%{ #include int yyerror(char *s); int yylex(); int regs[26]; int base; %} %start digit %union { int a; } %token DIGIT LETTER %left '|' %left '&' %left '+' '-' %left '*' '/' '%' %left UMINUS /*supplies precedence for unary minus */ %% /* beginning of rules section */ digit: DIGIT; %% int main() { return(yyparse()); } int yyerror(s) char *s; { fprintf(stderr, "%s\n",s); return(0); } int yywrap() { return(1); }