translate

# File lib/rexml/functions.rb, line 228
    def Functions::translate( string, tr1, tr2 )
      from = string(tr1)
      to = string(tr2)

      # the map is our translation table.
      #
      # if a character occurs more than once in the
      # from string then we ignore the second &
      # subsequent mappings
      #
      # if a character maps to nil then we delete it
      # in the output.  This happens if the from
      # string is longer than the to string
      #
      # there's nothing about - or ^ being special in
      # http://www.w3.org/TR/xpath#function-translate
      # so we don't build ranges or negated classes

      map = Hash.new
      0.upto(from.length - 1) { |pos|
        from_char = from[pos]
        unless map.has_key? from_char
          map[from_char] = 
          if pos < to.length
            to[pos]
          else
            nil
          end
        end
      }

      string(string).unpack('U*').collect { |c|
        if map.has_key? c then map[c] else c end
      }.compact.pack('U*')
    end