Structure and Interpretation of Computer Programmers

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Saturday, May 31, 2008

Wistfully Wonderful Den of Coders

It’s the time of the year to acknowledge that yes, I am going to WWDC this year. Left it a bit last minute to get the flights and the hotel, but everything is in place now so hopefully I’ll see some of you guys/gals there. This is the first year that there’s been anything going on that isn’t Mac (it isn’t the first year there’s been non-MacDev, though; since the first WWDC I attended in 2005 there’s always been an IT track occupying around 20-25% of the sessions, though not much lab space). There have been mixed impressions of that – a representative sample:

About Time

New developers might screw up the experience

New developers might realise how cool Leopard is

I think this is going to be an exciting conference, especially for the new developers. I’ve never been as a newbie; in 2005 I’d already been doing GNUstep, WebObjects, Cocoa and NeXTSTEP development for varing numbers of years, though admittedly without particular expertise. From a perfeshunal perspective I’m not amazingly excited about iPhone development, I might drop in to a few of the sessions just to see what the state of play is, what people are interested in, what apps they’re creating and so on. No, for me this is the first year that I’ve actually got a project in full swing over the conference week so I’ll be most interested in heading down to the labs and getting mmalc to write my code finding out what I could improve.

And, of course, the networking (by which I mean the going out for beers and food every night)…

posted by Graham Lee at 11:01  

Thursday, May 22, 2008

Managers: Don’t bend it that far, you’ll break it!

Go on then, what’s wrong with the words we already have? I think they’re perfectly cromulent, it’s very hard to get into a situation where the existing English vocabulary is insufficient to articulate one’s thoughts. I expect that linguists and lexicographers have some form of statistic measuring the coverage in a particular domain of a language’s expression; I also expect that most modern languages have four or five nines of coverage in the business domain.

So why bugger about with it? Why do managers (and by extension, everyone trying to brown-nose their way into the management) have to monetise that which can readily be sold[1]? Why productise that which can also be sold? Why incentivise me when you could just make me happy? Why do we need to touch base, when we could meet (or, on the other hand, we could not meet)? Do our prospectives really see the value-add proposition, or are there people who want to buy our shit?

Into the mire which is CorpSpeak treads the sceadugenga that is TechRepublic, Grahames yrre bær. The first words in their UML in a Nutshell review is "Takeaway". Right, well, I don’t think they’re about to give us a number 27 with egg-fried rice. (As a noun, that meaning appears only in the Draft Additions to the OED from March 2007.) Nor is there likely to be some connection with golf. All right, let’s read on.

UML lets you capture, document, and communicate information about an application and its design, so it’s an essential tool for modeling O-O systems. Find out what’s covered in O’Reilly’s UML in a Nutshell and see if it belongs in your library.

Ah, that would be a précis, unless I’m very much mistaken. Maybe even a synopsis. Where did you get the idea this was a takeaway? I can’t even work out what the newspeak meaning for takeaway might be. Had I not seen the linked review, I had thought the “if you take away one idea from this article, make it this” part of the article. In other words, if you’re so stupid that you can only remember one sentence from a whole page, we’ll even tell you which sentence you should concentrate on. This use[2] doesn’t fit with that retroactive definition though, because the conclusion which can be drawn from the above-quoted paragraph is that one might want to read the whole article. I would much rather believe that management types in a hurry would remember the subsequent sentence as their only recollection of the article.

UML in a Nutshell: A Desktop Quick Reference is not misnamed.

[1]You may argue that the word should be spelled “monetize”, as the word most probably came from American English, but it doesn’t matter because it doesn’t bloody exist. Interestingly, the verb sell originated in the Old English verb sellan, meaning to give, with no suggestion of barter or trade.

[2]Language usage is the only place I’ll admit the existence of the word usage.

posted by Graham Lee at 23:22  

Monday, May 12, 2008

My name in lights

I’ve been published.

posted by Graham Lee at 18:14  

Monday, May 5, 2008

Social and political requirements gathering

I was originally going to talk about API: Design Matters and Cocoa, but, and I believe the title of this post may give this away, I’m not going to now. That’s made its way into OmniFocus though, so I’ll do it sooner or later. No, today I’m more likely to talk about The Cathedral and the Bazaar, even though that doesn’t seem to fit the context of requirements gathering.

So I’ve been reading a few papers on Requirements Engineering today, most notably Goguen’s The Dry and the Wet. One of the more interesting and subtle conclusions to draw from such a source (or at least, it’s subtle if you’re a physics graduate who drifted into Software Engineering without remembering to stop being a physicist) is the amount of amount of political influence in requirements engineering. Given that it costs a couple of orders of magnitude more to mend a broken requirement in maintenance than in requirements-gathering (Boehm knew this back in 1976), you’d think that analysts would certainly leave their own convictions at the door, and would try to avoid the "write software that management would like to buy" trap too.

There are, roughly speaking, three approaches to requirements elicitation. Firstly, the dry, unitarian approach where you assume that like a sculpture in a block of marble, there is a single "ideal" system waiting to be discovered and documented. Then there’s the postmodern approach, in which any kind of interaction between actors and other actors, or actors and the system, is determined entirely by the instantaneous feelings of the actors and is neither static nor repeatable. The key benefit brought by this postmodern approach is that you get to throw out any idea that the requirements can be baselined, frozen, or in any other way rendered static to please the management.

