LISTING 1.  Header File for FuncEval Object


/*****************************************
*                                        *
*  FuncEval.hpp                          *
*                                        *
*  Definition file for FuncEval class.   *
*                                        *
*  Implementation in FuncEval.cpp.       *
*                                        *
******************************************
*                                        *
*  Copyright 1995  Randy C. Finch        *
*                                        *
*****************************************/

#ifndef CLASS_FUNCEVAL
#define CLASS_FUNCEVAL


/*--------------  INCLUDES  ----------------*/

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <float.h>
#include <stdlib.h>
#include <ctype.h>


/*----------------  DEFINES  -----------------*/

/* Variable Types */

typedef unsigned char UCHAR;
typedef unsigned int  UINT;
typedef unsigned long ULONG;

/* Errors */

#define MISPLACEDOP     1    /* Misplaced operator */
#define ILLEGALCHAR     2    /* Illegal character */
#define ILLEGALEXP      3    /* Illegal exponent */
#define ILLEGALFUNC     4    /* Illegal function */
#define MISSINGOP       5    /* Missing operator */
#define MISSINGOPRP     6    /* Missing operator or right parenthesis */
#define MISSINGLP       7    /* Missing left parenthesis */
#define MISSINGRP       8    /* Missing right parenthesis */
#define MISSINGPARM     9    /* Missing parameter */
#define LONEDECIMAL    10    /* Lone decimal point */
#define EXTRADECIMAL   11    /* Extra decimal point */
#define EXTRAE         12    /* Extra E in exponent */
#define STACKUNDERFLOW 13    /* Stack underflow */
#define STACKOVERFLOW  14    /* Stack overflow */
#define TOOMANYCONST   15    /* Too many constants in function */

/* Constants in formula */

#define NUMSYM    128  /* Number of constants allowed in function */
#define SYMBASE   128  /* Base value for constants symbols */

/* Stack size */

#define STACKSIZE 256  /* Stack size */

/* Functions in formula */

#define SIN         1  /* Symbol for sine */
#define COS         2  /* Symbol for cosine */
#define TAN         3  /* Symbol for tangent */
#define ASIN        4  /* Symbol for arcsine */
#define ACOS        5  /* Symbol for arccosine */
#define ATAN        6  /* Symbol for arctangent */
#define SINH        7  /* Symbol for hyperbolic sine */
#define COSH        8  /* Symbol for hyperbolic cosine */
#define TANH        9  /* Symbol for hyperbolic tangent */
#define EXP        10  /* Symbol for exponential */
#define SQRT       11  /* Symbol for square root */
#define LN         12  /* Symbol for natural logarithm */
#define LOG        13  /* Symbol for logarithn base 10 */

/* Logical stuff */

#define TRUE        1  /* Symbol for true condition */
#define FALSE       0  /* Symbol for false condition */


/*----------- STRUCTURE DEFINITIONS ----------*/

struct CharStackType {
   UCHAR c[STACKSIZE];
   long          top;
};
typedef struct CharStackType CharStack;

struct NumStackType {
   double n[STACKSIZE];
   long   top;
};
typedef struct NumStackType NumStack;


/*------------ CLASS DEFINITION -------------*/

class FuncEval {
public:
   FuncEval();  // Constructor
   double Evaluate(double x, double y);
   int Convert(UCHAR *FunctionString);
   int GetSyntaxErrNum();
   char *GetSyntaxErrMessage();
   int GetErrPosition();
private:
   int SyntaxErr;
   char *ErrMessage;
   int ErrPosition;
   CharStack cstack;
   NumStack nstack;
   double Constants[NUMSYM];
   UCHAR CurConstant;
   UCHAR fstr[512];
   UCHAR NewExpr[256];

   char CharInStr(UCHAR *s, UCHAR c);
   void Deposit(double num);
   void Substitute(UCHAR symb, UCHAR *ptr, ULONG len);
   void RemoveSpaces(UCHAR *str);
   void AddZero(UCHAR *ptr);
   UCHAR CPop();
   char CPush(UCHAR c);
   UCHAR CTopOfStack();
   double NPop();
   void NPush(double n);
   char IsFunction(UCHAR c);
   char IsSymbol(UCHAR c);
   char Precedence(UCHAR c1, UCHAR c2);
   UCHAR *CheckSyntax(UCHAR *str);
   char ConvertConstants(UCHAR *str);
   void ConvertFunctions(UCHAR *str);
   char InfixToPostfix(UCHAR *str);
   double Calculate(UCHAR s, double n2, double n1);
};

#endif