5 ms·

APL Demonstration (1975) [video]

85 points by nequo 2y ago

dang 2y ago
Related. Others? APL Demonstration (1975) [video] - https://news.ycombinator.com/item?id=32118279 https://news.ycombinator.com/item?id=32118279 - July 2022 (1 comment) APL Demonstration (1975) [video] - https://news.ycombinator.com/item?id=21104698 https://news.ycombinator.com/item?id=21104698 - Sept 2019 (51 comments) APL Demonstration From 1975 [video] - https://news.ycombinator.com/item?id=7817593 https://news.ycombinator.com/item?id=7817593 - May 2014 (7 comments) APL demonstration 1975 [video] - https://news.ycombinator.com/item?id=6155639 https://news.ycombinator.com/item?id=6155639 - Aug 2013 (1 comment
- wood_spirit 2y ago
  The APL game of life video is another awesome thing worth reposting :) https://news.ycombinator.com/item?id=1041500 https://news.ycombinator.com/item?id=1041500
  - benji-york 2y ago
    I watch this video every couple of years. It is a thing of beauty. Direct link: https://www.youtube.com/watch?v=a9xAKttWgP4 https://www.youtube.com/watch?v=a9xAKttWgP4
- sossupummi 2y ago
  I mean yeah but you can't comment them.
  - dang 2y ago
    You can read them and comment here!
- OldGuyInTheClub 2y ago
  I'm here reasonably often but have missed prior posts. I love these old school (literal in this case!) presentations. Information density is off the charts.
Pompidou 2y ago
Regarding APL and array languages related topics I love theses youtube channel : https://www.youtube.com/@code_report https://www.youtube.com/@code_report https://www.youtube.com/@arraycast https://www.youtube.com/@arraycast https://www.youtube.com/@bobtherriault https://www.youtube.com/@bobtherriault https://www.youtube.com/@tangentstorm https://www.youtube.com/@tangentstorm
lbatista 2y ago
Convolutional Neural Networks in APL blog←{⍺×⍵×1-⍵} backbias←{+/,⍵} logistic←{÷1+*-⍵} maxpos←{(,⍵)⍳⌈/,⍵} backavgpool←{2⌿2/⍵÷4}⍤2 meansqerr←{÷∘2+/,(⍺-⍵)*2} avgpool←{÷∘4{+/,⍵}⌺(2 2⍴2)⍤2⊢⍵} conv←{s←1+(⍴⍵)-⍴⍺⋄⊃+/,⍺×(⍳⍴⍺){s↑⍺↓⍵} ⊂⍵} backin←{(d w in)←⍵⋄⊃+/,w{(⍴in)↑(-⍵+⍴d)↑⍺×d} ⍳⍴w} multiconv←{(a ws bs)←⍵⋄bs{⍺+⍵ conv a}⍤(0,(⍴⍴a))⊢ws} https://dl.acm.org/doi/pdf/10.1145/3315454.3329960 https://dl.acm.org/doi/pdf/10.1145/3315454.3329960
- dbcurtis 2y ago
  A friend once described APL as a “write-only language”. You make his case well :) It is pretty easy to write unmaintainable APL, it seems to me.
  - 7thaccount 2y ago
    I'd bet money that I could figure out what this code is doing easier than the equivalent in Python, which is my daily driver. You just need to look up the symbols and piece it together. Yes, that takes an extra step, but so did learning any new language. Also, I can see all of this in one spot.
    - RodgerTheGreat 2y ago
      The value of being able to see the entire implementation of a nontrivial program at once cannot be overstated. This is the real magic of APLs: no unnecessary abstraction, boilerplate, or structural fluff, just algorithms composed from general high-level building-blocks.
      - rbanffy 2y ago
        The right level of abstraction is key. If your problem maps neatly to the primitives offered by APL, then the code will be readable idiomatic APL. If, however, they don’t, and you are using the APL abstractions in ways they were not intended to, and you are building new abstractions on top of them, then you’ll need to be a skilled programmer to keep it readable.
julienchastang 2y ago
I've watched this video in the past. If I recall correctly, he does not make a single typo or fat-fingering during the entire 27 minutes.
- bumbledraven 2y ago
  On an APL keyboard no less!
- llm_trw 2y ago
  When a typo means you've waster 24 hours waiting for the batch job to come back (if you're lucky) you learn pretty quickly not to make them.
- ziml77 2y ago
  I think that's largely because he wasn't typing very fast and was looking at the keys.
meken 2y ago
That’s so weird how he backspaces to overlay two characters on top of one another to achieve an operator
- PhilipRoman 2y ago
  Apparently this used to be a common thing, groff has a feature to output bold text for TTY devices by backspacing and re-printing each character twice. You can get underlined text in a similar way using backpace and underscore. It doesn't work out of the box on terminal emulators, but less(1) does this rendering for man pages, etc.
- sevensor 2y ago
  That's how we did it with typewriters, back in the day. You could backspace and overstrike with another character, to make a composite symbol.
skruger 2y ago
If you’re interested in learning APL, I wrote an intro for people coming from another language: https://xpqz.github.io/learnapl https://xpqz.github.io/learnapl

