Next CocoaHeads Swindon meeting

1st September (that's this coming Monday), in the Glue Pot, Swindon. 8:00pm start. Chris Walters will talk about, well, something, and we'll be drinking beer, listening and occasionally chipping in. See you there!

So are Macs uber-pricey?

No, but Sony Vaios are.

Back from holiday

I went on holiday to Stockholm this week. Of the ~1.5GB I downloaded from the camera, this was the photo I thought most apt to describe the experience on this blog:

Cocoa#, Mono and Me

My great application:

Yeah, OK, not so great. But this Inverse Hoffman is the result of a couple of hours hacking in Mono, with Cocoa#. My app's largely based on the Stupid Word Counter tutorial, though it's a from-scratch implementation of the famous Apple/NeXT sample application in C#.

Firstly, a little history. My first encounter with .NET was back in about 2003 at a Microsoft Developer Roadshow in the car park (and later lecture theatre) in Oxford's comlab. I was particularly interested in their discussions of cross-platform capability, Project Rotor (I kept in touch with one of the Rotor developers) and so on, but really didn't see much exciting in .NET. Nonetheless, being a fair man, I took my beta CDs of Windows 2003 and Visual Studio .NET and gave them a whirl. Unfortunately, still not much interesting. Largely due to buggy betas and a lack of beta documentation.

Now accessing Cocoa from non-ObjC languages is nothing new, we've been doing it from Perl, Python, Ruby and Java for ages and partcularly old farts might even remember Objective-Tcl. Why should I care about Cocoa#? Well for a start, there are likely to be a lot Windows developers out there with some (language that boils down to MS IL eventually) skills who are wanting to produce Mac applications, and it'd be interesting to see what we'll end up with when they do. And it's always fun to learn a new language, anyway ;-)

Good points

• Real NIB files. No really, that interface is genuinely an IB 3.x NIB based on the Cocoa Application template. The objects inside it are Objective-C objects, and there are good old outlets and actions (I haven't yet investigated whether Cocoa Bindings would work).


• macpack. A command-line tool which takes your IL executable and wraps it up in a Cocoa application bundle, ready for drag-deployment.


• Good inline bridging information. Unlike, say, PyObjC the language bridge isn't completely dynamic, but unlike the Java bridge or JIGS you don't have to keep a separate manual mapping of real classes onto ObjC shams. For instance, here's the controller from Currency Converter.net, complete with class, ivar and method exports:

namespace info.thaesofereode.CurrencyConverter
{
	[Cocoa.Register("CurrencyConverterController")]
	public partial class CurrencyConverterController : Cocoa.Object
	{
		public CurrencyConverterController(System.IntPtr native_object) : base(native_object) {}

		//Cocoa IBOutlets
		[Cocoa.Connect]
		private Cocoa.TextField inputCurrency;
		[Cocoa.Connect]
		private Cocoa.TextField outputCurrency;
		[Cocoa.Connect]
		private Cocoa.TextField conversionRate;

		//Cocoa IBAction
		[Cocoa.Export("calculate:")]
		public void calculate(Cocoa.Object sender)
		{
			//get the rate from the view
			System.String rate = conversionRate.Value;
			CurrencyConverterModel.Rate = System.Convert.ToDouble(rate);
			//get the currency
			System.String input = inputCurrency.Value;
			System.Double output = CurrencyConverterModel.convert(System.Convert.ToDouble(input));
			//update the UI
			outputCurrency.Value = System.Convert.ToString(output);
		}
	}
}

Bad points

• Not very Cocoa-like wrapper classes. I think this is deliberate; they've gone for making the Cocoa shim look like a .NET interface because after all, we're programming from .NET. This is a bit disappointing as I'm more familiar with PyObjC and the Perl-ObjC-Bridge where the APIs are left pointedly alone, but given the target audience of Cocoa# it's unsurprising.


• MonoDevelop. Luckily, using it isn't mandated.

So, overall, one more good point than bad (and a tentative two, if you overlook MonoDevelop); a pretty good initial evaluation and I might give this a deeper scrape.

Microblogging

For a long time, I deliberately avoided microblogs like twitter. I thought that they were simply an acknowledgement that people want to be published more than they want to have something to say. However, it would be rude of me to completely disavow the medium without actually giving it a go.

To that end, I may indeed be iamleeg on twitter, as soon as twitter actually finishes processing the signup form.

I'd like to point out that one problem I'm going to have is brevity - I have spent 650 characters telling you what my username is. Constraining myself to SMS-sized wibblings will indeed be tricksy.

Common sense writ large

Looking at the bottom of Apple's Q3 results, as indeed with any similar publication from a US publicly-traded company, we see the following text.

This press release contains forward-looking statements including without limitation those about the Company’s estimated revenue and earnings per share. These statements involve risks and uncertainties, and actual results may differ. Risks and uncertainties include without limitation potential litigation from the matters investigated by the special committee of the board of directors and the restatement of the Company’s consolidated financial statements; unfavorable results of other legal proceedings; the effect of competitive and economic factors, and the Company’s reaction to those factors, on consumer and business buying decisions with respect to the Company’s products; war, terrorism, public health issues, and other circumstances that could disrupt supply, delivery, or demand of products; continued competitive pressures in the marketplace; the Company’s reliance on sole service providers for iPhone in certain countries; the continued availability on acceptable terms of certain components and services essential to the Company’s business currently obtained by the Company from sole or limited sources; the ability of the Company to deliver to the marketplace and stimulate customer demand for new programs, products, and technological innovations on a timely basis; the effect that product transitions, changes in product pricing or mix, and/or increases in component costs could have on the Company’s gross margin; the effect that product quality problems could have on the Company’s sales and operating profits; the inventory risk associated with the Company’s need to order or commit to order product components in advance of customer orders; the effect that the Company’s dependency on manufacturing and logistics services provided by third parties may have on the quality, quantity or cost of products manufactured or services rendered; the Company’s dependency on the performance of distributors and other resellers of the Company’s products; the Company’s reliance on the availability of third-party digital content; and the potential impact of a finding that the Company has infringed on the intellectual property rights of others. More information on potential factors that could affect the Company’s financial results is included from time to time in the Company’s public reports filed with the SEC, including the Company’s Form 10-K for the fiscal year ended September 29, 2007; its Forms 10-Q for the quarters ended December 29, 2007 and March 29, 2008; and its Form 10-Q for the quarter ended June 28, 2008, to be filed with the SEC. The Company assumes no obligation to update any forward-looking statements or information, which speak as of their respective dates.

Erm, like, duh. Stuff which we say might happen in the future, might not actually happen. Really? You've got to get out of the financial industry, there's a lucrative career ahead of you in construction.

Designing a secure Cocoa application

That's the title of next month's CocoaHeads Swindon, and I'll be leading the presentation/discussion. So if you want to learn a little about how to ensuring your Cocoa app doesn't give away the keys to the kingdom, or have some experiences to share with the rest of the group, come along! We'll be at the Glue Pot, which is nice and near the train station as well as reasonably close to a car park. We'll be congregating at 7:00 but will wait for everyone to be settled with a beer in their hand before starting ;-).

Ah, the sweet sound of my own voice

The title is a linky to the press release regarding the edition of Sophos Podcasts I recorded with Carole, and which has now (clearly) gone live. In it we mainly talk about the data theft and Macs technical paper I've already posted about. This is the first podcast I've ever been involved in, so any feedback you have (apart from telling me that I sound drunk in my first sentence, I'm not sure what that's all about) will be most welcome!

CocoaHeads Swindon

Just got back from the first meeting of Swindon CocoaHeads, featuring a bunch of people who live nowhere near Swindon, some good beer and the occasional discussion of Cocoa. Special mention to Scott who came all the way from sunny Warsaw to be with us!

