parse_stream (REXML::Document)

    # File rexml/document.rb, line 161
      def Document.parse_stream( source, listener )
    			if			source.kind_of? Source
    				# do nothing
    			elsif		source.kind_of?  IO
    				source = IOSource.new(source)
    			elsif		source.kind_of? String
    				source = Source.new source
    			else
    				raise "Unknown source type!"
    			end

    			while not source.empty?
    				word = source.match( /^\s*(<.*?)>/um )
    				source.match( /^\s*/um, true )
    				word = word[1] unless word.nil?
    				case word
    				when nil
    					word = source.match( /\s*(\S+)/um, true )
    					return if word.nil?
    					word = word[0]
    					raise "data found outside of root element ('#{word}')" if word.strip.length > 0
    				when Comment::START_RE
    					Comment.parse_stream source, listener
    				when DocType::START_RE
    					DocType.parse_stream source, listener
    				when XMLDecl::START_RE
    					XMLDecl.parse_stream source, listener
    				when Instruction::START_RE
    					Instruction.parse_stream source, listener
    				else
    					Element.parse_stream source, listener
    				end
    			end
    			# Here we need to check for invalid documents.
    		end