def prev

bend-collections@1.0.0.0 · src/containers/internal/dlist_storage.bend:309

import Base
import bend-collections@1.0.0.0/src/containers/types/internal_dlist.bend as E

309def prev(~T: Data, s: DList<T>, h: E.Handle) -> DList<T> & Result<&2, &2, E.Error, Maybe<&2, E.Handle>>:
310  DL{+tag, +fresh, +free, +count, +head, +tail, +depth, +cap, vals, prevs, nexts} = s
311  E.H{+l, +i} = h
312  nbr_checked(~T, False{}, U32.is_lt(i, fresh), tag, fresh, free, count, head, tail, depth, cap, vals, prevs, nexts, i, U32.is_eq(l, tag))