编译原理词法分析器C++

#include <iostream.h> #include <fstream.h> #include<stdio.h> #include<stdlib.h> #include<string.h> #include<ctype.h> const long stakmaxsize=6000; int flag; const char keyword[][20]={{'i','n','t'},{'v','o','i','d'},{'i','f'}, {'c','h','a','r'},{'b','o','o','l'},{'b','r','e','a','k'},{'c','a','s','e'}, {'c','a','t','c','h'},{'c','o','n','s','t'},{'f','o','r'},{'e','l','s','e'}, {'c','o','n','t','i','n','u','e'},{'c','l','a','s','s'},{'w','h','i','l','e'}, {'d','o'},{'g','o','t','o'},{'f','l','o','a','t'},{'d','o','u','b','l','e'}, {'l','o','n','g'},{'s','w','i','t','c','h'},{'f','r','i','e','n','d'},{'s','t','a','t','i','c'}, {'p','u','b','l','i','c'},{'p','r','i','v','a','t','e'},{'p','r','o','t','e','c','t','e','d'}, {'r','e','t','u','r','n'},{'i','n','l','i','n','e'},{'t','r','y'},{'s','t','r','u','c','t'}}; char Ischeck[]={' ','\n','+','-','*','(',')','{','}', ';','=','\"',',','&','[',']','!',':','<','>','\'','/'}; bool isCheck(const char& ch) { for(int i=0;i<27;i++) if(ch==Ischeck[i]) return true; return false; } struct stack { char stak[stakmaxsize]; int top;}; void initstak(stack& s) {s.top=-1;} void clearstak(stack& s) {s.top=-1;} void push(stack& s,const char& item) {if(s.top==stakmaxsize-1) { cerr<<"溢出"<<endl; exit(1);} s.top++; s.stak[s.top]=item; } bool isKeyword(stack& s) { for(int i=0;i<29;i++) if(!strcmp(s.stak,keyword[i])) return true; return false; } void printout(stack& s) { if(isKeyword(s)) cout<<"关键字："<<s.stak<<endl; else cout<<"标识符："<<s.stak<<endl; } void digitpush(stack& s,const char& item) { if(s.top==stakmaxsize-1) {cerr<<"溢出"<<endl; exit(1);} s.top++; s.stak[s.top]=item; } void Getchar(FILE *fp,char& ch) { ch=fgetc(fp); if(ch=='\n') flag++; } void digitprint(stack& s) {cout<<"数:"<<s.stak<<endl;} void check(char *fname) { FILE *fp; bool watch=false,checked=true; flag=1; if((fp=fopen(fname,"r"))==NULL) {cerr<<"文件"<<"\'"<<fname<<"\'"<<"找不到"<<endl; getchar(); exit(1);} stack a; initstak(a); char ch; Getchar(fp,ch); while(!feof(fp)) {if(ch==' '||ch=='\n') {Getchar(fp,ch); checked=true; continue;} else if(checked && (isalpha(ch)||ch=='_'))//判断是否为字母，是字母返回1，否则返回0，checked查看上次有没有输入错误。 { while(isalnum(ch)||ch=='_')//判断是否是字母和数字的组成，是返回1，否则返回0 { if(isCheck(ch)) break; push(a,ch); Getchar(fp,ch); if(feof(fp)) {push(a,'\0'); printout(a); fclose(fp); getchar(); exit(0); } } if(isCheck(ch)) { push(a,'\0'); printout(a); clearstak(a); } else { cout<<"错误位置"<<flag<<endl; checked=false; clearstak(a); continue; } } else if(isdigit(ch) && checked)//判断是否为数字。