Tree.build: def of bend-lawful-stdlib@0.1.0.0
Import: import bend-lawful-stdlib@0.1.0.0/src/tree.bend as Tree
Lines 40-48 of bend-lawful-stdlib@0.1.0.0/src/tree.bend: https://jend.leeeet.dev/read.txt?path=bend-lawful-stdlib@0.1.0.0/src/tree.bend&start_line=40&end_line=48

import Base

# a balanced tree with 2^d leaves f(lo), f(lo+1), ..., so both halves of
# each parallel call do the same amount of work
def build(~A: Data, ~f: Nat -> A, +d: Nat, +lo: Nat) -> Tree<A>:
  match d:
    case 0n:
      Tip{f(lo)}
    case 1n+p:
      l r = build(~A, ~f, p, lo) build(~A, ~f, p, Nat.add(lo, Nat.pow(2n, p)))
      Fork{l, r}

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.pow
  https://jend.leeeet.dev/definition.txt?path=bend-lawful-stdlib@0.1.0.0/src/tree.bend&name=Tree