Settings View Source Credo.Check.Refactor.MapInto (Credo v1.7.7-rc.0)

Basics

This check is disabled by default.

Learn how to enable it via .credo.exs.

This check has a base priority of high and requires Elixir < 1.8.0.

Explanation

Enum.into/3 is more efficient than Enum.map/2 |> Enum.into/2.

This should be refactored:

[:apple, :banana, :carrot]
|> Enum.map(&({&1, to_string(&1)}))
|> Enum.into(%{})

to look like this:

Enum.into([:apple, :banana, :carrot], %{}, &({&1, to_string(&1)}))

The reason for this is performance, because the separate calls to Enum.map/2 and Enum.into/2 require two iterations whereas Enum.into/3 only requires one.

NOTE: This check is only available in Elixir < 1.8 since performance improvements have since made this check obsolete.

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.