PersistenceJS provides specialized, immutable, persistent data structures built on-top of ImmutableJS. PersistenceJS offers highly efficient immutable linked-lists, heaps, and search trees, with more data structures coming soon.
Immutable data cannot be changed once created... Persistent data presents a mutative API which does not update the data in-place, but instead always yields new updated data (source).
To learn more about immutable data, persistent data structures, or any of the individual data structures implemented by PersistenceJS, please explore the appendix.
PersistenceJS is available as an npm package.
Install module from command-line
npm install persistence-js
Require module for use in desired file
var Persist = ;
This object provides all of the data structures offered by PersistenceJS.
var Persist = ;
var LList = PersistLinkedList;var exampleLList = ;
var CLList = PersistCircularLinkedList;var exampleCLList = ;
var Heap = PersistHeap;var exampleHeap = ;
var BSTree = PersistBSTree;var exampleBST = ;
The future of PersistenceJS is managed through this repository's issues — view the roadmap here.
We welcome contributions, but please read our contribution guidelines before submitting your work. The development requirements and instructions are below.
Install Node (bundled with npm) using Homebrew:
brew install node
Install project and development dependencies using npm:
After installing the above dependencies, tests can be run using the following command:
Copyright 2015 Clark Feusier & Sze-Hung Daniel Tsui
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
A persistent data structure ... always preserves the previous version of itself when modified.
An immutable object is an object whose state cannot be modified after it is created.
Note, persistent data structures are generally immutable, since the API returns a new structure, despite appearing mutable.