6 ms·

A Letter from Dijkstra on APL (1982)

71 points by tosh 6mo ago

Hendrikto 6mo ago
Ironically, I think the examples given in the post validate Dijkstra’s points, instead of disproving them, as the author intended.
- bear8642 6mo ago
  How so? I'm struggling to see how Roger's manipulation of the expressions without executing each line validates Dijkstra's point...
  - empath75 6mo ago
    "This is easy to understand, see:" 5 lines of completely inscrutable symbols follow. If you are expecting someone to learn a completely new notational language before you can communicate a basic algorithm, you have gone wrong somewhere. You could also similarly write down merge sort in pure lambda calculus, which is interesting as an exercise, but not especially useful as working code, or as a way to explain how merge sort works.
wood_spirit 6mo ago
The opening paragraphs about how people enamoured by a shiny gadget will overlook a terrible interface brings immediately to my mind the modern day LLMs.
- dsecurity49 6mo ago
  [dead]
- asdfasgasdgasdg 6mo ago
  I don't find this observation of Djikstra's to be one of his best. If there is a gadget that does a thing that no other gadget does, what does it even mean for the interface to be "terrible?" How can you even know if the interface is terrible, given that a better one has yet to be invented? Maybe the interface is as good as it can be for the tool in question. I also don't love your mapping of this observation onto modern LLMs. The interface of an LLM is natural language text, along with some files written in plain text or markdown. Can it be improved? Undoubtedly! But as a baseline, it doesn't seem half bad to me. If it is so terrible, it should not be hard to propose an interface that will be significantly more productive. Can you?
  - empath75 6mo ago
    > If there is a gadget that does a thing that no other gadget does, what does it even mean for the interface to be "terrible?" How can you even know if the interface is terrible, given that a better one has yet to be invented? Maybe the interface is as good as it can be for the tool in question. That's just a taste judgement, and you can decide the interface sucks on a one of a kind item quite easily, and people often do.
Almondsetat 6mo ago
One can appreaciate striving for simplicity (a programming language that can be taught and explained with pen and paper), but one must also consider that computers are meta-devices. Before computers, we could write things only on paper, either with our hands or a typewriter. So, naturally, when computers came about, the way of thinking about programming was very text-driven, with an emphasis on what a typewriter could represent. But then, code could be written directly with computers, opening up more typesetting possibilities thanks to keyboards not being bound anymore by the mechanical limitations of typewriters. You could add keys and combinations to your heart's desire, and they would be natively digital and unlimited. Now, with graphics, both 2D and 3D, and a myriad or other HIDs, shouldn't we try to make another cognitive jump?
- deleted 6mo ago
  [deleted]
- VorpalWay 6mo ago
  We do have syntax highlighting these days. And our editors work like hypertext, where I can go to definitions, find usages, get inheritance hierarchies etc. Quite a ways from your suggestion, but also a few steps removed from a type writer. I think any such leap would have to be a really big one to catch on though, due to inertia. Colorforth is not exactly popular, and I can't think of any other examples.
  - jmalicki 6mo ago
    With LLMs you can write your code by hand drawing a diagram on a touch screen.
    - ModernMech 6mo ago
      This has been possible since Sketchpad in 1963.
      - WillAdams 6mo ago
        Yes, but there don't seem to be any current implementations which are more than academic exercises (I'd love to be wrong about that and be pointed to something which I could try).
shrubble 6mo ago
I wonder if EWD would have had the same opinion if he were alive today, with every Unicode font having the APL characters immediately available on the screen. Did he feel the language design was bad, or would having TTF fonts being able to show "rho", "iota", "grade up" have removed one or more of his objections?
- mlajtos 6mo ago
  Oh, he would definitely hate it even more. It was too high-level for his taste. What I would like to know is how he would bend Algol 60 if he had tablet with pencil that could evaluate it in real-time.
  - Jtsummers 6mo ago
    > It was too high-level for his taste. That's a pretty silly claim. Is Haskell not high-level? https://www.cs.utexas.edu/~EWD/transcriptions/OtherDocs/Haskell.html https://www.cs.utexas.edu/~EWD/transcriptions/OtherDocs/Hask... Someone happy to see Haskell used in freshman CS education is not someone who opposes high-level languages.
    - mlajtos 6mo ago
