CSV::Writer#prepare_format

# File tmp/rubies/ruby-3.3.0/lib/csv/writer.rb, line 133
def prepare_format
  @column_separator = @options[:column_separator].to_s.encode(@encoding)
  row_separator = @options[:row_separator]
  if row_separator == :auto
    @row_separator = InputRecordSeparator.value.encode(@encoding)
  else
    @row_separator = row_separator.to_s.encode(@encoding)
  end
  @quote_character = @options[:quote_character]
  force_quotes = @options[:force_quotes]
  if force_quotes.is_a?(Array)
    prepare_force_quotes_fields(force_quotes)
    @force_quotes = false
  elsif force_quotes
    @force_quotes_fields = nil
    @force_quotes = true
  else
    @force_quotes_fields = nil
    @force_quotes = false
  end
  unless @force_quotes
    @quotable_pattern =
      Regexp.new("[\r\n".encode(@encoding) +
                 Regexp.escape(@column_separator) +
                 Regexp.escape(@quote_character.encode(@encoding)) +
                 "]".encode(@encoding))
  end
  @quote_empty = @options.fetch(:quote_empty, true)
end