elixir pattern matching fun

pattern.md

Its very easy to refactor nested code like this in elixir. if/else can be easily pattern matched

defp check_operation(operation) do
  if operation.done do
    if operation.error do
      {:error, "Something went wrong in GCP"}
    else
      {:ok, "Project creation successful"}
    end
  else
    {:error, :retry}
  end
end

Each and every if else can be transformed into a separate function call. So, above code can be written as:

defp check_operation(%{done: true} = operation) do
  if operation.error do
    {:error, "Something went wrong in GCP"}
  else
    {:ok, "Project creation successful"}
  end
end

defp check_operation(operation) do
  {:error, :retry}
end

This can be further broken down into this:

defp check_operation(%{done: true, error: true}) do
  {:error, "Something went wrong in GCP"}
end

defp check_operation(%{done: true} do
  {:ok, "Project creation successful"}
end

defp check_operation(_operation) do
  {:error, :retry}
end

another code golf 😄

check_operation = fn
  %{done: true, error: true} -> {:error, "Something went wrong in GCP"}
  %{done: true} -> {:ok, "Project creation successful"}
  _ -> {:error, :retry}
end