View Source Credo.Check.Refactor.MapMap (Credo v1.7.10)

Basics

This check is disabled by default.

Learn how to enable it via .credo.exs.

This check has a base priority of 0 and works with any version of Elixir.

Explanation

One Enum.map/2 is more efficient than Enum.map/2 |> Enum.map/2.

This should be refactored:

[:a, :b, :c]
|> Enum.map(&inspect/1)
|> Enum.map(&String.upcase/1)

to look like this:

Enum.map([:a, :b, :c], fn letter ->
  letter
  |> inspect()
  |> String.upcase()
end)

The reason for this is performance, because the two separate calls to Enum.map/2 require two iterations whereas doing the functions in the single Enum.map/2 only requires one.

Check-Specific Parameters

There are no specific parameters for this check.

General Parameters

Like with all checks, general params can be applied.

Parameters can be configured via the .credo.exs config file.