Writing a Pratt parser as part of this forced me to understand how it works. Figuring out how to process a sheet led me into algorithms and structures like directed acyclic graphs (as mentioned in the article). I found myself referencing Introduction to Algorithms and really studying it .
In the end I turned it into a talk at Big Sky Dev Con in Montana. The whole thing was a good experience - from researching how to do it, to sticking it out through the implementation, to distilling it to a 45 minute talk. Be sure to check out the recording  and code  if you're interested.
Any of these suggestions will lead you down a rabbit hole of learning with a clear objective in sight to keep you motivated to dig deeper.
It's all in there. Put away a week of time to really start digging into it, get into the habit of learning from a book. I'd say it's worth it.
- Clean Code (by "Uncle Bob")) [https://www.amazon.com/Clean-Code-Handbook-Software-Craftsma...]
- Design Patterns (by "Gang of 4") [https://www.amazon.com/Design-Patterns-Elements-Reusable-Obj...]
- Introduction to Algorithms (by "CLRS") [https://www.amazon.com/Introduction-Algorithms-3rd-MIT-Press...]
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