Multiple-methods NPM

Multiple-methods

Multiple-methods is a micro library that implements multi methods in javascript. This allows you to do things like the following:

var multi = require('multiple-methods');
var area = multi(_.property('shape'));
area.defaultMethod(() => 0);
area.method('circle', (s) => Math.PI * Math.pow(s.radius,2));
area.method('square', (s) => Math.pow(s.side, 2));

area({shape:'circle', radius: 1});
// 3.141592653589793
area({shape:'square', side: 4});
// 16
area({shape:'nothing'});
// 0

This library is incredibly small, so you should feel free to read the source. In fact you have seen everything that the library can do above. It only has one entry point "multi". Which has two properties, method and defaultMethod. It doesn't implement clojure style instance checking, although it would be easy to do yourself with it.