6 ms·

APL is the only language I've ever dreamt about writing (as in: I could see the characters); I'd dreamt about programming in the past, but those dreams were usu

by adregan 5mo ago

APL is the only language I've ever dreamt about writing (as in: I could see the characters); I'd dreamt about programming in the past, but those dreams were usually what I would categorized as a nightmare—desperately trying to fix a bug that I couldn't figure out. Due to my affinity for the language, and my wish to have worked in its heyday (would love to have an APL gig someday), I have been exposed to various writings and recordings of Ken Iverson. I've also been exposed to a few of Dijkstra's thoughts on APL. I have to say that Iverson generally comes across as a very generous and curious individual while Dijkstra seems to have been a miserable ass. Maybe, given the lens, I've not given Dijkstra a proper chance to demonstrate a more positive attitude, so I'm open to any suggestions of writings where he doesn't seem like such a grump.

mlajtos 5mo ago
> Maybe, given the lens, I've not given Dijkstra a proper chance to demonstrate a more positive attitude, so I'm open to any suggestions of writings where he doesn't seem like such a grump. Kinda hard to find where Dijkstra praised something (except Algol 60). One funny example: he called FORTRAN "an infantile disorder", though he said this about the team behind it: "At that time this was a project of great temerity and the people responsible for it deserve our great admiration.". On LISP: "LISP has jokingly been described as 'the most intelligent way to misuse a computer'. I think that description is a great compliment because it transmits the full flavor of liberation: it has assisted a number of our most gifted fellow humans in thinking previously impossible thoughts." Alan Kay on Dijkstra: "Arrogance in computer science is measured in nano-dijkstras."
- tristramb 5mo ago
  "Kinda hard to find where Dijkstra praised something (except Algol 60)." Hamilton Richards, who was one of Dijkstra's colleagues at the University of Texas, told me in an email that Dijkstra was impressed by the work of Richard Bird on functional programming.
  - mlajtos 5mo ago
    Interesting. Bird-Meertens formalism? That was directly influenced by APL. In the broader scope — algebra of programs — Dijkstra heavily disliked Backus’ FP.
- layer8 5mo ago
  Alan Kay elaborating on that quote: https://news.ycombinator.com/item?id=11796557#11799963 https://news.ycombinator.com/item?id=11796557#11799963 “This quote keeps on showing up out of context. […]”
rramadass 5mo ago
Your comments on Dijkstra are blasphemous ;-) I often see a lot of folks here on HN who are too eager to pass judgement on Dijkstra without having read and understood his writings nor giving much thought to the context and times which shaped his thinking. All of his opinions should be thought over and appropriately adapted for use in our context. He was a wide-ranging polymath philosopher (technical and non-technical) with a laser-like focus on exactitude using Mathematics. Radical approaches must be pushed, particularly when they are hard/difficult to learn and understand. If his language was biting, then it was so much the better for promulgating his cause viz. "correctness over easy", "mathematical reasoning underpinning everything", "structure in aid of the previous", "proper language syntax/design in aid of the previous" etc. As an example; read EWD 1036: On the cruelty of really teaching computing science (https://www.cs.utexas.edu/~EWD/transcriptions/EWD10xx/EWD1036.html https://www.cs.utexas.edu/~EWD/transcriptions/EWD10xx/EWD103...) in entirety and carefully. The thesis is that computing is "radically novel" from other forms of human endeavour and hence it cannot be taught by simplifying to known analogues and adhoc procedural operations. You need the rigor and exactitude of Mathematical Logic to build a "Scientific" basis. Excerpts: ... What is a program? ... I prefer to describe it the other way round: the program is an abstract symbol manipulator, which can be turned into a concrete one by supplying a computer to it. After all, it is no longer the purpose of programs to instruct our machines; these days, it is the purpose of machines to execute our programs. So, we have to design abstract symbol manipulators. We all know what they look like: they look like programs or —to use somewhat more general terminology— usually rather elaborate formulae from some formal system. It really helps to view a program as a formula. Firstly, it puts the programmer's task in the proper perspective: he has to derive that formula. Secondly, it explains why the world of mathematics all but ignored the programming challenge: programs were so much longer formulae than it was used to that it did not even recognize them as such. Now back to the programmer's job: he has to derive that formula, he has to derive that program. We know of only one reliable way of doing that, viz. by means of symbol manipulation. And now the circle is closed: we construct our mechanical symbol manipulators by means of human symbol manipulation. ...The point to get across is that if we have to demonstrate something about all the elements of a large set, it is hopelessly inefficient to deal with all the elements of the set individually: the efficient argument does not refer to individual elements at all and is carried out in terms of the set's definition. ... Back to programming. The statement that a given program meets a certain specification amounts to a statement about all computations that could take place under control of that given program. And since this set of computations is defined by the given program, our recent moral says: deal with all computations possible under control of a given program by ignoring them and working with the program. We must learn to work with program texts while (temporarily) ignoring that they admit the interpretation of executable code. Another way of saying the same thing is the following one. A programming language, with its formal syntax and with the proof rules that define its semantics, is a formal system for which program execution provides only a model. It is well-known that formal systems should be dealt with in their own right, and not in terms of a specific model. And, again, the corollary is that we should reason about programs without even mentioning their possible "behaviours". ... a program is no more than half a conjecture. The other half of the conjecture is the functional specification the program is supposed to satisfy. The programmer's task is to present such complete conjectures as proven theorems. He then goes on to describe the importance of teaching Predicate Calculus via a simple imperative language where its semantics are given by proof rules. This language is described in EWD 472: Guarded commands, non-determinacy and formal derivation of programs - https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD472.html https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD472... There is no compiler for this language and so the student is forced to implement the program and its proof by hand. However this radical approach is not being accepted by educationists/industry. He concludes; Teaching to unsuspecting youngsters the effective use of formal methods is one of the joys of life because it is so extremely rewarding. Within a few months, they find their way in a new world with a justified degree of confidence that is radically novel for them; within a few months, their concept of intellectual culture has acquired a radically novel dimension. To my taste and style, that is what education is about. Universities should not be afraid of teaching radical novelties; on the contrary, it is their calling to welcome the opportunity to do so. Their willingness to do so is our main safeguard against dictatorships, be they of the proletariat, of the scientific establishment, or of the corporate elite.
broken-kebab 5mo ago
He liked to make fun of emerging CS, it was his thing, and he did it pretty well. He wasn't "miserable ass", he was a man of different culture. "Positive attitude" as you used it is a late americanism FWIW. In many parts of the world we often bring our criticisms in similar caustic manner, and we enjoy it while being resilient and optimistic. It doesn't mean that he was always right, of course.
- adregan 5mo ago
  I suppose the thing that stuck in my craw is what I perceived as a personal slight: > Your writings made me wonder in which discipline you got your doctor’s degree. It’s ambiguous, so I can give the benefit of the doubt. However, if intended as an insult, I believe that goes beyond speaking frankly about one’s feelings about a programming language in a manner consistent with one’s culture.
  - broken-kebab 5mo ago
    I see what you mean, and in fact I'm sure it is an insult. However, sensitivity to it is still a matter of particular culture-time. Some cultures tend to consider such things to be an attack against someone's social status no matter what context. Others may take them as banter, or emotional coloring if you like. Another example: Americans seemingly normalized public swearing using what was originally sex-related slang, while in many other cultures it is a very-very dangerous minefield. And let's not forget that the whole field at that time was orders of magnitude smaller, which implies less formal spectrum of accepted styles of communication.

