Getting private member functions working in CoffeeScript, by scoping differently

gistfile1.coffee

# This is an example in a post about private members in CoffeeScript.
# Read more: http://evanhahn.com/?p=1126

class Sorcerer
  that = null
  constructor: (@spell) ->
    that = this
  conjureSpell = ->       # private
    that.spell.conjure()  # Note this hack
  useSpell: ->
    conjureSpell()
    @spell.use()

s = new Sorcerer
  conjure: -> console.log "Brewing potion..."
  use: -> console.log "Now I have superpowers!"

s.useSpell()

# This code by Evan Hahn (evanhahn.com) is licensed under the Unlicense.
# http://unlicense.org/