[That’s where my oblique CatB reference comes in – the Unitary analysis model is similar to ESR’s cathedral, and is pretty much as much of a straw man in that ‘purely’ Unitary requirements are seldom seen in the real world; and the postmodern model is similar to ESR’s bazaar, and is similarly infrequent in its pure form. The only examples I can think of where postmodern requirements engineering would be at all applicable are in social collaboration tools such as Facebook or Git.]

Most real requirements engineering work takes place in the third, intermediate realm; that which acknowledges that there is a plurality among the stakeholders identified in the project (i.e. that the end-user has different goals from his manager, and she has different goals than the CEO), and models the interactions between them in defining the requirements. Now, in this realm software engineering goes all quantum; there aren’t any requirements until you look for them, and the value of the requirements is modified by the act of observation. A requirement is generated by the interaction between the stakeholders and the analyst, it isn’t an intrinsic property of the system under interaction.

And this is where the political stuff comes in. Depending on your interaction model, you’ll get different requirements for the same system. For instance, if you’re of the opinion that the manager-charge interaction takes on a Marxist or divisive role, you’ll get different requirements than if you use an anarchic model. That’s probably why Facebook and Lotus Notes are completely different applications, even though they really solve the same problem.

Well, in fact, Notes and Facebook solve different problems, which brings us back to a point I raised in the second paragraph. Facebook solves the "I want to keep in contact with a bunch of people" problem, while Notes solves the "we want to sell a CSCW solution to IT managers" problem. Which is itself a manifestation of the political problem described over the last few paragraphs, in that it represents a distortion of the interaction between actors in the target environment. Of course, even when that interaction is modelled correctly (or at least with sufficient accuracy and precision), it’s only valid as long as the social structure of the target environment doesn’t change – or some other customer with a similar social structure comes along ;-)

This is where I think that the Indie approach common in Mac application development has a big advantage. Many of the Indie Mac shops are writing software for themselves and perhaps a small band of friends, so the only distortion of the customer model which could occur would be if the developer had a false opinion of their own capabilities. There’s also the possibility to put too many “developer-user” features in, but as long as there’s competition pushing down the complexity of everybody’s apps, that will probably be mitigated.

posted by Graham Lee at 20:36  

Thursday, May 1, 2008

The Dock should be destroyed, or at least changed a lot

I found an article about features Windows should have but doesn’t, which I originally got to from OSNews’ commentary on the feature list. To quote the original article:

The centerpiece of every Mac desktop is a little utility called the Dock. It’s like a launchpad for your most commonly used applications, and you can customize it to hold as many–or as few–programs as you like. Unlike Windows’ Start Menu and Taskbar, the Dock is a sleek, uncluttered space where you can quickly access your applications with a single click.

Which OSNews picked up on:

PCWorld thinks Windows should have a dock, just like Mac OS X. While they have a point in saying that Windows’ start menu and task bar are cumbersome, I wouldn’t call the dock a much better idea, as it has its own set of problems. These two paradigms are both not ideal, and I would love someone to come up with a better, more elegant solution.

The problem I have with the Dock (and had with the LaunchPad in OS/2, the switcher in classic Mac OS, and actually less so with the task bar, though that and the Start Menu do suffer this problem) is that their job basically involves allowing the internal structure of the computer to leak into the user’s experience. Do I really want to switch between NeoOffice Writer, KeyNote and OmniOutliner, or do I want to switch between the document I’m writing, the presentation I’m giving about the paper and the outline of that paper? Actually the answer is the latter, the fact that these are all in different applications is just an implementation detail.

So why does the task bar get that right? Well, up until XP when MS realised how cluttered that interface (which does seem to have been lifted from the NeXT dock) was getting, each window had its own entry in the task bar. Apart from the (IMO, hideously broken) MDI paradigm, this is very close to the “switch between documents” that I actually want to perform. The Dock and the XP task bar have similar behaviour, where you can quickly switch between apps, or with a little work can choose a particular document window in each app. But as I said, I don’t work in applications, I work in documents. This post is a blog post, not a little bit of MarsEdit (in fact it will never be saved in MarsEdit because I intend to finish and publish it in one go), the web pages I referenced were web pages, not OmniWeb documents, and I found them from an RSS feed, not a little bit of NetNewsWire. These are all applications I’ve chosen to view or manipulate the documents, but they are a means, not an end.

The annoying thing is that the Dock so flagrantly breaks something which other parts of Mac OS X get correct. The Finder uses Launch Services to open documents in whatever app I chose, so that I can (for instance) double-click an Objective-C source file and have it open in Xcode instead of TextEdit. Even though both apps can open text files, Finder doesn’t try to launch either of them specifically, it respects the fact that what I intend to do is edit the document, and how I get there is my business. Similarly the Services menu lets me take text from anywhere and do something with it, such as creating an email, opening it as a URL and so on. Granted some app authors break this contract by putting their app name in the Service name, but by and large this is a do something with stuff paradigm, not a use this program to do something one.

Quick Look and Spotlight are perhaps better examples. If I search for something with Spotlight, I get to see that I have a document about frobulating doowhackities, not that I have a Word file called “frobulating_doowhackities.doc”. In fact, I don’t even necessarily have to discover where that document is stored; merely that it exists. Then I hit space and get to read about frobulating doowhackities; I don’t have to know or care that the document is “owned” by Pages, just that it exists and I can read it. Which really is all I do care about.

posted by Graham Lee at 00:13  

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