def pin
import bolt@1.27.0.0/src/rules/pedantic/rewalk.bend as Rewalkimport Base
751# marked collection arguments become slots
752def pin(+ps: List<&2, Pos>, sites: List<&2, Site>) -> List<&2, Site>:
753 match sites:
754 case Nil{}:
755 Nil{}
756 case Con{s, rest}:
757 pin_one(ps, s) <> pin(ps, rest)