lastName']);

var person1 = {firstName: 'Bill', lastName: 'William'},
  person2 = {firstName: 'Bob', lastName: 'William'};

ha.add(person1, person2);

console.log(ha.getAsArray('William')); // [person1, person2]

** Retrieving Sets by Multiple Keys (getAll) **

var ha = new HashArray(['firstName', 'lastName']);

var person1 = {firstName: 'Victor',  lastName: 'Victor'},
  person2 =   {firstName: 'Victor',  lastName: 'Manning'},
  person3 =   {firstName: 'Manning', lastName: 'Victor'};
  person4 =   {firstName: 'John',    lastName: 'Smith'};

ha.add(person1, person2, person3, person4);

console.log(ha.getAll(['Victor', 'Smith'])); // [person1, person2, person3, person4]
console.log(ha.getAll(['John', 'Smith'])); // [person4]

Multi-level Keys

var HashArray = require ('hasharray');
var ha = new HashArray([
      ['name', 'last'], // Internally maps obj.name.last -> obj
      ['name', 'first'], // Internally maps obj.name.first -> obj
      'zip'
    ]);

ha.add({
    name: {
      first: 'Josh',
      last: 'Jung'
    },
    zip: 60616
  });

console.log(ha.get(60616) === ha.get('Josh') == ha.get('Jung')); // true

Key Duplicates

If two items contain the same key, they are appended to an array at that key location.

var HashArray = require ('hasharray');
var ha = new HashArray([
      ['name', 'last'],
      ['name', 'first']
    ]);

ha.add({
    name: {
      first: 'Josh',
      last: 'Jung'
    }
  },
  {
    name: {
      first: 'Josh',
      last: 'Mills'
    }
  },
  {
    name: {
      first: 'Josh',
      last: 'Willis'
    }
  });

console.log(ha.get('Josh').length); // Will be 3
console.log(ha.get('Willis')); // Will be {name: {first: 'Josh', last: 'Willis'} }

Cloning

Cloning makes a new HashArray clone of the original, ensuring that no Array objects are shared.

Keep in mind that cloning does deep clone objects in the collection. Therefore if you clone an object with three Object items, the clonee will be a new HashArray but will contain references to the original objects.

var HashArray = require ('hasharray');
...
var ha = new HashArray(['someKey']);
...
var clonee = ha.clone();

License

The MIT License (MIT)

Copyright (c) 2014 Joshua Jung

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.