Histogram.grp: def of bend-parallel@0.1.0.0
Import: import bend-parallel@0.1.0.0/histogram.bend as Histogram
Lines 230-243 of bend-parallel@0.1.0.0/histogram.bend: https://jend.leeeet.dev/read.txt?path=bend-parallel@0.1.0.0/histogram.bend&start_line=230&end_line=243

import Base

# Pass 2a's forks (sort.bend's too, with sc): d levels down to the lanes
# under lane i, with two handles to the table. Lane i reads and writes
# only its group's rows in its columns: no two lanes touch one slot.
def grp(+d: Nat, +sc: Bool, +i: U32, +gc: Nat, +w: Nat, +m: Nat, +kb: Nat, +k: U32, ft: Array<U32> & Array<U32>) -> Array<U32>:
  match d:
    case 0n:
      (t, t2) = ft
      Array.join(U32, grp.leaf(sc, i, gc, w, m, kb, k, t), t2)
    case 1n+p:
      (t0, t1) = ft
      +j = (i * 2 : U32)
      l r = grp(p, sc, j, gc, w, m, kb, k, Array.fork(U32, t0))
        grp(p, sc, (j + 1 : U32), gc, w, m, kb, k, Array.fork(U32, t1))
      Array.join(U32, l, r)

Uses (11):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array.fork
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array.join
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.mul
  https://jend.leeeet.dev/definition.txt?path=bend-parallel@0.1.0.0/histogram.bend&name=grp.leaf