Yet another directory recursive delete function for Erlang

myFiles.erl

ensureDirSlash(Dir, Child) ->
  case lists:suffix("/", Dir) of
    true -> Dir ++ Child;
    false -> Dir ++ "/" ++ Child
  end.

-spec deleteDir(Dir :: nonempty_string()) -> none().
deleteDir(Dir) ->
  case {filelib:is_dir(Dir), isFileOrLink(Dir)} of
    {_, true} -> throw("The specified path is not a directory: " ++ Dir);
    {true, _} -> deleteDirImpl([Dir]);
    {false, _} -> ok %% nothing to delete;
end.

isFileOrLink(F) -> filelib:is_regular(F) or (ok == element(1, file:read_link(F))).

deleteDirImpl([]) -> ok;
deleteDirImpl([Current | Rest]) ->
  {ok, ChildrenNames} = file:list_dir(Current),
  Children = lists:map(fun(F) -> ensureDirSlash(Current, F) end, ChildrenNames),
  {FilesOnly, DirsOnly} = lists:partition(fun isFileOrLink/1, Children),
  lists:foreach(fun(F) -> ok = file:delete(F) end, FilesOnly),

  if
    length(DirsOnly) == 0 -> ok = file:del_dir(Current), deleteDirImpl(Rest);
    true -> deleteDirImpl(DirsOnly ++ [Current] ++ Rest)
  end.