code / tomo

   1 // The logic for unsigned bytes
   2 #include <stdbool.h>
   3 #include <stdint.h>
   4 
   5 #include "bytes.h"
   6 #include "integers.h"
   7 #include "stdlib.h"
   8 #include "text.h"
   9 #include "util.h"
  10 
  11 public
  12 const Byte_t Byte$min = 0;
  13 public
  14 const Byte_t Byte$max = UINT8_MAX;
  15 
  16 PUREFUNC public Text_t Byte$as_text(const void *b, bool colorize, const TypeInfo_t *info) {
  17     (void)info;
  18     if (!b) return Text("Byte");
  19     Byte_t byte = *(Byte_t *)b;
  20     char digits[] = {
  21         '0',
  22         'x',
  23         (byte / 16) <= 9 ? '0' + (byte / 16) : 'a' + (byte / 16) - 10,
  24         (byte & 15) <= 9 ? '0' + (byte & 15) : 'a' + (byte & 15) - 10,
  25         '\0',
  26     };
  27     Text_t text = Text$from_str(digits);
  28     if (colorize) text = Text$concat(Text("\x1b[35m"), text, Text("\x1b[m"));
  29     return text;
  30 }
  31 
  32 public
  33 CONSTFUNC bool Byte$is_between(const Byte_t x, const Byte_t low, const Byte_t high) {
  34     return (low <= x && x <= high) || (high <= x && x <= low);
  35 }
  36 
  37 public
  38 OptionalByte_t Byte$parse(Text_t text, OptionalInt_t base, Text_t *remainder) {
  39     OptionalInt_t full_int = Int$parse(text, base, remainder);
  40     if (full_int.small != 0L && Int$compare_value(full_int, I(0)) >= 0 && Int$compare_value(full_int, I(255)) <= 0) {
  41         return (OptionalByte_t){.has_value = true, .value = Byte$from_int(full_int, true)};
  42     } else {
  43         return NONE_BYTE;
  44     }
  45 }
  46 
  47 public
  48 Text_t Byte$hex(Byte_t byte, bool uppercase, bool prefix) {
  49     struct Text_s text = {.tag = TEXT_ASCII};
  50     text.ascii = GC_MALLOC_ATOMIC(8);
  51     char *p = (char *)text.ascii;
  52     if (prefix) {
  53         *(p++) = '0';
  54         *(p++) = 'x';
  55     }
  56 
  57     if (uppercase) {
  58         *(p++) = (byte / 16) > 9 ? 'A' + (byte / 16) - 10 : '0' + (byte / 16);
  59         *(p++) = (byte & 15) > 9 ? 'A' + (byte & 15) - 10 : '0' + (byte & 15);
  60     } else {
  61         *(p++) = (byte / 16) > 9 ? 'a' + (byte / 16) - 10 : '0' + (byte / 16);
  62         *(p++) = (byte & 15) > 9 ? 'a' + (byte & 15) - 10 : '0' + (byte & 15);
  63     }
  64     text.length = (int64_t)(p - text.ascii);
  65     return text;
  66 }
  67 
  68 public
  69 bool Byte$get_bit(Byte_t x, Int_t bit_index) {
  70     if (Int$compare_value(bit_index, I(1)) < 0) fail("Invalid bit index (expected 1 or higher): ", bit_index);
  71     if (Int$compare_value(bit_index, I(8)) > 0)
  72         fail("Bit index is too large! There are only 8 bits in a byte, but index "
  73              "is: ",
  74              bit_index);
  75     return ((x & (Byte_t)(1L << (Int64$from_int(bit_index, true) - 1L))) != 0);
  76 }
  77 
  78 #ifdef __TINYC__
  79 #define __builtin_add_overflow(x, y, result)                                                                           \
  80     ({                                                                                                                 \
  81         *(result) = (x) + (y);                                                                                         \
  82         false;                                                                                                         \
  83     })
  84 #endif
  85 
  86 typedef struct {
  87     OptionalByte_t current, last;
  88     Int8_t step;
  89 } ByteRange_t;
  90 
  91 static OptionalByte_t _next_Byte(ByteRange_t *info) {
  92     OptionalByte_t i = info->current;
  93     if (i.has_value) {
  94         Byte_t next;
  95         bool overflow = __builtin_add_overflow(i.value, info->step, &next);
  96         if (overflow || (info->last.has_value && (info->step >= 0 ? next > info->last.value : next < info->last.value)))
  97             info->current = (OptionalByte_t){.has_value = false};
  98         else info->current = (OptionalByte_t){.has_value = true, .value = next};
  99     }
 100     return i;
 101 }
 102 
 103 public
 104 Closure_t Byte$to(Byte_t first, Byte_t last, OptionalInt8_t step) {
 105     ByteRange_t *range = GC_MALLOC(sizeof(ByteRange_t));
 106     range->current = (OptionalByte_t){.has_value = true, .value = first};
 107     range->last = (OptionalByte_t){.has_value = true, .value = last};
 108     range->step = step.has_value ? step.value : (last >= first ? 1 : -1);
 109     return (Closure_t){.fn = _next_Byte, .userdata = range};
 110 }
 111 
 112 public
 113 PUREFUNC Byte_t Byte$from_int(Int_t i, bool truncate) {
 114     if unlikely (!truncate && Int$compare_value(i, I_small(0xFF)) > 0)
 115         fail("This value is too large to convert to a byte without truncation: ", i);
 116     else if unlikely (!truncate && Int$compare_value(i, I_small(0)) < 0)
 117         fail("Negative values can't be converted to bytes: ", i);
 118     return (Byte_t)(i.small >> 2);
 119 }
 120 public
 121 PUREFUNC Byte_t Byte$from_int64(Int64_t i, bool truncate) {
 122     if unlikely (!truncate && i != (Int64_t)(Byte_t)i)
 123         fail("This value can't be converted to a byte without truncation: ", i);
 124     return (Byte_t)i;
 125 }
 126 public
 127 PUREFUNC Byte_t Byte$from_int32(Int32_t i, bool truncate) {
 128     if unlikely (!truncate && i != (Int32_t)(Byte_t)i)
 129         fail("This value can't be converted to a byte without truncation: ", i);
 130     return (Byte_t)i;
 131 }
 132 public
 133 PUREFUNC Byte_t Byte$from_int16(Int16_t i, bool truncate) {
 134     if unlikely (!truncate && i != (Int16_t)(Byte_t)i)
 135         fail("This value can't be converted to a byte without truncation: ", i);
 136     return (Byte_t)i;
 137 }
 138 
 139 public
 140 const TypeInfo_t Byte$info = {
 141     .size = sizeof(Byte_t),
 142     .align = __alignof__(Byte_t),
 143     .metamethods =
 144         {
 145             .as_text = Byte$as_text,
 146         },
 147 };