[erlang-questions] Orelse and andalso as short-hand for case

[Pierre Fenoll]

I don’t understand the strong answers.
To me the semantics of orelse/and also are well known. They are even known
as ||/&& in the mainstream.
They have their use as the common boolean shortcut operators. They are even
more than that:
case ShouldOpen andalso file:open(...) of
false ->
{error,_} ->
{ok,_} ->
end

These operators are very interesting semantics. Erlang is not exactly a
pure language. Being able to express side effects in such an
easy-to-comment amount of code that’s just priceless. Here’s a legit
example:
https://github.com/2600hz/kazoo/blob/master/applications/tasks/src/kz_tasks_scheduler.erl#L526

So why the big words? What’s next, the process dictionary, using list
comprehensions with 1-element lists generators?
To me if you don’t like this kind of code it’s only because you have not
needed / seen it much. So, read more code?

On Tue 24 Jul 2018 at 05:42, <zxq9@REDACTED> wrote:

> On 2018年7月22日日曜日 14時25分00秒 JST Viktor Söderqvist wrote:
> > Hey everyone,
> >
> > I've seen these short-circuit operators with a non-boolean second
> > operand, usually where the second operand is doing some side-effect and
> > the return value is not important. It seems to be a trend. Example:
> >
> >     Msg /= undefined andalso io:format("Message: ~s~n", [Msg]),
> >
> > I this good or bad style?
>
> That code should die in a fire and the author should say repent with
> the chanting of 100 Hail McCarthys.
>
> -Craig
> _______________________________________________
> erlang-questions mailing list
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> http://erlang.org/mailman/listinfo/erlang-questions
>
-- 

Cheers,
-- 
Pierre Fenoll
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