1 files changed, 136 insertions, 0 deletions
diff --git a/arraylist.c b/arraylist.c
new file mode 100644
index 0000000..048299f
--- /dev/null
+++ b/arraylist.c
@@ -0,0 +1,136 @@
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "arraylist.h"
+
+#define PUBLIC /* nothing */
+#define PRIVATE static
+
+// size doubles whenever it is exceeded
+#define ARRAYLIST_DEFAULT_SIZE 4
+//#define ARRAYLIST_DEBUG
+
+struct array_list_type {
+	void* data; // the arraylist data
+	int element_size;
+	int max_num_elements;
+	int num_elements;
+};
+
+PRIVATE bool al_grow(Arraylist* al) {
+	void* result = realloc(
+			al->data,
+			al->max_num_elements * al->element_size * 2
+			);
+	if(result != NULL) {
+		al->data = result;
+		al->max_num_elements *= 2;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+void al_delete_last(Arraylist *al) {
+	if(al->num_elements > 0)
+		al->num_elements -= 1;
+}
+
+bool al_delete_at(Arraylist *al, int position) {
+	if(position == (al->num_elements - 1)) {
+		al_delete_last(al);
+		return true;
+	}
+	else if((position >= 0) && (position < al->num_elements)) {
+		memcpy(
+				al->data + (position * al->element_size),
+				al->data + ((position + 1) * al->element_size),
+				al->element_size * (al->num_elements - position)
+			  );
+		al->num_elements -= 1;
+		return true;
+	}
+	printf("Error: deletion out of bounds\n");
+	return false;
+}
+
+int al_len(Arraylist* al) {
+	return al->num_elements;
+}
+
+bool al_allocate_at_least(Arraylist* al, int size) {
+	if(al->max_num_elements >= size) return true;
+	void* result = realloc(
+			al->data,
+			size * al->element_size
+			);
+	if(result != NULL) {
+		al->data = result;
+		al->max_num_elements = size;
+#ifdef ARRAYLIST_DEBUG
+		printf("Grew arraylist to %i\n", al->max_num_elements);
+#endif
+		return true;
+	} else {
+		return false;
+	}
+}
+
+
+Arraylist* al_create(int type_size) {
+	Arraylist* al = malloc(sizeof(Arraylist));
+
+	al->data = malloc(sizeof(type_size) * ARRAYLIST_DEFAULT_SIZE);
+	al->element_size = type_size;
+	al->num_elements = 0;
+	al->max_num_elements = ARRAYLIST_DEFAULT_SIZE;
+
+	return al;
+}
+
+void al_free(Arraylist* al) {
+	free(al->data);
+	free(al);
+}
+
+bool al_push(Arraylist* al, void* item) {
+	if(al->num_elements >= al->max_num_elements) {
+		if(!al_grow(al)) {
+			printf("Error: Failed to grow arraylist to %i\n", al->max_num_elements);
+			return false;
+		}
+#ifdef ARRAYLIST_DEBUG
+		printf("Grew arraylist to %i\n", al->max_num_elements);
+#endif
+	}
+	memcpy(
+			al->data + (al->num_elements * al->element_size),
+			item,
+			al->element_size
+		  );
+	al->num_elements += 1;
+	return true;
+}
+
+void* al_access(Arraylist* al, int position) {
+	if((position >= al->num_elements) || (position < 0))
+		return NULL;
+	return al->data + (al->element_size * position);
+}
+
+bool al_overwrite_and_delete(Arraylist* al, int source, int target) {
+	if(source == target) return true;
+	else if((source >= al->num_elements) || (target >= al->num_elements) || (source < 0) || (target < 0)) {
+		printf("Error, out of bounds");
+		return false;
+	}
+	memcpy(
+			al->data + (target * al->element_size),
+			al->data + (source * al->element_size),
+			al->element_size
+			);
+	return al_delete_at(al, source);
+}
+
+