Bytes.copy.shift: def of bend-kit-bytes@0.3.3.0
Import: import bend-kit-bytes@0.3.3.0/bytes.bend as Bytes
Lines 80-89 of bend-kit-bytes@0.3.3.0/bytes.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-bytes@0.3.3.0/bytes.bend&start_line=80&end_line=89

import Base

# m bytes to a word-aligned d from an unaligned s: each out word joins two source words.
# lo = 8*(s%4) and hi = 32 - lo; r holds source word k, prev the word before it.
def copy.shift(n: Nat, +lo: Nat, +hi: Nat, +prev: U32, r: Array<U32> & U32, dst: Array<U32>, +k: U32, +d: U32) -> Array<U32> & Array<U32>:
  match n:
    case 0n:
      (a, w) = r
      (a, dst)
    case 1n+p:
      (a, +w) = r
      copy.shift(p, lo, hi, w, Array.get(U32, a, (k + 1 : U32)), Array.set(U32, dst, d, (U32.shrn(prev, lo) .|. U32.shln(w, hi) : U32)), (k + 1 : U32), (d + 1 : U32))

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.get
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array.set
  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.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.shln
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.shrn