diff options
Diffstat (limited to 'src/da.h')
| -rw-r--r-- | src/da.h | 99 |
1 files changed, 78 insertions, 21 deletions
@@ -9,12 +9,13 @@ * } * * The type ‘T’ is whatever type you want to store. The type ‘N’ is any numeric - * type, most likely ‘size_t’. + * type — most likely ‘size_t’ — but it could be sized as well. * - * You should include ‘err.h’ and ‘stdlib.h’ along with this file. If you want - * to use da_remove(), include ‘string.h’. The da_remove() macro also doesn’t - * bother with shrinking your array when the length is far lower than the - * capacity. If you care about that, do it yourself. + * The daremove() macro also doesn’t bother with shrinking your array when the + * length is far lower than the capacity. If you care about that, do it + * yourself. + * + * Remember to call free() on your dynamic arrays ‘buf’ field after use. * * * Macro Overview @@ -22,43 +23,99 @@ * The argument ‘a’ to all of the below macros is a pointer to the dynamic array * structure. * - * da_init(a, n) Initialize the array with a capacity of ‘n’ items. - * da_append(a, x) Append the item ‘x’ to the array - * da_remove(a, x) Remove the item ‘x’ from the array + * dainit(a, n) Initialize the array with a capacity of ‘n’ items. + * dapush(a, x) Append the item ‘x’ to the array + * daremove(a, x) Remove the item at index ‘x’ from the array * da_remove_range(a, x, y) Remove the items between the range [x, y) + * da_foreach(a, p) Iterate the pointer ‘p’ over each element of the + * array. The type of ‘p’ is inferred. + * + * The ‘dapush()’ macro will double the arrays capacity when it gets full. If + * you would like your arrays to grow with a different scale, edit this file. + * + * + * Example + * ――――――― + * + * struct { + * int *buf; + * size_t len, cap; + * } nums; + * + * // Initialize nums with capacity == 4 + * dainit(&nums, 4); + * + * // Append 69, 1337, and 420 to nums + * dapush(&nums, 69); + * dapush(&nums, 1337); + * dapush(&nums, 420); + * + * da_foreach (&nums, n) { + * int x = *n << 1; + * printf("n = %d; n² = %d\n", *n, x); + * } + * + * // Remove 1337 and 420 from nums + * da_remove_range(&nums, 1, 3); + * + * // Remove 69 from nums + * daremove(&nums, 0); */ #ifndef MANGO_DA_H #define MANGO_DA_H -#define __da_s(a) (sizeof(*(a)->buf)) +#include <err.h> +#include <errno.h> +#include <stddef.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> + +#if __STDC_VERSION__ >= 202311L +# define DA_NULL nullptr +#else +# define DA_NULL NULL +#endif + +#define DA_ALLOC(p, n) \ + do { \ + if ((n) && SIZE_MAX / (n) < sizeof(*(p))) { \ + errno = EOVERFLOW; \ + err(EXIT_FAILURE, "realloc"); \ + } \ + if (!((p) = realloc((p), (n) * sizeof(*(p))))) \ + err(EXIT_FAILURE, "realloc"); \ + } while (0) -#define da_init(a, n) \ +#define dainit(a, n) \ do { \ - (a)->cap = n; \ + (a)->buf = DA_NULL; \ + (a)->cap = (n); \ (a)->len = 0; \ - (a)->buf = malloc((a)->cap * __da_s(a)); \ - if ((a)->buf == NULL) \ - err(EXIT_FAILURE, "malloc"); \ + if (n) \ + DA_ALLOC((a)->buf, (a)->cap); \ } while (0) -#define da_append(a, x) \ +#define dapush(a, x) \ do { \ if ((a)->len >= (a)->cap) { \ - (a)->cap = (a)->cap * 2 + 1; \ - (a)->buf = realloc((a)->buf, (a)->cap * __da_s(a)); \ - if ((a)->buf == NULL) \ - err(EXIT_FAILURE, "realloc"); \ + (a)->cap = (a)->cap ? (a)->cap * 2 : 1; \ + DA_ALLOC((a)->buf, (a)->cap); \ } \ (a)->buf[(a)->len++] = (x); \ } while (0) -#define da_remove(a, i) da_remove_range((a), (i), (i) + 1) +#define daremove(a, i) da_remove_range((a), (i), (i) + 1) #define da_remove_range(a, i, j) \ do { \ - memmove((a)->buf + (i), (a)->buf + (j), ((a)->len - (j)) * __da_s(a)); \ + memmove((a)->buf + (i), (a)->buf + (j), \ + ((a)->len - (j)) * sizeof(*(a)->buf)); \ (a)->len -= j - i; \ } while (0) +#define da_foreach(a, p) \ + for (auto p = (a)->buf; (size_t)(p - (a)->buf) < (a)->len; p++) + #endif /* !MANGO_DA_H */ |