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+/* VARIOUS DATA STRUCTURES
+- dynamic array
+- string builder
+- string hash table
+*/
+
+
+// functions in this file suffixed with _ are not meant to be used outside here, unless you
+// know what you're doing
+
+// IMPORTANT NOTE: If you are using this with structures containing `long double`s, do
+// #define ARR_LONG_DOUBLE
+// before including this file
+// ( otherwise the long doubles will not be aligned.
+// this does mean that arrays waste 8 bytes of memory.
+// which isnt important unless you're making a lot of arrays.)
+
+#include <stddef.h>
+typedef union {
+ long num;
+ void *ptr;
+ void (*fnptr)(void);
+#ifdef ARR_LONG_DOUBLE
+ long
+#endif
+ double flt;
+} ArrMaxAlign;
+#if __STDC_VERSION__ < 199901L && !defined inline
+#define inline
+#endif
+
+
+typedef struct {
+ u32 len;
+ u32 cap;
+ ArrMaxAlign data[];
+} ArrHeader;
+
+// watch out! do not call this function if arr is NULL.
+static inline ArrHeader *arr_hdr_(void *arr) {
+ return (ArrHeader *)((char *)arr - offsetof(ArrHeader, data));
+}
+
+static inline u32 arr_len(const void *arr) {
+ return arr ? arr_hdr_((void*)arr)->len : 0;
+}
+
+static inline u32 arr_cap(void *arr) {
+ return arr ? arr_hdr_(arr)->cap : 0;
+}
+
+static inline unsigned arr_lenu(void *arr) {
+ return (unsigned)arr_len(arr);
+}
+
+// grow array to fit one more member
+static void *arr_grow1_(void *arr, size_t member_size) {
+ if (arr) {
+ ArrHeader *hdr = arr_hdr_(arr);
+ if (hdr->len >= hdr->cap) {
+ u32 new_capacity = hdr->cap * 2;
+ ArrHeader *old_hdr = hdr;
+ hdr = (ArrHeader *)realloc(old_hdr, sizeof(ArrHeader) + new_capacity * member_size);
+ if (hdr) {
+ hdr->cap = new_capacity;
+ } else {
+ free(old_hdr);
+ return NULL;
+ }
+ }
+ return hdr->data;
+ } else {
+ // create a new array
+ u32 initial_capacity = 2; // allocate enough space for two members
+ ArrHeader *ret = (ArrHeader *)calloc(1, sizeof(ArrHeader) + initial_capacity * member_size);
+ if (ret) {
+ ret->cap = initial_capacity;
+ return ret->data;
+ } else {
+ return NULL;
+ }
+ }
+}
+
+static inline void *arr_add_ptr_(void **arr, size_t member_size) {
+ u8 *ret;
+ *arr = arr_grow1_(*arr, member_size);
+ if (*arr) {
+ ret = (u8 *)*arr + member_size * (arr_hdr_(*arr)->len++);
+ memset(ret, 0, member_size);
+ } else {
+ ret = NULL;
+ }
+ return ret;
+}
+
+static void arr_reserve_(void **arr, size_t member_size, size_t n) {
+ if (n >= U32_MAX-1) {
+ // too big; free arr.
