Structure and Interpretation of Computer Programmers

It’s about time someone made a UNIX keyboard for the Mac. I still love my Tactile Pro, and have obviously configured the caps lock key as an additional Control, but that key doesn’t feel like the same buckling spring as the rest so it feels weird when I hit it. I just wonder now whether someone’s going to make a keyboard with a Command key up there. Probably not, they never did for either the earlier Macs or the NeXT. It would be handy to be able to do cut/copy/paste without having to buckle my thumb or little finger under my hand…Matias’ Optimise keyboard looks like it might be efficient but have a confusion curve.

Yesterday I had a little problem with the iBook, which was saved by some age-old knowledge from before the OS X release. Almost.

When I use an external USB mouse, I disable the internal trackpad. Now I wanted to take the computer into a different room in order to watch some TV (on the EyeTV), so unplugged all the USB stuff, plugged the EyeTV in….and the trackpad was still disabled. Now, a lesser person would have gone back into the original room, plugged the USB mouse in, and used it (or taken it with them). An equally lesser, but richer, person would own a Bluetooth mouse. But not I! I remembered a trick from the NeXT days, and returned my computer to trackpad-workingness in but a jiffy. Three jiffies.

The first thing to do is to log out – "as any fule kno" this is done from the keyboard by Command-Option-Shift-Q. At the loginwindow there still wasn’t any trackpad activity, so I thought restarting the WindowServer might fix that. This is done by entering ">exit" as the username in loginwindow. Sadly, no joy. My next thought was to drop to a text console, unload the trackpad’s driver kext, reload it and see what difference that made. Doing so requires entering ">console" as the username. However I decided not to pursue this as >console has been sadly broken throughout 10.4, and on some systems was broken in 10.3 too. It’s annoying as occasional glitches where the graphical environment is FUBARed could probably be fixed in console mode. But this left one course of action. Enter ">restart" in the loginwindow and wait…

I should probably point out that I waited for the reboot longer than it would have taken to retrieve the mouse. But at least I wasn’t defeated.

So I’m reviewing a book, and it happens to cover the way method lookups are performed in a particular language’s object model. I’m not going to say what the book is because it’s not relevant, and nothing discussed here has anything to do with that publication. But reading it made me realise just why even when the language allows it, my internal pain aversion system will always skip multiple inheritance as an option. Consider this Python code (with built-in python shell promptness):

>>> class One(object):
...     def doStuff(self):
...         print "One.doStuff()"
... 
>>> class Two(One):
...     pass
... 
>>> class Three(One):
...     def doStuff(self,x):
...         print "Three.doStuff(%d)" % x
... 
>>> class Four(Two,Three):
...     pass
... 
>>> class Five(Three,Two):
...     pass
... 
>>> a=Four()
>>> b=Five()

so, what is the method signature of a.doStuff() and b.doStuff()? Well, it depends entirely on the order in which the class hierarchy gets inspected, Python does things by leftright-bottomtop so both a and b inherit Three.doStuff(self,x). In the case of a, Four doesn’t have doStuff() so it looks at Two, which doesn’t so it looks at Three and finds it. However, Python also has another lookup mechanism (which was the only one available pre-2.3 or possibly 2.4, and can still be triggered by omitting the “object” superclass from One) which is left-bottomtop-right, so a inherits One‘s doStuff() and b inherits Three‘s. In the words of Peter Cook, that could confuse a stupid person…

So luckily Objective-C avoids this problem by only having an inheritance tree, and we can’t add method implementations via protocols either. And my specific example is moot, because -doStuff and -doStuff: are different selectors.

Bottom of the page, under Media Reviews. I’ve got another couple of review copies sat here, too…

So, they said that Steve Wozniak would be there, and that he’d be signing books. So I took my book to be signed. That wasn’t wrong, was it?

N.B.: yes, I bought a copy of iWoz and had that signed too. But the iBook is cooler ;-)

The people credited with bringing GNUstep support to OCUnit a few versions back (at least one of whom I recognise as a competent programmer who really knows what they’re doing), as the current version just won’t work at all ;-).  It’ll be more future-proof on the Apple platform, as it uses @try/@catch blocks.  However, as I want to use it on the GNU platform, this means a lot of #ifdef __NEXT_RUNTIME__ wrappers and NS_DURING/NS_HANDLER/NS_ENDHANDLER blocks…

In the spirit of My Dream App, I’ve invented my own dream app.  BestAppEvar.app would be able to divine what needs to be done by detecting my brainwaves, and would then do it when I hit the button.  To make it easy for you to implement, I’ve already designed the UI:

So, why hasn’t it been made yet?  Come on, you lazy coders!  The hardest bit would be the brain-computer interface, but there are example I/O Kit projects on the ADC site.

