[erlang-questions] To name a function

[Pierpaolo Bernardi]

Here's my try (not tested).
It scans the list once, stops early, and all the hard work is made by
library functions!

categorize(P, [X|Xs]) ->
  case P(X) of
    true ->
      case lists:all(P, Xs) of
        true -> all
        false -> some
      end
    false ->
      case lists:any(P, Xs) of
        true -> some
        false -> none
      end
  end.

Cheers
P.