5 ms·

While it's interesting (pretty funny) that this language exists, it looks downright awful to program in. Has anyone ever programmed anything sizable in it?

lucozade 9y ago
I had the pleasure of retiring a large APL application a few years ago. Although I hadn’t spent time developing in it, I did spend a lot of time with the devs who had. I also had to understand it well enough to replace it. I’ve worked on a lot of systems and a fair few languages in my time. I’d rank it as the 3rd worst application I’ve ever dealt with. It’s also one of the few where I didn’t end up with a grudging admiration for the original developers. And I’ve replaced a “real time” event based system written in Sybase stored procs so I have a really low threshold.
- girvo 9y ago
  What were the two other worse applications?
  - lucozade 9y ago
    The worst, as a piece of code, was a Byzantine C++ application. It had been written with abstractions and indirections to cater for every conceivable eventuality. And it seemed to incubate Heisenbugs. Usually, with a C++ app you can fix it incrementally but we tried and it was just impossible. Far too intertwined. In the end I wrote a replacement from scratch. The other one was a Smalltalk system. Actually, pretty well written and documented. But once Smalltalk gets above a certain size it can become impossible to reason about. And it’s very hard to replace parts. Sadly, this one was a failure. It never got fixed or replaced. Just went out of business.
- nickpeterson 9y ago
  I would love more particulars about this.
marvy 9y ago
Apparently yes: https://news.ycombinator.com/submitted?id=arcfide https://news.ycombinator.com/submitted?id=arcfide And his website: https://news.ycombinator.com/from?site=sacrideo.us https://news.ycombinator.com/from?site=sacrideo.us I'm sure there are others, but this I happened to know from memory.
deleted 9y ago
[deleted]
DonaldPShimoda 9y ago
There are other languages that operate within the same paradigm, such as J, which do not make use of the specialized symbols and so are somewhat more accessible. /u/Godspiral is a Reddit user who moderates the /r/DailyProgrammer sub, and he occasionally posts solutions to the challenges in J [0]. It's still plenty difficult to read, as you'd expect haha. [0] https://www.reddit.com/r/dailyprogrammer/comments/7t6fnc/20180126_challenge_348_hard_square_sum_chains/dtacdqi/ https://www.reddit.com/r/dailyprogrammer/comments/7t6fnc/201... (This is just the most recent non-trivial example I could find of his.)
grayrest 9y ago
> Has anyone ever programmed anything sizable in it? A significant fraction of wall street operates on kdb+, which is a commercial programming environment in Q (a dialect of K), which is APL derived. APL derived languages operate with a different idea of what makes a programming language good and there was an APL patterns presentation [0] posted yesterday. In brief, the goal is to be able to see and manipulate the entire solution to a problem at once instead of isolating subproblems into layers and abstractions. [0] https://news.ycombinator.com/item?id=16513393 https://news.ycombinator.com/item?id=16513393 I wouldn't write a web browser in Q but I've done enough daily programming problems in it that I can see how it'd be useful for writing programs in what would be the 3-5k LoC of Python range.
wenc 9y ago
Kdb+ [0], a very high-performance and very expensive proprietary time-series database, was written in a dialect of APL. I've seen demos of Kdb+ and it is very impressive. It is the top ranking non-GPU database in this benchmark [1]. It is however not the easiest of databases to use -- it uses Q (another APL dialect) as a query language. There was an HN discussion a while back about its maintainability and long-term prospects. [2] [0] https://en.wikipedia.org/wiki/Kdb%2B https://en.wikipedia.org/wiki/Kdb%2B [1] http://tech.marksblogg.com/benchmarks.html http://tech.marksblogg.com/benchmarks.html [2] https://news.ycombinator.com/item?id=11561573 https://news.ycombinator.com/item?id=11561573
- arnon 9y ago
  I wouldn't trust Marksblogg's tests. They focus on single-table "NYC Taxi" rides which don't represent most database use-cases. He also claims he takes the fastest runtime of the queries over several runs, which is not how real tests are performed.
  - coldtea 9y ago
    >I wouldn't trust Marksblogg's tests. They focus on single-table "NYC Taxi" rides which don't represent most database use-cases. No, but they represent a hell of a lot of big data use cases. >He also claims he takes the fastest runtime of the queries over several runs, which is not how real tests are performed. Assuming he already checks for data not being on fs cache, what else would you take? You don't want to measure other load going on in your system and impacting your queries.
  - minitoar 9y ago
    It is common practice to take the fastest runtime. This will get you as close to the actual runtime of your code as possible, assuming it's deterministic.
  - jerf 9y ago
    "He also claims he takes the fastest runtime of the queries over several runs, which is not how real tests are performed." It isn't, but it should be. For any non-randomized run of the exact same work [1], by definition of non-randomized, any noise that appears in the results of multiple test runs can only be due to factors unrelated to the test being run, such as the OS decisions and such. Taking the minimum is the most honest way to factor those out. A possible exception for the first run, before CPU caches are warmed up. [1]: Ponder that closely; a lot of the knee-jerk reactions to what I just said is handled by that; e.g., if the second time something is cached by the algorithm itself that was not cached the first time around, that's not the same work. Conceptually you can imagine that I'm shooting for the exact same sequence of CPU instructions being run on the exact same data values, though in practice that can be a tall bar to leap even before considering concurrency; as with almost everything in life if you look closely enough the boundaries get fuzzy.
PeCaN 9y ago
Yes, someone wrote an APL-to-ArrayFire compiler in APL. https://news.ycombinator.com/item?id=13797797 https://news.ycombinator.com/item?id=13797797 It's really pleasant to program in APL once you get used to it. I would put it on the same level of ease and pure fun as SNOBOL and Haskell, which are both really fun and productive to work with for me.
- spc476 9y ago
  And someone else wrote an APL interpreter in Lua: https://github.com/dlaurie/lua-apl https://github.com/dlaurie/lua-apl
jonex 9y ago
Upvoted to compensate down-votes. While this is an opinion that tends to be repeated in APL threads and can seem ignorant. It it also the initial reaction many of us have had. Presenting it with a reasonable follow up question like this gives a perfect opportunity to provide examples of it being used and the reasoning behind why it might not be as terrible as it might seem at first. Down-voting such comments only discourages conversation IMO, what about giving a good answer instead. (or in this case, just link to arcfide and his interesting explanations about how he uses Dyalog to be productive.)
StreamBright 9y ago
I guess you won't know until you tried. I got to know APL when got introduced Q and KDB+ by accident and I could not believe that you can be so terse with programming while having an unmatched performance. There are entire industries relying on Q (which is heavily influenced by APL).

