ChatGPT in education has been all the rage but there's another twist on AI that was getting some buzz even earlier - AI based code completions. GitHub's Copilot has gotten the most air time but there are others out there as well.

When you code with Copilot, you type in a function name and maybe a comment above it and the AI system will fill in the function.

A canonical example seems to be Mergesort. Type in mergesort, hit the magic key, and the function appears.

I was asked by a friend how this might affect teaching programming and I've been thinking about it for a while.

I was going to share my thoughts today but realized that first, we have to talk about products like Copilot as a programmers aid and then we can talk about it as a learning tool. Today, we'll cover the former and next post the latter.

Now, I'm not a professional programmer - at least I haven't been one since before I started teaching. I've done personal projects, some one off contracts and a few applications for work but I haven't written one of those since I wrote a resume/interview managing system when Hunter won the CUNY2X grant.

Even so, I think I've got a few thoughts worth sharing.

Let's first consider what these tools can do right now.

I started by playing with the mergesort exampe. I asked for it and the AI's obliged. This could be seen as a time saver but is it? It turned out every time I tried I got a good basic mergesort but the merge part was always another function call - still had to write or generate that so it's not just specify and move on. It's specify, verify, and then either tweak or move on. It also wasn't optimized in any way. You can decide for yourself if that's good or bad.

A pro can tell me if using Copilot in this sense is a time saver but I'm not so sure. Even if it is, wouldn't most programmers just use the built in sort function? It seems like in this sense, tools like Copilot are like using a library but with inline expansion and without verification. A mixed bag at best.

Even if the AI always got it right and was clear I wonder how much time would really be saved. Most of my time programming is spent thinking and editing and Copilot is about the generating. I don't doubt that it can be useful but in it's current state, maybe not so much.

The big benefit using it this way is if you ask it to write something that you don't know how to write but is that really a good idea given that the code still has to be verified?

The other sense I've seen these tools used in is more like how Gmail autocompletes sentences in your email. Again, very cool but I'm not sure how useful. For the Gmail stuff, I always see the completions but almost always just continue typing. I guess it's similar to how a fast typist frequently won't fix errors, they'll retype them. For example, if you accidentally type Froderick instead of Frederick, a fast typist probably wouldn't fix the o. They'd probably delete the word backwards and retype it. More keystrokes but they stay in the flow.

So, right now these tools seem cool but maybe not all that useful. I could see benefit today by having them generate language idioms like "sum a list" - things that templates and current autocomplete can't quite do but can be verified on the fly in no time but that's about it.

In the future, however things could change.

The idea that at some point one could generate code from a description is pretty appealing. Of course, that brings a challenge that many beginner programmers have to deal with - specification. I tell my students all the time "Computers are lousy at doing what you want them to do but great at doing what you tell them to do." Writing a program for these not-yet-existing AIs will be all about writing specifications and the specification will turn into our program. This really isn't too different than what goes on today. A for loop is a higher level specification for some gotos and conditionals. A foreach, a higher level specification of a for and when you add in Lisp like higher level functions like map and filter that's higher level still. An AI like a future generation of Copilot can be just that.

My verdict? Are they cool? Yes. An aid to productivity? I'm not sure. Will they get there? Probably but I don't know when.

Next time, we'll talk about how these tools can change the landscape of teaching and learning programming.