pull_event

# File lib/rexml/parsers/baseparser.rb, line 190
      def pull_event
        if @closed
          x, @closed = @closed, nil
          return [ :end_element, x ]
        end
        return [ :end_document ] if empty?
        return @stack.shift if @stack.size > 0
        #STDERR.puts @source.encoding
        @source.read if @source.buffer.size<2
        #STDERR.puts "BUFFER = #{@source.buffer.inspect}"
        if @document_status == nil
          #@source.consume( /^\s*/um )
          word = @source.match( /^((?:\s+)|(?:<[^>]*>))/m )
          word = word[1] unless word.nil?
          #STDERR.puts "WORD = #{word.inspect}"
          case word
          when COMMENT_START
            return [ :comment, @source.match( COMMENT_PATTERN, true )[1] ]
          when XMLDECL_START
            #STDERR.puts "XMLDECL"
            results = @source.match( XMLDECL_PATTERN, true )[1]
            version = VERSION.match( results )
            version = version[1] unless version.nil?
            encoding = ENCODING.match(results)
            encoding = encoding[1] unless encoding.nil?
            if need_source_encoding_update?(encoding)
              @source.encoding = encoding
            end
            if encoding.nil? and /\AUTF-16(?:BE|LE)\z/ =~ @source.encoding
              encoding = "UTF-16"
            end
            standalone = STANDALONE.match(results)
            standalone = standalone[1] unless standalone.nil?
            return [ :xmldecl, version, encoding, standalone ]
          when INSTRUCTION_START
            return process_instruction
          when DOCTYPE_START
            md = @source.match( DOCTYPE_PATTERN, true )
            @nsstack.unshift(curr_ns=Set.new)
            identity = md[1]
            close = md[2]
            identity =~ IDENTITY
            name = $1
            raise REXML::ParseException.new("DOCTYPE is missing a name") if name.nil?
            pub_sys = $2.nil? ? nil : $2.strip
            long_name = $4.nil? ? nil : $4.strip
            uri = $6.nil? ? nil : $6.strip
            args = [ :start_doctype, name, pub_sys, long_name, uri ]
            if close == ">"
              @document_status = :after_doctype
              @source.read if @source.buffer.size<2
              md = @source.match(/^\s*/m, true)
              @stack << [ :end_doctype ]
            else
              @document_status = :in_doctype
            end
            return args
          when /^\s+/
          else
            @document_status = :after_doctype
            @source.read if @source.buffer.size<2
            md = @source.match(/\s*/m, true)
            if @source.encoding == "UTF-8"
              @source.buffer.force_encoding(::Encoding::UTF_8)
            end
          end
        end
        if @document_status == :in_doctype
          md = @source.match(/\s*(.*?>)/m)
          case md[1]
          when SYSTEMENTITY
            match = @source.match( SYSTEMENTITY, true )[1]
            return [ :externalentity, match ]

          when ELEMENTDECL_START
            return [ :elementdecl, @source.match( ELEMENTDECL_PATTERN, true )[1] ]

          when ENTITY_START
            match = @source.match( ENTITYDECL, true ).to_a.compact
            match[0] = :entitydecl
            ref = false
            if match[1] == '%'
              ref = true
              match.delete_at 1
            end
            # Now we have to sort out what kind of entity reference this is
            if match[2] == 'SYSTEM'
              # External reference
              match[3] = match[3][1..-2] # PUBID
              match.delete_at(4) if match.size > 4 # Chop out NDATA decl
              # match is [ :entity, name, SYSTEM, pubid(, ndata)? ]
            elsif match[2] == 'PUBLIC'
              # External reference
              match[3] = match[3][1..-2] # PUBID
              match[4] = match[4][1..-2] # HREF
              match.delete_at(5) if match.size > 5 # Chop out NDATA decl
              # match is [ :entity, name, PUBLIC, pubid, href(, ndata)? ]
            else
              match[2] = match[2][1..-2]
              match.pop if match.size == 4
              # match is [ :entity, name, value ]
            end
            match << '%' if ref
            return match
          when ATTLISTDECL_START
            md = @source.match( ATTLISTDECL_PATTERN, true )
            raise REXML::ParseException.new( "Bad ATTLIST declaration!", @source ) if md.nil?
            element = md[1]
            contents = md[0]

