code / tomo

   1 // Logic for parsing numbers
   2 
   3 #include <ctype.h>
   4 #include <gc.h>
   5 #include <stdarg.h>
   6 #include <stdbool.h>
   7 #include <string.h>
   8 
   9 #include <unictype.h>
  10 #include <uniname.h>
  11 
  12 #include "../ast.h"
  13 #include "context.h"
  14 #include "errors.h"
  15 #include "utils.h"
  16 
  17 static const double RADIANS_PER_DEGREE = 0.0174532925199432957692369076848861271344287188854172545609719144;
  18 
  19 ast_t *parse_int(parse_ctx_t *ctx, const char *pos) {
  20     const char *start = pos;
  21     (void)match(&pos, "-");
  22     if (!isdigit(*pos)) return NULL;
  23     if (match(&pos, "0x")) { // Hex
  24         pos += strspn(pos, "0123456789abcdefABCDEF_");
  25     } else if (match(&pos, "0b")) { // Binary
  26         pos += strspn(pos, "01_");
  27     } else if (match(&pos, "0o")) { // Octal
  28         pos += strspn(pos, "01234567_");
  29     } else { // Decimal
  30         pos += strspn(pos, "0123456789_");
  31     }
  32     char *str = GC_MALLOC_ATOMIC((size_t)(pos - start) + 1);
  33     memset(str, 0, (size_t)(pos - start) + 1);
  34     for (char *src = (char *)start, *dest = str; src < pos; ++src) {
  35         if (*src != '_') *(dest++) = *src;
  36     }
  37 
  38     if (match(&pos, "e") || match(&pos, "f")) // floating point literal
  39         return NULL;
  40 
  41     if (match(&pos, "%")) {
  42         double n = strtod(str, NULL) / 100.;
  43         return NewAST(ctx->file, start, pos, Num, .n = n);
  44     } else if (match(&pos, "deg")) {
  45         double n = strtod(str, NULL) * RADIANS_PER_DEGREE;
  46         return NewAST(ctx->file, start, pos, Num, .n = n);
  47     }
  48 
  49     return NewAST(ctx->file, start, pos, Int, .str = str);
  50 }
  51 
  52 ast_t *parse_num(parse_ctx_t *ctx, const char *pos) {
  53     const char *start = pos;
  54     bool negative = match(&pos, "-");
  55     if (!isdigit(*pos) && *pos != '.') return NULL;
  56     else if (*pos == '.' && !isdigit(pos[1])) return NULL;
  57 
  58     size_t len = strspn(pos, "0123456789_");
  59     if (strncmp(pos + len, "..", 2) == 0) return NULL;
  60     else if (pos[len] == '.' && is_xid_start_next(pos + len + 1)) return NULL;
  61     else if (pos[len] == '.') len += 1 + strspn(pos + len + 1, "0123456789");
  62     else if (pos[len] != 'e' && pos[len] != 'f' && pos[len] != '%') return NULL;
  63     if (pos[len] == 'e') {
  64         len += 1;
  65         if (pos[len] == '-') len += 1;
  66         len += strspn(pos + len, "0123456789_");
  67     }
  68     char *buf = GC_MALLOC_ATOMIC(len + 1);
  69     memset(buf, 0, len + 1);
  70     for (char *src = (char *)pos, *dest = buf; src < pos + len; ++src) {
  71         if (*src != '_') *(dest++) = *src;
  72     }
  73     double d = strtod(buf, NULL);
  74     pos += len;
  75 
  76     if (negative) d *= -1;
  77 
  78     if (match(&pos, "%")) d /= 100.;
  79     else if (match(&pos, "deg")) d *= RADIANS_PER_DEGREE;
  80 
  81     return NewAST(ctx->file, start, pos, Num, .n = d);
  82 }