I’m confused. You said it’s used in ExUnit. I’m not necessarily saying that’s the right home for it, but…
Let’s look to another example: Erlang.
When you start a project in Erlang, instead of just getting :elixir by default, you get 3, IIRC.
One could argue that Erlang’s packages are too modular… and I’d agree with that!
But by the same token, I’d say Elixir’s core has some things that could be revised.
Now if 1.8 truly is the slowdown point, fine. It’s small enough.
But again, Valim’s whole argument for not adding new functions to say ExUnit (such as 2 that I proposed) is the notion that Elixir should be extensible.
At the end of the day, I think there’s a double-standard: the Core Team adds things even when the separation of concerns is poor or unexplained. And when I worked off of that, suggesting 2 macros, I get this line about extensibility.
The irony is I agreed with Valim’s point in principle, so I’m confused by the resistance here when I apply this same principle to the core itself… 
