Zeth.net

Taking control of your own technology

Everything is just C with bells on

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In this post I thought about the world of cool that lies between high-level languages and C. Thought is too strong, it is more of a seed of a thought that has not germinated yet. This is not a fable with a moral at the end.

When I first came across C#, I thought that is much better than Visual Basic, perhaps Microsoft’s .Net platform could be interesting one day, but not personally having an obvious project to use it in, I put it to one side and have never touched it since.

When Vala was first announced, I thought wow, that is so sexy and I played with it for about a week. Not personally having an obvious project to use it in, I put it to one side and have never touched it since.

I had pretty much the same reaction to Go (aka golang) - wow that’s cool, perhaps not as sexy as Vala but I like the goroutines. I did the trendy web based tour, I installed everything locally and played with the standard library. Then, not personally having an obvious project to use it in, I put it to one side and have never touched it since.

I could go on and on. Whatever piece of tech that comes into (or back into) fashion seems to follow this pattern, Haskell, Erlang, Java, Scala, etc etc. A lot of the developer tools industry and technology media needs something shiny and new to promote this year.

Don’t get me wrong, I love all this stuff, I would love to do projects in different programming languages but obviously, as I have a reputation for writing Python or JavaScript or doing system administration, people hire me to do that and don’t perhaps think of me for other things.

Maybe there is more too it than that, since in whatever I am doing, in my head I seem to think of any algorithm in Python first as executable pseudocode even if it gets typed in using JavaScript or another language.

I had a long stint as an academic, but basically my whole career in software is as a freelancer or contractor. A journeyman who works to live.

Often the customer has an existing project or specific library, toolkit or team which pre-determines the choice of programming language.

Otherwise, my usual process for creating software is to prototype it in a high level language (normally always Python but sometimes JavaScript). 90% of the time, once it works the customer has solved their immediate problem and wants to move their focus onto their next problem, which may not be software and may not involve paying freelance programmers. Sad I know, thanks for all the fish, I am here, like the song says, etc etc :)

When the prototype is working, there is a lot to be done to optimise it and keep it as a Python application, and almost always there is some specific other bottleneck (such as network, database or some industrial requirement) that means that CPU usage is not the problem and so cutting out the Python interpreter wouldn’t actually make much difference in the short and medium time-frames that most companies care about.

Indeed I have seen cases where the customer has gotten someone to rewrite the prototype application in Java, and found that the new version is actually slower. A lot of the heavy duty work in the Python version was actually happening inside a C library that has been highly optimised over the last 30 years; changing the dependency from that to a poorly implemented Java library caused the poor performance.

If we imagine a Python application is like a commissioning a photograph, a C app is commissioning a sculpture. You only do it when you want something to really last or really be the core of something fundamental for your future success.

All the above notwithstanding, the genius of Python’s initial design is that once your application has taken a stable(ish) form, it is normally pretty straightforward to convert the application to C.

Most of the standard library inherits Linux/Unix best practice (and even the same function names) and a lot of the best external libraries in Python are just wrappers around the C equivalents. You always have the fully working Python application to test it against.

It takes a long time yes, going through line by line, but you are not troubling the boundaries of computer science or software engineering as we know it. I actually love those kind of cathartic jobs, but I am a freak.

Apologies if I am stating the bleeding obvious, none of the above text is news to anyone, any Python developer knows the same thing, however it is the foundation for what follows.

So the real reason why I have not personally had an obvious project to use a lot of these fashionable and ‘cool’ languages and toolkits is that they fall in the luke-warm middle ground between the extremely high-level Python (and JS/Ruby/LISP etc) and the low level C language.

For most use cases, all these middle ground languages are slower and less portable than C. If you have decided on a re-implementation, then it takes no longer to rewrite a Python project to C than to Go, Java, C# or whatever, indeed it might often be quicker to C.

I have actually used C hardly at all, far less than I would like to have done, but I have used these middle-ground languages even less. Everything just stays in high level code.

So as I warned, I have no moral for this fable, no conclusion to offer, it is just the beginnings of a thought that ran through my brain, I like to think I will pick up this theme later, but I will probably look back in five years to find I have put it to one side and have never touched it since.