编译原理实验参考.doc

完成内容 1、增加单词：保留字 ELSE，FOR，STEP，UNTIL，RETURN 运算符 *=，/=，，||，！ 2、修改单词：不等号# 改为 3、增加条件语句的ELSE子句 设计思路 1、扩充单词 (1) 修改变量定义 1) 关键字个数增加5个 const NORW = 14+5;  2) 符号表修改 typedef enum { NUL, IDENT, NUMBER, PLUS, MINUS, TIMES, SLASH, ODDSYM, EQL, NEQ, LSS, LEQ, GTR, GEQ, LPAREN, RPAREN, COMMA, SEMICOLON, PERIOD, BECOMES, BEGINSYM, ENDSYM, IFSYM, THENSYM, WHILESYM, WRITESYM, READSYM, DOSYM, CALLSYM, CONSTSYM, VARSYM, PROCSYM, PROGSYM, ELSESYM , FORSYM,STEPSYM,UNTILSYM,RETURNSYM, TIMESBECOMES,SLASHBECOMES, PLUSPLUS, MINUSMINUS, AND, OR, NOT } SYMBOL; char *SYMOUT[] = {NUL, IDENT, NUMBER, PLUS, MINUS, TIMES,SLASH, ODDSYM, EQL, NEQ, LSS, LEQ, GTR, GEQ,LPAREN, RPAREN, COMMA, SEMICOLON, PERIOD,BECOMES, BEGINSYM, ENDSYM, IFSYM, THENSYM, WHILESYM, WRITESYM, READSYM, DOSYM, CALLSYM,CONSTSYM, VARSYM, PROCSYM, PROGSYM, ELSESYM,FORSYM,TOSYM, DOWNTOSYM,RETURNSYM ,TIMESBECOMES, SLASHBECOMES, PLUSPLUS,  MINUSMINUS, AND, OR, NOT }; 3) 修改关键字表 strcpy(KWORD[ 1],BEGIN); strcpy(KWORD[ 2],CALL); strcpy(KWORD[ 3],CONST); strcpy(KWORD[ 4],DO); strcpy(KWORD[ 5],ELSE); strcpy(KWORD[ 6],END); strcpy(KWORD[ 7],FOR); strcpy(KWORD[ 8],IF); strcpy(KWORD[9],ODD); strcpy(KWORD[10],PROCEDURE); strcpy(KWORD[11],PROGRAM); strcpy(KWORD[12],READ); strcpy(KWORD[13],RETURN); strcpy(KWORD[14],STEP); strcpy(KWORD[15],THEN); strcpy(KWORD[16],UNTIL); strcpy(KWORD[17],VAR); strcpy(KWORD[18],WHILE); strcpy(KWORD[19],WRITE); 修改关键字的机内表示 WSYM[ 1]=BEGINSYM; WSYM[ 2]=CALLSYM; WSYM[ 3]=CONSTSYM; WSYM[ 4]=DOSYM; WSYM[ 5]=ELSESYM; WSYM[ 6]=ENDSYM; WSYM[ 7]=FORSYM; WSYM[ 8]=IFSYM; WSYM[9]=ODDSYM; WSYM[10]=PROCSYM; WSYM[11]=PROGSYM; WSYM[12]=READSYM; WSYM[13]=RETURNSYM; WSYM[14]=STEPSYM; WSYM[15]=THENSYM; WSYM[16]=UNTILSYM; WSYM[17]=VARSYM; WSYM[18]=WHILESYM; WSYM[19]=WRITESYM; 5) 修改单字符