"I'm increasingly convinced this asynchronous callback style of programming is too difficult for most developers to manage," Robinson said. "Without extreme discipline it can easily lead to 'callback hell,' with deeply nested callbacks and complex code to implement logic that would be simple on a synchronous platform." What's next for him? He sees the older framework being rethought and reworked using the best ideas from Node.js. In place of callbacks, he sees ideas like "promises," "co-routines," "actors," and other objects that hang on to the information in the variables for use later. These objects may be easier to juggle than the callbacks.
Callbacks and promises are not mutually exclusive. In particular, a promise API can be built on top of callbacks. This has been well-understood for a long time in both the Ajax world (e.g. dojo.Deferred), and in Node.js development (e.g. node-promise module by Kris Zyp). So, I think this critique is a bit unwarranted.
Here's the project I worked on for GSoC 2010:
http://commons.apache.org/sandbox/gsoc/2010/scxml-js/
I haven't done a stable release yet, due to some process overhead with Apache Commons, but the project itself is pretty stable, is becoming more widely known, and I'm continuing to develop it as part of my Master thesis.
This was a project I had thought of several years ago, and the funding from GSoC finally enabled me to properly implement it. So, I think that's a success story.
I saw that with libimobiledevice, it's possible to control your iOS device with your Ubuntu desktop, including doing things like installing apps: https://help.ubuntu.com/community/PortableDevices/iPhone
What I'm wondering is, would it now be possible to develop apps for the iPhone from your GNU/Linux desktop, using a free software stack? What I have in mind is something like this: you write the application in C (a strict subset of Objective C), compile it using GCC (targeting ARM architecture?), using headers obtained from the Apple SDK (I suppose GNUStep wouldn't do), and then use libimobiledevice to deploy it to your phone. I suppose this still lacks some important parts, such as a device emulator which can hook back into a debugger, but still I think it's interesting to think about.
Is anyone currently pursuing this kind of work?
I'm going to be heading to Belgium soon on exchange, and so I've been looking into buying an auxiliary device that I can take with me traveling so that I don't have to bring my 7.5 lbs. beast of a laptop. The things that were most important to me were to have decent hardware and overall user experience (touchscreen responsiveness, etc.), the ability to make VoIP calls using Skype or SIP, and to have a decent terminal emulator and Unix-like subsystem (bash, ssh, vi, and GNU screen are most important for me). Ideally, it would also cost around $200 (I'm a student, after all).
What I found was that in order to install a Unix subsystem on an iOS or Android device, you need root access. And, rather than just giving you root access, for some reason all devices, including the Android ones, require you to jailbreak the device via some exploit in the OS. I was expecting this of Apple devices (and I'm still waiting for the jailbreak for iOS 4.1, which should be any day now), but somehow I thought that Android devices would be more "open" or something because they are running Linux. But in fact, they are often, in effect, even more locked down than the Apple devices, as there is not a dedicated team of hackers searching for exploits, and so jailbreak techniques may not exist. For example, this is the case for the new Archos internet tablets, which at this moment may not be jailbroken.
It dawned on me that this was the difference between old-school PDAs (remember those?), and these new handheld iOS and Android devices. With PDAs, I think it was unquestionable that you would have administrator rights on your device. Why? Because they were seen as personal computers that incidentally could also fit in your pocket. Somehow, the expectation of these new devices is not the same - they are seen as phones or media players instead - and for that reason, it is seen as acceptable to lock them down, restricting what the user can do with them. This shift in the expectation of the manufacturer regarding what the user may do with their device seems to have happened very quickly and quietly, perhaps commencing with the release of the iPhone, and it's something that I'm only beginning to grasp now. This is not something that anyone seems to be talking about, however.
Unfortunately, this is a complete deal-breaker for me. I won't be able to buy an Android device until it comes with root access out of the box.
I took notes on my laptop extensively all through my undergraduate degree in Computer Science, and I always used OpenOffice.org Writer's equation editor. It has a nice, concise syntax, and it was, in fact, possible to enter even very complex mathematical expressions in real time, faster than my prof was able to write them on the board. This was true even for matrixes.
Here's an example of some of my notes made with OO.o: http://csus.cs.mcgill.ca/wiki/COMP-330_(Panangaden%2C_Fall_06)_Lectures
My linear algebra notes would be more impressive, because they often involved fairly large and complex matrix equations, but I never made those notes available online.
I had a colleague who also took notes in class who had quite a nice method - he wrote all of his notes in wiki markup, with latex for the mathematical expressions. He didn't have a laptop, but instead used a PDA and small, foldable keyboard.
An example of his notes are here: http://csus.cs.mcgill.ca/wiki/COMP-302_(Panangaden%2C_Pientka%2C_Winter_06)_Lectures
I think it's quite a nice result.
There are two ways to write error-free programs; only the third one works.
