class REXML::Validation::RelaxNG

def initialize source
  parser = REXML::Parsers::BaseParser.new( source )
  @count = 0
  @references = {}
  @root = @current = Sequence.new(self)
  @root.previous = true
  states = [ @current ]
  begin
    event = parser.pull
    case event[0]
    when :start_element
      case event[1]
      when "empty"
      when "element", "attribute", "text", "value"
        states[-1] << event
      when "optional"
        states << Optional.new( self )
        states[-2] << states[-1]
      when "choice"
        states << Choice.new( self )
        states[-2] << states[-1]
      when "oneOrMore"
        states << OneOrMore.new( self )
        states[-2] << states[-1]
      when "zeroOrMore"
        states << ZeroOrMore.new( self )
        states[-2] << states[-1]
      when "group"
        states << Sequence.new( self )
        states[-2] << states[-1]
      when "interleave"
        states << Interleave.new( self )
        states[-2] << states[-1]
      when "mixed"
        states << Interleave.new( self )
        states[-2] << states[-1]
        states[-1] << TEXT
      when "define"
        states << [ event[2]["name"] ]
      when "ref"
        states[-1] << Ref.new( event[2]["name"] )
      when "anyName"
        states << AnyName.new( self )
        states[-2] << states[-1]
      when "nsName"
      when "except"
      when "name"
      when "data"
      when "param"
      when "include"
      when "grammar"
      when "start"
      when "externalRef"
      when "notAllowed"
      end
    when :end_element
      case event[1]
      when "element", "attribute"
        states[-1] << event
      when "zeroOrMore", "oneOrMore", "choice", "optional",
        "interleave", "group", "mixed"
        states.pop
      when "define"
        ref = states.pop
        @references[ ref.shift ] = ref
      #when "empty"
      end
    when :end_document
      states[-1] << event
    when :text
      states[-1] << event
    end
  end while event[0] != :end_document
end

def receive event
  validate( event )
end