This file's purpose is to keep me from obsessing over Picky performance and focus on other things.

Speed
=====

https://www.youtube.com/watch?v=fGFM_UrSp70

* yield >>> block.call
* flat_map >> map.flatten
* gsub vs. sub
* Use tr where appropriate.

Memory
======

* Hint `key_format :to_i`: Use narray for numeric arrays, https://github.com/masa16/narray-devel.
* Use Triez? https://github.com/luikore/triez
* Add option to only insert when anything has changed in an entry, per category.