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Array languages are such a mind twist and so fun. I dabbled in J at one point, and I love explaining +/%# to people. But the real expressive power comes when

Array languages are such a mind twist and so fun. I dabbled in J at one point, and I love explaining +/%# to people. But the real expressive power comes when you start to get into tacit expressions yourself, understand function exponents, and "get" under. Hmmm... maybe I need a refresher...

cess11 1y ago
There's an APK, for dabbling on the phone at times when there's no larger computer available but still time to spend. https://code.jsoftware.com/wiki/Guides/JAndroid https://code.jsoftware.com/wiki/Guides/JAndroid
- liveranga 1y ago
  Having J on the phone in your pocket is great. And lots of the "labs" (interactive tutorials) are built in too: 3 dots -> Help -> Labs.. Edit: I should also have mentioned that Termux on android can build ngn-k, goal and a bunch of other open source array languages too. There's also Rob Pike's Ivy language for Android too.
  - ofalkaed 1y ago
    For android and apl we also have dzaima's AndroidIDE which is the best android array implementation that I have found. https://github.com/dzaima/APL/tree/master/AndroidIDE https://github.com/dzaima/APL/tree/master/AndroidIDE
1-more 1y ago
> I love explaining +/%# Based on the one thing I remember in APL I'm guessing the first two characters are "sum over some data structure" and the data structure is what the next two mean. What does it mean entirely?
- Romario77 1y ago
  avg=: +/ % # +/ sums the items of the array. # counts the number of items in the array. % divides the sum by the number of items.
  - 1-more 1y ago
    delightful, ty. How does it handle empty arrays? Throw? Average is zero? Average is infinity?
    - bear8642 1y ago
      Average is zero empty =. 0$0 NB. zero length array +/empty 0 #empty 0 0%0 0
      - 1-more 1y ago
        Further validation for n / 0 = 0 in Elm and Pony and a couple other places! TYSM
  - deepsun 1y ago
    I'd call that code obfuscation. a.sum() / a.count() you would not need an explanation.
    - hatefulmoron 1y ago
      K et al. can look like that, but this example doesn't require any explanation to someone who has any familiarity.
    - pasquinelli 1y ago
      the thing about tacit programming is that it wouldn't use 'a' in the above. if you wrote average in j without it being tacit, it would probably be more readable to you. the question of how to thread data around without naming it is an interesting one to me.
      - 1y ago

cess11 1y ago

There's an APK, for dabbling on the phone at times when there's no larger computer available but still time to spend. https://code.jsoftware.com/wiki/Guides/JAndroid https://code.jsoftware.com/wiki/Guides/JAndroid

liveranga 1y ago
Having J on the phone in your pocket is great. And lots of the "labs" (interactive tutorials) are built in too: 3 dots -> Help -> Labs.. Edit: I should also have mentioned that Termux on android can build ngn-k, goal and a bunch of other open source array languages too. There's also Rob Pike's Ivy language for Android too.
- ofalkaed 1y ago
  For android and apl we also have dzaima's AndroidIDE which is the best android array implementation that I have found. https://github.com/dzaima/APL/tree/master/AndroidIDE https://github.com/dzaima/APL/tree/master/AndroidIDE

1-more 1y ago

> I love explaining +/%# Based on the one thing I remember in APL I'm guessing the first two characters are "sum over some data structure" and the data structure is what the next two mean. What does it mean entirely?

Romario77 1y ago
avg=: +/ % # +/ sums the items of the array. # counts the number of items in the array. % divides the sum by the number of items.
- 1-more 1y ago
  delightful, ty. How does it handle empty arrays? Throw? Average is zero? Average is infinity?
  - bear8642 1y ago
    Average is zero empty =. 0$0 NB. zero length array +/empty 0 #empty 0 0%0 0
    - 1-more 1y ago
      Further validation for n / 0 = 0 in Elm and Pony and a couple other places! TYSM
- deepsun 1y ago
  I'd call that code obfuscation. a.sum() / a.count() you would not need an explanation.
  - hatefulmoron 1y ago
    K et al. can look like that, but this example doesn't require any explanation to someone who has any familiarity.
  - pasquinelli 1y ago
    the thing about tacit programming is that it wouldn't use 'a' in the above. if you wrote average in j without it being tacit, it would probably be more readable to you. the question of how to thread data around without naming it is an interesting one to me.
    - 1y ago