add vec

1 files changed, 121 insertions, 0 deletions

diff --git a/lib/cbit/vec.h b/lib/cbit/vec.h
new file mode 100644
index 0000000..87e4c28
--- /dev/null
+++ b/lib/cbit/vec.h
@@ -0,0 +1,121 @@
+#pragma once
+#include "misc.h"
+#include <stdlib.h>
+#include <string.h>
+
+struct vec_internal {
+   size_t length;
+   size_t capacity;
+   void *els;
+   char storage[1]; // must be at least one byte so vec_free works correctly
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void vec_realloc_internal(struct vec_internal *vi, size_t new_capacity,
+                          size_t esize);
+void vec_realloc_internal_as_necessary(struct vec_internal *vi,
+                                       size_t min_capacity,
+                                       size_t esize);
+#ifdef __cplusplus
+}
+#endif
+
+#define DECL_VEC(ty, name) \
+   typedef ty __VEC_TY_##name; \
+   struct vec_##name { \
+      union { \
+         struct vec_internal vi; \
+         struct { \
+            size_t length; \
+            size_t capacity; \
+            VEC_TY(name) *els; \
+            VEC_TY(name) storage[1]; \
+         }; \
+      }; \
+   }; \
+   UNUSED_STATIC_INLINE \
+   void vec_free_storage(struct vec_##name *v) { \
+      if (v->els != v->storage) \
+         free(v->els); \
+   } \
+   UNUSED_STATIC_INLINE \
+   struct vec_##name vec_borrow(VEC_TY(name) *els, size_t length) { \
+      struct vec_##name v; \
+      v.length = v.capacity = length; \
+      v.els = els; \
+      return v; \
+   } \
+   UNUSED_STATIC_INLINE \
+   void vec_realloc_##name(struct vec_##name *v, size_t new_capacity) { \
+      vec_realloc_internal(&v->vi, new_capacity, sizeof(v->els[0])); \
+   } \
+   UNUSED_STATIC_INLINE \
+   void vec_resize_##name(struct vec_##name *v, size_t new_length) { \
+      if (new_length >= v->capacity || new_length < v->capacity / 3) \
+         vec_realloc_internal_as_necessary(&v->vi, new_length, sizeof(v->els[0])); \
+      v->length = new_length; \
+   } \
+   UNUSED_STATIC_INLINE \
+   VEC_TY(name) *vec_appendp_##name(struct vec_##name *v) { \
+      size_t i = v->length++; \
+      if (i == v->capacity) \
+         vec_realloc_internal_as_necessary(&v->vi, i + 1, sizeof(v->els[0])); \
+      return &v->els[i]; \
+   } \
+   UNUSED_STATIC_INLINE \
+   void vec_append_##name(struct vec_##name *v, VEC_TY(name) val) { \
+      *vec_appendp_##name(v) = val; \
+   } \
+   UNUSED_STATIC_INLINE \
+   void vec_concat_##name(struct vec_##name *v1, const struct vec_##name *v2) { \
+      size_t l1 = v1->length, l2 = v2->length; \
+      vec_resize_##name(v1, safe_add(l1, l2)); \
+      memcpy(&v1->els[l1], v2->els, l2 * sizeof(v1->els[0])); \
+   } \
+   UNUSED_STATIC_INLINE \
+   void vec_add_space_##name(struct vec_##name *v, size_t idx, size_t num) { \
+      /* todo optimize */ \
+      size_t orig = v->length; \
+      vec_resize_##name(v, orig + num); \
+      memmove(&v->els[idx + num], &v->els[idx], \
+              (orig - idx) * sizeof(v->els[0])); \
+   } \
+   UNUSED_STATIC_INLINE \
+   void vec_remove_##name(struct vec_##name *v, size_t idx, size_t num) { \
+      /* todo optimize */ \
+      size_t orig = v->length; \
+      memmove(&v->els[idx], &v->els[idx + num], \
+              (orig - (idx + num)) * sizeof(v->els[0])); \
+      vec_resize_##name(v, orig - num); \
+   } \
+
+
+#define VEC_TY(name) __VEC_TY_##name
+
+#define VEC_STORAGE_CAPA(name, n) \
+   struct { \
+      struct vec_##name v; \
+      VEC_TY(name) rest[(n)-1]; \
+   }
+
+#define VEC_STORAGE(ty) \
+   VEC_STORAGE_CAPA(ty, 5)
+
+#define VEC_STORAGE_INIT(vs, name) do { \
+   struct vec_##name *v = &(vs)->v; \
+   v->length = 0; \
+   v->capacity = (sizeof((vs)->rest) / sizeof(VEC_TY(name))) + 1; \
+   v->els = v->storage; \
+} while (0)
+
+
+/* guaranteed to *not* cache vec->length - pretty simple */
+
+#define VEC_FOREACH(vec, idx_var, ptr_var, name) \
+   LET(struct vec_##name *__vfe_v = (vec)) \
+      for (size_t idx_var = 0; idx_var < __vfe_v->length; idx_var++) \
+         LET_LOOP(ptr_var = &__vfe_v->els[idx_var])
+