Tonight's event was an informal, "what do we want from Swindon CocoaHeads?" event, but it looks like being successful enough that we'll be doing it again. The format will be a presentation or directed conversation, followed by general chit-chat about all things Cocoa. In fact, um, I may have volunteered to give the first presentation at the next meeting. The subject is: well, that would be telling, wouldn't it… ;-). You'll have to find out by coming along to the Glue Pot in Swindon at 8pm on Monday, August 4th. Look out for further announcements and a mailing list over at Scotty's place in the forthcoming month!

Objective-C NAQs

Never-Asked Questions :-)

In Code Complete 2 §6.5, Steve McConnell presents a list of class-related design issues that "vary significantly depending on the language". So why don't we look at them for Objective-C? Especially as I can't find anyone else who's done so based on a couple of Google searches… N.B. as ever, I'm really considering Cocoa + Objective-C here, as the language itself doesn't provide enough policy for many of the issues to have an answer (only method resolution and the existence of isa are defined by the runtime and the compiler - ignoring details like static string instances, @protocol and so on).

Behaviour of overridden constructors and destructors in an inheritance tree. Constructors are simple. If you can initialise an object, return it. If you can't, return nil. The -[NSObject init] method is documented as simply returning self.

For destructors, we have to split the discussion into twain; half for garbage collection and half for not. In the world of the Apple GC, destruction is best done automatically, but if you need to do any explicit cleanup then your object implements -finalize. The two rules are that you don't know whether other objects have already been finalized or not, and that you must not resurrect your object. In the world of non-GC, an object is sent -dealloc when it has been released enough times not to stick around. The object should then free any memory claimed during its lifetime, and finally call [super dealloc]. Note that this means objects which use the voodoo cohesion of "OK, I'll clean up all my resources in -dealloc" probably aren't going to work too well if the garbage collection switch is flipped.

Behaviour of constructors and destructors under exception-handling conditions. Exceptions are a rarity in Cocoa code (we didn't have language-level exceptions for the first decade, and then there was a feeling that they're too expensive; C++ programmers like the Leopard 64-bit runtime because ObjC exceptions and C++ exceptions are compatible but that's not the case in the NeXT runtime) but obviously a constructor is an atomic operation. You can either initialise an object or you can't; there's no half-object. Therefore if an -init… method catches, the thing to do is unwind the initialisation and return nil. The only thing I can think to say for having exceptions around destruction time is "don't", but maybe a commenter will have better ideas.

Importance of default constructors. All classes implement -init, except those that don't ;-). Usually if there's a parameterised initialiser (-initWithFoo:) then that will be the designated initialiser, and -init will just return [self initWithFoo: someReasonableDefaultValueForFoo];. If there's no reasonable default, then there's no -init. And sometimes you just shouldn't use -init, for instance NSNull or NSWorkspace.

Time at which a destructor or finalizer is called. See How does reference counting work? for a discussion of when objects get dealloced. In the garbage-collected world, an object will be finalized at some time after it is no longer reachable in the object graph. When that is exactly really depends on the implementation of the collector and shouldn't be relied on. Temporal cohesion ("B happens after A, therefore A has been done before B") is usually bad.

Wisdom of overriding the language's built-in operators, including assignment and equality. This is such a brain-damaged idea that the language doesn't even let you do it.

How memory is handled as objects are created and destroyed or as they are declared and go out of scope. How does reference counting work? How do I start using the garbage collector?

WWDC day crosspost

WWDC summary on SophosLabs blog, written by yours truly. I wonder how many Sophos readers (I should probably avoid the term sophist, shouldn't I?) have an interest in Mac and iPhone stuff (and subequently how many comment via the e-mail address on the Labs blog).

Local KDC on Leopard

via Nigel Kersten, a great description of the operation of Leopard's built-in local KDC. I think the most exciting thing about the local KDC is the Bonjour support; could we see simple cross-system trust in the near future? Could there be someone in the world who can actually make Kerberos simple?

WWDC day 00000000000000000000000000000101

Technically day five isn't over yet, but with just one session and a taxi ride remaining I doubt I'm going to get anything prematurely wrong here. In fact, I'm no longer entirely sure that I'll remain awake through the rest of the day so even if something entirely different does happen (still haven't heard anything about IXKit this millennium) I expect I'd miss it.

Planning an east-bound flight is always difficult, because an 11-hour flight through eight time zones "takes" 19 hours. So if I sleep on the plane I'll wake up in the middle of the afternoon UK time, and going back to sleep at newly-local night-time might be complicated. Conversely if I don't sleep on the plane then I won't be going to sleep until at least 9am currently-local time, for a total of about 28 hours uptime. I was just talking to someone who recommended fasting, I'm not sure whether it's worth going through that hardship for an unverified theory (stuff all of that "in the name of science" crap). The other option would be to go into work 3pm-11pm for the beginning of the week, I'm not sure everyone else will appreciate having their meetings moved to the middle of the night and I don't think the canteen's open that late either ;-).

Still, of the three WWDCs I've been to this is definitely in the top ten list of interesting and exciting WWDCs. There definitely still are fellow NeXT fans in the woodwork (actually, *tap* *tap* I think it's gypsum board) who worm their way out during these events, I guess that most have no motivation not to be working on Cocoa. Actually, I don't recall having seen Andrew Stone this week, and I know of a couple of other guys who aren't here, but have definitely managed to gain some traction for the phrase "NeXTSTEP Mobile ;-)

WWDC day four

Not so many sessions attended today - partly because I've reached the limit of what the human physiology can achieve on a diet of coffee and doughnuts. But also due to ducking out of sessions to meet with ex-NeXT guys, ex-Lighthouse guys and ex-colleagues for most of the afternoon. Of course, this was followed by the beer bash, no longer the campus bash which we all know and fondly remember (or at least we all fondly remember queueing for a couple of hours at each end for the coach) but still a good event. Speaking of ex-Lighthouse guys, Wylie and I spent a bit of time putting Sun's world to rights (essentially, if they were to stop diluting the Java brand, stop pulling themselves in every which way and try to make some money, they might do OK).

So tomorrow is the NeXT meetup at the beginning of lunch, I have a lab appointment at exactly 12 which is a little annoying but I'll try to make it over. If the G4 cube is the right shape, wrong CPU and Real Men's Objects use the NX prefix, then come over to the front of the Moscone West after the second session.

WWDC: afp548 Venn competition

I, with some help from Ken and the guys, did a better job.

WWDC day three

Today was not quite a full day, so I managed to spend about an hour or so milling around Yerba Buena park, doing a little gift shopping and generally existing outside of the Mascarpone centre. Also put in another update to the c.l.o-c FAQ (though I didn't update the date! oops…) to better discuss retain/release memory management. There are still situations (GNUstep, Cocotron, and some particular OS X environments) where garbage collection is either unavailable or unsuitable, and it turns out that a lot of questions on either the group or cocoa-dev recently have been about the memory management system.

In the evening, after dinner at Chevy's with the u.c.s.m guys (and yet more discussion of the Sophos feature set), checked in to the Apple Design Awards for the first 30 mins or so. All of the winners (and runners-up) I saw were worthy applications, although it was interesting to note that while most of the "productivity" app winners were from small shops, both of the games (runner-up was Command and Conquer 3, winner was Guitar Hero 3) were from large studios, ports of Windows/console games and in existing long-running series. They're both great games, too, of course. Ian was, of course, rooting for Delicious Library 2, and sadly disappointed ;-).

This was all followed by the AFP548 beer bash over at Thirsty Bear. Yet more "oh, you're from Sophos? Yeah, let me say this one thing…", which I really enjoy because if something's either good or bad enough to be the subject of a beer-fuelled rant in a party, I should probably hear about it. Also submitted a couple of entries to Peter's "Leopard bug Venn diagram" contest; I'm not sure I could do a better job of describing the situation than that but for those who were there, I came up with: \Omega = "Closed/Duplicate" and \Omega = "NeXTSTEP 7.0".

