Hi everyone!

My colleagues and I ran into challenges with atoms and tuples in our Elixir codebases, especially when modeling domain states or structured data clearly.
Atoms are handy but also sometimes annoying. They’re global, easy to typo and need extra tests to ensure correctness. Not to mention converting strings safely to atoms isn’t very straightforward (and sometimes unsafe/unreliable even with String.to_existing_atom/1).

I had an idea to solve this and built a PoC library but to be honest I’m not entirely sure if the community would like it. Especially I’m curious to know if you see this in a codebase would it make understanding the code easier or more difficult?

Here is my PoC: (It is called Enuma and is available on Hex.pm if you want to try it out)

defmodule Shape do
  use Enuma

  defenum do
    item :circle, args: [float()]   # Circle with radius
    item :rectangle, args: [float(), float()]  # Rectangle with width and height
    item :triangle
  end
end

circle = Shape.circle(5.0) # = {:circle, 5.0}

require Shape

case shape do
  # Can use them in pattern matching as they are compile time macros
  Shape.circle(r) -> :math.pi() * r * r
  # Above case clause is same as
  # {:circle, r} -> :math.pi() * r * r
  Shape.rectangle(w, h) -> w * h
  Shape.triangle() -> raise "Triangle Area Not Supported!"
end

Generally what Enuma does it generating macros based on the enum definition. It also generates is_* guards that can be used in “when” clauses.

Back to the question

Here’s the thing: Enuma does slightly alter how you’d typically write Elixir code, which might make some developers uncomfortable or lead to mixed styles in codebases.

I’m curious:

• Do you think libraries like Enuma enhance clarity, or do they risk complicating Elixir’s simplicity?

• Would Enuma fit well into your projects, or does it feel too different?

• How do you currently handle structured domain modeling in your code?

• If you compare it with Ecto.Enum, would you see useful benefits for your usecases?

I’m looking forward to your thoughts!
https://github.com/alisinabh/enuma/