def inside
import ezx@1.11.0.0/src/tool/plan.bend as Planimport Base
651# a path's part under a directory, "" when it is not under it
652def inside(+dir: String, +path: String) -> String:
653 Bool.pick(String, String.starts_with(path, dir ++ "/"),
654 String.drop(path, Nat.add(String.length(dir), 1n)), "")