J Has the Best Development Environment (2009)

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by epsylon • 12 years ago

84 41 12 years ago

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minikomi3• 12 years ago

I've been dabbling with learning J recently and, yes, it's really really humbling. However, I think it can be much easier. The thing I have the most trouble with is, predictably, unfamiliarity with the large amount of verbs.

So, what to do?

I'm beginning to think approaching it more like a foreign language will make more sense - i.e., reading & spaced repetition of phrases (short programs - J's specialty!) / vocab (useful hooks, forks) using a flash card system.

It's a compelling language to learn (even just for the fact you can pretty much program using a pen and paper while waiting for the bus - short little rows of verbs you build out gradually as you reason about it or type them in your iphone), and I hope my approach has merit.

qznc• 12 years ago

There is a public Anki (spaced repetition app) deck available: https://ankiweb.net/shared/info/832417998

That one still looks very cryptic, though.

minikomi3• 12 years ago

Ah, good find! I'll give it a whirl.

klibertp3• 12 years ago

I learned J in very much this way, although instead of reading J code I chose to write it. I worked my way through a cheatsheet (http://www.jsoftware.com/jwiki/HenryRich?action=AttachFile&d...) inventing little toy problems to solve with particular verbs along the way. But words (verbs, gerunds, etc.) are not enough - you need to know the rules for composing them. Fortunately this is rather easy to learn.

I'd say that you need to know about hooks, forks (trains in general) and ranks before starting to learn the vocabulary. But maybe you can learn those things along the vocabulary too.

eggy2• 12 years ago

I have been toying with J for the past few years, and I think you only appreciate it when you see it as equivalent to mathematical notation, alien at first, but succinct and very useable when you know what the symbols mean. See Iverson's paper on 'Notation as a Tool of Thought' (http://www.jsoftware.com/papers/tot.htm). I am self-teaching mathematics, and even when trying Julia as a math tool, I find the basic unit of J, the array, as more amenable to my studies. It's interesting how there is all the talk about 'vectorization' and such in other languages, which J has been doing for decades. J is functional, and can have 'for' loops, but loopless programming is encouraged and easy. When dealing with images or large data sets that are memory mapped, the operations are succinct and powerful and eye-opening. My latest epiphany from moving away from using J as just a sophisticated calculator came after watching the 4 videos by Martin Saurer (https://www.youtube.com/watch?v=VSJpJt3c11c). Iverson's books on arithmetic and calculus using J are mind-blowing. You are engaged, not distracted by the language. J is fast too. From another talk (https://www.youtube.com/watch?v=IKfJRyoiBlY&feature=youtu.be), creating a 1x10^6 element array and summing over columns or rows is fast, and the code is simply:

  b=: ? 1000 1000 $ 10
  +/+/b

These two lines create a 1x10^6 element array and then sums the columns, and then sums the single row total. Fast. These guys have really distilled the libraries and made them work well with J (lapacke c interface to lapack). You get c speeds from an interpreter. I guess this is why q with kdb+ is used so much by the finance community despite how expensive it is. Anyway, I am currently staying with J, and I am writing my little tasks in J and julia to see how they fare against each other in speed and development efforts. Now that I have the knowledge to do Qt interfaces for J, I may just stick with J for the sheer joy.

oddthink2• 12 years ago

IMHO, q's (and K's) big advantage over J is that they have tables and dictionaries as an available data type. This makes basic tasks like reading csv files and merging different data sources much easier in q. q also has a nicer syntax for anonymous functions. Of course, q is also very expensive, and it tries to be too clever at times: I remember running in to all sorts of weird corner cases, with things like NAs being skipped in float arrays, but not in int arrays, etc.

adamnemecek2• 12 years ago

Speaking of exotic languages, I'm somewhat intrigued by Rebol and Red. How bad of an idea is investing any time into learning either of these?

erikb• 12 years ago

Well, it's better than watching a movie instead, but not much.

k__• 12 years ago

Depends on the movie.

The stuff from Jim Jarmusch is rather nice.

purpletoned• 12 years ago

Depends on what you want to do with it. If you're looking to develop mobile or desktop applications it's almost useless. The desktop GUI is stuck in the 80s and as far as I know even that isn't an option for mobile.

If you're doing web apps, it's probably worth a try provided you don't mind writing your own libraries for a lot of stuff.

kbd• 12 years ago

The desktop GUI is stuck in the 80s and as far as I know even that isn't an option for mobile.

It's a shame that REBOL was open sourced a decade and a half too late. Back when Perl was still king of scripting languages and Python/Ruby etc. hadn't taken over for Perl yet, REBOL could have had success. The community was fun and creative and the implementation seemed like it would be small and able to be improved through open source.

