%{ #include #include #include extern int yylex(void); void yyerror(uint32_t *result, const char *s) { fprintf(stderr, "Error: %s\n", s); } %} %token NUMBER HEX_NUMBER %start input %define api.value.type { uint32_t } %parse-param { uint32_t *result } %left '-' '+' %left '*' '/' %% input : expression { *result = $1; } ; expression : number { $$ = $1; } | expression '+' expression { $$ = $1 + $3; } | expression '-' expression { $$ = $1 - $3; } | expression '*' expression { $$ = $1 * $3; } | expression '/' expression { $$ = $1 / $3; if($3 == 0) perror("Devide by 0\n");} | '-' number { $$ = -$2; } | '(' expression ')' { $$ = $2; } number : NUMBER | HEX_NUMBER %%