Histogram.count.grp: def of bend-parallel@0.1.0.0
Import: import bend-parallel@0.1.0.0/histogram.bend as Histogram
Lines 299-311 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=299&end_line=311

import Base
import bend-parallel@0.1.0.0/scan.bend as Scan

# Pass 2a over 2^r groups of 2^m rows by 2^min(d, kb) groups of columns,
# then 2b; below 2^12 rows, 2b alone, over 2^d groups of one row.
def count.grp(lo: Bool, +d: Nat, +k: U32, +kb: Nat, counts: Array<U32>, p: Two) -> Array<U32> & Bufs:
  match lo:
    case True{}:
      Two{keys, table} = p
      count.cols(d, 0n, Nat.min(d, kb), k, kb, keys, counts, table)
    case False{}:
      Two{keys, table} = p
      +g = Nat.min(d, kb)
      +r = Scan.half(d)
      +m = Nat.sub(d, r)
      count.cols(r, m, g, k, kb, keys, counts, grp(Nat.add(r, g), False{}, 0, g, Nat.sub(kb, g), m, kb, k, Array.fork(U32, table)))

Uses (14):
  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=Bool
  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.min
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=bend-parallel@0.1.0.0/histogram.bend&name=Bufs
  https://jend.leeeet.dev/definition.txt?path=bend-parallel@0.1.0.0/histogram.bend&name=Two
  https://jend.leeeet.dev/definition.txt?path=bend-parallel@0.1.0.0/histogram.bend&name=count.cols
  https://jend.leeeet.dev/definition.txt?path=bend-parallel@0.1.0.0/histogram.bend&name=grp
  https://jend.leeeet.dev/definition.txt?path=bend-parallel@0.1.0.0/scan.bend&name=half