How to handle nested case

[Attila Rajmund Nohl]

Hello!

The functions *are* executed conditionally - if get_radius_host()
doesn't return {ok, Server}, then get_radius_port() won't be called.

Michael Malter <airlangue@REDACTED> ezt írta (időpont: 2021. szept.
19., V, 10:08):
>
> Hi
>
> Now it's kinda ugly.
> You could just keep the lines from your try clauses and put the result in a case or a function.
>
> Anyway, the execution flow is different now. I think OP wanted the get functions executed conditionaly.
>
> I will repeat, just put the cases in functions.
>
> Michaël Malter
>
> Le dim. 19 sept. 2021 à 09:07, Attila Rajmund Nohl <attila.r.nohl@REDACTED> a écrit :
>>
>> Hello!
>>
>> One way (I haven't actually tried to compile this, but hopefully you
>> get the idea):
>>
>> get_nas_from_conf() ->
>>   try
>>     {ok, Server} = get_radius_host(),
>>     {ok, Port} = get_radius_port(),
>>     {ok, Secret} = get_radius_secret(),
>>     {Server, Port, Secret};
>>   catch
>>     error:{badmatch, E} ->
>>       E
>> end.
>>
>> Of course, if the badmatch comes from the get_* functions, this
>> construct might catch that too, but you might be able to  ensure this
>> doesn't happen.
>>
>> Gian Lorenzo Meocci <glmeocci@REDACTED> ezt írta (időpont: 2021.
>> szept. 18., Szo, 22:50):
>> >
>> > Hi,
>> > I have a function like this:
>> >
>> > get_nas_from_conf() ->
>> > case get_radius_host() of
>> > {ok, Server} ->
>> > case get_radius_port() of
>> > {ok, Port} ->
>> > case get_radius_secret() of
>> > {ok, Secret} ->
>> > {Server, Port, Secret};
>> > E -> E
>> > end;
>> > E ->
>> > E
>> > end;
>> > E ->
>> > E
>> > end.
>> >
>> > Which is the best way to write this kind of function?
>> >
>> > I'd like to have a with operator like in Elixir, to rewrite my function in this way:
>> >
>> > get_nas_from_conf() ->
>> > with {ok, Server} <- get_radius_host(),
>> > {ok, Port} = get_radius_port(),
>> > {ok, Secret} = get_radius_secret() ->
>> > {Server, Port, Secret};
>> > catch
>> > {error, _Reason} = E ->
>> > E
>> > end.
>> >
>> > Any suggestion?
>> >
>> > --
>> > GL
>> > https://www.meocci.it