Ed25519.public_key_at: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/spec/crypto/ed25519.bend as Ed25519
Lines 251-258 of bend-collections-laws-crypto@1.0.0.0/spec/crypto/ed25519.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/ed25519.bend&start_line=251&end_line=258

import Base
import bend-collections-laws-crypto@1.0.0.0/spec/crypto/sha512.bend as SHA

# at p = prime(one); a function of p first, so the checker keeps it a call
# (p is symbolic) instead of expanding it whenever it compares two of them
def public_key_at(+one: Nat, p: Nat, +seed: List<&2, U32>) -> List<&2, U32>:
  match p:
    case 0n:
      public_of(one, 0n, dconst(one, 0n), SHA.sha512_bytes(seed))
    case 1n+ +q:
      public_of(one, 1n+q, dconst(one, 1n+q), SHA.sha512_bytes(seed))

Uses (6):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  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=bend-collections-laws-crypto@1.0.0.0/spec/crypto/ed25519.bend&name=dconst
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/ed25519.bend&name=public_of
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/sha512.bend&name=sha512_bytes