operationtoken.java

用JAVA写的计算一段数学表达式的程序

package net.csksoft.util.expcomp;
import java.util.*;
abstract public class OperationToken extends ExpToken {
//Finish CodeFans.net
	abstract public boolean Calc(Stack<OpObj> objStack);
	public OperationToken()
	{
		arg_num = 2;
	}
	public int getTokenType()
	{
		return ExpToken.TOKEN_OPERATION;
	}
	public int getArgNum(){
		return arg_num;
	}
	public boolean setArgNum(int newNum){
		if (newNum==2)
		{
		arg_num = newNum;
		return true;
		}
		else
		{
			return false;
		}
	}
	static final int OPERATION_PLUS = 1;
	static final int OPERATION_MINUS = 2;
	static final int OPERATION_DIV = 3;
	static final int OPERATION_MUL = 4;	
	protected int arg_num;
}