3 ms·

For a real eye opener compare the length of these K versions of the Alioth benchmarks to their more verbose brethren http://kparc.com/$/z/comp.k http://kparc.co

For a real eye opener compare the length of these K versions of the Alioth benchmarks to their more verbose brethren http://kparc.com/$/z/comp.k http://kparc.com/$/z/comp.k. I found these on the K OS project page - http://kparc.com/os.htm http://kparc.com/os.htm. There's a great description of Arthur Whitney building a Notepad like text editor (1K) in 30 minutes or so using this system here - http://coding-is-like-cooking.info/2013/09/an-introduction-to-array-languages/ http://coding-is-like-cooking.info/2013/09/an-introduction-t.... Personally K is a bit too terse for my tastes - I think something like Nile achieves some of the terseness of APL without looking like line noise - http://github.com/damelang/nile/blob/master/examples/text-layout.nl http://github.com/damelang/nile/blob/master/examples/text-la....

fennecfoxen 13y ago
a quick Internet also reveals: life:{3=a-x*4=a:2{+(0+':x)+1_x,0}/x}
- beagle3 13y ago
  Explantion: x is a 0/1 matrix of live cells. 0+':x -> "sum each element with one to the left (0 left of the first)" 1_x,0 -> "drop first, add zero at the end" (0+':x)+1_x,0 -> "sum each element with the one to the left and the one to the right (sum of previous expressions)" a:2{+...}/x -> "do that; transpose; do that; transpose again, and assign to a. 2{}/ means 'do twice'" At this point, "a" has the same shape of "x", but in every element is the sum of the elements of x from that location, one above, one below, one left, and one right. 4=a -> "1 where a=4, 0 otherwise" x*4=a -> "1 where x is 1 and a=4, 0 otherwise" a-x*4=a -> "decrease a from 4 to 3 if x=1 in the that place" 3=a-x*4=a -> "1 where one has 3 neighbours" So, if x is a 1/0 matrix "life x" does one iteration of Conway's game of life. And "1000 life/ x" would seek convergence or return to first state (but no more than 1000 iterations). There is code golfing here; It would have been purely readable K code if it wasn't golfed. But it would also have been two to three times as long.
gruseom 13y ago
http://coding-is-like-cooking.info/2013/09/an-introduction-t.. http://coding-is-like-cooking.info/2013/09/an-introduction-t.... Thanks, I enjoyed that article. It gives a vivid picture of the gap between the array languages niche and mainstream programming culture.
- vorg 13y ago
  > Despite my head start with J, by the end of the conference I found APL code easier to grasp – J seems more extreme to me. Roger calls J “executable mathematical notation”, and I’ve always been a bit more of an engineer than a mathematician. I found this too, when I tried them both, first J then APL, perhaps because: * APL uses () [] and {} in their pairs to parenthesize things, just like other languages, while J uses the 6 symbols as standalones, harder to read the code. * All verbs in APL are single characters, whereas J symbols might be more than one. * J, unlike APL, uses the concepts of rank, and forks and hooks, which are both difficult to grasp and don't seem to add much to the array processing idea.

fennecfoxen 13y ago

a quick Internet also reveals: life:{3=a-x*4=a:2{+(0+':x)+1_x,0}/x}

beagle3 13y ago
Explantion: x is a 0/1 matrix of live cells. 0+':x -> "sum each element with one to the left (0 left of the first)" 1_x,0 -> "drop first, add zero at the end" (0+':x)+1_x,0 -> "sum each element with the one to the left and the one to the right (sum of previous expressions)" a:2{+...}/x -> "do that; transpose; do that; transpose again, and assign to a. 2{}/ means 'do twice'" At this point, "a" has the same shape of "x", but in every element is the sum of the elements of x from that location, one above, one below, one left, and one right. 4=a -> "1 where a=4, 0 otherwise" x*4=a -> "1 where x is 1 and a=4, 0 otherwise" a-x*4=a -> "decrease a from 4 to 3 if x=1 in the that place" 3=a-x*4=a -> "1 where one has 3 neighbours" So, if x is a 1/0 matrix "life x" does one iteration of Conway's game of life. And "1000 life/ x" would seek convergence or return to first state (but no more than 1000 iterations). There is code golfing here; It would have been purely readable K code if it wasn't golfed. But it would also have been two to three times as long.

gruseom 13y ago

http://coding-is-like-cooking.info/2013/09/an-introduction-t.. http://coding-is-like-cooking.info/2013/09/an-introduction-t.... Thanks, I enjoyed that article. It gives a vivid picture of the gap between the array languages niche and mainstream programming culture.

vorg 13y ago
> Despite my head start with J, by the end of the conference I found APL code easier to grasp – J seems more extreme to me. Roger calls J “executable mathematical notation”, and I’ve always been a bit more of an engineer than a mathematician. I found this too, when I tried them both, first J then APL, perhaps because: * APL uses () [] and {} in their pairs to parenthesize things, just like other languages, while J uses the 6 symbols as standalones, harder to read the code. * All verbs in APL are single characters, whereas J symbols might be more than one. * J, unlike APL, uses the concepts of rank, and forks and hooks, which are both difficult to grasp and don't seem to add much to the array processing idea.