lru-set 
Set implementation with lur feature for node.
Getting Started
Install the module with: npm install lru-set
var LRUSET = require('lru-set');
var set = LRUSET(1, 2, 3);
set.len();
set.contain(3);
set.contain(4);
set.add(3);
set.len();
set.add(4);
set.len();
set.pop();
set.len();
Contributing
In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.
Release History
License
Copyright (c) 2013 Guan Qing
Licensed under the MIT license.