def drain_take_go

bend-collections@1.0.0.0 · src/containers/binary_heap.bend:345

import Base

345# Take the root out of a copy holding `n` elements. Emptiness is decided by
346# the count, not by reading slot 0: the drain must stop at `n = 0` whatever
347# the slots above the heap hold (and it saves one array read per element).
348def drain_take_go(~A: Data, +n: U32, arr: Array<Maybe<&2, A>>, empty: Bool) -> Drain<A>:
349  match empty:
350    case True{}:
351      DrDone{arr}
352    case False{}:
353      drain_take(~A, U32.sub(n, 1), Array.get(Maybe<&2, A>, arr, 0))