ego.istic.org

I was pleased today to find a box of computer science waiting for me at work: it was my Amazon order. Apart from Ben Pierce's much-recommended book on types, there was also his less-well known ‘Basic Category Theory for Computer Scientists’.

I've often felt that I missed out by doing a degree that didn't involve category theory, and when I took Denotational Semantics in Part II it was clear from occasional cryptic references to HOPLA that categories were basic knowledge for more advanced studies in this field, just as set theory is for undergrad compsci. Whenever someone young and naïve has asked me what category theory is, I have always answered that category theory is a generalisation of everything, including itself. I may continue to answer in that way after learning more about the subject, but perhaps learning more about the subject will allow me to give a more complete answer.

I was a bit worried by the title of the book. IME of academic books, “basic” or “introduction to” in the title are code for “does not contain any of the information you are looking for.” However, Pierce is generally regarded as a dude, and nosing around a bit I am led to believe that in this case, and in conjunction with “for computer scientists” (rather than “for mathmos”), it may well just mean “does not give proofs of everything,” which is fine by me.

You can probably expect to see some posts on category theory and how elegant, demented, useful, mind-bending, and/or thought-provoking it is here in the near future, and a review of this book. I'm still in the middle of the Torah and I also bought a pile of sf recently to take on various trips, so I'm not expecting to get through it too quickly.