StringBuilder class in CoffeeScript

gistfile1.coffee

do (root = if exports? and module.exports? then module.exports else @) ->

  class root.StringReader
  
    constructor: (@input) ->
      @buffer = ""
      @reset()
  
    readUntil: (character, omitCharacter = false, notFoundFn) ->
      loop
        if @end()
          notFoundFn(@buffer) if notFoundFn
          break
  
        if character.length is 1
          break if @input[@currentIndex] is character
        else
          skip = true
  
          counter = 0
  
          for c in character when @input[@currentIndex + counter] isnt c
            skip = false
            break
  
          counter++
  
          break if skip
  
        @buffer += @input[@currentIndex]
        @currentIndex++
  
      @currentIndex += character.length if omitCharacter
  
      @buffer
  
    clearBuffer: -> @buffer = ""
  
    reset: ->
      @currentIndex = 0
      @clearBuffer()
  
    end: -> @currentIndex >= @input.length