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Edsger Dijkstra carried computer science on his shoulders (2020)

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Re: Edsger Dijkstra carried computer science on his shoulders (2020)

#11

Post by photonthug »

psychoslave wrote: post #7

Ok, the first thought reading the title was "ah, surely this is about Dijkstras." The immediate second thought that came was the famous quote “I don't know how many of you have ever met Dijkstra, but you probably know that arrogance in computer science is measured in nano-Dijkstras”, from Alan Kay should I believe https://www.goodreads.com/quotes/69528-i-don-t-know-how-many...

Hmm, time will tell on this rivalry. OOP may not be as harmful as GOTO, but it does seem to be falling out of favor. Dijkstras point of view may be as vindicated with one as with the other.

Re: Edsger Dijkstra carried computer science on his shoulders (2020)

#12

Post by Uehreka »

litenboll wrote: post #10
sambalbadjak wrote: post #9

I like Dijkstra's quote: "The question of whether machines can think is about as relevant as the question of whether submarines can swim."

Maybe I'm stupid, but does he mean that as long as the task at hand is solved it doesn't matter how we categorize it. In the submarine case it would be "move through water", for example. Or is it deeper than that?

> does he mean that as long as the task at hand is solved it doesn't matter how we categorize it.

Yes

Re: Edsger Dijkstra carried computer science on his shoulders (2020)

#15

Post by Animats »

NhanH wrote: post #5
sspiff wrote: post #2

I read this title and automatically assumed this was going to be about Dijkstra. While perhaps less directly impactful on the industry, in computer science teaching and academia, there are few names who loom as large as his. He has touched so many aspects of computer science that we now consider fundamental.

The whole structured programming practically birthed the industry, so it’s hard to say he has less direct impact in the industry though.

It was controversial at the time.

Dijkstra advocated "single entry, single exit" for each control block. Programs should be composed of such blocks. Makes for very neat flowcharts. Good for entry and exit conditions.

Single entry wasn't that controversial. Single exit, though, means no "break", or "continue" for loops, and no early returns from functions. This forces a rather convoluted style. Try writing a loop of the form "get thing, if done quit, process thing, put thing" in that style. You have to have two calls to "get thing", or extra flags.

Turns out you don't need that for program proofs, once you have machine assistance to make sure all the cases were covered. It makes for cleaner hand proofs, though.

(I never met Dijkstra. Knew people who worked with him.)

Re: Edsger Dijkstra carried computer science on his shoulders (2020)

#16

Post by rcbdev »

Dijkstra is a wonderful source of memorable quotes and hot takes from the early days of software.

A sampling:

> “The competent programmer is fully aware of the limited size of his own skull. He therefore approaches his task with full humility, and avoids clever tricks like the plague.” (Dijkstra, 1972)

> “The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offense.” (Dijkstra, 1982)

> “Object-oriented programming is an exceptionally bad idea which could only have originated in California.” (Dijkstra, 1989)

Re: Edsger Dijkstra carried computer science on his shoulders (2020)

#17

Post by Hendrikto »

photonthug wrote: post #6

Lots of interesting threads to chase down but this biographical piece was cool: > together with his wife, he purchased a Volkswagen bus, dubbed the Touring Machine, which they used to explore national parks Maybe not so surprising for a guy who would not indulge in a vcr, cinema, smartphone or even a computer :) more info would be neat if anyone knows from a longer biographic. Photographer? Bird watcher? Hiker? Campe…

Smartphones were not even a thing during his lifetime.

Re: Edsger Dijkstra carried computer science on his shoulders (2020)

#19

Post by photonthug »

Hendrikto wrote: post #17
photonthug wrote: post #6

Lots of interesting threads to chase down but this biographical piece was cool: > together with his wife, he purchased a Volkswagen bus, dubbed the Touring Machine, which they used to explore national parks Maybe not so surprising for a guy who would not indulge in a vcr, cinema, smartphone or even a computer :) more info would be neat if anyone knows from a longer biographic. Photographer? Bird watcher? Hiker? Campe…

Smartphones were not even a thing during his lifetime.

OP does say mobile phone. But you're wrong according to Wikipedia.. some 5-10 years of overlap depending on what qualifies as smart

Re: Edsger Dijkstra carried computer science on his shoulders (2020)

#20

Post by tristramb »

psychoslave wrote: post #7

Ok, the first thought reading the title was "ah, surely this is about Dijkstras." The immediate second thought that came was the famous quote “I don't know how many of you have ever met Dijkstra, but you probably know that arrogance in computer science is measured in nano-Dijkstras”, from Alan Kay should I believe https://www.goodreads.com/quotes/69528-i-don-t-know-how-many...

I think Peter Medewar once said of James Watson and Francis Crick that "they have done somthing worth being arrogant about".

The same applies to Dijkstra.

You could start with this account of the Dijkstra-Zonneveld Algol 60 compiler written by Kruseman Aretz: https://ir.cwi.nl/pub/4155.

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