Aliases in Elixir

In part 13 of my Elixir journey I'll share how to use aliases for modules.

Alias

If you have a long module name you can create an `alias` and use that to reference the original module.

    defmodule Foo do
      def add(num) do
        num + 1
      end
      defmodule Bar do
        def transform(list) do
          add_one = &Foo.add/1
          Enum.map(list, add_one)
        end
      end
      defmodule Zap do
        def speak(result) do
          IO.puts "hello #{inspect result}"
        end
      end
    end
    defmodule Baz do
      alias Foo.Bar, as: Bar
      def fire(list) do
        Bar.transform(list)
      end
    end

In this example the `Bar` alias allows us to avoid typing out the full module path `Foo.Bar`. The `as` parameter defaults to the last segment of the module name referenced so in this case it's redundant.

    defmodule Baz do
      alias Foo.Bar
      def fire(list) do
        Bar.transform(list)
      end
    end

Alias also offers the ability to define multiple aliases in a single line when both modules share a common parent.

    defmodule Baz do
      alias Foo.{Bar, Zap}
      def fire(list) do
        Bar.transform(list)
        |> Zap.speak()
      end
    end