Handling nil in case

You can also do like this, if topic is some kind of struct.

|> case do
  %Topic{} = topic -> ...
  nil -> ...
end

Oops, I made a mistake. I should have changed topic to x
topic in the latter way is binary, so I only thought out the 2 ways.
Thank you!

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

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

I’d like to use value of x in the process, so I chose case.
Do you give me an idea if the value is used in the pipelines?

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.