[akkartik]

Most interesting. I recently did some work on a new, version-control-inspired layout for programs, but from a different angle than you suggest: http://akkartik.name/post/wart-layers. I'd love to chat more about the details of what you're trying (email in profile).

[dkuntz2]

Two questions:

1. How is that different than functionizing things? And, is it better? Especially because in wart it looks like your snippets can only be used once.

2. Does this bring you any advantages that well commented code doesn't? From my admittedly limited point of view (I haven't run it, just looked at your two examples) it looks like following the flow of control is a little more difficult, because it looks like your snippets are, when compiled, just placed where their comments are. Because variables are accessible and manipulable in your snippets there isn't any containment like you get with functions.

Again, this is from me only looking at your two examples.

[akkartik]

The biggest limitation of functions is precisely what you point out: they create scopes. So you end up complecting (http://www.infoq.com/presentations/Simple-Made-Easy) what variables you need access to at a time with what variables you want to describe and explain at a time.

I don't think it's controversial that functions have limitations. For example, OO in many ways was an attempt to work around the limitations of functions. But what OO discovered, I think, was that any sort of modularity mechanism when baked into the language brings in its own constraints, which limit the situations where it can be used. The classic example is all the constraints on C prototypes that make any sort of refactoring of include files an NP-hard problem, dooming lots of codebases to never get the reorganization they need to free them from historical baggage. So I've gradually, grudgingly started to focus on more language-independent, tool-based approaches that can overlay an 'untyped' layer atop even the most rigid language.

"Because variables are accessible and manipulable in your snippets there isn't any containment like you get with functions."

My claim (http://akkartik.name/post/readable-bad) is that in seeking local properties like containment/encapsulation we deemphasize global understanding. Both are useful, certainly, but they're often in tension and our contemporary rhetoric ignores the tension. The pendulum has swung so much in favor of local rules for 'good style' that it's worth temporarily undoing some of that work to see what we're giving up, what the benefits of playing fast and loose with local structure might be.

"..following the flow of control is a little more difficult.."

Yeah that's a valid concern. I think literate programming failed to catch on partly because we need at times to see the entire flow of control in a function. Like when we're debugging. I have a vague vision that programmers of the future will work with the expository and 'tangled' views of a program side by side. (In addition to perhaps a view of the runtime execution of a single unit test: http://akkartik.name/post/tracing-tests.)

Your point about reusing snippets is also a good one. That's the benefit of naming fragments in literate programming, isn't it? I hadn't considered that; the examples I've seen never mention it. But emacs org-mode and http://leoeditor.com certainly seem to find reuse useful. Hmm. I haven't encountered the need for reusing snippets so far. That might change, and we can probably come up with some syntax to support it if so. I suspect, however, that our languages already have plenty of primitives for enabling reuse. We don't need any extra tool or meta-linguistic support.

---

Clicking through to your profile I ended up at http://essays.kuntz.co/you-re-probably-not-for-hackers, which suggests we have kindred sensibilities about these questions! (Compare http://akkartik.name/about)

[dkuntz2]

I think the emphasis on containment and local understanding is good, especially considering that programs are getting huge (which is a separate problem, and what I think really needs to get fixed). With huge programs it's infeasible to fully comprehend the whole program, which means the only thing you can really do is hope that other programmers' functions work as advertised, and focus on perfecting your local domain.

The easiest way to alleviate this, in my opinion, is to focus on building smaller programs which focus on doing one thing well, and combining those together to create larger applications, with preferably a minimum of glue code. In my mind this leads to even more containment as each domain is now accessible only through the specified API.

This could lead to similar problems that you have with the deemphasis of global understanding, because it's still compartmentalizing things, and at each higher level the programmer is just trusting that the lower levels have implemented what they said they would, just like in a huge, single program.

The idea of being T-shaped specifically when it comes to the overall knowledge of the projects you work on seems to be the best way to work on those applications: have a general understanding of the whole project, and a really good understanding of your specific domain (and perhaps an intermediate understanding of those around yours).