dependency injection

di.js

var FN_ARGS        = /^function\s*[^\(]*\(\s*([^\)]*)\)/m;
var FN_ARG_SPLIT   = /, ?/g;
var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg;

var injector = {
    store: {},
    register: function(key, value) {
        this.store[key] = value;
    },
    invoke: function(fn) {
        var self    = this;
        var $inject = [];
        if (fn.length) {
            fnText  = fn.toString().replace(STRIP_COMMENTS, '');
          
            argDecl = fnText.match(FN_ARGS)[1];
          
            args    = argDecl.split(FN_ARG_SPLIT);
          
            $inject = args.map(function(arg) {
                return self.store[arg];      
            });
          
            fn.apply(undefined, $inject);
        }
    }
};


injector.register('add', function(a, b) {
    return a + b;
});

injector.invoke(function(add) {
    console.log(add(3, 4));
});