老外写的表达式求值C++封装类,计算器源码

// Function.cpp : Defines the class behaviors for the application. // #include "stdafx.h" #include "math.h" #include "express.h" #include <ctype.h> #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif IMPLEMENT_SERIAL(CExpression, CObject, 0) ////////////////////////////////////////////////////////////////////// // CExpression Class ////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////// // Variabile Globale //parametrii Global(50); ///////////////////////////////////////////////////////////////////////////////// // Eliberarea memorie ocupate de arbore void CExpression::elibmem ( arbore a) { if (a==NULL) return; if (a->left!=NULL) elibmem(a->left); if (a->right!=NULL) elibmem(a->right); if (a->operatie == '`') delete a->valoarestr; delete a; } ////////////////////////////////////////////////////////////////////// // Construction/Destruction ////////////////////////////////////////////////////////////////////// CExpression::CExpression() { m_Arbore = NULL; m_definitie = ""; pozitie = 0; m_pvariabile = NULL; } CExpression::CExpression(CMapVariabile * vars) { m_Arbore = NULL; m_definitie = ""; pozitie = 0; m_pvariabile = vars; } CExpression::~CExpression() { elibmem (m_Arbore); } void CExpression::Serialize(CArchive & ar) { if (ar.IsStoring()) { // TODO: add storing code here ar << m_definitie; } else { // TODO: add loading code here ar >> m_definitie; m_Arbore = NULL; pozitie = 0; UpdateArbore(); // After loading this object if it contains variables you should atach a variable // Table to it } } int CExpression::UpdateArbore() { if (m_definitie.IsEmpty()) return 0; elibmem(m_Arbore); // Eliberarea memoriei ocupate de arbore m_Arbore = NULL; pozitie = 0; m_Arbore = expresie(); if (m_definitie[pozitie]!='\0') { elibmem(m_Arbore); m_Arbore = NULL; } if (m_Arbore == NULL) return pozitie; else return -1; } CExpression::arbore CExpression::expresie() { arbore nod; arbore arb1 = termen(); arbore arb2; if (arb1 == NULL) return NULL; // In caz de eroare terminate while ((m_definitie[pozitie]=='-') || (m_definitie[pozitie]=='+')) { nod=new NOD; nod->left=arb1; nod->operatie=m_definitie[pozitie]; pozitie++; arb2 = termen(); nod->right=arb2; if (arb2 == NULL) { elibmem(nod); return NULL; // In caz de eroare terminate } arb1 = nod; } return arb1; } CExpression::arbore CExpression::termen() { arbore nod; arbore arb1 = putere(); arbore arb2; if (arb1 == NULL) return NULL; // In caz de eroare terminate while ((m_definitie[pozitie]=='*') || (m_definitie[pozitie]=='/')) { nod=new NOD; nod->left=arb1; nod->operatie=m_definitie[pozitie]; pozitie++; arb2 = putere(); nod->right=arb2; if (arb2 == NULL) { elibmem(nod); return NULL; // In caz de eroare terminate } arb1 = nod; } return arb1; } CExpression::arbore CExpression::putere() { arbore nod = NULL; arbore arb1 = logicalOp(); arbore arb2; if (arb1 == NULL) return NULL; // In caz de eroare terminate while (m_definitie[pozitie]=='^') { nod=new NOD; nod->left=arb1; nod->operatie=m_definitie[pozitie]; pozitie++; arb2 = logicalOp(); nod->right=arb2; if (arb2 == NULL) { elibmem(nod); return NULL; // In caz de eroare terminate } arb1 = nod; } return arb1; } CExpression::arbore CExpression::factor() { arbore nod = NULL,nod2 = NULL,left = NULL; while(m_definitie[pozitie] == ' ' && m_definitie[pozitie] != '\0') pozitie++; if (m_definitie[pozitie]=='-') { nod = new NOD; left = new NOD; left->right=NULL; left->left=NULL; left->operatie='@'; left->valoare=-1; nod->left=left; nod->operatie='*'; pozitie++; nod->right = expresie(); if (nod->right == NULL) return NULL; return nod; } if (m_definitie[pozitie]=='(') { pozitie++; nod = expresie(); if (nod == NULL) return NULL; if (m_definitie[pozitie]!=')') { elibmem(nod); return NULL; } pozitie++; return nod; } else if (m_definitie[pozitie]=='|') { pozitie++; nod2 = expresie(); if (nod2 == NULL) return NULL; if (m_definitie[pozitie]!='|') { elibmem(nod); return NULL; } nod = new NOD; nod->left=nod2; nod->right=NULL; nod->operatie='|'; pozitie++; return nod; } else return identificator(); return nod; } CExpression::arbore CExpression::identificator() { int poz; arbore nod = NULL,nod2 = NULL; arbore result = NULL; poz=pozitie; SkipSpaces(); if (m_definitie[pozitie]=='\0') result = NULL; if (isdigit(m_definitie[pozitie])) // Este numar ? { while ((isdigit(m_definitie[pozitie]) || (m_definitie[pozitie]=='.'))) pozitie++; nod = new NOD; nod->left = NULL; nod->right = NULL; nod->operatie = '@'; #ifdef UNICODE nod->valoare = _wtof(m_definitie.Mid(poz,pozitie-poz)); #else nod->valoare = atof(m_definitie.Mid(poz,pozitie-poz)); #endif result = nod; } if (isalpha(m_definitie[pozitie])) // Am i an identifier ? { while (isalnum(m_definitie[pozitie])) pozitie++; CString id = m_definitie.Mid(poz,pozitie-poz); CString nid = id; id.MakeUpper(); if (id =="SIN") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=150; SkipSpaces(); return nod; } if (id =="COS") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=151; SkipSpaces(); return nod; } if (id =="EXP") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=152; SkipSpaces(); return nod; } if (id =="SQRT") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=153; SkipSpaces(); return nod; } if (id =="LOG") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=154; SkipSpaces(); return nod; } if (id =="TG") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=155; SkipSpaces(); return nod; } if (id =="CTG") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=156; SkipSpaces(); return nod; } if (id =="ASIN") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=157; SkipSpaces(); return nod; } if (id =="ACOS") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=158; SkipSpaces(); return nod; } if (id =="ATG") // Functia sinus CString { nod2 = factor(); nod = new NOD; nod->left = nod2; nod->right=NULL; nod->operatie=159; SkipSpaces(); return nod; } CValue *valoare; if (m_pvariabile->Lookup(nid,valoare)) { nod = new NOD; nod -> left = NULL; nod -> right = NULL; nod -> operatie = '`'; nod -> valoarestr = new CString(nid); result = nod; } else result = NULL; } SkipSpaces(); return result; } int CExpression::ChangeExpression(CString & expresie) { m_definitie = expresie + '\0' + '\0'; ret