by adregan 5mo ago

mlajtos 5mo ago

> Maybe, given the lens, I've not given Dijkstra a proper chance to demonstrate a more positive attitude, so I'm open to any suggestions of writings where he doesn't seem like such a grump. Kinda hard to find where Dijkstra praised something (except Algol 60). One funny example: he called FORTRAN "an infantile disorder", though he said this about the team behind it: "At that time this was a project of great temerity and the people responsible for it deserve our great admiration.". On LISP: "LISP has jokingly been described as 'the most intelligent way to misuse a computer'. I think that description is a great compliment because it transmits the full flavor of liberation: it has assisted a number of our most gifted fellow humans in thinking previously impossible thoughts." Alan Kay on Dijkstra: "Arrogance in computer science is measured in nano-dijkstras."

tristramb 5mo ago
"Kinda hard to find where Dijkstra praised something (except Algol 60)." Hamilton Richards, who was one of Dijkstra's colleagues at the University of Texas, told me in an email that Dijkstra was impressed by the work of Richard Bird on functional programming.
- mlajtos 5mo ago
  Interesting. Bird-Meertens formalism? That was directly influenced by APL. In the broader scope — algebra of programs — Dijkstra heavily disliked Backus’ FP.
layer8 5mo ago
Alan Kay elaborating on that quote: https://news.ycombinator.com/item?id=11796557#11799963 https://news.ycombinator.com/item?id=11796557#11799963 “This quote keeps on showing up out of context. […]”

