[HN Gopher] J vs. K by Example (2005)
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J vs. K by Example (2005)
Author : Tomte
Score : 54 points
Date : 2024-02-18 21:13 UTC (1 days ago)
(HTM) web link (olegykj.sourceforge.net)
(TXT) w3m dump (olegykj.sourceforge.net)
| avmich wrote:
| Awesome resource; however both J and K are evolving, so we either
| have multitude of various versions of the languages or a
| comparison which is outdated - referring to the latest versions
| of the languages.
| abrudz wrote:
| J is quite stable. In a set of simple examples, everything
| would be backwards compatible.
| abrudz wrote:
| Seems a bit strange to put spaces around (some!) J primitives,
| but not around K primtives.
| 5- wrote:
| i thought that was author's impression of the prevailing coding
| styles in each language.
|
| i think the only consistently whitespace-abundant k (not q!)
| code i have seen is by bob armstrong:
| http://cosy.com/K/CoSy.htm
| dang wrote:
| Related:
|
| _J vs. K by Example_ -
| https://news.ycombinator.com/item?id=26041598 - Feb 2021 (13
| comments)
| behnamoh wrote:
| Were APL, K, J, etc. ever used in production? Array programming
| seems like a cool idea (albeit being counterintuitive sometimes),
| and it's maybe one of the tersest syntaxes I've ever seen.
| itishappy wrote:
| I've heard it's seen limited adoption in finance.
|
| https://github.com/interregna/arraylanguage-companies
| mianos wrote:
| I mainly work in financial markets. I have personally seen it
| used many times in some places at most of the places I have
| worked at. KDB/Q is an important component for historical data
| and order capture here at OSL. The only issue I have is there
| are few developers and they cost a lot of money. We are lucky
| we have a very good one.
| devin wrote:
| How much is "a lot"?
| 7thaccount wrote:
| APL came out a LONG time ago and was sold by IBM for awhile. If
| you look for Dyalog's customers you'll see some recognizable
| names. Volvo has their entire inventory system in Dyalog APL or
| something like that if iirc. Kdb+ is used a good bit on Wall
| Street and also by F1 racing and a few other places. I'm sure J
| is in use somewhere, but it's probably a bit rarer.
|
| https://www.dyalog.com/case-studies/hercules.htm
| jasonwatkinspdx wrote:
| APL had non trivial uptake during its heyday.
|
| J is apparently somewhat popular with actuaries and similar.
|
| K/Q is used by a number of finance companies, via the KDB
| vector database. Here the selling point was that the overall
| system was great for in memory vector processing of stock tick
| data.
|
| Arthur Witney also built a language named A+ while at Morgan
| Stanley that was used in production as an improvement over
| various previous APL apps.
|
| They're odd languages but have found successful niches.
| airstrike wrote:
| I read the K (K9) manual[0] and it points to https://shakti.com/
| as the authoritative place to download K, but the download link
| is gone and Wayback Machine hasn't helped
|
| [0]
| https://estradajke.github.io/k9-simples/k9/Introduction.html...
| 7thaccount wrote:
| Yeah. Arthur Whitney's old company is Kx Systems which sells a
| vector in memory database for things like financial stock
| ticker analysis called Kdb+. I forget which version of K it is
| on. It mostly doesn't matter as most folks use the q-sql DSL on
| top of it. He then started another company called Shakti with
| some changes and what I guess is a later version of K. He had a
| download link up for a bit, but took it down iirc. I wish the
| site had more about the product listed, but we're not exactly
| the target audience (more for big banks).
| acrispino wrote:
| Look at one of the captures around the end of 2021.
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