Module Core_kernel__Doubly_linked_intf

Doubly-linked lists.

Compared to other doubly-linked lists, in this one:

1. Calls to modification functions (insert*, move*, ...) detect if the list is being iterated over (iter, fold, ...), and if so raise an exception. For example, a use like the following would raise:

iter t ~f:(fun _ -> ... remove t e ...)

2. There is a designated "front" and "back" of each list, rather than viewing each element as an equal in a ring.

3. Elements know which list they're in. Each operation that takes an Elt.t also takes a t, first checks that the Elt belongs to the t, and if not, raises.

4. Related to (3), lists cannot be split, though a sort of splicing is available as transfer. In other words, no operation will cause one list to become two. This makes this module unsuitable for maintaining the faces of a planar graph under edge insertion and deletion, for example.

5. Another property permitted by (3) and (4) is that length is O(1).

module type S = sig ... end
module type Doubly_linked = sig ... end