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C'est la Z

SIGCSE 2022 APCS - Alternate Languages

I think I've hit on the big points on APCS-A language but a couple more remain. This time, let's look at alternative languages.

When APCS started in 1984, Pascal probably made sense - it was the primary learning language at the time. It wasn't really used in industry but it was the language you cut your teeth on. A few years later when I went from college to Goldman Sacks I found very few companies using Pascal. C was big and there were more than a few opportunities using PL/I and of course, lots of COBOL in the business world but no Pascal to be found.

Of course there's nothing wrong with that. A lot of people claim that the language for APCS-A or college CS1 has to be a mainstream language used in industry. It really doesn't. If someone is going to continue through a multi-year sequence of classes for CS or a related field it's safe to say they will be exposed to many languages and tools and the one you start with isn't necessarily the one you end with. Even if you insist on using an industry language, there are many to choose from. Python is big in a number of areas but it isn't the only game in town. Java and C++ are still heavy hitters and will be for a long time and many other languages have enough traction to be considered commonly used in industry.

I thought here we could do some quick hits on some possible alternate languages.

For all of these, I'll be talking about the language as of the last time I used it so in some cases, I could be years out of date but I think you'll get the idea as to what I'm driving at.

Racket (nee Scheme).

Really quick here. I designed Scheme into my CS0 course at Stuy. I think it works very well in that context. That said, it would be a tough sell today. Racket/Scheme are not widely used in industry even though you will find LISP variants here and there.

I like it because the syntax is super simple. Just a handful of rules and that's it. I also liked that it's syntax was different and new - it leveled the playing field between people who thought they knew something coming in and the rest. On the other hand it is esoteric and some find it scary. Back when I created the course with it, MIT was still using Scheme for their CS1 so that made it an easier sell as did my reputation in the school.

That said, I don't think I could start a new program easily with Racket and the only place that I know that uses it big time is Bootstrap World, a program that I've mentioned many times before and like very much. It's not that it's bad - you can develop wonderful courses that use it but rather, there are alternatives that would be easier to sell to students, parents, and communities.


There's a vocal contingent for JS as a language in both CS1 and CS0. I like JS a lot. In fact I was using it as much as any other language until I discovered Clojure and Clojurescript which are now my primary personal languages.

JS fans point out that it's ubiquitous. If you have a browser, you have a JS interpreter. It's also the front end language of the web (although you can transpile other languages like Clojurescript to JS) and via Node you can run it server side as well.

Although I love JS, I disagree with this contingent. First and foremost, JS has a number of, well, let's say, issues. If you haven't seen this video, take a few minutes: The JS part starts at about 1:20 in. JS has also had issues with types. Now admitedly some of these things have been at least partly addressed like using val and var but I don't think this is strictly enforced which is problematic in a learning language.

I've also found the tooling lacking. If you're doing front end work and there's a problem with your code, if you're lucky you'll get some feedback but sometimes things just won't run and won't get a clue.

Languages like Typescript could address some of these issues but I'm not familiar enough with Typescript to say.

A final issue wiht JS is the tooling. Sure, you can just inject some code in a web page but doing the real deal requires diving into a crazy complex ecosystem. Grunt, Gulp, Webpack, Parcel, Rollup, Yeoman and these are just the ones I can come up with off the top of my head and none of them are trivial to know or to use. Yes, you can kindof just take a template and use it but to really understand what's going on? Not so much.

So, I'll take a pass on JS as a CS0 or CS1 language.


This is the language that got me thinking about this post. Adacore has been at SIGCSE every time I've attended and they push Ada as a language. I stopped by to chat with them. Mostly because one of the Adacore founders, Robert Dewar, who passed away a few years ago, was a big time mentor to me. I just wanted to chat with the people in the booth just really to say hi.

I hadn't used Ada in decades and probably won't in the near future but the Ada I remember could be a very nice language for a CS1 class.

Ada's industrial strength but I seem to recall required less magic to get started than Java. It had all the typing you could want for people who think that's important. I also like how it did objects back when I used it. Ada back then didn't have inheritence but was what was called Object Typed as opposed to Object Oriented (I think). You could essentially use class type constructs for abstraction and to encapsulate state but it didn't have inheritance. To me this is perfect. Inheritance is forced in CS1/CS2 and from what I've seen is really something for tool and library builders and not nearly as much for most people doing day to day programming.

Ada's also the first, and maybe only language that I was able to consistently write large complex programs and have them work the first time. Even with tons of dynamic memory management. This was due to the language specification and the compiler.

Are students going to use Ada in the real world? Perhaps though it's far more likely that they'll work in Java, C++, Python or JS but that doesn't mean that Ada can't be a great starting point in CS1 to learn important concepts and to develop good habits


Next up, Go. One of the downsides of Go is it's hard to search for unless you specify golang. Other than that, Ada got me thinking of Go since I think it shares some traits.

Go was created to address some of the perceived deficiencies in C/C++. A small language with a clean design that could still be used for low level tasks. I haven't used it much, just some fiddling but I could see the appeal.

The language is small and relatively simple so it should be easy to learn. It also supports objects but no inheritance which is fine by me. Actually, the object model is pretty different from Java or C++ and I like it a lot. Instead of declaring a Class with variables and methods you define a struct with variables and associate methods with it via interfaces.

Go also encourages consistent code. Python does this with indentation. Go does it with gofmt a program that takes Go source code and formats it to the Go standard. Editors can hook into gofmt so as to call it whenever your program is saved.

Go also has a nice model for concurrency but that probably won't come up in a CS1 but then again, it's so clean in Go, it might.

Two other features are a super fast compiler - yes this can make a difference and a great set of libraries. A friend of mine once described Go as a small, clean language with libraries designed by "a bunch of really smart programmers with good taste."

I could think of far worse choices for a CS1 class.

Interestingly enough, Go was created to replace C/C++ but most of the adoption has come from the Python world. I personally know a number of software engineers who ported their products from Python to Go. Maybe Go could be a sensible alternative to Python as a Java replacement.

Misc Languages

There are few more languages that I want to briefly mention.

Java not only provides the language but also the Java Virtual Machine and many languages run on the JVM. These include Scala, Kotlin, Clojure (my favorite), Groovy and others. I don't see Clojure as a great CS1 choice in most cases and don't know enough about the others to comment other than they all have some level of interoperability.

Then, you have languages like Haskel or OCAML but I'm just not going there.

Rust is another one to look at. It seems to have all the features but is a little more imposing to the beginner - at least that's what I'm thinking from first glance but I want to dive in more sometime in the future.

Finally, a word on Ruby - the other language mentioned in the Wat video I linked above. Ruby came around a little after Python. Looking at both I decided I was a Python guy and never really pursued Ruby. It didn't talk to me. Years later, Ruby on Rails hit and Ruby exploded. Ruby and Rails were HUGE and everywhere in the startup world. Bootcamps in fact started to appear left and right and all focused on Ruby on Rails.

A few years later, I started to hear left and right "why don't you teach Ruby in high schools." The answer was, of course "because in a few years, you'll be asking why we don't teach some new thing."

Now, a decade later, Ruby has fallen to the wayside and nobody's demanding that we teach it in high schools.

Maybe that's a cautionary tale. We shouldn't be teaching something, particularly in high schol because it's the hot language or it's big in industry. We come back once again to what's the goal of the course. What do the students need and what's the best tool to accomplish that.

So, that's it for this series. I'll do one more adendum on AP vs non Ap but it's been six posts in six days - that's a lot for me. I hope it spurs some thought and good discussion.

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