class REXML::IOSource

# File rexml/source.rb, line 163
def initialize(arg, block_size=500, encoding=nil)
  @er_source = @source = arg
  @to_utf = false
  @pending_buffer = nil

  if encoding
    super("", encoding)
  else
    super(@source.read(3) || "")
  end

  if !@to_utf and
      @buffer.respond_to?(:force_encoding) and
      @source.respond_to?(:external_encoding) and
      @source.external_encoding != ::Encoding::UTF_8
    @force_utf8 = true
  else
    @force_utf8 = false
  end
end

# File rexml/source.rb, line 215
def consume( pattern )
  match( pattern, true )
end

# File rexml/source.rb, line 244
def current_line
  begin
    pos = @er_source.pos        # The byte position in the source
    lineno = @er_source.lineno  # The XML < position in the source
    @er_source.rewind
    line = 0                    # The \r\n position in the source
    begin
      while @er_source.pos < pos
        @er_source.readline
        line += 1
      end
    rescue
    end
    @er_source.seek(pos)
  rescue IOError
    pos = -1
    line = -1
  end
  [pos, lineno, line]
end

# File rexml/source.rb, line 235
def empty?
  super and ( @source.nil? || @source.eof? )
end

# File rexml/source.rb, line 219
def match( pattern, cons=false )
  rv = pattern.match(@buffer)
  @buffer = $' if cons and rv
  while !rv and @source
    begin
      @buffer << readline
      rv = pattern.match(@buffer)
      @buffer = $' if cons and rv
    rescue
      @source = nil
    end
  end
  rv.taint if RUBY_VERSION < '2.7'
  rv
end

# File rexml/source.rb, line 239
def position
  @er_source.pos rescue 0
end

# File rexml/source.rb, line 207
def read
  begin
    @buffer << readline
  rescue Exception, NameError
    @source = nil
  end
end

# File rexml/source.rb, line 184
def scan(pattern, cons=false)
  rv = super
  # You'll notice that this next section is very similar to the same
  # section in match(), but just a liiittle different.  This is
  # because it is a touch faster to do it this way with scan()
  # than the way match() does it; enough faster to warrant duplicating
  # some code
  if rv.size == 0
    until @buffer =~ pattern or @source.nil?
      begin
        @buffer << readline
      rescue Iconv::IllegalSequence
        raise
      rescue
        @source = nil
      end
    end
    rv = super
  end
  rv.taint if RUBY_VERSION < '2.7'
  rv
end

# File rexml/source.rb, line 286
def encoding_updated
  case @encoding
  when "UTF-16BE", "UTF-16LE"
    @source.binmode
    @source.set_encoding(@encoding, @encoding)
  end
  @line_break = encode(">")
  @pending_buffer, @buffer = @buffer, ""
  @pending_buffer.force_encoding(@encoding)
  super
end

# File rexml/source.rb, line 266
def readline
  str = @source.readline(@line_break)
  if @pending_buffer
    if str.nil?
      str = @pending_buffer
    else
      str = @pending_buffer + str
    end
    @pending_buffer = nil
  end
  return nil if str.nil?

  if @to_utf
    decode(str)
  else
    str.force_encoding(::Encoding::UTF_8) if @force_utf8
    str
  end
end