WWDC aside

None of Perl, Cocoa or some weird XML toolkit came up with the "simple things simple, complex things possible" quote.

WWDC day 2

Tuesday is typically associated with "starting to learn stuff" at WWDC, and today was definitely spent learning stuff. Learning, for instance, that doughnuts are considered adequate breakfast material, or that if you are prepared to pay the tiny wi-fi fee at Starbucks you can get faster INTARWEBS than all the people on the steps outside the Mascarpone. It was also a day of nice food; I've just got back from dinner with Alex at the Chevy's, having had lunch with Michael at the Ozuma sushi restaurant. More discussing Sophos-for-Mac with customers and potential customers ensued (apparently we've saved some people from the "hell that is Norton", and I point out for legal purposes that that's a direct quote and not my own opinion or words), and I got some pretty good photos of the Bay Bridge and treasure island which I'll upload as soon as I locate the USB cable.

ObjC FAQ update

Added a question about the ObjC 2.0 garbage collector. Sorry it's been so long in coming! I'll try and add a few more ObjC 2.0 questions over the coming days.

WWDC - day one

The WWDC keynote is always an odd event to attend. It's put on for the benefit of the investors and the media, with the developers being invited purely to act as braying masses expressing their adulation for His Steveness. It's rare for any technical content to make it into the session, except in unavoidable cases such as the 2005 keynote. The focus of that was the Intel transition, so by necessity there had to be some technical justification of the switch.

With this in mind, it's not hard to see that the keynote can be a somewhat dull affair. Obviously as both an Apple customer and member of the "economic ecosystem" of the Mac, it's always good to be as informed as possible of the company's position and direction. That said, yesterday's keynote (no wi-fi in this hotel, so a late post) contained less of interest to me than usual.

As I mentioned I'm financially dependent on Apple (in an indirect sense of course; I'm paid to write Mac software for Sophos, therefore no Mac = no job at Sophos), though as I'm not an indie dev I have a bit more of a comfort buffer than many people. The enterprise iPhone video Steve showed was basically a backslap in front of the shareholders; look, there are people who really do use this stuff! Then the laundry list of every developer who's downloaded the SDK and managed to get something to compile; interesting to see the wealth of different domains into which the iPhone is entering, but seriously. Two demos, three tops. Not all four thousand of the known apps. Good to see TEH CHEAP being applied to the 3G iPhone, though; I may have to
have a discussion with Orange about a PAC when that's available.

Which left Mobile Me. This is actually a pretty cool reboot of iTools^W.Mac, OK it looks like there might be no more iCards but on the other hand the Mobile Me syncing is really beneficial. I can see that becoming more of a cash cow for Apple, though mainly because they opened it up to the PC; people who have an iPod and Windoze could buy MM to synchronise their contacts, mail and so on, as well as getting webmail access (and webmail access which doesn't suck balls as much as
Exchange's OWA, may I add). That then might make them more amenable to the Halo Effect and the purchase of a Mac down the line.

The rest of the day was interesting but obviously undisclosable, except for the evening I spent in a couple of bars down the financial district (the Golden%Braeburn event at 111 Minna, where I went with Steffi from BNR and a couple of Cocotron committers; then Dave's bar where I met Nigel and most of Apple UK). Conversation ranged from Sophos feature requests to the drinkability of American IPAs; all good stuff!

WWDC part 0

well, here it is, the pre-WWDC "I'm jetlagged so you have to put up with my wittering" post. I'm just waiting for a softwareupdate to finish so that I can go out with my camera, taking some early-morning pictures before heading off to stand in line for the Stevenote. I was out for beers with Ian and Neil last night, we'd all heard rumours of a 5 a.m. start to the queue. On the two previous occasions that I've been, 9 a.m. has been sufficient; but with the sellout nature of the event it's likely that the room will fill up rather quickly so we've compromised on a 7 a.m. start. Actually, forget the 5 a.m. nonsense, there's a line of overnight campers - I can't decide whether they're deliberately trying to re-enact a Joy of Tech cartoon, or actually have nothing to do with their lives.

This means business

This is the design of the business card I'll be taking to WWDC. Let's look at some notable features.

• Photo in top left. I don't know about you, but I find it much easier to remember what someone looks like than who they are - this card is available so that people can combine the two.


• Plenty of blank space. The back is also entirely empty and can be written on. When people exchange business cards there'll usually be some context, it can help you remember what that is if you write it down. For instance, I've got cards from previous WWDCs with handwritten notes like "webobjects employer", "bindings", "parallels openstep" and "huge hat" (bonus points for identifying all four).


• Questionable source code snippit. This is a deliberate ploy to annoy fellow-developers with our compulsive attention to detail, thus helping to cement the meeting in their mind as well as providing an inoffensive conversation starter.


• Minimal contextual detail. I'm pretty sure I won't get through all 250 cards in one sitting, so they ought to remain relevant for as long as possible.

Little hack to help with testing

Want the ability to switch in different test drivers, mock objects, or other test-specific behaviour? Here's a pattern I came up with (about a year ago) to do that in a GNUstep test tool, which can readily be used in Cocoa:

NSString *driverClassName = [[NSUserDefaults standardUserDefaults] stringForKey: @"Class"];
Class driverClass = NSClassFromString(driverClassName);
id myDriver = [[driverClass alloc] init];

With a healthy dose of no, seriously, don't do this in production code, you now have the ability to specify your test driver on the command-line like this:

$ ./myTestingTool -Class GLTestDriver

This uses the oft-neglected behaviour of NSUserDefaults, in which it parses the executable's command-line arguments to create a defaults domain, higher in priority than even the user's preferences file. You can use that behaviour in a graphical app too, where it comes in handy when working in Xcode. It then uses a combination of the runtime's duck typing and introspection capabilities to create an instance of the appropriate class.

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)…

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.

My name in lights

I've been published.

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.

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.

Yeah, we've got one of those

Title linkey (which I discovered via slashdot) goes to an interview in DDJ with Paul Jansen, the creator of the TIOBE Programmer Community Index, which ranks programming languages according to their web presence (i.e. the size of the community interested in those languages). From the interview:

C and C++ are definitely losing ground. There is a simple explanation for this. Languages without automated garbage collection are getting out of fashion. The chance of running into all kinds of memory problems is gradually outweighing the performance penalty you have to pay for garbage collection.

So, to those people who balked at Objective-C 2.0's garbage collection, on the basis that it "isn't a 4GL", I say who cares? Seemingly, programmers don't - or at least a useful subset of Objective-C programmers don't. I frequently meet fellow developers who believe that if you don't know which sorting algorithm to use for a particular operation, and how to implement it in C with the fewest temporary variables, you're not a programmer. Bullshit. If you don't know that, you're not a programmer who should work on a foundation framework, but given the existence of a foundation framework the majority of programmers in the world can call list.sort() and have done with it.

Memory management code is in the same bucket as sorting algorithms - you don't need for everybody to be good at it, you need for enough people to be good at it that everyone else can use their memory management code. Objective-C 2.0's introduction of a garbage collector is acknowledgement of this fact - look at the number of retain/release-related problems on the cocoa-dev list today, to realise that adding a garbage collector is a much bigger enhancement to many developers' lives than would be running in a VM, which would basically go unnoticed by many people and get in the way of the others trying to use Instruments.

Of course, Objective-C and ApPLE's developer tools have a long history of moving from instrumental programming (this is what the computer must do) to declarative programming (this is what I am trying to achieve, the computer must do it). Consider InterfaceBuilder. While Delphi programmers could add buttons to their views, they then had to override that button's onClick() method to add some behaviour. IB and the target-action approach allow the programmer to say "when this button is clicked, that happens" without having to express this in code. This is all very well, but many controls on a view are used to both display and modify the value of some model-level property, so instead of writing lots of controller code, let's just declare that this view binds to that model, and accesses it through this controller (which we won't write either). In fact, rather than a bunch of boilerplate storage/accessors/memory management model-level code, why don't we just say that this model has that property and let someone who's good at writing property-managing code do the work for us? Actually, coding the model seems a bit silly, let's just say that we're modelling this domain entity and let someone who's good at entity modelling do that work, too.

