Ideas for light-weight node middleware functions

reinvent_the_wheel.js

/*
  Ideas for light-weight node middleware functions
  Riffing on ideas for weaving functions together in a middleware architecture for node.


  Overview:
    a function that returns a rack-style array of status, headers and body

  Function Requirements:
    access to the environment (essentially the raw node request and response objects) 
    access to the output array of any middleware higher in the stack

  Writing these down, I currently like Option 2, but not 100% convinced. 

*/

  // option 1
  // out is the current output array of the stack
  function hello(out) {
    var env = this.env;
    return [200, {"Content-Type": "text/plain"}, "hello"]
  }


  // option 2
  // receive the current stack as individual parameters
  function hello(status, headers, body) {
    var env = this.env;
    return [200, {"Content-Type": "text/plain"}, "hello"]
  }


  // option 3
  // no parameters, access via this
  function hello() {
    var env = this.env;
    var out = this.out;
    return [200, {"Content-Type": "text/plain"}, "hello"]
  }


  // option 4
  // no parameters, but this has individual properties for the current output
  function hello() {
    var env = this.env;
    var status = this.status;
    return [200, {"Content-Type": "text/plain"}, "hello"]
  }


  // option 5
  // both env and out are parameters
  function hello(env, out) {
    return [200, {"Content-Type": "text/plain"}, "hello"]
  }


  // option n?
  // better ideas?