Chacha20.xor_front: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/src/crypto/chacha/chacha20.bend as Chacha20
Lines 66-70 of bend-collections@1.0.0.0/src/crypto/chacha/chacha20.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/src/crypto/chacha/chacha20.bend&start_line=66&end_line=70

import Base

# XOR the keystream onto the front of xs, as far as both go.
def xor_front(ks: List<&2, U32>, xs: List<&2, U32>) -> List<&2, U32>:
  match ks xs:
    case k <> kt x <> xt: U32.xor(x, k) <> xor_front(kt, xt)
    case _ _: Nil{}

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