lucozade 9y ago

I had the pleasure of retiring a large APL application a few years ago. Although I hadn’t spent time developing in it, I did spend a lot of time with the devs who had. I also had to understand it well enough to replace it. I’ve worked on a lot of systems and a fair few languages in my time. I’d rank it as the 3rd worst application I’ve ever dealt with. It’s also one of the few where I didn’t end up with a grudging admiration for the original developers. And I’ve replaced a “real time” event based system written in Sybase stored procs so I have a really low threshold.

girvo 9y ago
What were the two other worse applications?
- lucozade 9y ago
  The worst, as a piece of code, was a Byzantine C++ application. It had been written with abstractions and indirections to cater for every conceivable eventuality. And it seemed to incubate Heisenbugs. Usually, with a C++ app you can fix it incrementally but we tried and it was just impossible. Far too intertwined. In the end I wrote a replacement from scratch. The other one was a Smalltalk system. Actually, pretty well written and documented. But once Smalltalk gets above a certain size it can become impossible to reason about. And it’s very hard to replace parts. Sadly, this one was a failure. It never got fixed or replaced. Just went out of business.
nickpeterson 9y ago
I would love more particulars about this.

marvy 9y ago

Apparently yes: https://news.ycombinator.com/submitted?id=arcfide https://news.ycombinator.com/submitted?id=arcfide And his website: https://news.ycombinator.com/from?site=sacrideo.us https://news.ycombinator.com/from?site=sacrideo.us I'm sure there are others, but this I happened to know from memory.

deleted 9y ago

[deleted]

DonaldPShimoda 9y ago

There are other languages that operate within the same paradigm, such as J, which do not make use of the specialized symbols and so are somewhat more accessible. /u/Godspiral is a Reddit user who moderates the /r/DailyProgrammer sub, and he occasionally posts solutions to the challenges in J [0]. It's still plenty difficult to read, as you'd expect haha. [0] https://www.reddit.com/r/dailyprogrammer/comments/7t6fnc/20180126_challenge_348_hard_square_sum_chains/dtacdqi/ https://www.reddit.com/r/dailyprogrammer/comments/7t6fnc/201... (This is just the most recent non-trivial example I could find of his.)

