def names.once

ezx@1.11.0.0 · src/lock/plan.bend:1243

import Base
import ezx@1.11.0.0/src/lock/lock.bend as L

1243# every name of a list once, each where it first stands
1244def names.once(nvs: List<&2, String>, +seen: List<&2, String>) -> List<&2, String>:
1245  match nvs:
1246    case []:
1247      []
1248    case +h <> t:
1249      names.once.put(L.seen.holds(seen, h), h, names.once(t, h <> seen))