The Manuscripts of Edsger W. Dijkstra

Post by OptionOfT » Mon, Nov 10, 2025, 5:18 AM UTC

braincat31415 wrote: post #78

adrian_b wrote: post #71

Earlier quoted context omitted.

One should always use a single kind of half-open range, i.e. with the start closed and the ending open. The whole point here is to use a single kind of range, without exceptions, in order to avoid the errors caused by using the wrong type of range for the context. For backwards iteration the right range is [-1,-1-n), i.e. none of those listed by you. Like for any such range, the number of accessed elements is the dif…

What would you do if your array is so large that it requires an unsigned int64 index?

Post by commandersaki » Mon, Nov 10, 2025, 5:47 AM UTC

4b11b4 wrote: post #10

I really enjoyed the this one: Some meditations on Advanced Programming https://www.cs.utexas.edu/~EWD/transcriptions/EWD00xx/EWD32.... As I'm currently in a Functional Programming course in Haskell... This resonated. I know that we'll always need to write programs which directly interface with memory. However, when we don't need to do that... Maybe we shouldn't write programs in this style (i.e. imperative). Maybe w…

Post by rramadass » Mon, Nov 10, 2025, 6:47 AM UTC

webdevver wrote: post #60

the only meaningful contribution this guy made was his prose. certainly a talented constructor of sentences, i could never write as precisely as him. but as far as meaningful technical contributions, i struggle to find anything. his path search algorithm, no offence, is self-evident. for all the disdain he appears to have had for (what we now call) the 'move fast and break things' style of engineering/science, they w…

  1) Algol60 language/compiler 
  2) THE Operating System 
  3) Graph Algorithms (shortest-path etc.) 
  4) Concurrent Algorithms (semaphores, CSP etc.) 
  5) Distributed Algorithms (dining philosophers etc.)
  6) Fault-Tolerant Computing (which he called "Self-Stabilizing Systems") 
  7) Programming Language Design (GCL etc.) 
  8) Structured Programming Techniques. 
  9) Program Correctness Methodologies based on Predicate Calculus to derive Programs (weakest-precondition etc.)
  10) Essays giving insights into "How to Think and Reason Systematically" using commonsense and mathematical Tools.

Post by zkmon » Mon, Nov 10, 2025, 7:43 AM UTC

oh_my_goodness wrote: post #72

zkmon wrote: post #59

Earlier quoted context omitted.

If they use letters instead of numbers, note that letter "A" is the first alphabet, not zeroth alphabet.

When I'm counting letters it's more convenient to go "one, two, three." When I'm finding the offset between letters it's more convenient to go "zero, one, two." Neither of these methods is going to displace the other. Definitions are fine, and I agree that "A" is the first letter. But that's no use to people who need to think clearly about the offset between "A" and "C" right now. Should I tell them they're wrong, th…

Post by Scarblac » Mon, Nov 10, 2025, 8:46 AM UTC

torben-friis wrote: post #34

Completely silly fact: knowing 0 about the guy except that he gave his name to the famous algorithm, I had somehow assumed he was Indian. Weird to see a white Dutchman in the picture.