1 files changed, 51 insertions, 0 deletions
diff --git a/vec.c b/vec.c
new file mode 100644
index 0000000..719344e
--- /dev/null
+++ b/vec.c
@@ -0,0 +1,51 @@
+#include <string.h>
+
+#include "mem.h"
+#include "vec.h"
+
+#define DEFAULT_LEN 8
+
+void vec_init(struct vec *v, size_t unit_size)
+{
+	v->data = NULL;
+	v->len = 0;
+	v->cap = 0;
+	v->unit_size = unit_size;
+}
+
+void vec_push(struct vec *v, const void *item)
+{
+	void *target;
+
+	if (v->len == v->cap) {
+		v->cap = (v->cap == 0) ? DEFAULT_LEN : v->cap * 2;
+		v->data = REALLOC(v->data, v->cap * v->unit_size);
+	}
+
+	target = (char *)v->data + (v->len * v->unit_size);
+	memcpy(target, item, v->unit_size);
+	v->len++;
+}
+
+void *vec_pop(struct vec *v)
+{
+	if (v->len == 0) 
+		return NULL;
+	v->len--;
+	return (char *)v->data + (v->len * v->unit_size);
+}
+
+void *vec_top(struct vec *v)
+{
+	if (v->len == 0) 
+		return NULL;
+	return (char *)v->data + ((v->len - 1) * v->unit_size);
+}
+
+void vec_free(struct vec *v)
+{
+	free(v->data);
+	v->data = NULL;
+	v->len = v->cap = 0;
+}
+