arraylist

src/array.c

@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+union arraylist_meta {
+        max_align_t dummy_align;
+        struct {
+            size_t len;
+            size_t cap;
+            size_t sizeof_one_element;
+        };
+    };
+
+void* arraylist_create(size_t array_size, size_t sizeof_one_element) {
+	union arraylist_meta *arraylist_new = malloc(array_size * sizeof_one_element + sizeof*arraylist_new);
+	arraylist_new->len = array_size;
+	arraylist_new->cap = array_size;
+	arraylist_new->sizeof_one_element = sizeof_one_element;
+	return arraylist_new+1;
+}
+
+void* arraylist_append(void *arraylist_void, void *element_void) {
+	char *element = element_void;
+	union arraylist_meta *arraylist = arraylist_void;
+	--arraylist;
+	if(arraylist->len == arraylist->cap) {
+		arraylist->cap = arraylist->len + 10;
+		arraylist = realloc(arraylist, arraylist->cap * arraylist->sizeof_one_element + sizeof *arraylist);
+	}
+	char *arraylist_char = (char*)(arraylist+1);
+	arraylist_char += arraylist->sizeof_one_element * arraylist->len;
+	for(size_t i = 0; i < arraylist->sizeof_one_element; ++arraylist_char, ++element, ++i) {
+		*arraylist_char = *element;
+	}
+	++arraylist->len;
+	return arraylist+1;
+}