Just checked, and the repository hasn't had a checkin for 7 months:

https://github.com/rebol/rebol

akavel2• 12 years ago

I believe REBOL and Red shouldn't be confused. The Red project seems to be going on quite lively, with the most recent commit some 9 days ago at the time I'm writing this (see https://github.com/red/red ). That said, it's still not fully complete, but it does most certainly have more modern goals than REBOL -- see e.g. the Roadmap Status page (http://www.red-lang.org/p/roadmap.html) for information about Android bridge (currently reported "90% complete", look for it at the bottom of the page).

adamnemecek2• 12 years ago

I was intrigued by the fact that it's inspired by Self, Lisp and Forth. It seems like a weird mixture of languages all of which are generally considered well designed.

draegtun2• 12 years ago

Thankfully R3-GUI as dragged the Rebol desktop out of the 80's :)

And there are alpha versions that run on Android - http://rebol.informe.com/blog/2013/04/15/rebol-3-on-android/

But yes still got some way to go. Good news is that there are versions for Windows & Linux - http://atronixengineering.com/downloads.html

SixSigma• 12 years ago

Rebol is dead. The closed source is not maintained and was released as abandonware.

A few people have tried to keep it going, there is even a version for Android, but there have been no commits for over a year.

zimpenfish• 12 years ago

Oh. Well, that's 4" of shelf space I can free up then.

akavel2• 12 years ago

Huh?

Rebol 3 ("alpha version") is open-sourced under Apache 2.0 license; most recent commit is dated Mar 04 2014; not quite yesterday, but certainly not "over a year ago". See:

https://github.com/rebol/rebol

As to Red, it is a totally separate project, kinda rewrite from scratch of Rebol (started when Rebol 3 was still closed source and seemed dead), and although still not complete, looks very lively:

https://github.com/red/red

-- see also the pretty status/completion tracking graphs for Red at:

http://www.red-lang.org/p/roadmap.html

draegtun2• 12 years ago

Not dead but development as become fragmented.

The main Rebol repo (https://github.com/rebol/rebol) keeps getting blocked due to a lack of stewardship :(

At some point this will be fixed. As a stop gap Rebolsources was created and was used by community to filter changes through to main repo. See https://github.com/rebolsource/r3 & http://rebolsource.net/

There are two other versions maintained by two commercial entities:

* Saphiron - http://development.saphirion.com/

* Atronix Engineering - http://atronixengineering.com/

Both are fixing/improving Rebol 3 whilst also developing the R3-GUI (Saphiron work on Windows version while Atronix ported it to Linux desktop).

Unfortunately the Saphiron development isn't kept public so the repo (https://github.com/saphirion/saphir) isn't up-to-date. Atronix is probably the best place to look at this moment (https://github.com/zsx/r3). The last commit was only 6 days ago.

chubot• 12 years ago

I like vectorized languages -- I know R fairly well, and used to use Matlab.

J's syntax, where everything is a single character, kind of turns me off. Is that incidental or is the syntax essential to the language? (In the case of Lisp, the "weird" syntax isn't incidental but rather essential, since code is data)

If it's incidental, I'd like to see some elegant J programs "written out" with some more friendly syntax.

EDIT: If you want a laugh, download the source for J, and run wc -l .c .h.

http://www.jsoftware.com/source.htm

minikomi3• 12 years ago

Check out Tracy Harms's talk:

http://www.infoq.com/presentations/j-language

Or, perhaps, this chapter of the (rather dense) "Learning J":

http://www.jsoftware.com/help/learning/03.htm

huehue• 12 years ago

I guess it's a matter of taste.

As someone versed in both APL and K/Kona, J's syntax puts me off as well.

klibertp3• 12 years ago

where everything is a single character

Most things in J are actually two characters, take a look at the Vocabulary (http://www.jsoftware.com/help/dictionary/vocabul.htm)

I'd like to see some elegant J programs "written out" with some more friendly syntax

The problem with J is that the syntax is highly context sensitive, not the length of identifiers. See here: http://www.jsoftware.com/jwiki/Guides/Language%20FAQ#Guides....

Also, you can use aliases for every word, which are defined in stdlib. You can write "each", "cut" etc. if you want. The reason nobody does that is a little complex.

J is suited for exploratory programming and rapid prototyping. This means that expressive power per character should be as high as possible - and J delivers on this promise. Also the standard J words you can see in the Vocabulary are all there is to J. Everything else is always defined in terms of those and you can't define words with symbolic names, like you can in Haskell, OCaml etc. - so once you know those, you can say you know the language. And as for reading J code, it's meant to be read with the help of the J system: you have at least three possible representation to choose from when viewing J code, and you have ability to evaluate each subexpression to see what it does.

