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The Q Language

code.kx.com

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Re: The Q Language

#121

Post by megaman22 »

greglindahl wrote: post #119
beagle3 wrote: post #64

Earlier quoted context omitted.

Several things: 1. K (and the entire APL family) eschew many of the layers upon layers of abstraction that modern software engineering uses, whether they are justified or not. It turns out, that they are mostly not justified. K gently pushes you toward thinking in a lower level of "what's really happening here?"; I'm not sure I can give a good example here - but the world looks different after taking the red pill. e.…

I'm confused what the relation is between alt-right ideology ("red pill") and the usual things one does for high performance.

Red pill is originally a Matrix reference...

Re: The Q Language

#122

Post by hoosieree »

kazinator wrote: post #52
kolme wrote: post #45

Earlier quoted context omitted.

Welp, you were not kidding: https://github.com/KxSystems/kdb/blob/master/c/c/curl.c This code is basically obfuscated by hand. Absolutely unapproachable. Only the original author(s) can understand it. Judging by other comments, it seems to work well. So they seem to be good programmers producing working code. It's just not intelligible by other human beings, which is a pretty bad thing, but not the only factor in sof…

I don't see where this code is getting a definition for K . (The return type of the ctype function). It's not in the "k.h" header, though that references it also. Maybe the build system injects it through the compiler command line or a forced-include header. Though the gcc command line alluded to in the block comment header shows no evidence of that. Edit: Found it! It's a typedef for a pointer to a struct k0 : typed…

That's the dominant data structure in the whole program. It's a little different from what's used in APL and J, but essentially it represents an array which carries around its length, shape, and pointer to items. An explanation for the J version is in An Implementation of J [1].

There are a handful of helper functions to get/set various parts of this structure, and most of the functions in the language (and its implementation) take 1 or 2 of these and return 1.

[1]: http://sblom.github.io/openj-core/iojNoun.htm#Arrays

Re: The Q Language

#123

Post by geocar »

modeless wrote: post #95
shitgoose wrote: post #86

Earlier quoted context omitted.

what a gap. an abyss. inventor, and users of kdb explicitly and deliberately DO NOT WANT these things (static analysis tools, debuggers, code editors). nor they need it. language is so simple, there is no need for static analysis or code editors. (they compromised on error messages somewhat recently, though; now error messages are two words instead of one) personally, i disagree with them on debugger. would be nice t…

You are right. There is an impassable abyss. I will never agree with anyone who believes that good error messages, analysis tools, or debuggers are not worth having.

> I will never agree with anyone who believes that good error messages, analysis tools, or debuggers are not worth having.

Even if they can do things you cannot do?

What are you doing here if so freely admit you have a closed mind?

Re: The Q Language

#124

Post by hoosieree »

geocar wrote: post #117
petermora wrote: post #112

I worked in Pascal, C/C++, Java, Python, R, Nim, Clojure, Rust, Go, Js, and created various projects in these languages. However, I couldn't get used to Q. I understand that it is fast, and I also started to like the functional programming aspect of it. But oh boy, there is no proper error messages (no, "`type" is not helpful). The short versions of various map and apply were handy, but there are no equivalent versio…

I have worked in C (twenty-five years), C++, Python, Perl (twenty years), JavaScript, Common Lisp (for ten years), OCaml, forth, postscript, and also q/Kdb. I think a lot can be done to improve teaching q/Kdb. The current “best practice” is to change you until it makes sense but this takes time- anywhere from 6 months to a couple years based on your other experiences. And you still have to want to “get it”. I want th…

> Nim and Python and JavaScript are all basically the same thing. You learned one of them, you kindof learned them all, so adding another one feels like these things are easy to learn. Alien technology is alien though, you haven't learned any of it. How can we even talk to each other?

This is an understatement. It helps explain why a person who has never programmed will pick up APL/J/K easier than someone who already knows Python or C.

Re: The Q Language

#125

Post by vram22 »

beagle3 wrote: post #64
vram22 wrote: post #51

Earlier quoted context omitted.

>My C code has become faster, simpler, shorter and less buggy after I dabbled in K. Interesting. Can you explain why you think that has happened?

Several things: 1. K (and the entire APL family) eschew many of the layers upon layers of abstraction that modern software engineering uses, whether they are justified or not. It turns out, that they are mostly not justified. K gently pushes you toward thinking in a lower level of "what's really happening here?"; I'm not sure I can give a good example here - but the world looks different after taking the red pill. e.…

Got it, thanks. Agree about the layers of abstraction. In fact, a similar example, though from BASIC: way back I had read a very good book on it, in which the author showed the creation and use of many data structures and algorithms using nothing but arrays, and indexes as pointers to other elements (in other arrays). It was not difficult to follow, either.

