module RailsI18n::Transliteration::Russian

def rule
  lambda do |string|
    next '' unless string
    chars = string.scan(%r{#{multi_keys.join '|'}|\w|.})
    result = +""
    chars.each_with_index do |char, index|
      if upper.has_key?(char) && lower.has_key?(chars[index+1])
        # combined case
        result << upper[char].downcase.capitalize
      elsif upper.has_key?(char)
        result << upper[char]
      elsif lower.has_key?(char)
        result << lower[char]
      else
        result << char
      end
    end
    result
  end
end