normalized?

# File lib/unicode_normalize/normalize.rb, line 144
  def self.normalized?(string, form = :nfc)
    encoding = string.encoding
    case encoding
    when Encoding::UTF_8
      case form
      when :nfc then
        string.scan REGEXP_C do |match|
          return false  if NF_HASH_C[match] != match
        end
        true
      when :nfd then
        string.scan REGEXP_D do |match|
          return false  if NF_HASH_D[match] != match
        end
        true
      when :nfkc then
        normalized?(string, :nfc) and string !~ REGEXP_K
      when :nfkd then
        normalized?(string, :nfd) and string !~ REGEXP_K
      else
        raise ArgumentError, "Invalid normalization form #{form}."
      end
    when Encoding::US_ASCII
      true
    when *UNICODE_ENCODINGS
      normalized? string.encode(Encoding::UTF_8), form
    else
      raise Encoding::CompatibilityError, "Unicode Normalization not appropriate for #{encoding}"
    end
  end