      Very interesting flip! For much of his life, Dijkstra opposed functional programming. He even more strongly criticised FP from Backus and APL from Iverson, which are both very funcional/function-level. As he said, Java is a mess and any sensible person would oppose the switch from Haskell to Java. I am almost sure he never used any of them. Might have read about them, but highly doubt he run any on computer. As for the high-level status of Haskell and APL — both languages are very mathematical. Haskell goes very into the abstract realm of computation, while APL tackles very raw form of computation. Semantically, Haskell is way more high-level. In terms of economy of notation and unified concepts, APL has no match.
      - deleted 6mo ago
        [deleted]
adregan 6mo 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 6mo 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 6mo 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 6mo ago
      Interesting. Bird-Meertens formalism? That was directly influenced by APL. In the broader scope — algebra of programs — Dijkstra heavily disliked Backus’ FP.
mlajtos 6mo ago
Dijkstra's go-to language (pun intended) was Algol 60 (& Pascal) – everything else was shit in his view. Some of his comments: FORTRAN — "an infantile disorder" COBOL — "the use of COBOL cripples the mind" BASIC — students exposed to it are "mentally mutilated beyond hope of regeneration" PL/I — "the fatal disease" APL — "a mistake, carried through to perfection" He liked his languages and programs to be easily traceable with pen & paper. He always wrote programs on the paper (and proved correctness) and only then into computer. REPL-driven development (what APL pioneered) was a foreign concept to him. He would be so appalled by LLM code generation.
- tristramb 6mo ago
  He liked to be able to reason about programs without running them. He preferred simpler languages because they contain less irrelevant noise which got in the way of that.
- ilayn 6mo ago
  Read the sources carefully. Fortran quote is not his; he quoted it. Also remember that he was talking about pre-Fortran77 era. F77 tried to fix some of the criticisms though did not succeed fully. Here is a nice dig-in about the quote https://limited.systems/articles/dijkstra-fortran/ https://limited.systems/articles/dijkstra-fortran/ Another note to remember that John Backus, the team lead of the Fortran gang, was in the Algol committee. So these folks knew what they are talking about and spoke to each other periodically. Even John Backus said, Fortran is not the final interface that we should have. It keeps spinning in the programming circles half-quoted versions of half-baked quotes from original sources. These pioneers, even when they disagreed, had pretty precise arguments and very rarely feeling the feelies.
  - mlajtos 6mo ago
    https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD498.html https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD498... – How do we tell truths that might hurt? 1975 FORTRAN —"the infantile disorder"—, by now nearly 20 years old, is hopelessly inadequate for whatever computer application you have in mind today: it is now too clumsy, too risky, and too expensive to use. He told the truth and in turn Fortran corrected its course, but Dijkstra probably didn't change his mind about it. --- > These pioneers, even when they disagreed, had pretty precise arguments and very rarely feeling the feelies. The feud between Backus and Dijkstra kinda persuaded me of the opposite. https://medium.com/@acidflask/this-guys-arrogance-takes-your-breath-away-5b903624ca5f https://medium.com/@acidflask/this-guys-arrogance-takes-your...
deleted 6mo ago
[deleted]
garyrob 6mo ago
I wrote a lot of APL for my undergraduate Senior Project in 1978/1979. I really enjoyed it because it was fun. You could do an incredible amount of work in a single line of code. The only problem was, that line would then be almost impossible to read and understand! It could easily be used as a "write-only" language even without a separate obfuscation step. When I become a professional programmer right after college, I never used it again, and learned to write code that was readable above all else.
- WillAdams 6mo ago
  Is this an instance of the maxim that one has to be twice as smart to debug code as to write it? Are you aware of any APL programs written using Literate Programming? Apparently there was at least one attempt: Lee J. Dickey. Literate programming in APL and APLWEB. APL Quote Quad, 23(4):11–??, June 1, 1993. CODEN APLQD9. ISSN 0163-6006. Perhaps that additional layer of documentation would help? (APL is a language I've always been fascinated by, but never had occasion to more than superficially examine)
- FartinMowler 6mo ago
  Yup, impossible to read. I was a paid APL coder in the early 80's. We called it WORN: Write Once, Read Never.
  - kstrauser 6mo ago
    That's what we called my friend's Jaz drive, which had a habit of dying.
boje 6mo ago
