bench-1.js

var Point = require('./' + (process.env.WHICH || 'closure'))
var iter = 1000000
var rand = Math.random
var hrtime = process.hrtime() 
for (var i = 0; i < iter; ++i) {
  var p = new Point(rand(), rand(), rand(), rand())
  for (var j = 0; j < 1000; ++j) {
    p.distance()
  }
}
hrtime = process.hrtime(hrtime) 

console.log(
    '%smb, %sms'
  , process.memoryUsage().heapTotal / 1048576
  , hrtime[0] * 1e3 + hrtime[1] / 1e6
)

bench.js

// ./bench.js
var Point = require('./' + (process.env.WHICH || 'proto'))
var iter = (1000000 * 1000)
var rand = Math.random
var hrtime = process.hrtime() 
var p = new Point(rand(), rand(), rand(), rand())
  , t = 0

for (var i = 0; i < iter; ++i) {
  t += p.distance()
}

hrtime = process.hrtime(hrtime) // get the difference since original measurement

console.log(
    '%sms'
  , hrtime[0] * 1e3 + hrtime[1] / 1e6
)

closure.js

// ./closure.js
// the closure utilizing version
module.exports = Point

function Point(x0, y0, x1, y1) {
  this.distance = function dist() {
    var x = x1 - x0

    var y = y1 - y0

    return Math.sqrt(x * x + y * y)
  }
}

hybrid.js

module.exports = Point

function Point(x0, y0, x1, y1) {
  this.x0 = x0
  this.x1 = x1
  this.y0 = y0
  this.y1 = y1

  this.distance = function distance() {
    var x = this.x1 - this.x0
      , y = this.y1 - this.y0

    return Math.sqrt(x * x + y * y)
  }
}

proto.js

// ./proto.js
// the prototype-utilizing version
module.exports = Point

function Point(x0, y0, x1, y1) {
  this.x0 = x0
  this.y0 = y0
  this.x1 = x1
  this.y1 = y1
}

Point.prototype.distance = function() {
  var x = this.x1 - this.x0
    , y = this.y1 - this.y0

  return Math.sqrt(x * x + y * y)
}