Anonymous functions as Module attributes?

[Sean Stavropoulos]

I'm just getting started with my Elixir Macro learning, so pardon my lack of understanding.

defmodule AnonymousFunctionTest do
  @anon fn() -> true end

  def anonymous_function,
    do: @anon
end

** (ArgumentError) cannot inject attribute @anon into function/macro because cannot escape #Function<0.35353592 in file:iex>. The supported values are: lists, tuples, maps, atoms, numbers, bitstrings, pids and remote functions in the format &Mod.fun/arity

Is there a particular reason why implementing anonymous functions  isn't technically feasible?  The reason I ask is because I have a particular scenario in mind where using an anonymous function in a macro could provide for a nicer user experience.

[Eric Meadows-Jönsson]

It's not allowed because anonymous functions does not survive compilation. A closure "closes" over an environment, the environment you have during compilation is not available after compilation finished.

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Eric Meadows-Jönsson

[Eric Meadows-Jönsson]

There are workaround if you are using macros because you can store the quoted expression of an anonymous function.

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Eric Meadows-Jönsson