# File lib/rexml/parsers/baseparser.rb, line 115
def initialize( source )
  self.stream = source
  @listeners = []
end

# File lib/rexml/parsers/baseparser.rb, line 120
def add_listener( listener )
  @listeners << listener
end

# File lib/rexml/parsers/baseparser.rb, line 146
def empty?
  return (@source.empty? and @stack.empty?)
end

# File lib/rexml/parsers/baseparser.rb, line 417
def entity( reference, entities )
  value = nil
  value = entities[ reference ] if entities
  if not value
    value = DEFAULT_ENTITIES[ reference ]
    value = value[2] if value
  end
  unnormalize( value, entities ) if value
end

# File lib/rexml/parsers/baseparser.rb, line 151
def has_next?
  return !(@source.empty? and @stack.empty?)
end

# File lib/rexml/parsers/baseparser.rb, line 428
def normalize( input, entities=nil, entity_filter=nil )
  copy = input.clone
  # Doing it like this rather than in a loop improves the speed
  copy.gsub!( EREFERENCE, '&' )
  entities.each do |key, value|
    copy.gsub!( value, "&#{key};" ) unless entity_filter and
                                entity_filter.include?(entity)
  end if entities
  copy.gsub!( EREFERENCE, '&' )
  DEFAULT_ENTITIES.each do |key, value|
    copy.gsub!( value[3], value[1] )
  end
  copy
end

# File lib/rexml/parsers/baseparser.rb, line 167
def peek depth=0
  raise %Q[Illegal argument "#{depth}"] if depth < -1
  temp = []
  if depth == -1
    temp.push(pull()) until empty?
  else
    while @stack.size+temp.size < depth+1
      temp.push(pull())
    end
  end
  @stack += temp if temp.size > 0
  @stack[depth]
end

# File lib/rexml/parsers/baseparser.rb, line 136
def position
  if @source.respond_to? :position
    @source.position
  else
    # FIXME
    0
  end
end

# File lib/rexml/parsers/baseparser.rb, line 182
def pull
  pull_event.tap do |event|
    @listeners.each do |listener|
      listener.receive event
    end
  end
end

# File lib/rexml/parsers/baseparser.rb, line 126
def stream=( source )
  @source = SourceFactory.create_from( source )
  @closed = nil
  @document_status = nil
  @tags = []
  @stack = []
  @entities = []
  @nsstack = []
end

# File lib/rexml/parsers/baseparser.rb, line 444
def unnormalize( string, entities=nil, filter=nil )
  rv = string.clone
  rv.gsub!( /\r\n?/, "\n" )
  matches = rv.scan( REFERENCE_RE )
  return rv if matches.size == 0
  rv.gsub!( /&#0*((?:\d+)|(?:x[a-fA-F0-9]+));/ ) {
    m=$1
    m = "0#{m}" if m[0] == ?x
    [Integer(m)].pack('U*')
  }
  matches.collect!{|x|x[0]}.compact!
  if matches.size > 0
    matches.each do |entity_reference|
      unless filter and filter.include?(entity_reference)
        entity_value = entity( entity_reference, entities )
        if entity_value
          re = /&#{entity_reference};/
          rv.gsub!( re, entity_value )
        else
          er = DEFAULT_ENTITIES[entity_reference]
          rv.gsub!( er[0], er[2] ) if er
        end
      end
    end
    rv.gsub!( /&/, '&' )
  end
  rv
end

# File lib/rexml/parsers/baseparser.rb, line 157
def unshift token
  @stack.unshift(token)
end

# File lib/rexml/parsers/baseparser.rb, line 474
def need_source_encoding_update?(xml_declaration_encoding)
  return false if xml_declaration_encoding.nil?
  return false if /\AUTF-16\z/i =~ xml_declaration_encoding
  true
end

# File lib/rexml/parsers/baseparser.rb, line 489
def parse_attributes(prefixes, curr_ns)
  attributes = {}
  closed = false
  match_data = @source.match(/^(.*?)(\/)?>/um, true)
  if match_data.nil?
    message = "Start tag isn't ended"
    raise REXML::ParseException.new(message, @source)
  end

  raw_attributes = match_data[1]
  closed = !match_data[2].nil?
  return attributes, closed if raw_attributes.nil?
  return attributes, closed if raw_attributes.empty?

  scanner = StringScanner.new(raw_attributes)
  until scanner.eos?
    if scanner.scan(/\s+/)
      break if scanner.eos?
    end

    pos = scanner.pos
    loop do
      break if scanner.scan(ATTRIBUTE_PATTERN)
      unless scanner.scan(QNAME)
        message = "Invalid attribute name: <#{scanner.rest}>"
        raise REXML::ParseException.new(message, @source)
      end
      name = scanner[0]
      unless scanner.scan(/\s*=\s*/um)
        message = "Missing attribute equal: <#{name}>"
        raise REXML::ParseException.new(message, @source)
      end
      quote = scanner.scan(/['"]/)
      unless quote
        message = "Missing attribute value start quote: <#{name}>"
        raise REXML::ParseException.new(message, @source)
      end
      unless scanner.scan(/.*#{Regexp.escape(quote)}/um)
        match_data = @source.match(/^(.*?)(\/)?>/um, true)
        if match_data
          scanner << "/" if closed
          scanner << ">"
          scanner << match_data[1]
          scanner.pos = pos
          closed = !match_data[2].nil?
          next
        end
        message =
          "Missing attribute value end quote: <#{name}>: <#{quote}>"
        raise REXML::ParseException.new(message, @source)
      end
    end
    name = scanner[1]
    prefix = scanner[2]
    local_part = scanner[3]
    # quote = scanner[4]
    value = scanner[5]
    if prefix == "xmlns"
      if local_part == "xml"
        if value != "http://www.w3.org/XML/1998/namespace"
          msg = "The 'xml' prefix must not be bound to any other namespace "+
            "(http://www.w3.org/TR/REC-xml-names/#ns-decl)"
          raise REXML::ParseException.new( msg, @source, self )
        end
      elsif local_part == "xmlns"
        msg = "The 'xmlns' prefix must not be declared "+
          "(http://www.w3.org/TR/REC-xml-names/#ns-decl)"
        raise REXML::ParseException.new( msg, @source, self)
      end
      curr_ns << local_part
    elsif prefix
      prefixes << prefix unless prefix == "xml"
    end

    if attributes.has_key?(name)
      msg = "Duplicate attribute #{name.inspect}"
      raise REXML::ParseException.new(msg, @source, self)
    end

    attributes[name] = value
  end
  return attributes, closed
end

# File lib/rexml/parsers/baseparser.rb, line 480
def process_instruction
  match_data = @source.match(INSTRUCTION_PATTERN, true)
  unless match_data
    message = "Invalid processing instruction node"
    raise REXML::ParseException.new(message, @source)
  end
  [:processing_instruction, match_data[1], match_data[2]]
end

# 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+)|(?:<[^>]*>))/um )
    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/i =~ @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*/um, 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*/um, 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*(.*?>)/um)
    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 and !last_tag
          message = "Unexpected top-level end tag (got '#{md[1]}')"
          raise REXML::ParseException.new(message, @source)
        end
        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*[^>]*>)/um)
        #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