code: func (ra *RunAutomaton) step(state, c int) int {
  	if ra.classmap == nil {
  		return ra.transitions[state*len(ra.points)+ra.charClass(c)]
  	} else {
  		return ra.transitions[state*len(ra.points)+ra.classmap[c]]
  	}
  }
docs: /*
  Returns the state obtained by reading the given char from the given
  state. Returns -1 if not obtaining any such state. (If the original
  Automaton had no dead states, -1 is returned here if and only if a
  dead state is entered in an equivalent automaton with a total
  transition function.)
  */