www.pudn.com > 4rd.rar > function.h
#include#include "stack2.h" #include "queue.h" #include int lookup(char lexeme[]) { int i; i=total; while(strcmp(lexeme,table[i].name)&&(i>0)) i--; return i; } int insert(char lexeme[]) { int i; i=lookup(lexeme); if(i==0) { total++; strcpy(table[total].name,lexeme); //将lexeme的内容复制到table[total].name里 return total; } else return i; } void getidentifer() { char lexeme[17]; //标识符缓冲区 int i; i=0; while(isalpha(buffer[position])||isdigit(buffer[position]))//(Is_letter(buffer[position])||Is_number(buffer[position])) { if(i<16) { lexeme[i]=buffer[position]; i++; } position++; } lexeme[i]='\0'; position--; //让position指回当前字符 identry=insert(lexeme); } bool Is_operator(char temp) { for(int i=0;i<6;i++) { if(temp==operators[i]) return true; } return false; } double num_analy() //数字的识别，多位整数，小数 { double radix,decval; numval=0.0; do { decval=buffer[position]-'0'; //整数部分 numval=numval*10+decval; position=position+1; }while(isdigit(buffer[position])); if (buffer[position]=='.'){ //小数部分 position=position+1; radix=0.1; while(isdigit(buffer[position])) { decval=radix*(buffer[position]-'0'); numval=numval+decval; radix=radix*0.1; position=position+1; } }//endif position=position-1; //gettoken()首先position=position+1; return numval; } void error() { isok=false; if(f_error==true) { CString str; str.Format("位置%d输入错误！",position-1); AfxMessageBox(str); buffer[position]='#'; f_error=false; } } node* expr(); node* term(); node* factor(); node *extr(); ///////////////////////////lookahead有关说明////////////////////////// // 1:+ 2:- 3:* 4:/ 5:( 6:) // 7:标识符 8:数字 9:整除DIV 10:求模MOD // 11:+= 12:-= 13:*= 14:/= ////////////////////////////////////////////////////////////////////// void gettoken() //语法树生成时用 { while(buffer[position]==' ') position++; if(Is_operator(buffer[position])) { switch(buffer[position]){ case '+': lookahead=1; position++; while(buffer[position]==' ') position++; if(buffer[position]=='=') { lookahead=11; position++; } break; case '-': lookahead=2; position++; while(buffer[position]==' ') position++; if(buffer[position]=='=') { lookahead=12; position++; } break; case '*': lookahead=3; position++; while(buffer[position]==' ') position++; if(buffer[position]=='=') { lookahead=13; position++; } break; case '/': lookahead=4; position++; while(buffer[position]==' ') position++; if(buffer[position]=='=') { lookahead=14; position++; } break; /* case '\\': lookahead=9; position++; break; case '%': lookahead=10; position++; break; */ case '(': lookahead=5; position++; break; case ')': lookahead=6; position++; break; } } else if(buffer[position]=='D'&&buffer[position+1]=='I'&&buffer[position+2]=='V')//整除DIV { position=position+3; lookahead=9; //整除DIV } else if(buffer[position]=='M'&&buffer[position+1]=='O'&&buffer[position+2]=='D') { position=position+3; lookahead=10; //求余MOD } else if(isalpha(buffer[position]))//(Is_letter(buffer[position])) { getidentifer(); lookahead=7; position++; ///////////////////// } else if(isdigit(buffer[position]))//(Is_number(buffer[position])) { num_analy(); lookahead=8; position++; ///////////////// } else if(buffer[position]=='#') lookahead=0; } node* mknode(double tokencode) { node *p; p=new node; if(tokencode==1||tokencode==2||tokencode==3||tokencode==4||tokencode==9||tokencode==10 ||tokencode==11||tokencode==12||tokencode==13||tokencode==14) { p->code=tokencode; //+,-,*,/ p->left=NULL; p->right=NULL; } else if(tokencode==7) { p->code=7; //标识符 p->entry=identry; p->left=NULL; ////////////// p->right=NULL; ///////////// } else if(tokencode==8) { p->code=8; //数字 p->value=numval; p->left=NULL; ////////////// p->right=NULL; ///////////// } else error(); p->No=number; number++; q.EnQueue(p); return p; } node* factor() { node *pf; if(lookahead==5) { gettoken(); pf=extr(); if(lookahead==6) gettoken(); else error(); } else if(lookahead==7||lookahead==8) { pf=mknode(lookahead); gettoken(); } else error(); return pf; } node* term() { double multoper; node *pt,*ptl,*ptr; ptl=factor(); while(lookahead==3||lookahead==4||lookahead==9||lookahead==10) { multoper=lookahead; gettoken(); ptr=factor(); pt=mknode(multoper); pt->left=ptl; pt->right=ptr; ptl=pt; } return ptl; } node* expr() { double addoper; node *pe,*pel,*per; pel=term(); while(lookahead==1||lookahead==2) { addoper=lookahead; gettoken(); per=term(); pe=mknode(addoper); pe->left=pel; pe->right=per; pel=pe; } return pel; } node *extr() { double addoper; node *pe,*pel,*per; pel=expr(); while(lookahead==11||lookahead==12||lookahead==13||lookahead==14) { addoper=lookahead; gettoken(); per=expr(); pe=mknode(addoper); pe->left=pel; pe->right=per; pel=pe; } return pel; } void ZuoBiao(node *ptr,node *parent,int row) //计算各个结点的坐标 { if(ptr!=NULL) { xy *p=new xy; if(parent->left==ptr) //左孩子 { p->x=Pos[parent->No]->x-200+row*40; p->y=Pos[parent->No]->y+100; Pos[ptr->No]=p; } else { p->x=Pos[parent->No]->x+200-row*40; p->y=Pos[parent->No]->y+100; Pos[ptr->No]=p; } row++; if(ptr->code<=4||ptr->code>=9) { ZuoBiao(ptr->left,ptr,row); ZuoBiao(ptr->right,ptr,row); } } listnode *p; p=q.front->next; ///////若最左的结点超出屏幕范围，则将它移到屏幕内///////// int delta=0-Pos[p->data->No]->x; if(delta>0) { for(int i=1;i<100;i++) { if(Pos[i]!=NULL) Pos[i]->x+=delta+5; } m_x+=delta+5; } /////////////////////////////////////////////////////////// } int ErrorTest(node* ptr) { if(ptr!=NULL) { listnode *p; p=q.front->next; while(p!=NULL) { if(p->data->code!=7&&p->data->code!=8&&(p->data->left==NULL||p->data->right==NULL)) return 0; p=p->next; } } return 1; }