init_separators

# File lib/csv.rb, line 2007
  def init_separators(col_sep, row_sep, quote_char, force_quotes)
    # store the selected separators
    @col_sep    = col_sep.to_s.encode(@encoding)
    @row_sep    = row_sep # encode after resolving :auto
    @quote_char = quote_char.to_s.encode(@encoding)
    @double_quote_char = @quote_char * 2

    if @quote_char.length != 1
      raise ArgumentError, ":quote_char has to be a single character String"
    end

    #
    # automatically discover row separator when requested
    # (not fully encoding safe)
    #
    if @row_sep == :auto
      if [ARGF, STDIN, STDOUT, STDERR].include?(@io) or
         (defined?(Zlib) and @io.class == Zlib::GzipWriter)
        @row_sep = $INPUT_RECORD_SEPARATOR
      else
        begin
          #
          # remember where we were (pos() will raise an exception if @io is pipe
          # or not opened for reading)
          #
          saved_pos = @io.pos
          while @row_sep == :auto
            #
            # if we run out of data, it's probably a single line
            # (ensure will set default value)
            #
            break unless sample = @io.gets(nil, 1024)
            # extend sample if we're unsure of the line ending
            if sample.end_with? encode_str("\r")
              sample << (@io.gets(nil, 1) || "")
            end

            # try to find a standard separator
            if sample =~ encode_re("\r\n?|\n")
              @row_sep = $&
              break
            end
          end

          # tricky seek() clone to work around GzipReader's lack of seek()
          @io.rewind
          # reset back to the remembered position
          while saved_pos > 1024  # avoid loading a lot of data into memory
            @io.read(1024)
            saved_pos -= 1024
          end
          @io.read(saved_pos) if saved_pos.nonzero?
        rescue IOError         # not opened for reading
          # do nothing:  ensure will set default
        rescue NoMethodError   # Zlib::GzipWriter doesn't have some IO methods
          # do nothing:  ensure will set default
        rescue SystemCallError # pipe
          # do nothing:  ensure will set default
        ensure
          #
          # set default if we failed to detect
          # (stream not opened for reading, a pipe, or a single line of data)
          #
          @row_sep = $INPUT_RECORD_SEPARATOR if @row_sep == :auto
        end
      end
    end
    @row_sep = @row_sep.to_s.encode(@encoding)

    # establish quoting rules
    @force_quotes = force_quotes
    do_quote = lambda do |field|
      field = String(field)
      encoded_quote = @quote_char.encode(field.encoding)
      encoded_quote + field.gsub(encoded_quote, encoded_quote * 2) + encoded_quote
    end
    quotable_chars = encode_str("\r\n", @col_sep, @quote_char)
    @quote         = if @force_quotes
      do_quote
    else
      lambda do |field|
        if field.nil?  # represent +nil+ fields as empty unquoted fields
          ""
        else
          field = String(field)  # Stringify fields
          # represent empty fields as empty quoted fields
          if field.empty? or
             field.count(quotable_chars).nonzero?
            do_quote.call(field)
          else
            field  # unquoted field
          end
        end
      end
    end
  end