Fast.append: def of lawful-bytes@0.1.1.0
Import: import lawful-bytes@0.1.1.0/fast.bend as Fast
Lines 138-144 of lawful-bytes@0.1.1.0/fast.bend: https://jend.leeeet.dev/read.txt?path=lawful-bytes@0.1.1.0/fast.bend&start_line=138&end_line=144

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

# dst with bytes s .. s+n-1 of src added at the end; src handed back. The
# first bytes, up to dst's next word boundary, go one at a time, the rest a
# word at a time.
def append(dst: D.Bytes, src: D.Bytes, +s: U32, +n: U32) -> D.Bytes & D.Bytes:
  D.Bytes{+dl, db} = dst
  +h = U32.min(((4 - (dl .&. 3 : U32) : U32) .&. 3 : U32), n)
  append.k((n - h : U32), (s + h : U32), B.append(D.Bytes{dl, db}, src, s, h))

Uses (9):
  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=Base/base.bend&name=U32.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.min
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.sub
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/bytes.bend&name=append
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/defs.bend&name=Bytes
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/fast.bend&name=append.k