是返回1，否则返回0，checked表示检查上次输入有没有错误 { while(isdigit(ch)||ch=='.') {if(ch=='.') watch=true; if(isCheck(ch)) break; digitpush(a,ch); Getchar(fp,ch); if(feof(fp)) {digitprint(a); fclose(fp); getchar(); exit(0);} } if(isCheck(ch)) { if(watch) { cout<<""; watch=false; digitpush(a,'\0'); digitprint(a); clearstak(a); } else { cout<<"整形"; digitpush(a,'\0'); digitprint(a); clearstak(a); } } else { cout<<"错误位置"<<flag<<endl; checked=false; clearstak(a); continue; } } else if(checked) { switch(ch) { case'=': Getchar(fp,ch); if(ch=='=') { cout<<"算符 "<<"=="<<endl; Getchar(fp,ch); checked=true; break;} else { cout<<"算符 "<<"="<<endl; checked=true;break;} case'+': Getchar(fp,ch); if(ch=='=') {cout<<"算符 "<<"+="<<endl; Getchar(fp,ch); checked=true;break;} else if(ch=='+') {cout<<"算符 "<<"++"<<endl; Getchar(fp,ch);checked=true;break;} else {cout<<"算符 "<<"+"<<endl; checked=true;break;} case'*': Getchar(fp,ch); if(ch=='=') {cout<<"算符 "<<"*="<<endl; Getchar(fp,ch);checked=true;break;} else {cout<<"算符 "<<"*"<<endl; checked=true;break;} case'/': cout<<"算符:"<<"/"<<endl; Getchar(fp,ch);checked=true;break; case'-': Getchar(fp,ch); if(ch=='=') {cout<<"算符 "<<"-="<<endl; Getchar(fp,ch);checked=true;break;} else if(ch=='-') {cout<<"算符 "<<"--"<<endl; Getchar(fp,ch); checked=true;break;} else {cout<<"算符 "<<"-"<<endl; checked=true;break;} case'!': Getchar(fp,ch); if(ch=='=') {cout<<"算符 "<<"!="<<endl; Getchar(fp,ch);checked=true;break;} else {cout<<"算符 "<<"!"<<endl; checked=true;break;} case'>': Getchar(fp,ch); if(ch=='=') {cout<<"算符 "<<">="<<endl; Getchar(fp,ch);checked=true;break;} else {cout<<"算符 "<<">"<<endl; checked=true;break;} case'<': Getchar(fp,ch); if(ch=='=') {cout<<"算符 "<<"<="<<endl; Getchar(fp,ch);checked=true;break;} else {cout<<"算符 "<<">"<<endl; checked=true;break;} case'(':cout<<"边界符"<<"("<<endl;Getchar(fp,ch);checked=true;break; case')':cout<<"边界符"<<")"<<endl;Getchar(fp,ch);checked=true;break; case'{':cout<<"边界符"<<"{"<<endl;Getchar(fp,ch);checked=true;break; case'[':cout<<"边界符"<<"["<<endl;Getchar(fp,ch);checked=true;break; case'}':cout<<"边界符"<<"}"<<endl;Getchar(fp,ch);checked=true;break; case']':cout<<"边界符"<<"]"<<endl;Getchar(fp,ch);checked=true;break; case';':cout<<"边界符"<<";"<<endl;Getchar(fp,ch);checked=true;break; case',':cout<<"边界符"<<","<<endl;Getchar(fp,ch);checked=true;break; case'%':cout<<"算符"<<"%"<<endl;Getchar(fp,ch);checked=true;break; case'#':cout<<"算符"<<"#"<<endl;Getchar(fp,ch);checked=true;break; case'&':cout<<"算符"<<"&"<<endl;Getchar(fp,ch);checked=true;break; case':':cout<<"算符"<<":"<<endl;Getchar(fp,ch);checked=true;break; case'\'':cout<<"算符"<<"\'"<<endl;Getchar(fp,ch);checked=true;break; case'\"':cout<<"算符"<<"\""<<endl;Getchar(fp,ch);checked=true;break; case'\\': Getchar(fp,ch); if(ch=='n') { cout<<"算符"<<"\\n"<<endl; Getchar(fp,ch);checked=true;break;} else {cout<<"算符"<<"\\"<<endl;checked=true;break;} case'\n':break; case' ': break; default: cout<<"错误在第"<<flag<<"行"<<endl; checked=false;Getchar(fp,ch); } } else Getchar(fp,ch); } if(feof(fp)) { fclose(fp); //getchar(); exit(1); } } void main() { char filename[10]; cout<<"-------------------------------------------------------------------"<<endl; cout<<"编译原理词法分析器程序，请正确输入你的文件名，注意文件格式，谢谢：）"<<endl; cout<<"-------------------------------------------------------------------"<<endl; cout<<"请输入文件名和路径 : "; cin>>filename; check(filename); }