Fun with RubyMotion! An extension of the Ruby String class to support transliteration using CFStringTransform()

ruby_cfstringtransform.rb

# encoding: UTF-8

class String

  # Extend string to include transliterations to different orthographies
  # from Latin character set or the reverse (`to_latin`)
  #
  # Supported Orthographies:
  # Arabic, Cyrillic, Greek, Hangul, Hiragana, Katakana, Latin, Thai
  #
  # Examples:
  # assert_equals "γειά σου", "geiá sou".to_greek
  # assert_equals "ひらがな",  "hiragana".to_hiragana
  # assert_equals "привет",   "privet".to_cyrillic
  #
  # assert_equals "privet",   "привет".to_latin
  # assert_equals "privet",   "privet".to_cyrillic.to_latin
  def method_missing meth, *args
    if meth =~ /^to_(\w+)$/
      if meth.to_s == "to_latin"
        transform(KCFStringTransformToLatin)
      else
        type = Object.const_get("KCFStringTransformLatin#{$1.capitalize}")
        transform(type)
      end
    end
  end

  private

  # Transform Strings by the power of Core Foundation!
  # Returns a transformed copy of self, or nil if the
  # transformation failed
  def transform type, reverse=false
    # clone the string first, since CFStringTransform does an
    # in-place transformation (and returns a boolean)
    string = self.clone
    if CFStringTransform(string, nil, type, reverse)
      string
    end
  end

  # initialize constants, to avoid uninitialized constant NameError
  def cf_constants
    [
      KCFStringTransformLatinGreek,
      KCFStringTransformLatinArabic,
      KCFStringTransformLatinCyrillic,
      KCFStringTransformLatinHangul,
      KCFStringTransformLatinHiragana,
      KCFStringTransformLatinKatakana,
      KCFStringTransformLatinThai
    ]
  end
end