#ifndef LIST_H_
#define LIST_H_
/* ----- List definition ----- */
#ifndef LIST_IMPLEMENTATION
#define DefList(type) \
struct Node##type { \
	type head; \
	struct Node##type* rest; \
}; \
typedef struct Node##type* List##type; \
void List##type##_deinit(List##type list); \
type List##type##_car(struct Node##type node); \
struct Node##type* List##type##_cdr(struct Node##type node); \
List##type List##type##_cons(type a, List##type list); \
List##type List##type##_rev(List##type list, List##type a); \
List##type List##type##_reverse(List##type list); \
size_t List##type##_length(List##type list); \
type List##type##_at(List##type list, size_t index);
#else
#define DefList(type) \
struct Node##type { \
	type head; \
	struct Node##type* rest; \
}; \
typedef struct Node##type* List##type; \
 \
void List##type##_deinit(List##type list) { \
	if (list != NULL) { \
		List##type##_deinit(list->rest); \
		assert(list->rest == NULL); \
		free(list); \
		list = NULL; \
	} \
} \
 \
type List##type##_car(struct Node##type node) { \
	List##type##_deinit(node.rest); \
	return node.head; \
} \
 \
struct Node##type* List##type##_cdr(struct Node##type node) { \
	return node.rest; \
} \
 \
List##type List##type##_cons(type a, List##type list) { \
	struct Node##type* node = (struct Node##type*)calloc(sizeof(struct Node##type), 1); \
	exists(node); \
	*node = (struct Node##type){ .head = a, .rest = list }; \
	return (List##type)node; \
} \
 \
List##type List##type##_rev(List##type list, List##type a) { \
	if (list != NULL) return List##type##_rev(list->rest, List##type##_cons(list->head, a)); \
	else              return a; \
} \
 \
List##type List##type##_reverse(List##type list) { \
	return List##type##_rev(list, NULL); \
} \
 \
size_t List##type##_length(List##type list) { \
	if (list != NULL) return List##type##_length(list->rest) + 1; \
	else              return 0; \
} \
 \
type List##type##_at(List##type list, size_t index) { \
	if (list != NULL) return index == 1 ? list->head : List##type##_at(list->rest, index - 1); \
	else              exists(NULL); \
	return (type){0}; \
}
#endif
#endif // LIST_H_