js-private-type-info

example.js

type_with_secrets = (function() {
    var secret_type_number = 0;
    
    var exported_type = function(){};
    exported_type.prototype.increment_secret = function() { secret_type_number += 1;};
    exported_type.prototype.get_secret = function() { return secret_type_number;};
    
    return exported_type;    
})();
    
var a = new type_with_secrets();
var b = new type_with_secrets();
 
a.increment_secret();
b.increment_secret();
a.increment_secret();

console.log("Hopefully this number will be 3:  " + b.get_secret());