APL suffers from the same apparent problems as Perl: They have friction coming from an unconventional syntax that's hard to understand without knowing the language beforehand, and when faced with competition, people went with the path of least resistance. * Out of all people, and especially in the newer generations, it is increasingly uncommon to find someone with a desktop or even a laptop. * Out of them, very few decide to do anything with it besides checking mail, social media, the web or play games. * Out of them, very few decide to learn a programming language. * Out of them, very few decide to learn anything besides Javascript or maybe Python. * Out of them, very few decide to learn anything besides Java/C#/C++, learn algorithms, or learn tools like Vim or Emacs. * Out of them, very few decide to learn anything besides Rust/Go/Haskell/Lisp/Scheme or even Fortran. * Out of them, very few decide to learn a language with an alien, symbolic notation that resembles a code golfing language, and which, too, requires them to possibly learn a completely new keyboard layout to type with proificiency. Not trying to discredit APL's contributions to functional programming and the like, but from the letter, it is pretty obvious Djkstra had little respect for friction. Not saying that he's right to dismiss it outright, though.
- boje 6mo ago
  Now that I think about it, and I don't know if this exists yet, but APL would probably very much benefit from having a Scratch-like or Factorio-like visual editor paired with a touch interface. You would drag and drop symbols, and long-pressing a symbol would popup its definition. You could also probably do nice things with the symbol "icon blocks" themselves, and provide them with colors or different visualizations to convey different contextual meanings.
  - lokedhs 6mo ago
    That wouldn't help much. People who don't use these languages doesn't understand that what makes the language different isn't the syntax. There are plenty of dialects that use English words instead of symbols (check out Ivy by Ron Pike for example). The difference is much deeper, but the best way to understand it is probably to check out an introduction (there is a lot on youtube). I'd personally be happy to give an introduction to anyone willing to listen, but this comment field is not the place to do it.
esquivalience 6mo ago
> Your writings made me wonder in which discipline you got your doctor’s degree. Is this a horrible sideswipe or do people think it was intended frankly?
- layer8 6mo ago
  I would assume it was intended humorously.
Jtsummers 6mo ago
https://news.ycombinator.com/item?id=16246544 https://news.ycombinator.com/item?id=16246544 - 27 Jan 2018, 26 comments.
gatestone 6mo ago
Reminds me when Russ Cox (Go, Google, Bell Labs) used Rob Pike's APL like Ivy to solve 2021 Advent of code puzzles: https://www.reddit.com/r/apljk/comments/uccbd6/russ_cox_solves_most_of_the_2021_advent_of_code/ https://www.reddit.com/r/apljk/comments/uccbd6/russ_cox_solv...
Animats 6mo ago
APL was the first language to have operators for "do this to all that stuff". They were headed for functional programming. But the syntax was too weird.
larodi 6mo ago
As if medieval math notation was not weird enough, people decided to invent APL to be even more bizarre. As a proud Perl5 dev, I totally don't buy it. Neither do I buy into Raku's brave use of all possible Unicode symbols. Perhaps I'm ageing.
- WillAdams 6mo ago
  What do you mean by "Medieval math notation"? Wasn't it mostly just textual descriptions? (which arguably would not be too far away from the natural language being used to interact with LLMs) It wasn't until Thomas Harriot's _Artis Analyticae Praxis_ was published that one got anything resembling consistent math notation as folks today would expect, and isn't the symbology used for APL just a formalization and/or extension of prevailing math symbol usage? (which was the point of the whole thing?)
  - larodi 6mo ago
    You are correct, most modern mathematical notation emerged during the Renaissance and Early Modern periods (late 15th-18th centuries). Indeed before that was rhetorical.
- anthk 6mo ago
  Try klong: https://t3x.org/klong/ https://t3x.org/klong/ Intro: https://t3x.org/klong/klong-intro.txt.html https://t3x.org/klong/klong-intro.txt.html Quick ref: https://t3x.org/klong/klong-qref.txt.html https://t3x.org/klong/klong-qref.txt.html Intro to statistics with Klong https://t3x.org/klong-stat/ https://t3x.org/klong-stat/
m463 6mo ago
It has been a long time since I used APL (in college) We had APL terminals which had APL keys and would print APL characters. It was significantly more immersive that way. Looking at this letter i start to vaguely recall things. Decades later, I recall the output operator, not shown anywhere here. ⎕←<something> which would print whatever <something> was. (was I misremembering?) I do recall using matrix operations in a similar way to the math classes I was taking at the same time. matrix multiplication, inversion, dot products seemed to be more "math oriented" than other computer languages. In other computer languages, you had to adapt to the language. For example: x = x + 1 y = mx + b in these two statements, one only makes sense in math class, one only makes sense to increment a variable in a computer language.
coldtea 6mo ago
The usual ramblings that emerged when Dijkstra talked about the practice of the field in general as opposed about algorithms.

