Getting typer to work for me

[Torben Hoffmann]

Hi.

I have the following code:

-module(ups).

-export([fup/1]).

-spec fup(integer()) -> {'ok',integer()} | 'wrong'.

fup(1) ->
    {ok,2};
fup(_) ->
    not_okay.

And I sort of expected that typer would find the problem in the fup(_) case,
but I have to use
dialyzer -Wspecdiffs --src ups.erl
in order to get the warning I want (namely that the code does not match the
spec), but the dialyzer docs warns against using this option.

Am I asking too much? Should I shake off more of my SML heritage? Am I doing
something wrong?

Any advice appreciated!

Cheers,
Torben
-- 
http://www.linkedin.com/in/torbenhoffmann