CSV::Parser#prepare_separators

# File tmp/rubies/ruby-3.2.0/lib/csv/parser.rb, line 568
def prepare_separators
  column_separator = @options[:column_separator]
  @column_separator = column_separator.to_s.encode(@encoding)
  if @column_separator.size < 1
    message = ":col_sep must be 1 or more characters: "
    message += column_separator.inspect
    raise ArgumentError, message
  end
  @row_separator =
    resolve_row_separator(@options[:row_separator]).encode(@encoding)

  @escaped_column_separator = Regexp.escape(@column_separator)
  @escaped_first_column_separator = Regexp.escape(@column_separator[0])
  if @column_separator.size > 1
    @column_end = Regexp.new(@escaped_column_separator)
    @column_ends = @column_separator.each_char.collect do |char|
      Regexp.new(Regexp.escape(char))
    end
    @first_column_separators = Regexp.new(@escaped_first_column_separator +
                                          "+".encode(@encoding))
  else
    if STRING_SCANNER_SCAN_ACCEPT_STRING
      @column_end = @column_separator
    else
      @column_end = Regexp.new(@escaped_column_separator)
    end
    @column_ends = nil
    @first_column_separators = nil
  end

  escaped_row_separator = Regexp.escape(@row_separator)
  @row_end = Regexp.new(escaped_row_separator)
  if @row_separator.size > 1
    @row_ends = @row_separator.each_char.collect do |char|
      Regexp.new(Regexp.escape(char))
    end
  else
    @row_ends = nil
  end

  @cr = "\r".encode(@encoding)
  @lf = "\n".encode(@encoding)
  @line_end = Regexp.new("\r\n|\n|\r".encode(@encoding))
  @not_line_end = Regexp.new("[^\r\n]+".encode(@encoding))
end