Chacha.hstate: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/spec/crypto/chacha.bend as Chacha
Lines 175-181 of bend-collections@1.0.0.0/spec/crypto/chacha.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/spec/crypto/chacha.bend&start_line=175&end_line=181

import Base

# HChaCha20 (draft-irtf-cfrg-xchacha-03 section 2.2): the state is set up as
# for ChaCha20 with the 16-byte nonce in words 12..15; after twenty rounds
# (no feed-forward) words 0..3 and 12..15 are the 32-byte subkey.
def hstate(+k: List<&2, U32>, +n: List<&2, U32>) -> List<&2, U32>:
  List.append(&2, U32, constants(),
    [get(k, 0n), get(k, 1n), get(k, 2n), get(k, 3n), get(k, 4n), get(k, 5n), get(k, 6n), get(k, 7n),
     get(n, 0n), get(n, 1n), get(n, 2n), get(n, 3n)])

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.append
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/chacha.bend&name=constants
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/chacha.bend&name=get