to demonstrate a typical singleton in coffeescript

singleton_parameter.coffee

class Parameter
  _instance=null
  someparam: 'bingo'
  constructor: ()->
    console.log 'Parameter got constructed'
  showparam: ->
    console.log 'someparam is ', @someparam
  setparam: (s)->
    @someparam = s
  @get: ->
    #_instance = new Parameter() if not _instance
    _instance
  _instance = new Parameter()

a = Parameter.get()
b = Parameter.get()

a.showparam()
b.showparam()

a.setparam 'qq'

a.showparam()
b.showparam()

a.someparam = 'ff'
b.showparam()

#can be required like the following
#param = require('parameter').get()
#param.mvr