@drewdevault
looks great, very cool.

1. How about negative wraparound indices, and using : instead for ranges?

2. Have you considered any concurrency primitives, like channels, waitgroups, mutexes? That's one thing I find myself missing a lot, and end up writing hacks with named pipes and flock.

https://git.torresjrjr.com/.sh/file/bin/gfa.html

3. Why the backticks for `{expansion} ?