+ if (*arr) free(arr_hdr_(*arr));
+ *arr = NULL;
+ }
+
+ if (!*arr) {
+ // create a new array with capacity n+1
+ // why n+1? i dont know i wrote this a while ago
+ ArrHeader *hdr = calloc(1, sizeof(ArrHeader) + (n+1) * member_size);
+ if (hdr) {
+ hdr->cap = (u32)n+1;
+ *arr = hdr->data;
+ }
+ } else {
+ // increase capacity of array
+ ArrHeader *hdr = arr_hdr_(*arr);
+ u32 curr_cap = hdr->cap;
+ if (n > curr_cap) {
+ ArrHeader *old_hdr = hdr;
+ while (n > curr_cap) {
+ if (curr_cap < U32_MAX/2)
+ curr_cap *= 2;
+ else
+ curr_cap = U32_MAX;
+ }
+ hdr = realloc(hdr, sizeof(ArrHeader) + curr_cap * member_size);
+ if (hdr) {
+ hdr->cap = curr_cap;
+ } else {
+ // growing failed
+ free(old_hdr);
+ *arr = NULL;
+ return;
+ }
+ }
+ *arr = hdr->data;
+ }
+}
+
+static void arr_set_len_(void **arr, size_t member_size, size_t n) {
+ arr_reserve_(arr, member_size, n);
+ if (*arr) {
+ ArrHeader *hdr = arr_hdr_(*arr);
+ if (n > hdr->len) {
+ // zero new elements
+ memset((char *)hdr->data + hdr->len * member_size, 0, (n - hdr->len) * member_size);
+ }
+ hdr->len = (u32)n;
+ }
+}
+
+static void *arr_remove_(void *arr, size_t member_size, size_t index) {
+ ArrHeader *hdr = arr_hdr_(arr);
+ assert(index < hdr->len);
+ memmove((char *)arr + index * member_size, (char *)arr + (index+1) * member_size, (hdr->len - (index+1)) * member_size);
+ if (--hdr->len == 0) {
+ free(hdr);
+ return NULL;
+ } else {
+ return arr;
+ }
+}
+
+#ifdef __cplusplus
+#define arr_cast_typeof(a) (decltype(a))
+#elif defined __GNUC__
+#define arr_cast_typeof(a) (__typeof__(a))
+#else
+#define arr_cast_typeof(a)
+#endif
+
+#define arr__join2(a,b) a##b
+#define arr__join(a,b) arr__join2(a,b) // macro used internally
+
+// if the array is not NULL, free it and set it to NULL
+#define arr_free(a) do { if (a) { free(arr_hdr_(a)); (a) = NULL; } } while (0)
+// a nice alias
+#define arr_clear(a) arr_free(a)
+// add an item to the array - if allocation fails, the array will be freed and set to NULL.
+// (how this works: if we can successfully grow the array, increase the length and add the item.)
+#define arr_add(a, x) do { if (((a) = arr_cast_typeof(a) arr_grow1_((a), sizeof *(a)))) ((a)[arr_hdr_(a)->len++] = (x)); } while (0)
+// like arr_add, but instead of passing it the value, it returns a pointer to the value. returns NULL if allocation failed.
+// the added item will be zero-initialized.
+#define arr_addp(a) arr_cast_typeof(a) arr_add_ptr_((void **)&(a), sizeof *(a))
+// set the length of `a` to `n`, increasing the capacity if necessary.
+// the newly-added elements are zero-initialized.
+#define arr_qsort(a, cmp) qsort((a), arr_len(a), sizeof *(a), (cmp))
+#define arr_remove_last(a) do { assert(a); if (--arr_hdr_(a)->len == 0) arr_free(a); } while (0)
+#define arr_remove(a, i) (void)((a) = arr_remove_((a), sizeof *(a), (i)))
+#define arr_insert(a, i, x) do { u32 _index = (i); (a) = arr_cast_typeof(a) arr_grow1_((a), sizeof *(a)); \
+ if (a) { memmove((a) + _index + 1, (a) + _index, (arr_len(a) - _index) * sizeof *(a));\
+ (a)[_index] = x; \
+ ++arr_hdr_(a)->len; } } while (0)
+#define arr_pop_last(a) ((a)[--arr_hdr_(a)->len])
+#define arr_size_in_bytes(a) (arr_len(a) * sizeof *(a))
+#define arr_lastp(a) ((a) ? &(a)[arr_len(a)-1] : NULL)
+#define arr_foreach_ptr_end(a, type, var, end) type *end = (a) + arr_len(a); \
+ for (type *var = (a); var != end; ++var)
+// Iterate through each element of the array, setting var to a pointer to the element.
+// You can't use this like, e.g.:
+// if (something)
+// arr_foreach_ptr(a, int, i);
+// You'll get an error. You will need to use braces because it expands to multiple statements.
+// (we need to name the end pointer something unique, which is why there's that arr__join thing
+// we can't just declare it inside the for loop, because type could be something like char *.)
+#define arr_foreach_ptr(a, type, var) arr_foreach_ptr_end(a, type, var, arr__join(_foreach_end,__LINE__))
+
+#define arr_reverse(a, type) do { \
+ u64 _i, _len = arr_len(a); \
+ for (_i = 0; 2*_i < _len; ++_i) { \
+ type *_x = &(a)[_i]; \
+ type *_y = &(a)[_len-1-_i]; \
+ type _tmp; \
+ _tmp = *_x; \
+ *_x = *_y; \
+ *_y = _tmp; \
+ } \
+ } while (0)
+
+// Ensure that enough space is allocated for n elements.
