PathEntry = object
  kind*: PathComponent
  path*: string

proc nativeToUnixPath(path: string): string {....raises: [], tags: [].}

iterator walkDirRecFilter(dir: string;
                          follow: proc (entry: PathEntry): bool = nil;
                          relative = false; checkDir = true): PathEntry {.
    ...tags: [ReadDirEffect], effectsOf: follow, ...raises: [OSError].}