85 points by nequo 2y ago

dang 2y ago

Related. Others? APL Demonstration (1975) [video] - https://news.ycombinator.com/item?id=32118279 https://news.ycombinator.com/item?id=32118279 - July 2022 (1 comment) APL Demonstration (1975) [video] - https://news.ycombinator.com/item?id=21104698 https://news.ycombinator.com/item?id=21104698 - Sept 2019 (51 comments) APL Demonstration From 1975 [video] - https://news.ycombinator.com/item?id=7817593 https://news.ycombinator.com/item?id=7817593 - May 2014 (7 comments) APL demonstration 1975 [video] - https://news.ycombinator.com/item?id=6155639 https://news.ycombinator.com/item?id=6155639 - Aug 2013 (1 comment

wood_spirit 2y ago
The APL game of life video is another awesome thing worth reposting :) https://news.ycombinator.com/item?id=1041500 https://news.ycombinator.com/item?id=1041500
- benji-york 2y ago
  I watch this video every couple of years. It is a thing of beauty. Direct link: https://www.youtube.com/watch?v=a9xAKttWgP4 https://www.youtube.com/watch?v=a9xAKttWgP4
sossupummi 2y ago
I mean yeah but you can't comment them.
- dang 2y ago
  You can read them and comment here!
OldGuyInTheClub 2y ago
I'm here reasonably often but have missed prior posts. I love these old school (literal in this case!) presentations. Information density is off the charts.

Pompidou 2y ago

Regarding APL and array languages related topics I love theses youtube channel : https://www.youtube.com/@code_report https://www.youtube.com/@code_report https://www.youtube.com/@arraycast https://www.youtube.com/@arraycast https://www.youtube.com/@bobtherriault https://www.youtube.com/@bobtherriault https://www.youtube.com/@tangentstorm https://www.youtube.com/@tangentstorm

lbatista 2y ago

Convolutional Neural Networks in APL blog←{⍺×⍵×1-⍵} backbias←{+/,⍵} logistic←{÷1+*-⍵} maxpos←{(,⍵)⍳⌈/,⍵} backavgpool←{2⌿2/⍵÷4}⍤2 meansqerr←{÷∘2+/,(⍺-⍵)*2} avgpool←{÷∘4{+/,⍵}⌺(2 2⍴2)⍤2⊢⍵} conv←{s←1+(⍴⍵)-⍴⍺⋄⊃+/,⍺×(⍳⍴⍺){s↑⍺↓⍵} ⊂⍵} backin←{(d w in)←⍵⋄⊃+/,w{(⍴in)↑(-⍵+⍴d)↑⍺×d} ⍳⍴w} multiconv←{(a ws bs)←⍵⋄bs{⍺+⍵ conv a}⍤(0,(⍴⍴a))⊢ws} https://dl.acm.org/doi/pdf/10.1145/3315454.3329960 https://dl.acm.org/doi/pdf/10.1145/3315454.3329960

dbcurtis 2y ago
A friend once described APL as a “write-only language”. You make his case well :) It is pretty easy to write unmaintainable APL, it seems to me.
- 7thaccount 2y ago
  I'd bet money that I could figure out what this code is doing easier than the equivalent in Python, which is my daily driver. You just need to look up the symbols and piece it together. Yes, that takes an extra step, but so did learning any new language. Also, I can see all of this in one spot.
  - RodgerTheGreat 2y ago
    The value of being able to see the entire implementation of a nontrivial program at once cannot be overstated. This is the real magic of APLs: no unnecessary abstraction, boilerplate, or structural fluff, just algorithms composed from general high-level building-blocks.
    - rbanffy 2y ago
      The right level of abstraction is key. If your problem maps neatly to the primitives offered by APL, then the code will be readable idiomatic APL. If, however, they don’t, and you are using the APL abstractions in ways they were not intended to, and you are building new abstractions on top of them, then you’ll need to be a skilled programmer to keep it readable.

julienchastang 2y ago

I've watched this video in the past. If I recall correctly, he does not make a single typo or fat-fingering during the entire 27 minutes.

bumbledraven 2y ago
On an APL keyboard no less!
llm_trw 2y ago
When a typo means you've waster 24 hours waiting for the batch job to come back (if you're lucky) you learn pretty quickly not to make them.
ziml77 2y ago
I think that's largely because he wasn't typing very fast and was looking at the keys.

meken 2y ago

That’s so weird how he backspaces to overlay two characters on top of one another to achieve an operator

PhilipRoman 2y ago
Apparently this used to be a common thing, groff has a feature to output bold text for TTY devices by backspacing and re-printing each character twice. You can get underlined text in a similar way using backpace and underscore. It doesn't work out of the box on terminal emulators, but less(1) does this rendering for man pages, etc.
sevensor 2y ago
That's how we did it with typewriters, back in the day. You could backspace and overstrike with another character, to make a composite symbol.

skruger 2y ago

If you’re interested in learning APL, I wrote an intro for people coming from another language: https://xpqz.github.io/learnapl https://xpqz.github.io/learnapl