Efficiently Counting Filtered Results from a List in Elixir

In this article, Rémi Prévost explains how to efficiently process a list of attribute maps in Elixir. The tasks include converting each map to a specific result using `Foo.run/1`, filtering out unwanted results (keeping only `{:ok, _}` tuples), and counting the remaining results. The initial approach involves separate mapping, filtering, and counting steps using `Enum.map/2`, `Enum.filter/2`, and `Enum.count/1`, respectively. However, @remi proposes a more optimized approach that reduces the loop count by combining mapping and filtering in a single step, and ultimately suggests using `Enum.count/2` to handle all operations in one loop. This results in performance improvements by minimizing iterations over the list.