Kernighan and Ritchie were well aware of Turing completeness. Dennis Ritchie started with Theoretical Computer Science before he wrote his first software (see http://www.gotw.ca/publications/c_family_interview.htm). You can be sure that designing C without Turing Completeness would have been for them like designing a car without tires.

Languages without Turing Completeness only make sense only in special applications because they are so limited (e.g. the C PreProcessor is not Turing Complete unless you use it recursively).

One of the marvels of the Turing machine is that it is so simple (you can describe what a Turing machine does on 2-3 pages) but it is as powefull in expression as modern languages with specification of thousands of pages are.

A lot of coders have no idea about the theories behind it. That is why a lot of code sucks. It's not the lack of Turing machines but on the theories that are connected to it (e.g automata theory, complexity theory).

What you are saying is like: I am tiler, i never check the foundation when i am building the roof, so it can't be important ;-).

You can make a living as a coder without all that knowledge. More than half of the coders do. But if you look at the people who shape the world of software (like Dennis Ritchie, Linus Torvalds, James Gosling, etc), you will notice they all are well versed in the area of computer science theories.

P.S. Concerning AI and Turing Test: computer games have no AI. The producers of computer games call their software opponents AI, but they are a collection heuristical algorithms cobbled together.

When you are playing agains an opponent, you can usually tell easily wether this is a computer or not. In fact, you are conducting a Turing Test then and the other side fails usually miserably.

I cannot blame you for not seeing it. I studied the theories for five years and thought them dull and boring. Then, after decades of having to work on real world problems, it hit me. Nowadays i can e.g. look at code or database designs and easily recognise coders who have understood the theories and those who didn't.

Not understanding the theoretical background will put and upper limit to anyones capabilities as a coder. This is like being restricted in World of Warcraft to Level 20: some skills in the skill tree will remain out of reach no matter the grinding.

The best way to illustrate the genius of Turing is: he saw computers coming before the first one ever being built. He developed a trivial "assembler language" (Turing machine) that is so powerfull that no computer and no programming language built today can compute something his machine could not.

When he was finished with that, he thought not about calculations (as the opposite German genius Konrad Zuse did) but of processing symbols. He thought of computer code being processed by computer code and thereby inventing compilers and interpreters without having a name for it yet.

Then he interpolated the capabilities of those (not yet existing) machines and recognised that they would appear to have some kind of artificial intelligence and started thinking about how to tell computers and humans apart (60 years before the first SPAM was sent).

Looking back, having all the tools already on your fingertips, all this may sound trivial. But to achieve only 1% of his visionary power, i would have to grow by several orders of magnitude.

C is Turing complete for all practical purposes.

The idea behind Turing complete is more complicated. It's about what kind of ideas you can formulate.

a) If you can do everything in C you can do with a Turing machine and vices versa and
b) you do the same thing for an exotic language (let's thay Haskell)

you have proven that C and Haskell can solve the same kind of problems (there is no problem you can solve in C but not in Haskell).

That is why the idea of quantum computing is so interesting. It would be the first kind of programming that may achieve solving a problem that may not be solved with a Turing machine. Until now, Turing has de facto established an upper boundary for computability until know.

The next thing is that Turing proved that there is no Turing machine that could determine for any other Turing machine if it ever comes to a stop in finite time.

Combining with the statement above says: There is no C program that could analyse every C program completely in finite time.

It's a simplified version of what Turing called the "halting problem".

The astounding thing is: he found out a lot of things about modern computers without ever having seen one. The theories came first. It's like Newton discovering gravitation without seeing apples falling first.

He has made a lot of contribtion to the basic theories, especially on the topic of computability,

A basic test for any programming language is (even today) if it is Turing complete. If you can implement a Turing machine (a theoretical universal computer) in a language, you can implement any problem that is computeable in that language and therefor the language is Turing complete.

This should have happened decades ago. Since the 70s his contribution to winning the WWII are known and there are very, very few humans that can rival his impact.

Instead of moderation, we have a mob.

No, the time bomb are people still running XP....

I gave my mother an iPad as "additional" device as a present. Soon afterwards, PC useage and resulting problems dropped by 80-90%. Very good investment...

Disclaimer: Not everything is perfect with an iPad for seniors (e.g. maximum font size is still too small, most apps ignore setting anyway). But even with 73 years she took to the device like a duch to water. A 13'' or even 15'' tablet would be a better choice for older people.

Hi,

thanks for bringing this topic up on Slashdot. I am currently looking into this too, but with another challenge on top. A relative of mine (80+ years) is going to be blind too. And he is looking for technology to help him cope with blindness.

A tablet with voice control and output would be a good solution (IMHO). Has anyone experiences with that?

From my first glance, the support in IOS for visually impaired is higher, but i may be wrong with that and the openess of Android may enable better 3rd-party tools enhancing that experience. Can you give me your input?

It is a pity, that those displays with tactile feedback are not here yet.

Thanks for any hint, Martin

Good news everyone: if you refrain from bitching about the ?SA on Slashdot, you will be allowed to board faster. Thank you for your cooperation :-(.

Actually i think, gaming is what currently keeps the PC industry alive (in the sense of innovation happening). From the enterprise perspective, the development mostly happens in the software. The would still use the PC from 2008 if they had more RAM. In fact, i know several companies where the average age of the PC infrastructure is 4+ years old and they are not unhappy with it.

I had once the idea to spin a story that the NSA had nude pictures of a celeb and anyone could get them with a FOIA request ;-). But that would be too evil.

12600 Links according to Google News ;-)

What do you expect from journalism?

As long as a story about Lindsay Lohans latest rehab draws ten times as much readers as some background article about the NSA spying capabilities while being less risky at the same time, the development is clear.

Do you really expect someone to risk the ire of that organisation that can dig (or make) up your dirtiest secrets in order to get less readers? You have to be an idealist or crazy (or preferably both) to do so.

I would not use the wording some others did, but i also am disappointed. The focus on additional funding which appeared over the time was not perceived from the initial project brief.

Clang has a great vision. Such visions can fail. But that would not create any disappointment from my side. That is the purpose of Kickstarter: to fund risky projects. My disappointment was created by what i perceived a creeping change of the project direction: from a game production into creating a startup company. The second i would have never backed via Kickstarter.

Getting funds from investors is (i know this very well from my own experiences) a very expensive business. I would ask Subutai here to create some transparency on how the Kickstarter funds were allocated. IMHO those funds were earmarked for the software R&D (and overhead) but not funding aquisition or marketing.

I ask for this because the state of the demo (from my perspective) does not reflect an investment of roughly 450K$. Other projects achieved much more output with a small percentile of the funding Clang has received. The demo resembles something cobbled together in a hurry and with little effort.

It may be, that i am overly critical and unfair. But after backing 60+ projects, Clang is the one where my expectations and the visible results differ the most. I have no idea where the money (of which i provided only a very small part) went.