Anyway, J is hard to learn, but after initial hump it's a pleasure to write, and then after a while it becomes possible to read it. In exchange for this difficulty level you get incredible expressive power and performance.

wyc• 12 years ago

I have some thin (read: incomplete) notes that hint at how math-oriented the J verbs are: http://wycd.net/notes/jlang/jlang.pdf

Among my favorite parts of the language is the sole set of vocabulary[0] that you have to learn to be proficient in J. It's daunting at first, but after this "alphabet" is internalized, you can understand most code. Just as our integral symbols save us from writing out "Integral()", J's operators are shorthand for fundamental computational functions. For example, here's a very naive kNN implementation in J, without pulling in any "jlearn" external libraries or anything:

https://github.com/wyc/snippets/blob/master/j/knn.ijs

One of the stated purposes of J is the clear expression of algorithms. How are you supposed to clearly do that with layers upon layers of abstractions? The language excels at matrix and statistical operations on sets of homogeneous data. Many financial institutions deploy J's close sister, K (also a descendant of APL) coupled with KDB[1].

Does it have potential for use on "Big Data"? Maybe. It's not SMP, but the interpreter is rather light, so it can be spun up in multiple processes. Cutting up the data correctly is still a problem. I would also not use J to write a webapp; CRUD isn't its strong point.

Some more examples of J: https://github.com/wyc/snippets/blob/master/j/jtalk/examples...

Come hang out at #jsoftware on freenode to find people much more knowledgeable than me. :P

[0] http://www.jsoftware.com/help/dictionary/vocabul.htm

[1] not the kernel debugger, but the time-series K database: http://kx.com/kdb-plus.php

agumonkey• 12 years ago

It recently came to my mind that Math, J, lisp, ml are just anti-marketing artefacts. But on the intellectual/UX they're on point. When you have a good abstractions, and very consistent and orthogonal ones, appearance becomes almost irrelevant. They help you think and that's what matters.

scottlocklin• 12 years ago

FWIIW, the Jd database is pretty good (which works much like kdb+). It's not designed to work on distributed systems (kdb+ can do this), but it wouldn't be too difficult to make it do this.

I recently wrote a discrete wavelet transform algorithm in J. It took 4 lines. I could probably have done it in 1. Granted it took me a while to write these 4 lines, but it's pretty cool being able to take the whole thing in at a glance.

While I was at it, I wrote my own query system for a much larger than memory dataset; that part only took a few minutes.

One of the great things about J: it teaches you to appreciate the matrix subsystems of things like R. You can do a lot of J in R if you stay away from data.frames.

Oh yeah, while the IDE is pretty nice, I use it in emacs.

Some resources: Minimal J for beginners: http://www.jsoftware.com/jwiki/DevonMcCormick/MinimalBeginni...

A more wordy vocabulary for beginners: http://www.jsoftware.com/jwiki/NuVoc

S4M3• 12 years ago

> The IDE is more akin to Python's IDLE than monstrosities which may come to mind. There's a window for entering commands and seeing the results, and you can open up separate, syntax-colored editor windows, running the contents of each with a keypress. It's nothing groundbreaking, but it's something that most languages don't provide.

What? I have considered that standard for all the languages that have an interpreter (which is roughly, everything except C,C++,C#, Java).

mgraczyk• 12 years ago

Both of the major C# distributions (mono and CLR with VS) come with a repl now:

    $ csharp
    Mono C# Shell, type "help;" for help

    Enter statements below.
    csharp> var seq = Enumerable.Range(0, 100); 
    csharp> var mod17 = from num in seq
          > where num % 17 == 0
          > select num
    csharp> foreach (var n in mod17) { 
          >    Console.WriteLine(n);
          > }
    0
    17
    34
    51
    68
    85
    csharp>

S4M3• 12 years ago

Oh, that's nice, thanks - I haven't used C# since 2008. What you said just reinforces my point: the OP boasts over a feature that is very, very common.

james_hague• 12 years ago

I'd like to clarify that I was using J6.02 for Windows when I wrote that. You can still download it from jsoftware.com.

Since then the priority has been for J to be platform independent, but it's resulted in some big steps backward for beauty and usability. That's for the environment only--not the language.

kevinSuttle• 12 years ago

I'd love to see screenshots or videos of the more visual parts of the environment. Especially the Labs.

ww2• 12 years ago

one hurdle of J is that the verb train approach is too raw.

J Has the Best Development Environment (2009)

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