In fact, with only a little more analysis of the mutation of Objective-C and the developer tools, we could probably build a description of the hypothetical Cen Kase, the developer most likely to benefit from developing in Cocoa. I would expect a couple of facts to hold; firstly that Cen is not one of the developers who believes that stuff about sorting algorithms, and secondly that the differences between my description of Cen and the description used by Apple in their domain modelling work would fit in one screen of FileMerge on my iBook.

Tracking the invisible, moving, unpredictable target

An idea which has been creeping up on me from the side over the last couple of weeks hit me square in the face today. No matter what standards we Cocoa types use to create our user interfaces, the official Aqua HIG, the seemingly-defunct IndieHIG, or whatever, ultimately producing what is considered a usable (or humane, if you like) interface for Mac OS X is not only difficult, but certainly unrepeatable over time.

The "interface" part of a Cocoa user interface is already hard enough to define, being a mash-up of sorts, and to differing degrees, between the Platinum HIG which directs the default behaviour of some of the *Manager controls and the OpenStep HIG which describes the default behaviour of most, if not all, of the AppKit controls. If that isn't enough, there is an inexact intersection - some controls work differently in (what are loosely called, and I'm not getting into the debate) Cocoa apps than in Carbon apps. There have also been innovative additions on top of the aforementioned guides, such as sheets, unified toolbars and (the already legacy) textured interfaces. There have been subtractions from both - miniwindows still exist but nobody uses 'em, and window shading went west with Rhapsody.

But all of that is related to the user interface, not to user interaction (I'm in the middle of reading Cooper's The Inmates Are Running the Asylum, I'm going to borrow some terminology but studiously avoid discussing any of the conclusions he presents until I'm done reading it). It's possible to make HIG-compliant inspectors, or HIG-compliant master-detail views, or HIG-compliant browser views and so on. It's also possible to make non-compliant but entirely Mac HID views, coverflow views, sidebars and so on. But which is correct? Well, whichever people want to use. But how do you know which people want to use? Well, you could get them to use them, but as that's typically left until the beta phase you could ask usability gurus instead. Or you could take the reference implementation approach - what would Apple (or Omni, or Red Sweater, or whoever) do?

Well, what Apple would do can, I think, be summed up thus: Apple will continue doing whatever Apple were previously doing, until the Master User takes an interest in the project, then they do whatever the Master User currently thinks is the pinnacle of interaction design. The Master User acts a little like an eXtreme Programming user proxy, only with less frequent synchronisation, and without actually consulting with any of the other 26M users. The Master User is like a reference for userkind, if it all works for the Master User then at least it all works for one user, so everyone else will find it consistent, and if they don't find it painful they should enjoy that. The official job title of the Master User role is Steve.

All of this means that even inside Apple, the "ideal" usability experience is only sporadically visited, changes every time you ask and doesn't follow any obvious trend such as would be gained by normalisation over the 26M users. Maybe one day, the Master User likes inspectors. Then another day he likes multi-paned, MDI-esque interaction. On a third day he likes master-detail control, in fact so much so that he doesn't want to leave the application even when it's time to do unrelated work. Of course you don't rewrite every application on each day, so only the ones that he actually sees get the modernisation treatment.

So now we come back to the obvious, and also dangerous, usability tactics which are so prevalent on the Windows platform, and one which I consciously abhor but subconsciously employ all the time: "I'm the developer, so I'll do it my way". Luckily there are usability, QA and other rational people around to point out that I'm talking shite most of the time, but the reasoning goes like this. I'm a Mac user, and have been for a long time. In fact, I might know more about how this platform works than anyone within a couple of miles of here, therefore(?) I know what makes a good application. One problem which affects my personal decisions when trying to control the usability is that I'm only tangentially a Mac person, I'm really a very young NeXTStep person who just keeps current with software and hardware updates. That means I have a tendency to inspector my way out of any problem, and to eschew custom views and Core Animation in favour of "HIG is king" standard controls, even when other applications don't. And the great thing is that due to Moving Target reference implementation, I can find an application which does something "my" way, if that will lend credence to my irrational interface.

The trick is simply to observe that taking pride in your work and expressing humility at your capabilities are not mutually exclusive. If tens of other Mac users are telling me they don't like the way it works, and I'm saying it's right, apply Occam's razor.

And if there isn't enough fun for you in one usability experience, a bunch of us are presumably going to be providing the iPhone HIG-compliant V on top of our Ms and Cs before long.

Come back, purple button, all is forgiven!

As a great philosopher once wrote: don't it always seem to go, that you don't know what you got 'til it's gone? Previews of Mac OS X had a user interface feature, known by all who saw it as the Purple Button. Look at this screenshot from System Preferences:

The boiled sweet on the top-right of the window would go purple, hence the name. Clicking on it activated a single-window mode. All documents except the one that you were working on would be minimised into the Dock, and switching between them would minimise the earlier one before restoring the newly-focused document. Of course, the problem with this in the developer previews/public beta which rendered it unusable were performance-related. The "lickable" eye-candy in Aqua was ambitious even on the top-end G4 systems available at the time, and so time spent in the Genie or Scale effects was really noticable. Add to that the effect of applications being slow enough not to update their views in time - the System Preferences application you can see above is a Cocoa-Java app, and back then the JVM wasn't amazing for performance - and you have a really sucky single-window experience.

On the other hand, it's really bloody useful. Look at apps like WriteRoom or GLTerminal, which go out of their way to get rid of all that other clutter. Or Spaces (or CDE virtual desktops, WindowMaker virtual desktops... you get the idea), also designed to let you forget all those other apps are there. Well, spaces is quite nice (and a little more flexible than purple button was), but playing spaces ping-pong tends to make me a bit seasick. Not to mention the time it wastes being about as great as the unperformant purple button switching...so please, purple button, come back!

Some environments provided the same user experience out of a lack of choice - for instance, OZ couldn't show more than one application if it wanted to, and certainly running more than one at once was out of the question (it would simulate multi-tasking by suspending background tasks).

How exciting

Today I was pleasantly surprised by Interface Builder. Not shiny, new, where the hell have they put that buttonstreamlined IB3, but boring old IB2 which even Slowlaris users could work out how to use. I dragged a header defining a category with an IBAction onto IB, and lo, nay even behold, it did the right thing.

That may seem unexciting and even expected, but it's one of those nice cases where it's pleasing that everything just works. I thought category headers might be edge-case enough to confuse the thing; many people would put their IBAction definitions in the "regular" @interface header so that the IBOutlets are in the same place.

Broke track mounting

For some reason, CDs occasionally don't automount for me on my iMac. Luckily that's easy to work around:
kalevala:~ leeg$ diskutil list
[...]
/dev/disk3
#: TYPE NAME SIZE IDENTIFIER
0: CD_partition_scheme Audio CD *620.3 Mi disk3
[...]
kalevala:~ leeg$ diskutil mountDisk disk3
Volume(s) mounted successfully
Job is, as they say, a good 'un.

Nice things about ObjC

Title linkies to a post by an F-Script guy (the F-Script guy? I'm not sure, I don't really follow F-Script development) about nice things he likes about the Objective-C language. Remembering that he wrote a Smalltalk scripting environment for Cocoa, some of the list is fairly unsurprising, much is made of the dynamic runtime, multiple-level dispatch and so on. I think the article is mainly bang on, though I do disagree with the author in a few places. The next paragraph is not one of those places.

