04_atoms.ex has unclear expectations

[DaneWeber]

I'm new to Elixir and using these koans. First of all: thanks! I really appreciate them.

For the 04_atoms koans, I wasn't clear what was expected. For example, assert true == ___ and assert false == ___ can be most easily completed by simply repeating true and false.

I was guessing that perhaps it should be completed with assert true == :true.

Another thought is that these could be triple-equal, such as assert :true === ___?

Bottom line: while this definitely succeeding in driving me to think more about atoms, I would have appreciated more of a nudge.

If someone more experienced with Elixir can explain the intent, I would be happy to submit a PR to improve this koan.

[iamvery]

@DaneWeber thank you for the feedback! Sorry it has taken so long to get a response. Sometimes it's really hard to build an example that provides enough hint to keep folks on the straight and narrow w/o giving everything away. If you have any ideas for how to help these examples explain themselves better, we'd love to see them! Maybe even as easy as a little more in the description? Or a comment?

[DaneWeber]

Thanks for the response! 😄 I'm on a pretty slow cycle too.

So, I'm an elixir newbie, but my suggestion was the following:
assert :true === ___

I would think that would point to a solution of assert :true === true. I'm assuming that is the intent of this exercise, but I wanted to make sure I'm not missing a deeper solution.

[iamvery]

Ah, I think I missed the subtlety of your suggestion. I like it! I agree that it would seem a bit easier to intuit what the lesson is trying to show you by going from atom to boolean rather than the opposite. Fwiw, I don't think the threequals is really necessary. I believe the only difference is numeric equality.

The only difference between == and === is that === is stricter when it comes to comparing integers and floats

What do you think @felipesere @ukutaht ?

[ukutaht]

Thank you for the suggestions @DaneWeber!

I agree with @iamvery here. Showing the atom is a good improvement to the exercise but I would keep the double-equals. In my experience the convention is to always use double-equals as the default and frankly seeing a triple-equals in an elixir codebase would be pretty confusing to me.

[DaneWeber]

Interesting! I came directly from 03_numbers.ex which uses === several times, and I clearly missed that it's only stricter when it comes to integers & floats. I was carrying baggage from other languages.

[iamvery]

I wonder if we could do more to emphasize "looky === matters for numbers"

[tkilgour]

Found this issue because I also had no idea what assert true == ___ and assert false == ___ were expecting.

My suggestion would be to follow the same pattern from the first two koans in Numbers:

assert true == :true == ___ // expects `true`
assert false == :false == ___ // expects `true`