identify_here_document

# File lib/irb/ruby-lex.rb, line 879
  def identify_here_document
    ch = getc
#    if lt = PERCENT_LTYPE[ch]
    if ch == "-"
      ch = getc
      indent = true
    end
    if /['"`]/ =~ ch
      lt = ch
      quoted = ""
      while (c = getc) && c != lt
        quoted.concat c
      end
    else
      lt = '"'
      quoted = ch.dup
      while (c = getc) && c =~ /\w/
        quoted.concat c
      end
      ungetc
    end

    ltback, @ltype = @ltype, lt
    reserve = []
    while ch = getc
      reserve.push ch
      if ch == "\\"
        reserve.push ch = getc
      elsif ch == "\n"
        break
      end
    end

    @here_header = false
    while l = gets
      l = l.sub(/(:?\r)?\n\z/, '')
      if (indent ? l.strip : l) == quoted
        break
      end
    end

    @here_header = true
    @here_readed.concat reserve
    while ch = reserve.pop
      ungetc ch
    end

    @ltype = ltback
    @lex_state = EXPR_END
    Token(Ltype2Token[lt])
  end