def prev_ready
bend-collections@1.0.0.0 · src/containers/doubly_linked_list.bend:325
import bend-collections@1.0.0.0/src/containers/doubly_linked_list.bend as DoublyLinkedList
import Base
import bend-collections@1.0.0.0/src/containers/internal/dlist_storage.bend as R
import bend-collections@1.0.0.0/src/containers/types/doubly_linked_list.bend as E
325def prev_ready(~T: Data, +h: E.Handle, r: DList<T> & Maybe<&2, E.Error>) -> DList<T> & Result<&2, &2, E.Error, Maybe<&2, E.Handle>>:
326 match r:
327 case Tuple{s, Some{e}}:
328 (s, Fail{e})
329 case Tuple{DL{tag, depth, cap, raw, gens}, None{}}:
330 project_neighbour(~T, neighbour_result(~T, tag, depth, cap, gens, R.prev(~T, raw, old_handle(h))))