Classes are objects. ++ This is the coolest thing ever about proper object-oriented languages, and one of my strongest arguments for design patterns are not language independent. Do patterns such as Prototype need to exist in ObjC code, when the Factory Method +new will give you an unconfigured typical instance?

Dynamic typing... Optional static typing. This is one of those slippery slopes where both edges are sharp enough to give you the rope required to shoot yourself in the foot. Duck typing (i.e. if an object looks like a duck, and quacks like a duck...) is useful in some cases and damned annoying in others. To avoid runtime exceptions with duck typing you either have to [i]mentally assert correctness in your code, [ii]perform all the runtime introspection needed to ensure your messages will be handled, or [iii]eschew the duck type completely and downcast to either an instance of a class or a conformant of a protocol (or both; you could do something like GLModelObject <NSCoding> * if you really felt like it). Another issue with the ObjC implementation of duck typing is that it doesn't always work as you'd think. When it does work, it's very powerful - when it doesn't, you probably won't find out until runtime, and could be spending a long while working out what happened.

Categories. No, afraid not. Nice idea, badly implemented. The point of categories is to let you decorate a class with additional functionality by adding methods - currently not ivars - in additional code objects, not all of which need be present at launch. This lets you work around the visibility contract of the class (can't see an @private ivar? Just chuck an instance method in!), though in fairness so does KVC. But perhaps the worst crime a category can commit is killing someone else's category. Or overwriting an "undecorated" method.

I still love Objective-C, mainly because I love Cocoa and GNUstep and making code that works like them, it's definitely powerful and fun too. But it's not without its rough edges and sharp spiky bits.

My discs have been Americanised!

For some reason, even though l10n and i18n have been fashionable terms in computing for the last few years, no-one seems able to localise properly into the lingua franca of computing, English. It may surprise some readers to learn that there's more than one dialect of english, and some of these even have their own ISO codes (such as en_GB, en_US and so on...I'm ignoring the "ang" language for now). Some words in these different dialects are not spelled in the same way. I live in the United Kingdom of Great Britain and Northern Ireland (Land of hope and glory, mother of the free...) and therefore those round things are known as discs. Indeed, when I insert my Mac OS X installer disc, it is called "Mac OS X Install Disc 1". Then I launch the Firmware Password application, which tells me: "The firmware password is used to prevent others from starting your computer with a different disk." Gah!

"Patently" obvious

Due to a lack of digit extraction I'm not at FOSDEM this weekend. That's unfortunate because as well as catching up with my friends at Brainstorm and on GNUstep, I really enjoyed the weekend last year and drank plenty of great Belgian beer and ate plenty of nice moules-frites.

So I've been spiritually living the Free lifestyle by reading what RMS and Torvalds have to say. Mostly I've been going over the essays in Free Software, Free Society. I find it very easy to accept the premises RMS uses, easy to follow, comprehend and agree with the arguments he presents but then somehow (perhaps for illogical reasons on my part, his part or both) hard to agree that the conclusions he draws are inevitable.

For instance, I agree that copyright law exists directly to benefit the public, and indirectly to benefit the authors (by providing incentives for authors in the shape of limited term monopoly over their authored content) and not at all to benefit Industry Associations. It even says that here, in the first ever copyright law: ...for the Encouragement of Learned Men to Compose and Write useful Books; May it please Your Majesty, that it may be Enacted... certainly doesn't seem to mention greedy lawyers or management.

Letters patent were never created for the same reason, of course. But because it became clear that patents from the Crown were obtained uppon Misinformacions and untrue pretences of publique good, many such Graunts have bene undulie obteyned and unlawfullie putt in execucion, to the greate Greevance and Inconvenience of your Majesties Subjects, contrary to the Lawes of this your Realme, and contrary to your Majesties royall and blessed Intencion soe published, so the whole system was rebooted so that patents were only grantable ... to the true and first Inventor and Inventors of such Manufactures, [...] soe as alsoe they be not contrary to the Lawe nor mischievous to the State, by raisinge prices of Commodities at home, or hurt of Trade, or generallie inconvenient....

The situation we find ourselves in now is that industries claim copyrights and inventions from the authors and inventors and lobby for more and more restrictive variants of the above laws, ignoring the previously-granted rights of the public at large and extending the previously-ungranted rights of the rights-owners, simultaneously removing those rights from the people granted the rights in the first place. So why in the case of copyright do the FSF assume copyright, but in the case of patents they refuse to deal with them? That inconsistency I don't understand.

Don't go there

From the title linky: " Mobility is only available for Windows and Linux." Good job no-one bases their mobile appliances on Mac OS X ;-)

Mach-OFS: aforementioned polish and functionality

It's getting there, now has the ability to display load commands (though it only reports useful information for LC_SEGMENT and LC_SEGMENT_64 commands):

Again the screenshot depicts the OmniDazzle binary for no reason other than it's a nontrivial file. The directions in which to take the filesystem are now numerous: I can add info about the remaining load commands (v. useful), the raw data for each segment (somewhat useful), and the sections in each segment (v. useful). Whether the filesystem will eventually get to the level of symbol resolution, I'm not sure :-).

Well, you could have told me

When looking through some of the configuration options on my laptop (well, it's either that or go to the pub and socialise with humans) I came across something I couldn't account — pardon the pun — for. A new user account on the system, short name messagebus, full name "Message\ Bus" user id 506. Now messagebus looks like the name of a system daemon user, but that full name looks like some clueless skiddie made a mistake creating the user account, especially as the uid is that of a regular user. That's the kind of mistake no self-respecting installer would make.

So, what had this phantom user done? Well, thankfully, nothing. Neither the shell nor home directory was real, and wtmp/utmp showed no activity. Neither did the ssh logs - but in looking for them I realised that I don't actually use ssh on the box, so turned it off.

Anyway, it turned out to be an innocuous issue - the MacPorts installer for dbus creates this bogus user, which I've since deleted. This Apple forums discussion explains more.

Mach-O FS (no really, MacFUSE does rule)

It needs some polishing and more functionality before I'd call it useful, then I have to find out whether I'm allowed to do anything with the source code ;-). But this is at least quite a cool hack; exploring a Mach-O file (thin or fat - in this case, I used the OmniDazzle executable which is a fat file) as if it's a file system. FUSE of course makes it easy, so thanks to Amit Singh for the port!

MacFUSE rules

One reason that microkernels win over everything else (piss off, Linus) is that stability is better, because less stuff is running in the dangerous and all-powerful kernel environment. MacFUSE, like FUSE implementations on other UNIX-like operating systems, takes the microkernel approach to filesystems, hooking requests for information out of the kernel and passing them to user-space processes to handle. Here's the worst that can happen when screwing up a FUSE filesystem:

Now that might sound not only like a recipe for lower-quality code, but also like I'm extolling the capability to create lower-quality code. Well no it isn't, and yes I am. The advantage is that now the develop-debug-fix cycle for filesystems is just as short as it is for other userland applications (and HURD translators and the like). This provides a lower barrier to entry (meaning that it's more likely that interesting and innovative filesystems can be created), but also a faster turnaround on bugfixes (no panic, restart, try to salvage panic log... no two-machine debugging with kdb...) so ultimately higher-quality filesystems.

Non-subscription updates means charged?

The justification for the iPod Touch upgrade fee (to enable the new apps, which are actually deployed-but-disabled by a free firmware upgrade) is the same as the justification given for the MacBook wireless upgrade fee last year - that adding new features to a product that isn't sold as a subscription service needs to be charged for. That in itself is odd - it means that the regulators in the States get to set a price (if not the price) for hitherto free products offered by companies. But it raises a more interesting question - what constitutes a new feature? If a bugfix renders a previously-unusable feature usable, is that charged for? If a security fix makes it possible to use a system in a different environment, should that be charged for?

