def swaps.put
import ezx@1.11.0.0/src/lock/up.bend as Upimport Base
import ezx@1.11.0.0/src/ledger/upgrade.bend as U
799# a moved hash, kept only when there is one
800def swaps.put(empty: Bool, +old: String, +new: String, rest: List<&2, U.Swap>) -> List<&2, U.Swap>:
801 match empty:
802 case True{}:
803 rest
804 case False{}:
805 U.Swap{old, new} <> rest