operator.cs

来自「编译原理语法分析和词法分析综合实验： 源程序、可执行程序、测试程序文件、程序运行」· CS 代码 · 共 107 行

using System;
using System.Collections.Generic;
using System.Text;

namespace syn
{
    public class Operator
    {
        public static readonly char LeftCurve = '(';
        public static readonly char RightCurve = ')';

        private char _operator;

        public Operator(char op)
        {
            this._operator = op;
        }

        public char Value
        {
            get { return this._operator; }
        }

        public bool IsLeftCurve()
        {
            return IsLeftCurve(this._operator);
        }

        public bool IsRightCurve()
        {
            return IsRightCurve(this._operator);
        }

        public static bool IsLeftCurve(char ch)
        {
            if (ch == LeftCurve)
                return true;
            else
                return false;
        }

        public static bool IsRightCurve(char ch)
        {
            if (ch == RightCurve)
                return true;
            else
                return false;
        }



        //判断是否是操作fu
        public static bool IsOperator(char ch)
        {
            char[] operators = { '+', '-', '*', '/', '(', ')' };
            for (int i = 0; i < operators.Length; i++)
                if (ch == operators[i])
                    return true;

            return false;
        }

        public int Priority
        {
            get
            {
                return GetPriority(this.Value);
            }
        }

        //返回运算符的优先级
        public static  int GetPriority(char ch)
        {
            int priority;

            switch (ch)
            {
                case '+':
                    priority = 1;
                    break;
                case '-':
                    priority = 1;
                    break;
                case '*':
                    priority = 2;
                    break;
                case '/':
                    priority = 2;
                    break;
                default:
                    priority = 0;
                    break;
            }

            return priority;
        }

        public override string ToString()
        {
            return this._operator.ToString();
        }



    }
}