grayrest 9y ago

> Has anyone ever programmed anything sizable in it? A significant fraction of wall street operates on kdb+, which is a commercial programming environment in Q (a dialect of K), which is APL derived. APL derived languages operate with a different idea of what makes a programming language good and there was an APL patterns presentation [0] posted yesterday. In brief, the goal is to be able to see and manipulate the entire solution to a problem at once instead of isolating subproblems into layers and abstractions. [0] https://news.ycombinator.com/item?id=16513393 https://news.ycombinator.com/item?id=16513393 I wouldn't write a web browser in Q but I've done enough daily programming problems in it that I can see how it'd be useful for writing programs in what would be the 3-5k LoC of Python range.

wenc 9y ago

Kdb+ [0], a very high-performance and very expensive proprietary time-series database, was written in a dialect of APL. I've seen demos of Kdb+ and it is very impressive. It is the top ranking non-GPU database in this benchmark [1]. It is however not the easiest of databases to use -- it uses Q (another APL dialect) as a query language. There was an HN discussion a while back about its maintainability and long-term prospects. [2] [0] https://en.wikipedia.org/wiki/Kdb%2B https://en.wikipedia.org/wiki/Kdb%2B [1] http://tech.marksblogg.com/benchmarks.html http://tech.marksblogg.com/benchmarks.html [2] https://news.ycombinator.com/item?id=11561573 https://news.ycombinator.com/item?id=11561573

arnon 9y ago
I wouldn't trust Marksblogg's tests. They focus on single-table "NYC Taxi" rides which don't represent most database use-cases. He also claims he takes the fastest runtime of the queries over several runs, which is not how real tests are performed.
- coldtea 9y ago
  >I wouldn't trust Marksblogg's tests. They focus on single-table "NYC Taxi" rides which don't represent most database use-cases. No, but they represent a hell of a lot of big data use cases. >He also claims he takes the fastest runtime of the queries over several runs, which is not how real tests are performed. Assuming he already checks for data not being on fs cache, what else would you take? You don't want to measure other load going on in your system and impacting your queries.
- minitoar 9y ago
  It is common practice to take the fastest runtime. This will get you as close to the actual runtime of your code as possible, assuming it's deterministic.
- jerf 9y ago
  "He also claims he takes the fastest runtime of the queries over several runs, which is not how real tests are performed." It isn't, but it should be. For any non-randomized run of the exact same work [1], by definition of non-randomized, any noise that appears in the results of multiple test runs can only be due to factors unrelated to the test being run, such as the OS decisions and such. Taking the minimum is the most honest way to factor those out. A possible exception for the first run, before CPU caches are warmed up. [1]: Ponder that closely; a lot of the knee-jerk reactions to what I just said is handled by that; e.g., if the second time something is cached by the algorithm itself that was not cached the first time around, that's not the same work. Conceptually you can imagine that I'm shooting for the exact same sequence of CPU instructions being run on the exact same data values, though in practice that can be a tall bar to leap even before considering concurrency; as with almost everything in life if you look closely enough the boundaries get fuzzy.

PeCaN 9y ago

Yes, someone wrote an APL-to-ArrayFire compiler in APL. https://news.ycombinator.com/item?id=13797797 https://news.ycombinator.com/item?id=13797797 It's really pleasant to program in APL once you get used to it. I would put it on the same level of ease and pure fun as SNOBOL and Haskell, which are both really fun and productive to work with for me.

spc476 9y ago
And someone else wrote an APL interpreter in Lua: https://github.com/dlaurie/lua-apl https://github.com/dlaurie/lua-apl

jonex 9y ago

Upvoted to compensate down-votes. While this is an opinion that tends to be repeated in APL threads and can seem ignorant. It it also the initial reaction many of us have had. Presenting it with a reasonable follow up question like this gives a perfect opportunity to provide examples of it being used and the reasoning behind why it might not be as terrible as it might seem at first. Down-voting such comments only discourages conversation IMO, what about giving a good answer instead. (or in this case, just link to arcfide and his interesting explanations about how he uses Dyalog to be productive.)

StreamBright 9y ago

I guess you won't know until you tried. I got to know APL when got introduced Q and KDB+ by accident and I could not believe that you can be so terse with programming while having an unmatched performance. There are entire industries relying on Q (which is heavily influenced by APL).