While a module system in JavaScript will be useful, this seems overly complicated.

I like Lua's approach to modules. In Lua, a file is basically equivalent to a function body. It accepts arguments and can return values. In JavaScript, this is not allowed.

In Lua, a function can accept multiple arguments in a tuple called `...`. Every file is implicitly a vararg function, so we can unpack the `...` to get arguments.

    > add.lua
      local a,b = ...
      return a + b 


    > file.lua
      local add = load 'add.lua'
      print(add(1,2)) --> 3

load takes a file path and returns that source file as a function. Most files ignore arguments, but they do return values.

    > add2.lua
      return function(a,b) return a + b end

    > file2.lua
      local add = require 'add'
      print(add(1,2))

`require` loads a source file, executes it, and returns the value that it returns. It is similar to `return load(fileName)()`, but it also has a search mechanism, and caches the result. So, the Lua equivalent of export default is simply returning a value at the end of a source file.

The named exports are also easy to replicate. You simply return an object with the keys you want.

    > math.lua
      return {
        add = function(a,b) return a + b end,
        sub = function(a,b) return a - b end
      }

    > other.lua
      local math = require 'math'
      local add, sub = math.add, math.sub

You can also have something similar to the `export function name(){}` declaration.

    > hello.lua
      local exports = {}

      function exports.hello()
        print "Hello World"
      end

      exports.VERSION = '0.0.1'

      return exports

    > file3.lua
      local hello = require'hello'.hello
      local version = require'hello'.VERSION

      hello() --> Hello World

In all, I think the Lua's require is a much cleaner way to implement modules. Unfortunately, it cannot handle circular references. It may be possible to add this feature using Lua's coroutines, however. I will have to research how it is handled in JavaScript to be sure.