状态机

/**
  * 运算符状态
 *
  * @param char // 状态字符
  * @param subStateIndex // 后继状态数组的索引
  * @param subStateCount // 后继状态个数
  * @param index // 运算符索引
  * @param state // 状态
  * @param symbol // 状态
  */
case class OperatorState(char:Char,subStateIndex:Int,subStateCount:Int,index:Int,state:Int,symbol:String){
}

object OperatorStateMachineConfig{
  val state0:List[OperatorState]=List[OperatorState](
    OperatorState('-',1,1,0,0,"-"),
    OperatorState('+',0,2,1,0,"+"),
    OperatorState('=',0,0,2,0,"=")
  )

  val state1:List[OperatorState]=List[OperatorState](
    OperatorState('+',0,1,3,1,"++"), // ++
    OperatorState('=',0,0,4,1,"+="), // +=
    OperatorState('=',0,0,5,1,"-=") // -=
  )

  val state2:List[OperatorState]=List[OperatorState](
    OperatorState('+',0,0,6,2,"+++") // +++
  )

}

 def matchState(operators:Array[Char]):OperatorState={
    def matchOperator(operators:Array[Char],opIndex:Int,group:Int,index:Int,stateCount:Int,operatorState: OperatorState):OperatorState={
      var result=operatorState
      val states=group match{
        case 0 => OperatorStateMachineConfig.state0
        case 1 => OperatorStateMachineConfig.state1
        case 2 => OperatorStateMachineConfig.state2
      }

      for(i <- index until (index+stateCount) if opIndex<operators.size){
        val state=states(i)
        val operator=operators(opIndex)
        operator match{
          case eqState if operator==state.char =>{
            state.subStateCount match{
              case 0 =>result= state
              case _ =>result= matchOperator(operators,opIndex+1,group+1,state.subStateIndex,state.subStateCount,operatorState)
            }

          }
          case _ =>{} // do nothing
        }
      }

      result
    }

    matchOperator(operators,0,0,0,OperatorStateMachineConfig.state0.size,null)
  }

  def main(args: Array[String]) {
    val command="+++"
    val operators=command.toCharArray
    var states=List[OperatorState]()
    states=states :+ matchState(operators)
    println(states)
  }
}