Absolutely unrelated, but there’s a Haskell-like syntax for Python: https://web.archive.org/web/20241205024857/https://pyos.gith...

  f = x -> raise if
    x :: int  => IndexError x
    otherwise => ValueError x

Complete with pipelines, of course:

  "> {}: {}".format "Author" "stop using stale memes"
    |> print