From the no-man's-land of the format wars

About nine and a half years ago, a sixteen-year-old gadget boy in Weymouth made a simple mistake. Given the already near-complete shift of the music industry from the cassette tape to the Philips compact disc, and the superior portability and resilience of the Sony MiniDisc format, this boy decided that it was obvious the world was going to adopt this format. So our protagonist went out and bought a MZ-R35 walkman. Three years later, and although the writing was by now on the wall for the storage format, he added an MD-M3 to his collection.

I now believe I own all five pre-recorded MiniDisc albums ever made (though I don't remember when I bought Hours by Bowie, and can only think that I bought Recurring Dream because at the time I fancied a girl who liked Crowded House), and have swathes of my vinyl and tape collection "backed up" to recordable MDs. But the rest of the world forgot to catch up with me! Where are the Hi-MD drives built in to laptops? Even Sony don't offer that... Come to that, why do we still put up with crappy scratchable CDs? iPods may be a damn sight more convenient than my MD walkman is, but the bandwidth of an amazon package containing MiniDiscs is still far higher than the connection between my laptop and iTunes.

I still intend to find the required cable and port the rest of my LPs to the format though, as MDs are definitely more portable and resilient than is vinyl. And I haven't actually listened to Bauhaus' 1979-1983 in years.

We! Haven't! Thought! This! Through!

So almost the entire world has exploded with news that Microsoft haven't bought Yahoo!, but are at least waving ridiculous amounts of TEH CAHS under the noses of the shareholders. But what would be the outcome of such a takeover? Microsoft and Yahoo! are in pretty much the same position, they both have technologically acceptable "online presence" services which are marketed really badly such that a competitor virtually owns the market. The only example of a service between them I can think of which is vaguely market-leading is Flickr, although Yahoo! Groups (which was eGroups) might still be popular, I expect that Facebook and Google groups are at least comparable, if not larger than it. Hotmail and Yahoo! Mail are both familiar names, but then online mail is now a free and worthless commodity, and everyone has been playing catchup with Gmail for the last couple of years. People don't "Windows Live Search" a thing, they "Google" it. People don't "Yahoo! Video" their dogs on skateboards, they "Youtube" them.

So the post-acquisition world would go from two implementations to one, but one that's still being marketed into the ground and with a few fewer workers. And all the transitional pain that Microsoft will impose on Yahoo! services, when someone remembers that FreeBSD isn't a Microsoft solution. M$ seem to be of the opinion that with a market they don't lead and $45Bn, the best approach is to lose the $45Bn and hire some other people who don't lead the market. Not, like, take that $45Bn and make their stuff better.

Permissions whee!

As in any good mystery, the question is who done it? MacNN reports a flaw in Tiger, Leopard in which an authenticated copy operation gives the destination files (the copies) the ownership of the logged-in user, not of the name they used to authenticate. The question is, which user did the copy?

Let's say there's a system with Alice Administrator and Richard Regular-User. Richard downloads a new application from the intarwebs, and wants to put it in /Applications (though why? Why can't he just put it in ~/Applications like a good little user? Never mind). The thing is, he doesn't have the right to do that. Finder presents him with an authentication dialogue, and no matter how many times he enters his username and password correctly, he can't acquire that right. However, he sees Alice walking past in the corridor and asks her to enter her admin credentials. For whatever reason, she agrees - now Alice has authenticated and Alice has acquired the right to copy the files. So even though Richard requested the copy, it was actually Alice who performed it. Therefore Alice created the files at the destination, so they should be owned by Alice.

The only thing which muddies the waters (and leads to the conflict of convenience vs. security which is described in that article) is that in many, or indeed most, cases on OS X where this will arise, Alice and Richard are actually the same person - Sammy the Single (Security-conscious, hence separating their use of the system into regular and admin accounts) User. It's a convenience that as Richard wanted the files copied, Richard now owns the copy - but this defeats the point of Richard existing, which is that Sammy doesn't want to be able to change /Applications without being warned.

Interestingly the same question doesn't get asked of the sudo command - it's clear that if I type sudo ditto Foobar.app /Applications/Foobar.app it's the super-user who does the work.

Side-by-side

A frequently-heard rider on the statement that Mac OS X "is more secure than Windows" is that fewer people are prodding its weak spots, because it has fewer users. Well, Windows Vista has a market share comparative to Mac OS X (all versions), and this report describes the security statistics as being somewhat comparable, too. So there we go.

How to solve every problem in Cocoa

Yes, really, every problem. Don't think of Cocoa as "simple things simple, complex things possible" (actually, was it Cocoapenextstepsody or Perl who started with that tagline? Or someone else? I digress) but "simple things simple, complex things simple but you're looking at it wrong". With Objective-C 2.0 (particularly properties), Core Data, Cocoa Bindings and Cocoa Scripting, almost every "it doesn't work" moment comes down to getting something wrong with KVC or with KVO - either observing the wrong key, or typoing a method name such that you aren't KVC-compliant for a key you need to be, getting validation wrong or unexpectedly going down the -setNilValueForKey: path. So do yourself a favour:

#define GLInstanceMethodEntryLog(format, ...) NSLog(@"-[%@(%p) %@] entry: %@", NSStringFromClass([self class]), self, NSStringFromSelector(_cmd), [NSString stringWithFormat: format, ##__VA_ARGS__])

Now because all of the retain count bugs disappeared when you turned the garbage collector on, the remaining issues are with that bit of code the PHBs are paying for ;-)

Project: Autonomous Revolutionary Goldfish

I was going to write, am still going to write, about how silly project names get bandied about in the software industry. But in researching this post (sorry blogosphere, I've let you down) I found that the Software-generated Gannt chart was patented by Fujitsu in the US in 1998, which to me just explains everything that is wrong with the way the US patent system is applied to software. For reference, Microsoft Project was written in 1987 (although is not strictly prior art for the patent. Project does everything in its power to prevent the user from creating a Gannt chart, in my experience).

Anyway, why is it that people care more about the fact that they're going to be using Leopard, Longhorn, Cairo, Barcelona or Niagara than about what any one of those is? As discussed in [1], naming software projects (though really I'm talking about projects in the general sense of collections of tasks in order to complete a particular goal) in the same way you might name your pet leads to an unhealthy psychological attachment to the project, causing it to develop its own (perceived) personality and vitality which can cause the project to continue long after it ought to have been killed. For every Cheetah, there's a Star Trek that didn't quite make it. And why should open source projects like Firefox or Ubuntu GNU/Linux need "code names" if their innards are supposed to be on public display?

I've decided that I know best, of course. My opinion is that, despite what people may say about project names being convenient shorthand to assist discussion, naming your project in an obtuse way splits us into the two groups which humanity adores: those of us who know, and those of you who don't. The circumstance I use to justify this is simple: if project names are mnemonics, why aren't the projects named in a mnemonic fashion? In what way does Rhapsody describe "port of OPENSTEP/Mach to PowerPC with the Platinum look and feel"? Such cultish behaviour of course leads directly to the point made in the citation; because we don't want to be the people in the know of something not worth knowing, we tend to keep our dubiously-named workflow in existence for far longer than could be dispassionately justified.

Of course, if I told you the name of the project I'm working on, you wouldn't have any idea what I'm working on ;-).

[1]Pulling the Plug: Software Project Management and the Problem of Project Escalation, Mark Keil. MIS Quarterly, Vol. 19, No. 4 (Dec., 1995), pp. 421-447

Objective-C Design Patterns

Certain events at work have turned me into a bit of a design patterns geek of late, and as such I stumbled across this DDJ article from 1997 (the title of this post is the link). According to del.icio.us not many other people have stumbled across it, but it's a great article. The code listing links seem to 404 even though the listings are at the bottom of page 1 of the article.