71 points by tosh 6mo ago

Ironically, I think the examples given in the post validate Dijkstra’s points, instead of disproving them, as the author intended.

bear8642 6mo ago
How so? I'm struggling to see how Roger's manipulation of the expressions without executing each line validates Dijkstra's point...
- empath75 6mo ago
  "This is easy to understand, see:" 5 lines of completely inscrutable symbols follow. If you are expecting someone to learn a completely new notational language before you can communicate a basic algorithm, you have gone wrong somewhere. You could also similarly write down merge sort in pure lambda calculus, which is interesting as an exercise, but not especially useful as working code, or as a way to explain how merge sort works.

wood_spirit 6mo ago

The opening paragraphs about how people enamoured by a shiny gadget will overlook a terrible interface brings immediately to my mind the modern day LLMs.

dsecurity49 6mo ago
[dead]
asdfasgasdgasdg 6mo ago
I don't find this observation of Djikstra's to be one of his best. If there is a gadget that does a thing that no other gadget does, what does it even mean for the interface to be "terrible?" How can you even know if the interface is terrible, given that a better one has yet to be invented? Maybe the interface is as good as it can be for the tool in question. I also don't love your mapping of this observation onto modern LLMs. The interface of an LLM is natural language text, along with some files written in plain text or markdown. Can it be improved? Undoubtedly! But as a baseline, it doesn't seem half bad to me. If it is so terrible, it should not be hard to propose an interface that will be significantly more productive. Can you?
- empath75 6mo ago
  > If there is a gadget that does a thing that no other gadget does, what does it even mean for the interface to be "terrible?" How can you even know if the interface is terrible, given that a better one has yet to be invented? Maybe the interface is as good as it can be for the tool in question. That's just a taste judgement, and you can decide the interface sucks on a one of a kind item quite easily, and people often do.

Almondsetat 6mo ago

One can appreaciate striving for simplicity (a programming language that can be taught and explained with pen and paper), but one must also consider that computers are meta-devices. Before computers, we could write things only on paper, either with our hands or a typewriter. So, naturally, when computers came about, the way of thinking about programming was very text-driven, with an emphasis on what a typewriter could represent. But then, code could be written directly with computers, opening up more typesetting possibilities thanks to keyboards not being bound anymore by the mechanical limitations of typewriters. You could add keys and combinations to your heart's desire, and they would be natively digital and unlimited. Now, with graphics, both 2D and 3D, and a myriad or other HIDs, shouldn't we try to make another cognitive jump?

deleted 6mo ago
[deleted]
VorpalWay 6mo ago
We do have syntax highlighting these days. And our editors work like hypertext, where I can go to definitions, find usages, get inheritance hierarchies etc. Quite a ways from your suggestion, but also a few steps removed from a type writer. I think any such leap would have to be a really big one to catch on though, due to inertia. Colorforth is not exactly popular, and I can't think of any other examples.
- jmalicki 6mo ago
  With LLMs you can write your code by hand drawing a diagram on a touch screen.
  - ModernMech 6mo ago
    This has been possible since Sketchpad in 1963.
    - WillAdams 6mo ago
      Yes, but there don't seem to be any current implementations which are more than academic exercises (I'd love to be wrong about that and be pointed to something which I could try).

shrubble 6mo ago

I wonder if EWD would have had the same opinion if he were alive today, with every Unicode font having the APL characters immediately available on the screen. Did he feel the language design was bad, or would having TTF fonts being able to show "rho", "iota", "grade up" have removed one or more of his objections?

mlajtos 6mo ago
Oh, he would definitely hate it even more. It was too high-level for his taste. What I would like to know is how he would bend Algol 60 if he had tablet with pencil that could evaluate it in real-time.
- Jtsummers 6mo ago
  > It was too high-level for his taste. That's a pretty silly claim. Is Haskell not high-level? https://www.cs.utexas.edu/~EWD/transcriptions/OtherDocs/Haskell.html https://www.cs.utexas.edu/~EWD/transcriptions/OtherDocs/Hask... Someone happy to see Haskell used in freshman CS education is not someone who opposes high-level languages.
  - mlajtos 6mo ago
    Very interesting flip! For much of his life, Dijkstra opposed functional programming. He even more strongly criticised FP from Backus and APL from Iverson, which are both very funcional/function-level. As he said, Java is a mess and any sensible person would oppose the switch from Haskell to Java. I am almost sure he never used any of them. Might have read about them, but highly doubt he run any on computer. As for the high-level status of Haskell and APL — both languages are very mathematical. Haskell goes very into the abstract realm of computation, while APL tackles very raw form of computation. Semantically, Haskell is way more high-level. In terms of economy of notation and unified concepts, APL has no match.
    - deleted 6mo ago
      [deleted]

adregan 6mo 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 6mo 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 6mo 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 6mo ago
    Interesting. Bird-Meertens formalism? That was directly influenced by APL. In the broader scope — algebra of programs — Dijkstra heavily disliked Backus’ FP.

