const.c

   1 #include "const.h"
   2 #include "ctype.h"
   3 #include "math.h"
   4
   5 void const_parse_number(struct const_value *restrict cv, const char *restrict str)
   6 {
   7     const char *restrict p = str;
   8     long double place_value, exponent;
   9     cv->type = CBT_INT;
  10     cv->v.i = 0;
  11     if (*p == '0'){
  12         // octal or hexadecimal
  13         p++;
  14         if (tolower(*p) == 'x'){
  15             // hexadecimal
  16             p++;
  17             while (isdigit(*p) || (tolower(*p) >= 'a' && tolower(*p) <= 'f')){
  18                 if (isdigit(*p)){
  19                     cv->v.i = (cv->v.i << 4) | (*p - '0');
  20                 } else {
  21                     cv->v.i = (cv->v.i << 4) | ((tolower(*p) - 'a') + 10);
  22                 }
  23                 p++;
  24             }
  25         } else {
  26             // octal
  27             p++;
  28             while (*p >= '0' && *p <= '7'){
  29                 cv->v.i = (cv->v.i << 3) | (*p - 0);
  30                 p++;
  31             }
  32         }
  33     } else if (*p >= '0' && *p <= 9){
  34         // decimal
  35         while (*p >= '0' && *p <= '9'){
  36             cv->v.i = (cv->v.i * 10) + (*p - '0');
  37             p++;
  38         }
  39         if (*p == '.'){
  40             // decimal part
  41             cv->v.ld = cv->v.i;
  42             cv->type = CBT_LONGDOUBLE;
  43             place_value = 0.1;
  44             p++;
  45             while (*p >= '0' && *p <= '9'){
  46                 cv->v.ld = (*p - '0') * place_value;
  47                 place_value /= 10.0;
  48                 p++;
  49             }
  50         }
  51         if (tolower(*p) == 'e'){
  52             // exponent part
  53             if (cv->type != CBT_LONGDOUBLE){
  54                 cv->v.ld = cv->v.i;
  55                 cv->type = CBT_LONGDOUBLE;
  56             }
  57             p++;
  58             exponent = 0.0;
  59             while (*p >= '0' && *p <= '9'){
  60                 exponent = (exponent * 10.0) + (*p - '0');
  61                 p++;
  62             }
  63             cv->v.ld *= powl(10, exponent);
  64         }
  65     }
  66 }
  67