+ # Pre-release version, denoted by appending a hyphen
+ # and a series of dot separated identifiers
+ pre_release =
+ [git_pre_release, branch_name]
+ |> Enum.filter(fn string -> string && string != "" end)
+ |> Enum.join(".")
+ |> (fn
+ "" -> nil
+ string -> "-" <> String.replace(string, identifier_filter, "-")
+ end).()
+