Blake2s.keep: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/src/crypto/blake/blake2s/blake2s.bend as Blake2s
Lines 82-90 of bend-collections@1.0.0.0/src/crypto/blake/blake2s/blake2s.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/src/crypto/blake/blake2s/blake2s.bend&start_line=82&end_line=90

import Base

# The final block keeps the bytes before the logical length and zeroes the rest.
# keep(n, w) keeps the low n bytes of w.
def keep(n: Nat, +w: U32) -> U32:
  match n:
    case 0n: 0
    case 1n: U32.and(255,w)
    case 2n: U32.and(65535,w)
    case 3n: U32.and(16777215,w)
    case 4n+p: w

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.and