mlajtos 6mo ago

Dijkstra's go-to language (pun intended) was Algol 60 (& Pascal) – everything else was shit in his view. Some of his comments: FORTRAN — "an infantile disorder" COBOL — "the use of COBOL cripples the mind" BASIC — students exposed to it are "mentally mutilated beyond hope of regeneration" PL/I — "the fatal disease" APL — "a mistake, carried through to perfection" He liked his languages and programs to be easily traceable with pen & paper. He always wrote programs on the paper (and proved correctness) and only then into computer. REPL-driven development (what APL pioneered) was a foreign concept to him. He would be so appalled by LLM code generation.

tristramb 6mo ago
He liked to be able to reason about programs without running them. He preferred simpler languages because they contain less irrelevant noise which got in the way of that.
ilayn 6mo ago
Read the sources carefully. Fortran quote is not his; he quoted it. Also remember that he was talking about pre-Fortran77 era. F77 tried to fix some of the criticisms though did not succeed fully. Here is a nice dig-in about the quote https://limited.systems/articles/dijkstra-fortran/ https://limited.systems/articles/dijkstra-fortran/ Another note to remember that John Backus, the team lead of the Fortran gang, was in the Algol committee. So these folks knew what they are talking about and spoke to each other periodically. Even John Backus said, Fortran is not the final interface that we should have. It keeps spinning in the programming circles half-quoted versions of half-baked quotes from original sources. These pioneers, even when they disagreed, had pretty precise arguments and very rarely feeling the feelies.
- mlajtos 6mo ago
  https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD498.html https://www.cs.utexas.edu/~EWD/transcriptions/EWD04xx/EWD498... – How do we tell truths that might hurt? 1975 FORTRAN —"the infantile disorder"—, by now nearly 20 years old, is hopelessly inadequate for whatever computer application you have in mind today: it is now too clumsy, too risky, and too expensive to use. He told the truth and in turn Fortran corrected its course, but Dijkstra probably didn't change his mind about it. --- > These pioneers, even when they disagreed, had pretty precise arguments and very rarely feeling the feelies. The feud between Backus and Dijkstra kinda persuaded me of the opposite. https://medium.com/@acidflask/this-guys-arrogance-takes-your-breath-away-5b903624ca5f https://medium.com/@acidflask/this-guys-arrogance-takes-your...

deleted 6mo ago

[deleted]

garyrob 6mo ago

I wrote a lot of APL for my undergraduate Senior Project in 1978/1979. I really enjoyed it because it was fun. You could do an incredible amount of work in a single line of code. The only problem was, that line would then be almost impossible to read and understand! It could easily be used as a "write-only" language even without a separate obfuscation step. When I become a professional programmer right after college, I never used it again, and learned to write code that was readable above all else.

WillAdams 6mo ago
Is this an instance of the maxim that one has to be twice as smart to debug code as to write it? Are you aware of any APL programs written using Literate Programming? Apparently there was at least one attempt: Lee J. Dickey. Literate programming in APL and APLWEB. APL Quote Quad, 23(4):11–??, June 1, 1993. CODEN APLQD9. ISSN 0163-6006. Perhaps that additional layer of documentation would help? (APL is a language I've always been fascinated by, but never had occasion to more than superficially examine)
FartinMowler 6mo ago
Yup, impossible to read. I was a paid APL coder in the early 80's. We called it WORN: Write Once, Read Never.
- kstrauser 6mo ago
  That's what we called my friend's Jaz drive, which had a habit of dying.

