parameterize

# File activesupport/lib/active_support/inflector/transliterate.rb, line 82
    def parameterize(string, sep = :unused, separator: '-', preserve_case: false)
      unless sep == :unused
        ActiveSupport::Deprecation.warn("Passing the separator argument as a positional parameter is deprecated and will soon be removed. Use `separator: '#{sep}'` instead.")
        separator = sep
      end
      # Replace accented chars with their ASCII equivalents.
      parameterized_string = transliterate(string)

      # Turn unwanted chars into the separator.
      parameterized_string.gsub!(/[^a-z0-9\-_]+/, separator)

      unless separator.nil? || separator.empty?
        if separator == "-".freeze
          re_duplicate_separator        = /-{2,}/
          re_leading_trailing_separator = /^-|-$/
        else
          re_sep = Regexp.escape(separator)
          re_duplicate_separator        = /#{re_sep}{2,}/
          re_leading_trailing_separator = /^#{re_sep}|#{re_sep}$/
        end
        # No more than one of the separator in a row.
        parameterized_string.gsub!(re_duplicate_separator, separator)
        # Remove leading/trailing separator.
        parameterized_string.gsub!(re_leading_trailing_separator, ''.freeze)
      end
      
      parameterized_string.downcase! unless preserve_case
      parameterized_string
    end