Bytes.shift: def of lawful-bytes@0.1.1.0
Import: import lawful-bytes@0.1.1.0/bytes.bend as Bytes
Lines 161-164 of lawful-bytes@0.1.1.0/bytes.bend: https://jend.leeeet.dev/read.txt?path=lawful-bytes@0.1.1.0/bytes.bend&start_line=161&end_line=164

import Base
import lawful-bytes@0.1.1.0/defs.bend as D

# The first k bytes dropped, the rest moved to the start (for k <= len).
def shift(b: D.Bytes, +k: U32) -> D.Bytes:
  D.Bytes{+n, buf} = b
  truncate(shift.go(Nat.sub(U32.to_nat(n), U32.to_nat(k)), at(D.Bytes{n, buf}, k), 0, k), (n - k : U32))

Uses (8):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.to_nat
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/bytes.bend&name=at
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/bytes.bend&name=shift.go
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/bytes.bend&name=truncate
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/defs.bend&name=Bytes