expression.h

用C++编写的一个计算器

/*This program can solve simple formula
 *by adder, subtraction, multiplication and division,
 *whose operand is float, including minus float.
 */
//Expression.h
#if !defined (_EXPRESSION_HEAD_)
#define _EXPRESSION_HEAD_

#if     _MSC_VER > 100
#pragma once
#endif

#include "SqStack.h"

typedef char OptrType;
typedef double OpndType;

class Expression{
	//Epression class
public:
	Expression(char *);
	OpndType calPostExpression(void);
private:
	int In(char c);
	char Precede(OptrType,OptrType);
	OpndType Operate(OpndType x,OptrType o,OpndType y);
	SqStack<OptrType> OPTR; 
	SqStack<OpndType> OPND;
	char* s;
};

#endif