Does node.js support a let statement something like what's described on MDN??

var x = 8,

    y = 12;



let ( x = 5, y = 10) {

    return x + y;

} //15

If not, is there a way to duplicate the functionality with a self-executing anonymous function or something?

And/or is there another js environment that

1. has let and and


2. has a REPL, as node does? Rhino?

EDIT:

This question was asked quite a while ago. As of now, late 2015, the answer is Yes, yes it does. Harmony features were included by default in io.js 3.3, and have been recently brought back to node.js with the 4.x release.