Add other arities for IFn protocol about clojuredart

[cgrand]

There's no limitation but is there any strong reason to align?
Is there a strong case of existing cljc code whose performance would degrade if the threshold is at 10 rather than 20?

[pfeodrippe]

There's no limitation but is there any strong reason to align? Is there a strong case of existing cljc code whose performance would degrade if the threshold is at 10 rather than 20?

It's not for performance, it's to make it work with SCI (or other libraries which implement IFn in full)
without having to creating special cases for it, e.g. https://github.com/babashka/sci/blob/1dc44b30044e387c0069bc051a511d6fc889f3f1/src/sci/impl/vars.cljc#L326

I can open the PR tonight if you want, thanks for the great job you both are doing o/

[cgrand]

ok, I will review your pr

[ruseel]

Maybe.. this is not a good first issue. I tried very naive PR in #65.