Papillon6814
Handling nil in case
Hello. I’m thinking the way to handle nil in case.
|> case do
x when not is_nil(x) ->
...
{:ok, "xxxxxx"}
nil ->
...
{:error, "xxxxxxxx"}
end
|> case do
nil ->
...
{:error, "xxxxxxxx"}
topic ->
...
{:ok, "xxxxxxxx"}
end
When I handle nil in case, I write codes in a latter way. What do you think of that?
Most Liked
dimitarvp
In case, I always go from most concrete to least concrete, like so:
case something do
nil -> "nil"
:a -> "the atom :a"
text when is_binary(text) -> "text"
list when is_list(list) -> "list"
other -> raise(ArgumentError, "unexpected value: #{inspect(other)}"
end
kokolegorille
You can also do like this, if topic is some kind of struct.
|> case do
%Topic{} = topic -> ...
nil -> ...
end
dmitrykleymenov
About piping into case a good mention was in Good and Bad Elixir post. May be you should consider to match it to some variable? Especially with nil result possibility, you could rewrite it to if some_result, do: something, else: another
dmitrykleymenov
At least that is said in the article 
If you think it makes sence, yeah, you may assign intermediate result into variable and use it in case explicit. But it’s hard to tell without upstream code.
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
The deployment platform built for Elixir: PaaS ease, VPS control.
Categories:
Sub Categories:
Forums
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Practical resources that improve the lives of professional developers.
Producing high quality Elixir screencasts since 2017.
The deployment platform built for Elixir: PaaS ease, VPS control.
Courses that'll move you from confusion to "Aha, now I get it!"