Protein.sum_count_atoms: def of bend-prot@0.1.0.0
Import: import bend-prot@0.1.0.0/protein.bend as Protein
Lines 68-74 of bend-prot@0.1.0.0/protein.bend: https://jend.leeeet.dev/read.txt?path=bend-prot@0.1.0.0/protein.bend&start_line=68&end_line=74

import Base
import bend-prot@0.1.0.0/geom.bend as G

# Sum positions + count in one pass (list consumed once)
def sum_count_atoms(xs: List<&2, Atom>) -> G.Vec3 & Nat:
  match xs:
    case Nil{}:
      (G.V3{0.0, 0.0, 0.0}, 0n)
    case h <> t:
      sum_count_extend(h, sum_count_atoms(t))

Uses (7):
  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=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=bend-prot@0.1.0.0/geom.bend&name=Vec3
  https://jend.leeeet.dev/definition.txt?path=bend-prot@0.1.0.0/protein.bend&name=Atom
  https://jend.leeeet.dev/definition.txt?path=bend-prot@0.1.0.0/protein.bend&name=sum_count_extend