boje 6mo ago

APL suffers from the same apparent problems as Perl: They have friction coming from an unconventional syntax that's hard to understand without knowing the language beforehand, and when faced with competition, people went with the path of least resistance. * Out of all people, and especially in the newer generations, it is increasingly uncommon to find someone with a desktop or even a laptop. * Out of them, very few decide to do anything with it besides checking mail, social media, the web or play games. * Out of them, very few decide to learn a programming language. * Out of them, very few decide to learn anything besides Javascript or maybe Python. * Out of them, very few decide to learn anything besides Java/C#/C++, learn algorithms, or learn tools like Vim or Emacs. * Out of them, very few decide to learn anything besides Rust/Go/Haskell/Lisp/Scheme or even Fortran. * Out of them, very few decide to learn a language with an alien, symbolic notation that resembles a code golfing language, and which, too, requires them to possibly learn a completely new keyboard layout to type with proificiency. Not trying to discredit APL's contributions to functional programming and the like, but from the letter, it is pretty obvious Djkstra had little respect for friction. Not saying that he's right to dismiss it outright, though.

boje 6mo ago
Now that I think about it, and I don't know if this exists yet, but APL would probably very much benefit from having a Scratch-like or Factorio-like visual editor paired with a touch interface. You would drag and drop symbols, and long-pressing a symbol would popup its definition. You could also probably do nice things with the symbol "icon blocks" themselves, and provide them with colors or different visualizations to convey different contextual meanings.
- lokedhs 6mo ago
  That wouldn't help much. People who don't use these languages doesn't understand that what makes the language different isn't the syntax. There are plenty of dialects that use English words instead of symbols (check out Ivy by Ron Pike for example). The difference is much deeper, but the best way to understand it is probably to check out an introduction (there is a lot on youtube). I'd personally be happy to give an introduction to anyone willing to listen, but this comment field is not the place to do it.

esquivalience 6mo ago

> Your writings made me wonder in which discipline you got your doctor’s degree. Is this a horrible sideswipe or do people think it was intended frankly?

layer8 6mo ago
I would assume it was intended humorously.

Jtsummers 6mo ago

https://news.ycombinator.com/item?id=16246544 https://news.ycombinator.com/item?id=16246544 - 27 Jan 2018, 26 comments.

gatestone 6mo ago

Reminds me when Russ Cox (Go, Google, Bell Labs) used Rob Pike's APL like Ivy to solve 2021 Advent of code puzzles: https://www.reddit.com/r/apljk/comments/uccbd6/russ_cox_solves_most_of_the_2021_advent_of_code/ https://www.reddit.com/r/apljk/comments/uccbd6/russ_cox_solv...

Animats 6mo ago

APL was the first language to have operators for "do this to all that stuff". They were headed for functional programming. But the syntax was too weird.

larodi 6mo ago

As if medieval math notation was not weird enough, people decided to invent APL to be even more bizarre. As a proud Perl5 dev, I totally don't buy it. Neither do I buy into Raku's brave use of all possible Unicode symbols. Perhaps I'm ageing.

WillAdams 6mo ago
What do you mean by "Medieval math notation"? Wasn't it mostly just textual descriptions? (which arguably would not be too far away from the natural language being used to interact with LLMs) It wasn't until Thomas Harriot's _Artis Analyticae Praxis_ was published that one got anything resembling consistent math notation as folks today would expect, and isn't the symbology used for APL just a formalization and/or extension of prevailing math symbol usage? (which was the point of the whole thing?)
- larodi 6mo ago
  You are correct, most modern mathematical notation emerged during the Renaissance and Early Modern periods (late 15th-18th centuries). Indeed before that was rhetorical.
anthk 6mo ago
Try klong: https://t3x.org/klong/ https://t3x.org/klong/ Intro: https://t3x.org/klong/klong-intro.txt.html https://t3x.org/klong/klong-intro.txt.html Quick ref: https://t3x.org/klong/klong-qref.txt.html https://t3x.org/klong/klong-qref.txt.html Intro to statistics with Klong https://t3x.org/klong-stat/ https://t3x.org/klong-stat/

m463 6mo ago

It has been a long time since I used APL (in college) We had APL terminals which had APL keys and would print APL characters. It was significantly more immersive that way. Looking at this letter i start to vaguely recall things. Decades later, I recall the output operator, not shown anywhere here. ⎕←<something> which would print whatever <something> was. (was I misremembering?) I do recall using matrix operations in a similar way to the math classes I was taking at the same time. matrix multiplication, inversion, dot products seemed to be more "math oriented" than other computer languages. In other computer languages, you had to adapt to the language. For example: x = x + 1 y = mx + b in these two statements, one only makes sense in math class, one only makes sense to increment a variable in a computer language.

coldtea 6mo ago

The usual ramblings that emerged when Dijkstra talked about the practice of the field in general as opposed about algorithms.