编译原理(语法分析源代码)

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1、#include#include#includecharprog[80],token[8];charch;intsyn,p,m=0,n,sum=0,kk=0;char*rwtab[6]={"begin","if","then","while","do","end"};voidexpression();voidfactor();voidterm();voidstatement();voidyucu();voidscaner(){for(n=0;n<8;n++)token[n]=NU

2、LL;ch=prog[p++];while(ch==''){ch=prog[p];p++;}if((ch>='a'&&ch<='z')

3、

4、(ch>='A'&&ch<='Z')){m=0;while((ch>='0'&&ch<='9')

5、

6、(ch>='a'&&ch<='z')

7、

8、(ch>='A'&&ch<='Z')){token[m++]=ch;ch=prog[p++];}token[m++]='';p--;syn=10;for(n=0;n<6;n++)if(strcmp(token,rwtab[n])==0){syn=n+1;break

9、;}}elseif((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;}elseswitch(ch){case'<':m=0;token[m++]=ch;ch=prog[p++];if(ch=='>'){syn=21;token[m++]=ch;}elseif(ch=='='){syn=22;token[m++]=ch;}else{syn=23;p--;}br

10、eak;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

11、=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'':syn=-2;break;default:syn=-1;break;}}voidexpre

12、ssion(){term();while(syn==13

13、

14、syn==14){scaner();term();}return;}voidfactor(){if(syn==10)scaner();elseif(syn==11)scaner();elseif(syn==27){scaner();expression();if(syn==28){scaner();}else{cout<<"输出')'错误"<

15、;while(syn==15

16、

17、syn==16){scaner();factor();}return;}voidstatement(){if(syn==10){scaner();if(syn==18){scaner();expression();}else{cout<<"赋值号错误"<

18、r(){if(syn==1){scaner();yucu();if(syn==6){scaner();if(syn==0&&(kk==0)){cout<<"success"<