Polyfill for function.prototype.bind in coffeescript

function_bind_polyfill.coffee

if not Function.prototype.bind
  Function.prototype.bind = (oThis) ->
    if typeof @ is not 'function'
      throw new TypeError 'Function.prototype.bind - what is trying to be bound is not callable'
    aArgs = Array.prototype.slice.call arguments, 1
    fToBind = @
    fNOP = -> {}
    fBound = ->
      ctx = if @ instanceof fNOP then @ else oThis
      innerArgs = Array.prototype.slice.call arguments
      fToBind.apply ctx, aArgs.concat innerArgs
    fNOP.prototype = @prototype if @prototype
    fBound.prototype = new fNOP()
    fBound