PathExpress -- increased powers (like nil-safey) from `Kernel.get_in/2` calls

After 6.5 years of the first Elixir code I wrote, I have chosen to share a library on hex. I have a cautious view on libraries preferring to share patterns than “free as in puppy” libraries.

I had noted that Kernel.get_in/2 offers nil safety when navigating map keys, but not when navigating list elements. After discussion on the core mailing list there’s no clear path forward, so I offer my library to see how the community responds. I welcome community involvement and insights. My ultimate goal is to find something worth merging into the standard library. I want application authors to be able to work with nested data structures consistently in either a nil-safe or assertive manner as their needs dictate, without having to reinvent the wheel (or bring in a third party library).

PathExpress is the result.