refactor: changed arrayslice_to_arraylsit

src/arraylist.c

@@ -584,13 +584,17 @@ ArrayListErr arrayslice_advance(ArraySlice *slice, size_t n) {
     return ARRLIST_OK;
 }
 
-ArrayList *arrayslice_to_arraylist(const ArraySlice *slice) {
+ArrayListErr arrayslice_to_arraylist(ArrayList **arr, const ArraySlice *slice) {
     if (slice == NULL || slice->arr == NULL) {
-        return NULL;
+        return ARRLIST_NULL_ARG;
+    }
+
+    if (arr == NULL || *arr == NULL) {
+        return ARRLIST_NULL_ARG;
     }
 
     if (slice->start >= slice->end) {
-        return NULL;
+        return ARRLIST_INVALID_SLICE;
     }
 
     size_t len = slice->end - slice->start;
@@ -601,8 +605,9 @@ ArrayList *arrayslice_to_arraylist(const ArraySlice *slice) {
         arraylist_capacity(slice->arr),
         slice->arr->elem_size
     );
-    if (new_arr == NULL) {
-        return NULL;
+
+    if (init_err != ARRLIST_OK) {
+        return init_err;
     }
 
     memcpy(
@@ -613,5 +618,6 @@ ArrayList *arrayslice_to_arraylist(const ArraySlice *slice) {
 
     new_arr->len = len;
 
-    return new_arr;
+    *arr = new_arr;
+    return ARRLIST_OK;
 }