            pairs = {}
            values = md[0].scan( ATTDEF_RE )
            values.each do |attdef|
              unless attdef[3] == "#IMPLIED"
                attdef.compact!
                val = attdef[3]
                val = attdef[4] if val == "#FIXED "
                pairs[attdef[0]] = val
                if attdef[0] =~ /^xmlns:(.*)/
                  @nsstack[0] << $1
                end
              end
            end
            return [ :attlistdecl, element, pairs, contents ]
          when NOTATIONDECL_START
            md = nil
            if @source.match( PUBLIC )
              md = @source.match( PUBLIC, true )
              vals = [md[1],md[2],md[4],md[6]]
            elsif @source.match( SYSTEM )
              md = @source.match( SYSTEM, true )
              vals = [md[1],md[2],nil,md[4]]
            else
              raise REXML::ParseException.new( "error parsing notation: no matching pattern", @source )
            end
            return [ :notationdecl, *vals ]
          when DOCTYPE_END
            @document_status = :after_doctype
            @source.match( DOCTYPE_END, true )
            return [ :end_doctype ]
          end
        end
        begin
          if @source.buffer[0] == <<
            if @source.buffer[1] == //
              @nsstack.shift
              last_tag = @tags.pop
              md = @source.match( CLOSE_MATCH, true )
              if md.nil? or last_tag != md[1]
                message = "Missing end tag for '#{last_tag}'"
                message << " (got '#{md[1]}')" if md
                raise REXML::ParseException.new(message, @source)
              end
              return [ :end_element, last_tag ]
            elsif @source.buffer[1] == !!
              md = @source.match(/\A(\s*[^>]*>)/m)
              #STDERR.puts "SOURCE BUFFER = #{source.buffer}, #{source.buffer.size}"
              raise REXML::ParseException.new("Malformed node", @source) unless md
              if md[0][2] == --
                md = @source.match( COMMENT_PATTERN, true )

                case md[1]
                when /--/, /-\z/
                  raise REXML::ParseException.new("Malformed comment", @source)
                end

                return [ :comment, md[1] ] if md
              else
                md = @source.match( CDATA_PATTERN, true )
                return [ :cdata, md[1] ] if md
              end
              raise REXML::ParseException.new( "Declarations can only occur "+
                "in the doctype declaration.", @source)
            elsif @source.buffer[1] == ??
              return process_instruction
            else
              # Get the next tag
              md = @source.match(TAG_MATCH, true)
              unless md
                raise REXML::ParseException.new("malformed XML: missing tag start", @source)
              end
              prefixes = Set.new
              prefixes << md[2] if md[2]
              @nsstack.unshift(curr_ns=Set.new)
              attributes, closed = parse_attributes(prefixes, curr_ns)
              # Verify that all of the prefixes have been defined
              for prefix in prefixes
                unless @nsstack.find{|k| k.member?(prefix)}
                  raise UndefinedNamespaceException.new(prefix,@source,self)
                end
              end

              if closed
                @closed = md[1]
                @nsstack.shift
              else
                @tags.push( md[1] )
              end
              return [ :start_element, md[1], attributes ]
            end
          else
            md = @source.match( TEXT_PATTERN, true )
            if md[0].length == 0
              @source.match( /(\s+)/, true )
            end
            #STDERR.puts "GOT #{md[1].inspect}" unless md[0].length == 0
            #return [ :text, "" ] if md[0].length == 0
            # unnormalized = Text::unnormalize( md[1], self )
            # return PullEvent.new( :text, md[1], unnormalized )
            return [ :text, md[1] ]
          end
        rescue REXML::UndefinedNamespaceException
          raise
        rescue REXML::ParseException
          raise
        rescue => error
          raise REXML::ParseException.new( "Exception parsing",
            @source, self, (error ? error : $!) )
        end
        return [ :dummy ]
      end