+#define arr_reserve(a, n) arr_reserve_((void **)&(a), sizeof *(a), (n))
+// Similar to arr_reserve, but also sets the length of the array to n.
+#define arr_set_len(a, n) arr_set_len_((void **)&(a), sizeof *(a), (n))
+
+#if 0
+static void arrcstr_append_strn_(char **a, char const *s, size_t s_len) {
+ size_t curr_len = arr_len(*a);
+ size_t new_len = curr_len + s_len;
+ arr_reserve(*a, new_len + 1);
+ arr_set_len(*a, new_len);
+ memcpy(*a + curr_len, s, s_len);
+ (*a)[curr_len + s_len] = '\0';
+}
+
+static void arrcstr_shrink_(char **a, u32 new_len) {
+ ArrHeader *hdr = arr_hdr_(*a);
+ assert(hdr->cap > new_len);
+ hdr->len = new_len;
+ (*a)[new_len] = '\0';
+}
+
+// append to a C-string array
+#define arrcstr_append_str(a, s) arrcstr_append_strn_(&(a), (s), strlen(s))
+// take at most n bytes from s
+#define arrcstr_append_strn(a, s, n) arrcstr_append_strn_(&(a), (s), (n))
+// make the string smaller
+#define arrcstr_shrink(a, n) arrcstr_shrink_(&(a), (n))
+#endif
+
+#ifndef NDEBUG
+static void arr_test(void) {
+ u32 *arr = NULL;
+ u32 i;
+ assert(arr_len(arr) == 0);
+ for (i = 0; i < 10000; ++i) {
+ arr_add(arr, i*i);
+ }
+ assert(arr_len(arr) == 10000);
+ arr_remove_last(arr);
+ assert(arr_len(arr) == 9999);
+ for (i = 0; i < arr_len(arr); ++i)
+ assert(arr[i] == i*i);
+ while (arr_len(arr))
+ arr_remove_last(arr);
+ assert(arr_len(arr) == 0);
+}
+#endif
+
+typedef struct {
+ // dynamic array, including a null byte.
+ char *str;
+} StrBuilder;
+
+void str_builder_create(StrBuilder *builder) {
+ memset(builder, 0, sizeof *builder);
+ arr_add(builder->str, 0);
+}
+
+StrBuilder str_builder_new(void) {
+ StrBuilder ret = {0};
+ str_builder_create(&ret);
+ return ret;
+}
+
+void str_builder_free(StrBuilder *builder) {
+ arr_free(builder->str);
+}
+
+void str_builder_clear(StrBuilder *builder) {
+ str_builder_free(builder);
+ str_builder_create(builder);
+}
+
+void str_builder_append(StrBuilder *builder, const char *s) {
+ assert(builder->str);
+
+ size_t s_len = strlen(s);
+ size_t prev_size = arr_len(builder->str);
+ size_t prev_len = prev_size - 1; // null terminator
+ // note: this zeroes the newly created elements, so we have a new null terminator
+ arr_set_len(builder->str, prev_size + s_len);
+ // -1 for null terminator
+ memcpy(builder->str + prev_len, s, s_len);
+}
+
+void str_builder_appendf(StrBuilder *builder, PRINTF_FORMAT_STRING const char *fmt, ...) ATTRIBUTE_PRINTF(2, 3);
+void str_builder_appendf(StrBuilder *builder, const char *fmt, ...) {
+ // idk if you can always just pass NULL to vsnprintf
+ va_list args;
+ char fakebuf[2] = {0};
+ va_start(args, fmt);
+ int ret = vsnprintf(fakebuf, 1, fmt, args);
+ va_end(args);
+
+ if (ret < 0) return; // bad format or something
+ u32 n = (u32)ret;
+
+ size_t prev_size = arr_len(builder->str);
+ size_t prev_len = prev_size - 1; // null terminator
+ arr_set_len(builder->str, prev_size + n);
+ va_start(args, fmt);
+ vsnprintf(builder->str + prev_len, n + 1, fmt, args);
+ va_end(args);
+}
+
+// append n null bytes.
+void str_builder_append_null(StrBuilder *builder, size_t n) {
+ arr_set_len(builder->str, arr_len(builder->str) + n);
+}
+
+u32 str_builder_len(StrBuilder *builder) {
+ assert(builder->str);
+ return arr_len(builder->str) - 1;
+}
+