Multiline comment in Elixir

Macros could help here to some degree:

defmodule Comment do
  defmacro comment(_text) do
  end
end

defmodule TestComment do
  import Comment

  comment """
  Module
  Comment
  """

  def func do
    comment """
    Function
    Comment
    """
  end
end

Elixir does not have multiline comments.

However, one very common use case for multiline comments is documenting modules and functions, for which you can use the module attributes @doc and @moduledoc together with heredocs.

defmodule MyModule do
  @moduledoc """
  This module is great at X
  """

  @doc """
  Frobnicates the given string.
  """
  def frobnicate(s) do
  end
end