Erlang equivalent for `with` special form

Questions & Help Questions
1

Hi,
What would be the Erlang equivalent for the with special form like:

with {:ok, width} <- Map.fetch(opts, :width),
       {:ok, height} <- Map.fetch(opts, :height) do
       {:ok, width * height}
else
      :error -> {:error, :wrong_data}
end

I’m switching back and forth between the languages and still didn’t found a nice abstraction in Erlang for this.

Thanks,

2

Elixir’s with compiles to a nested case-statement. Unfortunately Erlang does not provide such an abstraction itself.

3

Yes, nested case statements is the problem I’m trying to solve :slight_smile:

4

There is no equivalent, although there are libraries such as erlando that implement the do-notation.

5

Ooo I hadn’t ran across erlando in a long time, that’s a blast from the past. ^.^

6 
maybe
    {ok, A} ?= a(),
    true = A >= 0,
    {ok, B} ?= b(),
    A + B
end