Guarded Function Definitions Package

Hi all!

I'm not very experienced with Scheme or Chicken, but I've written a small macro which I've found useless on a few learning projects which I thought I'd share with the hope of getting it included on the package list.

The repo is here <https://github.com/BirDt/guards/> (along with a release-info, provided I understand the format correctly), I'd appreciate any feedback on the macro itself as I'm sure it's written in a very inefficient way (I'm not even sure if using `assert` is best here, instead of a conditional `error`) and I'd like to improve it since I like using this syntax.

Also, is there a way to capture assertion failures at runtime? I've neglected to write any unit tests at present since I'd like to do this without any third party libraries simply for the learning experience.

Thanks and o7,
Jakub