def word(self, size, dist):
        """Get word
        """
        #split dist in index and action
        ndbits = self.NDBITS[size]
        index = dist&(1<<ndbits)-1
        action = dist>>ndbits
        #compute position in file
        position = sum(n<<self.NDBITS[n] for n in range(4,size))+size*index
        self.file.seek(position)
        return self.doAction(self.file.read(size), action)
Get word