Re: The Q Language

#126

Post by icen »

hoosieree wrote: post #124
geocar wrote: post #117

Earlier quoted context omitted.

I have worked in C (twenty-five years), C++, Python, Perl (twenty years), JavaScript, Common Lisp (for ten years), OCaml, forth, postscript, and also q/Kdb. I think a lot can be done to improve teaching q/Kdb. The current “best practice” is to change you until it makes sense but this takes time- anywhere from 6 months to a couple years based on your other experiences. And you still have to want to “get it”. I want th…

> Nim and Python and JavaScript are all basically the same thing. You learned one of them, you kindof learned them all, so adding another one feels like these things are easy to learn. Alien technology is alien though, you haven't learned any of it. How can we even talk to each other? This is an understatement. It helps explain why a person who has never programmed will pick up APL/J/K easier than someone who already…

One of the things that the GP complains about is evaluation order - in k it follows a simple rule very consistently - programs are evaluated top to bottom, and each expression is evaluated right to left. There are no precedence rules. The instance that I see trip people up all the time is the cast operator $ - people coming from other languages like C or Java expect this to bind more tightly than other operators, but doesn't.

Re: The Q Language

#127

Post by ghosthamlet »

ktamura wrote: post #22
jonathanapp wrote: post #5

Notes from my KX/kdb experience: 1.) The in-memory DB .exe was around 500 KB. Imagine that. 2.) The Q language syntax, while consistent, is fairly arcane and throwback to decades past. 3.) The documentation and driver support is abysmal. 4.) It's supposedly extremely fast, but I can't help but wonder if this is a lot of successful PR and hype (like hedge fund bosses insisting on Oracle because it's the only db that '…

I used to use KX/kdb/Q/K daily for several years. I wrote a full implementation of reinforcement learning (15 lines), a lightweight MVC framework (to show reports and tables in an internal webapp) and even a Q syntax checker (abusing table as a data structure to hold parse trees). Good or bad, for the longest time, Q was my "go-to" programming language. Based on that experience... 1) Yes, but that's not huge by moder…

Have you open source the reinforcement learning and MVC framework code? Can't wait to study it.

Re: The Q Language

#128

Post by fusiongyro »

throwaway7645 wrote: post #118
fusiongyro wrote: post #110

Earlier quoted context omitted.

Dyalog comes with a keyboard layout (on a Mac it just replaces the alt keys). It's quite easy to use. GNU APL's Emacs mode does the same thing, although mapped to super rather than alt (meta, in Emacs) by default. I'm aware of the licensing costs, I'm more curious about whether Dyalog is obtaining popularity versus J, and if so, why. Of course, three new people going to the Dyalog conference would be a 10% increase i…

Yea, I was just saying the key mappings can be a pain and your favorite keyboard probably doesn't have the APL symbols on it. The Dyalog IDE has a virtual keyboard, but I don't like those too much. If none of that bothers you, than no biggie. I'm guessing Dyalog has more production users and a bit more users than you see at the conference as they are typically held in the UK. J is free, so I bet a lot more people try…

My background is I know too many languages and don't get enough shit done and my need is probably to stop it and get back to work. :)

Being slightly more serious, I do web dev, mostly backend, for a radio astronomy observatory. I don't know anything about the science, but I wind up executing their routines in the cluster and doing typical database apps. I don't have much time on the side but I have been enjoying trying to learn J and realizing how much applied math is missing in my background!

Re: The Q Language

#129

Post by RodgerTheGreat »

throwaway7645 wrote: post #120
RodgerTheGreat wrote: post #105

Earlier quoted context omitted.

1010data's web UI isn't actually based on the K2-era GUI framework; it is architected as a reasonably conventional web application that happens to use K3 as a server-side language. The 1010data query language offers facilities for making data-driven UIs for interactive reports and the like, but any semantic similarity to the K2 GUI system is probably coincidental.

So 1010data's purpose is to sell analytics tools to kdb+ users? Does kdb+ not come with a simple way to pipe output to a chart? For the price, I'd hope they had something more than a REPL.

1010data's analytics tools and database are entirely their own product, developed separately from kdb+. While these are implemented in K (K3, which precedes kdb+/q/K4), the end users are not K programmers any more than WordPress users are PHP programmers.
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