#include<fstream.h>#include<string.h>#include<ctype.h>#include<math.h>#include<stdlib.h>char* word[]= {"begin","call","const","do","end","if","odd", "procedure","read","then","var","while","write"};char* wsym[]= {"beginsym","callsym","constsym","dosym","endsym", "ifsym","oddsym","procsym","readsym","thensym", "varsym","whilesym","writesym"};char* symbol[]= {"+","-","*","/","(",")","=",",",".","#",";"};char* sysm[]= {"plus","minus","times","slash","lparen","rparen", "eql","comma","peroid","neg","semicolon"};void main(){ char*sym=new char[20]; int num=0; char ch; char buffer[100]; int index=0; ifstream in("test1.java"); ofstream out("result.txt"); while(!in.eof()) { ch=in.get(); while(ch==' ') ch=in.get(); if(isalpha(ch)){ //如果为字母打头，则为保留字或标识符 while(isalpha(ch)||isdigit(ch)){ buffer[index++]=ch; ch=in.get(); } buffer[index]='/0'; index=0; int i=0; for(i=0; i<13; i++){ if(!strcmp(buffer,word[i])) break; } if(i==13) {sym="ident"; out<<"( "<<sym<<" , "<<buffer<<" )"<<endl;} else if(i<13) { sym=wsym[i]; out<<"( "<<sym<<" , "<<buffer<<" )"<<endl; } }
else if(isdigit(ch)){ //如果是数字打头，则拼数 char a[20]; sym="number"; int i=0; a[i]=ch; while(isdigit(ch)){ ch=in.get(); a[++i]=ch; } a[i]='/0'; i=0; num=atol(a); out<<"( "<<sym<<" , "<<num<<" )"<<endl; }
if(ch==':'){ ch=in.get(); while(ch==' ') ch=in.get(); if(ch=='=') { sym="becomes"; out<<"( "<<sym<<" , "<<":="<<" )"<<endl; } else{ sym="nul"; out<<"( "<<sym<<" , "<<":"<<" )"<<endl; } }
else if(ch=='<'){ ch=in.get(); while(ch==' ' && !isdigit(ch) && !isalpha(ch)) ch=in.get(); if(ch=='='){ sym="leq"; out<<"( "<<sym<<" , "<<"<="<<" )"<<endl; } else{ sym="lss"; out<<"( "<<sym<<" , "<<"<"<<" )"<<endl; } }
else if(ch=='>'){ ch=in.get(); while(ch==' ' && !isdigit(ch) && !isalpha(ch)) ch=in.get(); if(ch=='='){ sym="geq"; out<<"( "<<sym<<" , "<<">="<<" )"<<endl; } else{ sym="gtr"; out<<"( "<<sym<<" , "<<">"<<" )"<<endl; } }
else{ int count=0; buffer[0]=ch; buffer[1]='/0'; int i=0; for(i=0; i<11; i++) if(!strcmp(buffer,symbol[i])) break; if(i<11){ sym=sysm[i]; out<<"( "<<sym<<" , "<<ch<<" )"<<endl; } } } in.close();}