I’m currently having a Vaio VGN-S4M inflicted upon me.  I can’t say I dislike it totally; the X-black screen is rather nice and it has one killer feature in that there’s a (physical) radio kill switch on the front.  However, by and large I do dislike it.  The Centrino wireless jobbery is not fully documented, so only works with a binary blob driver which means it’s useless for most of the operating systems I care about (it doesn’t work in CEntOS, for instance, and I don’t have the luxury of being able to switch to Ubuntu where I’ve heard better results are possible).  It seems to run very hot doing anything (including nothing), so the fan constantly winds up and down.  And it’s a loud little fan.  The whole keyboard seems to bend a little when I press any key (although I’m used to the Tactile Pro, so probably whack a little harder than necessary…)  The only saving grace in the design is that PC manufacturers seem now to be getting over the desire to install legacy ports all over their laptops; but the thing’s still closer to the size of a 14″ iBoko (hi u.c.s.m) than that of its brother, the 13.3″ MacBoko.

So, with a recent cash injection and an ADC hardware discount coupon both burning a hole in my pocket, as well as a desire to crack on with the ObjC 2.0 work on the c.l.o-c FAQ; it seems an Intel Mac and a copy of some virtualisation tech are in order.  The question becomes simple: do I jump now, and get a MacBoko or MacBoko Pro, or do I hold on in case the Core 2 Duo variants are around the corner?  Or I could even combine the two and get an iMac, keeping the Vaio for corridor worrying?  I’m tempted by the “buy now” approach, as I actually need^Wwant a new system now, not in January…

An interesting time if you happen to be an aging startup superserver; Ubuntu are to replace init with Upstart from "Edgy Eft". That’s quite cool, the model in which everything needs to always come up and always in the same order put forward by both styles of init is long dead, and the system V style of init is particularly cumbersome (though someone at Apple clearly liked it, as they had both SystemStarter and watchdog in the past).

I’m actually both surprised and pleased to see a Linux distribution making the jump here, I’ve always considered them fairly conservative (apart from in throwing any old free package into the distribution; I mean from a "core stuff"[*] perspective. I know that FreeBSD attempted something with launchd last Summer, but the latter has too much mach_init magic which can’t cleanly be excised.

[*]now Apple are going to start a CoreStuff API and sue me. Fantastic.

One thing from TFA saddened me (though I really ought to have expected it), and that’s this:

To avoid reinventing the wheel, we first looked at how much effort it would be to use of modify the existing replacements to be able to do this. Sun SMF and Apple launchd were immediately ruled out due to licence issues. It was important for us that the solution be uncontroversially free so that other distributions might adopt it; many had already rejected these for GPL incompatibility reasons.

Yes, it’s the standard "GPL first, utility second" argument. I have a fairly strong opinion here: if something works, and I can see that it works, and it works better than any alternative I have access to, I’ll use it. That’s why I’m posting this from OmniWeb on a Mac, despite [i]there being free web browsers around, [ii]my work involving Linux. I prefer to have access to the source, except where that involves a retrograde step in terms of utility. Anyway, I digress; the point here is that launchd is released under (well, depends which version you look at) the Apache licence, and OpenSolaris under the CDDL; both of which are free software licences, but are incompatible with the GPL on technicalities. That’s nice if you really do want to split hairs, but GNU/Linux (if you like) is supposed to be a usable OS so shouldn’t utility come first? Admit it, how many of you have uninstalled kaffe or gcj and are using the Sun jdk? More to the point, how many of you are using Apache (which is also released under the Apache licence)? It’s time to get over it. I propose that if you want to work on a pure GNU system, you should indeed work on a pure GNU system and hie thineself over to the HURD mailing lists. I fully intend to, if a gobbet of spare time makes itself available soon…but more because I think the HURD’s cool ;-).

You can’t use a java.awt.Color in WebObjects, because to use AWT at all on OS X requires connection to the WindowServer.  And unless you’re mad, you probably aren’t running your WOA as root.  This means I can’t do things like, ooh, I don’t know, making a PDF table have a white border instead of a black one.