Use asserts in dbl_list

codegen/dbl_list/snippets/list_empty

@@ -1,6 +1,4 @@
-  if (!list) {{
-    return;
-  }}
+  assert(list != NULL);
 
   u64 count = list->node_count;
   for (u64 i = 0; i < count; ++i) {{

codegen/dbl_list/snippets/list_get

@@ -1,6 +1,4 @@
-  if (index >= list->node_count) {{
-    return NULL;
-  }}
+  assert(index < list->node_count);
 
   {NodeType} *output  = NULL;
   {NodeType} *current = list->first;

codegen/dbl_list/snippets/list_insert

@@ -1,6 +1,4 @@
-  if (!list || !node || !(node->item)) {{
-    return;
-  }}
+  assert(list != NULL && node != NULL && (node->item) != NULL);
 
   if (index == 0) {{
     wapp_{Tlower}_list_push_front(list, node);

codegen/dbl_list/snippets/list_pop_back

@@ -1,6 +1,8 @@
+  assert(list != NULL);
+
   {NodeType} *output = NULL;
 
-  if (!list || list->node_count == 0) {{
+  if (list->node_count == 0) {{
     goto RETURN_{Tupper}_LIST_POP_BACK;
   }}
 

codegen/dbl_list/snippets/list_pop_front

@@ -1,6 +1,8 @@
+  assert(list != NULL);
+
   {NodeType} *output = NULL;
 
-  if (!list || list->node_count == 0) {{
+  if (list->node_count == 0) {{
     goto RETURN_{Tupper}_LIST_POP_FRONT;
   }}
 

codegen/dbl_list/snippets/list_push_back

@@ -1,6 +1,4 @@
-  if (!list || !node || !(node->item)) {{
-    return;
-  }}
+  assert(list != NULL && node != NULL && (node->item) != NULL);
 
   {ListType} node_list = {Tlower}_node_to_list(node);
 

codegen/dbl_list/snippets/list_push_front

@@ -1,6 +1,4 @@
-  if (!list || !node || !(node->item)) {{
-    return;
-  }}
+  assert(list != NULL && node != NULL && (node->item) != NULL);
 
   {ListType} node_list = {Tlower}_node_to_list(node);
 

codegen/dbl_list/snippets/list_remove

@@ -1,7 +1,6 @@
+  assert(list != NULL);
+
   {NodeType} *output = NULL;
-  if (!list) {{
-    goto RETURN_{Tupper}_LIST_REMOVE;
-  }}
 
   if (index == 0) {{
     output = wapp_{Tlower}_list_pop_front(list);