def gap_left
import bend-collections@1.0.0.0/src/containers/dlist_iterator.bend as DlistIteratorimport Base
77def gap_left(prevs: Array<U32>, tail: U32, n: U32, empty: Bool) -> Array<U32> & U32:
78 match empty:
79 case True{}:
80 (prevs, tail)
81 case False{}:
82 Array.get(U32, prevs, U32.sub(n, 1))