It's Time to Start Programming (for) Adults

This week we're in Boston at DevNation, an awesome, young (second ever), and relatively intimate (~500 attendees) conference on anything and everything hard-core, cool-and-hot (DevOps, big data, Angular, IoT, you name it), and of course -- since the conference is organized by Red Hat -- totally open-source.

So far I've had in-depth conversations with five super-amazing engineers, attended several inspiring keynotes, and chatted with one skilled developer after another. We'll transcribe the deeper interviews shortly, including some on topics totally unrelated to this post. But meanwhile I'd like to offer some thoughts inspired by the first day of the event. The general theme is: we're just beginning to get serious about separation of concerns. The metaphor that keeps popping into my head comes from the first keynote: machines have finally grown up.

Imperatives: telling really unintelligent agents what to do (and then they sort of do whatever they please)

It is trivial to observe that computers are incredibly stupid. Turing's fundamental paper is about how to figure out whether a theoretical computer will keep calculating the values of a function until the heat death of the universe (okay that's a slight oversimplification). The fact that Edsger Dijkstra felt the need to rail gently against all goto statements in any higher-level language than machine code suggests that, in 1968, far too many computers needed instructions about how to read the instructions that tell them what to do in the first place. Richard Feynman's famous lecture on computer heuristics is the condescension of the man who conceived quantum computing to the level of functional composition (hmmm) and file systems (double sigh).

Stupid agents need to be told exactly what to do. Then they need to be told to pay attention to the exact part of the command that tells them exactly what they have been told to do (dude, just goto line 1343 already and shut up). Then they don't do what you told them (optimistically we call this an 'exception'), and then you send them into time out / set a break point and try to figure out where the idiot state muted off the rails. They stare blankly at the wall / variable / register and either do nothing or repeat another unintelligibly wrong result until you notice that your increment is (apparently meaninglessly to you) one bracket too deep. You sigh and tell them what to do again, and after a while they hit age thirty (life-years/debug-hours) and maybe do something useful with their (process-)lives.

Well, maybe I'm straining the metaphor a little here, but you get the point because it cuts too close to home. We spend far too much time fixing stupid mistakes that we didn't even know we were making because -- like all actual human beings -- we assumed that the agent we commanded will use their common sense to iron out those few whiffs of, admit it, frank nonsense that our step-by-step instructions will probably always contain.

So, at least, goes the imperative programming paradigm. The machine does what you tell it to; and the universe collapses onto itself before the last real number is computed.

Functions: reliable, predictable adults

Time to give credit where it's due: I'm really just riffing on the metaphor Venkat Subramanian offered in his highly enjoyable keynote on The Joy of Functional Programming yesterday morning His not-so-smart agents -- the 'programmed' of imperative programming -- were toddlers. Since I don't have any kids, I can't presume to understand this experience fully (although I did grow up with three younger brothers..). But the general idea is: imperative programming is tricky because, when you spell everything out super literally, it's very hard to tell exactly why what you thought should happen didn't.

Venkat's talk was a whirlwind of functional concepts, from the thrill of immutability to the self-evident utility of memoization. For random (Myers-Briggs?) reasons, the object-oriented paradigm never seemed very intuitive to me -- I've gravitated towards functional style even when the problem domain wasn't actually modeled very well by functions -- but Venkat's side-by-side implementations of simple calculations in OO and functional Java showed the readability delta very clearly. Functional code is beautiful because it looks like its purpose. It tells you flat-out: here is what I do; and then it does it.

But immutable functions are also beautiful because they do exactly the same thing every time. I couldn't count on my two year old brother very much at all because given a certain input I had pretty much no idea what would come out. But we all count on our grown-up collaborators to output exactly what they should, given a definite input, predictably and reliably every time. Of course, people also do more than expected -- every intervention of intelligence is an injection of creativity, not generated by the definition of the function -- but at least they do what you need them to do and no less.

Containers: grown-ups with good boundaries

I'm picking out just one aspect of the resurgent 'joy' of functional programming because the renaissance of containerization (another 'old' technology that is just now really taking off) is, I think, a part of the same shift toward, let's say, treating computers as adults. If functions are reliable agents, then applications in well-defined containers are self-sufficient agents who know exactly what they need from others and neither require nor demand anything more.

If apps on dedicated VMs are teenagers negotiating personal boundaries by waking/booting up independently (and taking far too long -- and far too many resources -- to do so, given their meager output) -- or bubble boys, isolated in ways that are unfortunate in order to isolate in ways that are absolutely necessary -- then containerized applications are subway-riders who jam into the train without offending anyone or campers who can live anywhere with just a backpack of just the stuff they need.

Of course, subway-riders and campers do more than just not-mess-up. But what's kind of neat about containers is that -- like an adult with good boundaries -- clearly defined bounds and interfaces free up the application / mind to do whatever world-changing thing the developer / human has cooked up.

I'll come back to this metaphor in a later article. (Mesh networks, SDN, and ad-hoc computing are all part of the same picture, I think. Kubernetes probably is too, along with event-driven and reactive programming, the actor model, dreams of Smalltalk, and of course REST, at least of the HATEOAS flavor.)

But maybe this isn't a good way to think about some of these recent sparks in devworld within a single paradigm -- and maybe my perpetual discomfort with OO is influencing me too much.

What do you think?