CoffeeScript StrCalc Kata Implementation

gistfile1.coffee

window.StrCalc = class StrCalc

  constructor: (myStr = 0) ->
    if myStr is '0' or myStr is 0
      @firstNum = 0
    else
      @parseMyNum myStr

  parseMyNum: (myStr) ->
    pattern = /(\d)+.*?(\d*)/gm
    result = myStr.match pattern
    @firstNum = parseInt result[0]
    @secondNum = parseInt result[1]
    @thirdNum = parseInt result[2]
    @add()

  add: ->
    @total = @firstNum + @secondNum + @thirdNum