Professor Frisby's Mostly Adequate Guide to Functional Programming

An excellent book to get a deeper understanding of fp. Unfortunately unfinished, better to read online version. It was in my read status for a long time because of that. I would recommend first to start from something easier and get some experience in fp with Scala, TS, JS, etc. Then read this to get an AHA moment about some functions you already used. Gets too complicated as for me in last chapters.