/* re2c lesson 001_upn_calculator, calc_003, (c) M. Boerger 2006 - 2007 */ /*!ignore:re2c - making use of YYFILL . Again provide the length of the input to generate the limit only once. Now we can use YYFILL() to detect the end and simply return since YYFILL() is only being used if the next scanner run might use more chars then YYLIMIT allows. . Note that we now use (s+l+2) instead of (s+l) as we did in lesson_001. In the first lesson we did not quit from YYFILL() and used a special rule to detect the end of input. Here we use the fact that we know the exact end of input and that this length does not include the terminating zero. Since YYLIMIT points to the first character behind the used buffer we use "+ 2". If we would use "+1" we could drop the "\000" rule but could no longer distinguish between end of input and out of data. */ #include #include #include int scan(char *s, int l) { char *p = s; char *q = 0; #define YYCTYPE char #define YYCURSOR p #define YYLIMIT (s+l+2) #define YYMARKER q #define YYFILL(n) { printf("OOD\n"); return 2; } for(;;) { /*!re2c re2c:indent:top = 2; "0"[0-9]+ { printf("Oct\n"); continue; } [1-9][0-9]* { printf("Num\n"); continue; } "0" { printf("Num\n"); continue; } "+" { printf("+\n"); continue; } "-" { printf("+\n"); continue; } "\000" { printf("EOF\n"); return 0; } [^] { printf("ERR\n"); return 1; } */ } return 0; } int main(int argc, char **argv) { if (argc > 1) { return scan(argv[1], strlen(argv[1])); } else { fprintf(stderr, "%s \n", argv[0]); return 0; } }