later.js
function short(callback) {
  var called = false

  return function cbOnceLater(err, data) {
    if (called) {
      return
    }

    called = true

    process.nextTick(function () {
      callback(err, data)
    })
  }
}
function short(callback) {
  var called = false

  return function cbOnceLater(err, data) {
    if (called) {
      return
    }

    called = true

    process.nextTick(function () {
      callback(err, data)
    })
  }
}
function short ( callback ) { var called = false return function cbOnceLater ( err , data ) { if ( called ) { return } called = true process . nextTick ( function ( ) { callback ( err , data ) } ) } }
Faster, common version
Faster common version