def backward_value

bend-collections@1.0.0.0 · src/containers/dlist_iterator.bend:152

import Base

152def backward_value(~T: Data, vals: Array<Maybe<&2, T>>, h: U32, empty: Bool) -> Array<Maybe<&2, T>> & Result<&2, &2, Error, T>:
153  match empty:
154    case True{}:
155      (vals, Fail{Exhausted{}})
156    case False{}:
157      backward_value_result(~T, Array.get(Maybe<&2, T>, vals, U32.sub(h, 1)))