Where does one even start learning type theory or category theory? I’ve had a passing interest from listening in on conversation between Rust friends, but never found a place to do a like type theory 101 for software engineers
Books. Some books on my shelf covering these topics:
"Type Theory and Functional Programming" by Simon Thompson (PDF available via quick search)
First 120 pages of "Type Theory and Formal Proof" by Rob Nederpelt / Herman Geuvers
For some early stuff on dependent types (also covered in the above), check out "Intuitionistic Type Theory" by Per Martin-Lof
"Computation and Reasoning: A Type Theory for Computer Science" by Zhaouhui Luo
"Type-Driven Development with Idris" by Edwin Brady
"Gentle Introduction to Dependent Types with Idris" by Boro Sitnikovski
"Types and Programming Languages" by Pierce
"Practical Foundations for Programming Languages" by Robert Harper (or any of his YouTube videos re/Type Theory)
"The Little Typer" by Friedman and Christiansen
"Modal Homotopy Type Theory: The Prospect of a New Logic for Philosophy" by David Corfield (just took this one to OBX North Carolina to enjoy on my beach vacation last week! Got some salt water in those pages. Also speaks to Category Theory.)
For Category Theory:
"The Joy of Abstraction" (2023) by Euginia Cheng
"Basic Category Theory for Computer Scientists" by Benjamin C. Pierce
"Conceptual Mathematics: A first introduction to categories" by Lawvere and Schanuel
"Categories for the Working Philosopher" by Landry
Bartosz Milewski’s Category Theory for Programmers lectures [1] are good. Especially paired with his book [2].
I actually find that category theory is remarkably simple. At least at the level where it applies to day-to-day programming concepts. The one major benefit I got from it, was that it helped me reason about high level/abstract structure better (which helps my architectural designs/thinking).
I enjoyed Types and Programming Languages by Benjamin Pierce. Also vaguely related is the Implementation of Functional Programming Languages by Simon Peyton Jones (this is more about lambda calculus, but I found that when you pair type theory with lambda calculus you get some nice synergies as a programmer).
I watched these https://www.youtube.com/@hottlectures5237, at least up to the point where they seemed to be diverging from things I could see application in. There's an associated book which is fairly tough going but enlightening (easier after watching some of the videos).