rramadass 5mo ago

Your comments on Dijkstra are blasphemous ;-) I often see a lot of folks here on HN who are too eager to pass judgement on Dijkstra without having read and understood his writings nor giving much thought to the context and times which shaped his thinking. All of his opinions should be thought over and appropriately adapted for use in our context. He was a wide-ranging polymath philosopher (technical and non-technical) with a laser-like focus on exactitude using Mathematics. Radical approaches must be pushed, particularly when they are hard/difficult to learn and understand. If his language was biting, then it was so much the better for promulgating his cause viz. "correctness over easy", "mathematical reasoning underpinning everything", "structure in aid of the previous", "proper language syntax/design in aid of the previous" etc. As an example; read EWD 1036: On the cruelty of really teaching computing science (https://www.cs.utexas.edu/~EWD/transcriptions/EWD10xx/EWD1036.html https://www.cs.utexas.edu/~EWD/transcriptions/EWD10xx/EWD103...) in entirety and carefully. The thesis is that computing is "radically novel" from other forms of human endeavour and hence it cannot be taught by simplifying to known analogues and adhoc procedural operations. You need the rigor and exactitude of Mathematical Logic to build a "Scientific" basis. Excerpts: ... What is a program? ... I prefer to describe it the other way round: the program is an abstract symbol manipulator, which can be turned into a concrete one by supplying a computer to it. After all, it is no longer the purpose of programs to instruct our machines; these days, it is the purpose of machines to execute our programs. So, we have to design abstract symbol manipulators. We all know what they look like: they look like programs or —to use somewhat more general terminology— usually rather elaborate formulae from some formal system. It really helps to view a program as a formula. Firstly, it puts the programmer's task in the proper perspective: he has to derive that formula. Secondly, it explains why the world of mathematics all but ignored the programming challenge: programs were so much longer formulae than it was used to that it did not even recognize them as such. Now back to the programmer's job: he has to derive that formula, he has to derive that program. We know of only one reliable way of doing that, viz. by means of symbol manipulation. And now the circle is closed: we construct our mechanical symbol manipulators by means of human symbol manipulation. ...The point to get across is that if we have to demonstrate something about all the elements of a large set, it is hopelessly inefficient to deal with all the elements of the set individually: the efficient argument does not refer to individual elements at all and is carried out in terms of the set's definition. ... Back to programming. The statement that a given program meets a certain specification amounts to a statement about all computations that could take place under control of that given program. And since this set of computations is defined by the given program, our recent moral says: deal with all computations possible under control of a given program by ignoring them and working with the program. We must learn to work with program texts while (temporarily) ignoring that they admit the interpretation of executable code. Another way of saying the same thing is the following one. A programming language, with its formal syntax and with the proof rules that define its semantics, is a formal system for which program execution provides only a model. It is well-known that formal systems should be dealt with in their own right, and not in terms of a specific model. And, again, the corollary is that we should reason about programs without even mentioning their possible "behaviours". ... a program is no more than half a conjecture. The other half of the conjecture is the functional specification the program is supposed to satisfy. The programmer's task is to present such complete conjectures as proven theorems. He then goes on to describe the importance of teaching Predicate Calculus via a simple imperative language where its semantics are given by proof rules. This language is described in EWD 472: Guarded commands, non-determinacy and formal derivation of programs - https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD472.html https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD472... There is no compiler for this language and so the student is forced to implement the program and its proof by hand. However this radical approach is not being accepted by educationists/industry. He concludes; Teaching to unsuspecting youngsters the effective use of formal methods is one of the joys of life because it is so extremely rewarding. Within a few months, they find their way in a new world with a justified degree of confidence that is radically novel for them; within a few months, their concept of intellectual culture has acquired a radically novel dimension. To my taste and style, that is what education is about. Universities should not be afraid of teaching radical novelties; on the contrary, it is their calling to welcome the opportunity to do so. Their willingness to do so is our main safeguard against dictatorships, be they of the proletariat, of the scientific establishment, or of the corporate elite.

broken-kebab 5mo ago

He liked to make fun of emerging CS, it was his thing, and he did it pretty well. He wasn't "miserable ass", he was a man of different culture. "Positive attitude" as you used it is a late americanism FWIW. In many parts of the world we often bring our criticisms in similar caustic manner, and we enjoy it while being resilient and optimistic. It doesn't mean that he was always right, of course.

adregan 5mo ago
I suppose the thing that stuck in my craw is what I perceived as a personal slight: > Your writings made me wonder in which discipline you got your doctor’s degree. It’s ambiguous, so I can give the benefit of the doubt. However, if intended as an insult, I believe that goes beyond speaking frankly about one’s feelings about a programming language in a manner consistent with one’s culture.
- broken-kebab 5mo ago
  I see what you mean, and in fact I'm sure it is an insult. However, sensitivity to it is still a matter of particular culture-time. Some cultures tend to consider such things to be an attack against someone's social status no matter what context. Others may take them as banter, or emotional coloring if you like. Another example: Americans seemingly normalized public swearing using what was originally sex-related slang, while in many other cultures it is a very-very dangerous minefield. And let's not forget that the whole field at that time was orders of magnitude smaller, which implies less formal spectrum of accepted styles of communication.