Something very important can be learned from this article, which is at best covered tangentially in the GoF book: Design patterns are not language-independent. Calling the C++ and Objective-C ways of writing code "pattern idioms" ignores the point that actually, the code you come up with is more important than the design (customers don't typically want to pay the same cash for your UML diagrams that they do for your executables), and gasp different languages require different code! Different patterns can be used in ObjC and Smalltalk than in C++, and different patterns again in object-oriented Perl. Different patterns will be appropriate for working with Foundation than with the NeXTSTEP (pre 4.0) foundation kit or with ICPak101. Designing your solution independent of the language and framework you're going to use will get you a solution, but will not necessarily produce the easiest solution to maintain, the most efficient solution or one that makes any sense to an expert in the realm of that language and framework.

FSF membership

I am now an associate member of the FSF. This is a good way to support Free Software development (including GNUstep, and you don't even need to be able to code :-). I've added a referral link to the sidebar - I don't get a kickback obviously, although I do get gifts if enough people are referred by me, and it helps the FSF to track where donors are getting their information from. If you use Free Software, you might consider donating some cash - especially now that the dollar's so crap ;-).

Post #100!

And to celebrate, we look at the differences between managers and humansprogrammers.

Upcoming Cocoa nerd stuff

I have organised a NSCoder Night for this coming Tuesday, November 27. It shall be in the Jericho Tavern pub at 8pm; bring yourself, bring an interest in Cocoa, and perhaps bring some code to talk about or work on. There won't be any agenda as such, just a group of NSCoders talking about NSCoding.

In January, PaulHR and I shall be entertaining OxMUG on the subject of Getting Things Done™ - in particular I have now started braindumping my many to-do lists into OmniFocus and I'm finding it very expressive and useful. In fact preparing that talk has just zoomed its way over to my OF inbox :-). That talk shall be Tuesday, January 8th.

Verify your backups

Apple shipped Mac OS X 10.5 this weekend, and three of the features are Time Machine, dtrace, and improved CHUD tools. Time Machine, dtrace, CHUD tools. iPod, mobile phone, web browser. Time Machine, dtrace, CHUD tools.

To spell that out in long hand, it's very easy now to see how various features in the Operating System behave. And in the case of Time Machine, we see that it walks through the source file system, copying the files to the destination. When I last gave a talk to OxMUG on the subject of data availability, it was interesting to notice how the people who had smugly put their hands up to indicate that they performed regular backups became crestfallen when I asked the second question: and how many of you have tested that backup in the last month?

Time Machine is no different in this regard. It makes copies of files, and that's all it does. It doesn't check that what it wrote at the other end matches what it saw in the first place, just like most other backup software doesn't. If the Carbon library reports that a file was successfully written to the destination, then it happily carries on to the next file. Just like any other backup software, you need to satisfy yourself that the backup Time Machine created is actually useful for some purpose.

+1-415-312-0555

Back in 1992, Robert X. Cringely wrote in Accidental Empires: How the boys of Silicon Valley make their billions, battle foreign competition, and still can't get a date [Oxford comma sic]:

Fifteen years from now, we [Americans] won't be able to function without some sort of machine with a microprocessor and memory inside. Though we probably won't call it a personal computer, that's what it will be.

Of course, by and large that's true; the American economy depends on microcomputers and the networks connecting them in a very intimate way. It's not obvious in 2007 just how predictable that was in 1992, as the "networks connecting them" had nothing like the ubiquity which is now the case. When "Accidental Empires" was written, the impact of a personal computer in an office was to remove the typewriter and the person trained to type, replacing both with someone who had other work to be doing typing on a system thousands of times more complicated than a typewriter.

What's most interesting though is the (carefully guarded; well done Bob) statement that "we probably won't call it a personal computer," as that part is only partially true. All of the people who have Tivos, or TVs, also have a personal computer. All of the people who have mobile phones and digital cameras also have a personal computer. The people who have Playstation 3s and Nintendo Wiis also have personal computers. In business, the people who annoy everyone else by playing with their palmtops in meetings instead of listening to what the amazingly insightful Cocoa programmer has to say are also wasting time trying to work out how to sync them with, yup, the personal computer they also have on their desk.

So the question to be asked is not why Cringely got it wrong, because he didn't, but why hasn't the PC already disappeared, to be completely replaced with the "it is a PC but we won't call it that" technology? Both already exist, both are pervasive, and the main modern use of both is remote publishing and retrieval of information, so why do we still tie ourselves to a particular desk where a heavy lump of metal and plastic, which can't do very much else, sits disseminating information like some kind of [note to self: avoid using the terms Oracle or Delphi here] groupthink prophet?

OmniWeb 5.6 tip of the day

defaults write com.omnigroup.OmniWeb5 WebKitOmitPDFSupport -bool TRUE

Sorry, but it doesn't view properly and doesn't print properly either :-(.

The times, they mainly stay the same

bbum displays a graph of the market capitalization (he's american, so the z sticks) of a few of the computer companies, noting that if after-hours trading isn't too surprising, then tomorrow (for Americans, again) the market will open with Apple being the biggest computer manufacturer on the planet. However, these figures fail to show something reasonably interesting.

What have IBM (up 24% y-o-y), HP (up 30 %) or Dell (up 21%) done to enamour you to their brand lately? If you're anything like me, then they've done nothing at all. Selling the same old Operating Systems on the same old hardware doesn't count as innovative. Compare them with Sun (up 13% year-on-year) or Apple (115%) and you'll see that there's basically no accounting for taste on the stock market. While Apple have been selling the shiny gadgets, Sun have been delivering the most observable operating environment on the planet and Dell have been doing, well, shit-all would be a polite phrase, and yet Dell have outstripped Sun in growing their stock price. In fact, HP have managed to blow up their stock price out of all proportion, while fighting scandals and the complete haemmorhaging of their management staff.

Nice-looking LaTeX Unicode

Because there was no other single location with all of this written:

\usepackage{ucs} % Unicode support
\usepackage[utf8x]{inputenc} % UCS' UTF-8 driver is better than the LaTeX kernel's
\usepackage[T1]{fontenc} % The default font encoding only contains Latin characters
\usepackage{ae,aecompl} % Almost European fonts/hyphenation do a better job than Computer Modern

There are a couple of characters I need (Latin letter yogh, Latin letter wynn + capitals) which aren't known by UCS, and I don't yet know how to add them. But this is a pretty good start.

Still trading as ClosedDarwin

It's not surprising, but while Apple's opensource page now includes a link to the iPhone software release (clicky the title), this only contains links to the WebCore and JavaScriptCore source, which is also available from the WebKit home on MacOSForge.org. While it is possible that the iPhone is distributed solely with software Apple can distribute without source, I wouldn't be surprised if there isn't just a teensy dollop of GPL code in there somewhere...

Old news

So the Inquirer thinks they've got a hot potato on their hands, with this "security flaw" in OS X. I've been using this approach for years (like, since NeXTSTEP): boot into single-user and launch NetInfo manually, then passwd root. Or in newer Mac OS X, nicl means you don't have to launch NetInfo.

Of course, if you give physical access to the computer without a Firmware password, then the 'attacker' may as well just boot from external media and do whatever they want from there. But the solution, as well as setting the Firmware password, is to edit the /etc/ttys file, change the line:

console "/System/Library/CoreServices/loginwindow.app/Contents/MacOS/loginwindow" vt100 on secure onoption="/usr/libexec/getty std.9600"

to:

console "/System/Library/CoreServices/loginwindow.app/Contents/MacOS/loginwindow" vt100 on onoption="/usr/libexec/getty std.9600"

Now the root password is required in single-user mode (as the console is no longer considered a secure terminal).

Holding a problem in your head

The linkied article (via Daring Fireball) describes the way that many programmers work - by loading the problem into their head - and techniques designed to manage and support working in such a way. Paul Graham makes the comparison with solving mathematics problems, which is something I can (and obviously have decided to) talk about due to the physics I studied and taught. Then I also have things to say about his specific recommendations.

