lex词法分析器课程设计

%% ///////////////////////////////////////////////////////////////////////////// // rules section // place your Lex rules here "else" {printf("ELSE:%s%c ",yytext,' ');return ELSE;} "if" {printf("IF:%s%c ",yytext,' ');return IF;} "int" {printf("INT:%s%c ",yytext,' ');return INT;} "return" {printf("RETURN:%s%c ",yytext,' ');return RETURN;} "void" {printf("VOID:%s%c ",yytext,' ');return VOID;} "while" {printf("WHILE:%s%c ",yytext,' ');return WHILE;} "<" {printf("LT:%s%c ",yytext,' ');return LT;} ">" {printf("GT:%s%c ",yytext,' ');return GT;} "<=" {printf("LE:%s%c ",yytext,' ');return LE;} ">=" {printf("GE:%s%c ",yytext,' ');return GE;} "==" {printf("EQ:%s%c ",yytext,' ');return EQ;} "!=" {printf("NE:%s%c ",yytext,' ');return NE;} "{" {printf("{:%s%c ",yytext,' '); return '{';} "}" {printf("}:%s%c ",yytext,' '); return '}';} "(" {printf("(:%s%c ",yytext,' ');return '(';} ")" {printf("):%s%c ",yytext,' ');return ')';} "[" {printf("[:%s%c ",yytext,' ');return '[';} "]" {printf("]:%s%c ",yytext,' ');return ']';} "+" {printf("+:%s%c ",yytext,' ');return '+';} "-" {printf("-:%s%c ",yytext,' ');return '-';} "*" {printf("*:%s%c ",yytext,' ');return '*';} "/" {printf("/:%s%c ",yytext,' ');return '/';} "%" {printf("%:%s%c ",yytext,' ');return '%';} ";" {printf(";:%s%c ",yytext,' ');return ';';} "=" {printf("=:%s%c ",yytext,' ');return '=';} "," {printf(",:%s%c ",yytext,' ');return ',';} {id} {printf("id:%s%c ",yytext,' ');return ID;} {number} {printf("number:%s%c ",yytext,' '); return NUMBER;} "/*" { char c; int done = FALSE; ECHO; do { while((c=input())!='*') putchar(c); putchar(c); while((c=input())=='*') putchar(c); putchar(c); if(c=='/') done =TRUE; } while(!done); printf("\n: There are the conment!"); return COMMENT; } %% 程序可以正确的运行，供有需要的同学使用