Blake3.partial: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/src/crypto/blake/blake3/blake3.bend as Blake3
Lines 95-103 of bend-collections@1.0.0.0/src/crypto/blake/blake3/blake3.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/src/crypto/blake/blake3/blake3.bend&start_line=95&end_line=103

import Base

# The block truncated to its first `len` bytes: the word at byte offset pos
# keeps its low len - pos bytes (all four when at least four remain).
def partial(w: U32, delta: Nat) -> U32:
  match delta:
    case 0n: 0
    case 1n: U32.and(w,255)
    case 2n: U32.and(w,65535)
    case 3n: U32.and(w,16777215)
    case 4n+q: 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