In my (limited) experience, both the physicist in me and the programmer in me like to have a scratch model of the problem available to refer to. Constructing such a model in both cases acts as the aide memoire to bootstrap the prolem domain into my head, and as such should be as quick, and as nasty, as possible. Agile Design has a concept known as "just barely good enough", and it definitely applies at this stage. With this model in place I now have a structured layout in my head, which will aid the implementation, but I also have it scrawled out somewhere that I can refer to if in working on one component (writing one class, or solving one integral) I forget a detail about another.

Eventually it might be necessary to have a 'posh' layout of the domain model, but this is not yet the time. In maths as in computing, the solution to the problem actually contains the structure you came up with, so if someone wants to see just the structure (of which more in a later paragraph) it can be extracted easily. The above statement codifies why in both cases I (and most of the people I've worked with, in each field) prefer to use a whiteboard than a software tool for this bootstrap phase. It's impossible - repeat, impossible - to braindump as quickly onto a keyboard, mouse or even one of those funky tablet stylus things as it is with an instantly-erasable pen on a whiteboard. Actually, in the maths or physics realm, there's nothing really suitable anyway. Tools like Maple or Mathematica are designed to let you get the solution to a problem, and really only fit into the workflow once you've already defined the problem - there's no adequate way to have large chunks of "magic happens here, to be decided at a later date". In the software world, CASE tools cause you to spend so long thinking about use-cases, CRC definitions or whatever that you actually have to delve into nitty-gritty details while doing the design; great for software architects, bad for the problem bootstrap process. Even something like Omnigraffle can be overkill. it's very quick but I generally only switch to it if I think my boardwriting has become illegible. To give an example, I once 'designed' a tool I needed at Oxford Uni with boxes-and-clouds-and-lines on my whiteboard, then took a photo of the whiteboard which I set as the desktop image on my computer. If I got lost, then I was only one keystroke away from hiding Xcode and being able to see my scrawls. The tool in question was a WebObjects app, but I didn't even open EOModeler until after I'd taken the photo.

---

Incidentally, I expect that the widespread use of this technique contributes to "mythical man-month" problems in larger software projects. A single person can get to work really quickly with a mental bootstrap, but then any bad decisions made in planning the approach to the solution are unlikely to be adequately questioned during implementation. A small team is good because with even one other person present, I discuss things; even if the other person isn't giving feedback (because I'm too busy mouthing off, often) I find myself thinking "just why am I trying to justify this heap of crap?" and choosing another approach. Add a few more people, and actually the domain model does need to be well-designed (although hopefully they're then all given different tasks to work on, and those sub-problems can be mentally bootstrapped). This is where I disagree with Paul - in recommendation 6, he says that the smaller the team the better, and that a team of one is best. I think a team of one is less likely to have internal conflicts of the constructive kind, or even think past the first solution they get concensus on (which is of course the first solution any member thinks of). I believe that two is the workable minimum team size, and that larger teams should really be working as permutations (not combinations) of teams of two.

Paul's suggestion number 4 to rewrite often is almost directly from the gospel according to XP, except that in the XP world the recommendation is to identify things which can be refactored as early as possible, and then refactor them. Rewriting for the hell of it is not good from the pointy-haired perspective because it means time spent with no observable value - unless the rewrite is because the original was buggy, and the rewritten version is somehow better. It's bad for the coder because it takes focus away from solving the problem and onto trying to mentally map the entire project (or at least, all of it which depends on the rewritten code); once there's already implementation in place it's much harder to mentally bootstrap the problem, because the subconscious automatically pulls in all those things about APIs and design patterns that I was thinking about while writing the inital solution. It's also harder to separate the solution from the problem, once there already exists the solution.

The final sentence of the above paragraph leads nicely into discussion of suggestion 5, writing re-readable code. I'm a big fan of comment documentation like headerdoc or doxygen because not only does it impose readability on the code (albeit out-of-band readability), but also because if the problem-in-head approach works as well as I think, then it's going to be necessary to work backwards from the solution to the pointy-haired bits in the middle required by external observers, like the class relationship diagrams and the interface specifications. That's actually true in the maths/physics sphere too - very often in an exam I would go from the problem to the solution, then go back and show my working.

Template change

I had to make some minor edits to the Blogger template used here anyway, so I decided to have a little monkey with the fonts. Here's what you used to get:

And here's what you now get:

I think that's much better. Good old Helvetica! I don't understand anything about typography at all, but I think that the latter doesn't look as messy, perhaps because of the spacing being tighter. Interestingly the title actually takes up more space, because the bold font is heavier. Marvellous.

Random collection of amazing stuff

The most cool thing that I noticed today ever is that Google Maps now allows you to add custom waypoints by dragging-and-dropping the route line onto a given road. This is great! I'm going to a charity biker raffle thing in Pensford next weekend, and Google's usual recommendation is that I stay on the M4 to Bristol, and drive through Bristol towards Shepton Mallet. This is, frankly, ludicrous. It's much more sensible to go through Bath and attack the A37 from the South, and now I can let Google know that.

Trusted JDS is über-cool. Not so much the actual functionality, which is somewhere between being pointy-haired enterprisey nonsense and NSA-derived "we require this feature, we can't tell you why, or what it is, or how it should work, but implement it because I'm authorised to shoot you and move in with your wife" fun. But implementing Mandatory Access Control in a GUI, and having it work, and make sense, is one hell of an achievement. Seven hells, in the case of Trusted Openlook, of which none are achievement. My favourite part of TJDS is that the access controls are checked by pasteboard actions, so trying to paste Top Secret text into an Unrestricted e-mail becomes a no-no.

There does exist Mac MAC (sorry, I've also written "do DO" this week) support, in the form of SEDarwin, but (as with SELinux) most of the time spent in designing policies for SEDarwin actually boils down to opening up enough permissions to stop from breaking stuff - and that stuff mainly breaks because the applications (or even the libraries on which those applications are based) don't expect to not be allowed to, for instance, talk to the pasteboard server. In fact, I'm going to save this post as a draft, then kill pbs and see what happens.

Hmmm... that isn't what I expected. I can actually still copy and paste text (probably uses a different pasteboard mechanism). pbs is a zombie, though. Killed an app by trying to copy an image out of it, too, and both of these symptoms would seem to fit with my assumption above; Cocoa just doesn't know what to do if the pasteboard server isn't available. If you started restricting access to it (and probably the DO name servers and distributed notification centres too) then you'd be in a right mess.

It's update o'clock

In other words, it's "Graham remembers that someone needs to write the interwebs, too" time. The main reason I haven't written in a while is that I'm enjoying the new job, so it's satiating my hacking desires. No hacking projects = nothing to talk about. I can't really talk about the work stuff, either; this is unfortunate because I did some really cool KVC-cheating in a prototype app I wrote, and it'd be a good article to describe that.

I've more or less dropped off the GNUstep radar recently. I still need to talk to the employers' legal eagles in order to update my FSF copyright assignment, and then find something to hack on. Currently I only have a Mac OS X machine so I'd probably switch to some app-level stuff. I have half a plan in my mind for a SOPE app, but despite reading all the documentation I still haven't worked out how to get started :-|. The code isn't too much of a problem, I've used WebObejcts before, but WebObjects has a 'hit this button to build and run your WebObjects code' button, and there's no description AFAICT for SOPE of what to put in the GNUmakefile to get built and running SOPE code, even whether you're supposed to provide your own main() or anything. Hmmm...I wonder if there's a sample project around...

Ich habe mein Handy verloren

Ooops. Left my mobile phone on holiday in Germany when I came back. This may explain why some people who were expecting to hear from me in Germany didn't...anyway, could anyone who thinks I ought to know their phone number please either leave a private comment on this livejournal entry (all comments are private by default on that post), or e-mail me? Thankyou! I promise to buy a filofax which I won't leave in foreign parts.