Slashdot Mirror
Dijkstra's Manuscripts Available Online
Bodrius writes "Salon has a short but interesting article called GOTO considered joyful, about E. W. Dijkstra's manuscripts, as published by the University of Texas, and their bloggish nature.
I'm not sure if the blog analogy is that accurate, but the articles are a must read for computer scientists and geeks in general." (Annoying but free click-through system for non-subscribers.)
Dijkstra had a very distinctive and very readable handwriting. It certainly influenced mine. I don't know which pens he used, but I do agree there is something about writing stuff by hand. For one, you write slower than you think. And it can be a really meditative experience putting words to paper by hand.
The article states that Dijskstra has said:
"Programming is one of the most difficult branches of applied mathematics; the poorer mathematicians had better remain pure mathematicians."
I do not agree with this. I mean, in pure mathematics there are not much to think about besides mathematics. Programming includes many other aspects, for example creativity. So if you are a poor mathematican but have other qualities that are needed for programming, you would have an easier time doing programming than pure mathemtaics I think.
Well, he started writing in the 1960's, so it was pretty non-trivial to fire up your computer and peck away at a keyboard in some very primitive text editor with (if one were lucky) a tiny amber monochrome display. At the point he started writing his JOURNAL (sorry, i just fucking hate the word "blog"), pen and paper was the easiest, most reliable, and most expediant option (also remember that at that time, mathematicians and engineers were still using slide rules). By the time word processing became a more viable option, he was entrenched in the habit of keeping a paper journal. Furthermore, until the advent of the portable computer, if you wanted to write in your journal regardless of where you were, pen and paper was the only option. Personally, I'd like to see more people keep pen and paper journals; one can tell a lot about people from their handwriting.
my pet machine
His teachings are not language specific.
Yes, Dijkstra is still relevant. That you should think he has anything to do with C++ is strange, and makes me wonder whether you're familiar with Dijkstra's work at all. Take a look at EWD 1243, and you'll see that he thought it was just another one of the messes pushed as the savior of us all. I dare say he'd say the same for Java and C#, which will be the legacy technology of tomorrow.
Dijkstra's work on writing programs so as to be confident in their correctness from the start is very relevant--how much do you think people would be willing to pay for an OS written that way?
> You could change the expiration on the temporary cookie they give you to get perminent access. Of course, this would be illegal.
I was winding myself up to sneer, but then I realized that this would be [circumventing] a technological measure that effectively controls access to a work protected under [Title 17].
While we're at it, remember that "No person shall [...] offer to the public [or] provide [...] any technology [...] or part thereof that is primarily designed or produced for the purpose of circumventing a technological measure that effectively controls access to a work protected under [Title 17]."
Citizen, remain at your console while the Secret Service analyzes the case against you and decides your guilt and an appropriate punishment.
If you were blocking sigs, you wouldn't have to read this.
I study CS @ Eindhoven University, where he came and teached a lot(his and his compatriots were good in programming methodology: http://www.win.tue.nl/pm/ - horrible looking webpage) Trust me, it shows. Most of the 'hardcore' faculty members were friends/exstudents/what have you, and work the way he did. Dijkstra (and the folks at my faculty) did not bother himself with implementations of programming languages. Nor with what function to call for what. They all strive to understand the nature of the problem, and from that they try to derive the solution.
That's a totally different approach to programming, which is a *lot* of work. However, it shows in areas where simplicity is key. There is a reason why Dijkstra used Semaphores (what do you think Java uses?). Or have you ever seen a good proof of Peterson's Algorithm? (I know Feijen and van Gasteren gave a generic derivation in 'On a Method of Multiprogramming', but that's just me having had to read it because it's part of my study there, of course. A book which delves into seemingly simplistic problems, but then gathers a framework which can tackle much bigger problems then you would expect.)
The problems for single-process computing are easy. For those of you who program in them, I'm not trying to critisize or anything (I personally know that it's still damn hard from time to time), but there are no synchronisation problems, for one. To ensure that these are all systematicly handled you'd really want to have a proof that nothing can go wrong. Java and exceptions? Fine, it's just a way to get away with bad programming. There are a lot of places where you simply cannot get away with dirty programming: you don't want your car to deadlock going at 90 MpH, now would you? You want to be absolutely positive that it will *never* happen. THat means having either done extensive testing (which you can only hope it was sufficient), or having formal proof that it cannot go wrong.
That is why Dijkstra held himself to the 'very hard problems'. The easy ones you can mess up with and still have not too much problems. The hard ones are problematic if they fail.
He did not believe in cluttered code. Everything should be there for a reason, should be proven to be there and exactly there for a reason.
To excel in Computer Programming you must be so smart as to be able to tackle the really hard problems. That means tackling problems on the problem field. You don't need languages for that, you need proof. Languages are but a tool for describing a solution and verifying your proof. Some languages describe easier then others, yes, but the solution is the same.
I can write a C to Haskell to C++ to Prolog to Java compiler. Pretty straightforward too. The languages are the same. You just don't want to see the spaghetti which comes out of a program once I'm through with it. And that's the reason why you use a specific language for a solving a problem: some languages simply are much easier to express the solution in.
However, that does NOT solve the problem, it merely makes it easier to program a solution understandibly.
Dijkstra was above all a scientist, and thus had to convince the scientific community of his ideas. This normally is done by using formal methods which describe both the problem as the solution in such a away that they can be easily understood.
That is still the holy grail for may solutions: how can they be written such that they can be understood more easily.
But I'm starting to rant here...
(1) He obviously can't tell the difference between pure and applied mathematics and
That conclusion is not obvious. Given that the real world introduces complications that can be ignored in the world of pure mathematics, his (presumed) premise that "if applied is hard, the weaker might better stick with pure" makes logical sense.
(2) How come all the loser mathematicians who can't hack it end up becoming programmers?.
Both of your premises of "loser" and "can't hack it" are just some sort of pejorative that mean nothing in practice if you're trying to make a logical argument, and the "end up becoming programmers" is patently false. So the statement is just plain empty of value.
I've never had much respect for Dijkstra. I have even less now.
Well, as a personal statement of your dislike for someone, it requires no rational justification and hence cannot be faulted. Whether others will feel a consequent lack of respect for your own self as a result is hard to say, but it's pretty safe to assume that they won't be impressed by your ability to reason.
"The question of whether machines can think is no more interesting than [] whether submarines can swim" - Dijkstra