#include #include #include char prog[80],token[8]; char ch; int syn,p,m=0,n,sum=0,kk=0; char *rwtab[6]={"begin","if","then","while","do","end"} ; void expression(); void factor(); void term(); void statement(); void yucu(); void scaner() { for(n=0;n<8;n++) token[n]=NULL; ch=prog[p++]; while(ch==' ') { ch=prog[p]; p++; } if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z')) { m=0; while((ch>='0'&&ch<='9')||(ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z')) { token[m++]=ch; ch=prog[p++]; } token[m++]='\0'; p--; syn=10; for(n=0;n<6;n++) if(strcmp(token,rwtab[n])==0) { syn=n+1; break; } } else if((ch>='0'&&ch<='9')) { { sum=0; while((ch>='0'&&ch<='9')) { sum=sum*10+ch-'0'; ch=prog[p++]; } } p--; syn=11; if(sum>32767) syn=-1; } else switch(ch) { case'<':m=0;token[m++]=ch; ch=prog[p++]; if(ch=='>') { syn=21; token[m++]=ch; } else if(ch=='=') { syn=22; token[m++]=ch; } else { syn=23; p--; } break; case'>':m=0;token[m++]=ch; ch=prog[p++]; if(ch=='=') { syn=24; token[m++]=ch; } else { syn=20; p--; } break; case':':m=0;token[m++]=ch; ch=prog[p++]; if(ch=='=') { syn=18; token[m++]=ch; } else { syn=17; p--; } break; case'*':syn=15;token[0]=ch;break; case'/':syn=16;token[0]=ch;break; case'+':syn=13;token[0]=ch;break; case'-':syn=14;token[0]=ch;break; case'=':syn=25;token[0]=ch;break; case';':syn=26;token[0]=ch;break; case'(':syn=27;token[0]=ch;break; case')':syn=28;token[0]=ch;break; case'#':syn=0;token[0]=ch;break; case'\n':syn=-2;break; default: syn=-1;break; } } void expression() { term(); while(syn==13||syn==14) { scaner(); term(); } return; } void factor() { if(syn==10) scaner(); else if(syn==11) scaner(); else if(syn==27) { scaner(); expression(); if(syn==28) { scaner(); } else { cout<<"输出')'错误"<
