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Comment by gjulianm | Hacker News Reader

> (Or at least, the idea is, do you know what dialect it uses? Where's the code from?)

From Wikipedia page of K programming language https://en.wikipedia.org/wiki/K_(programming_language)

> filter(lambda x:all(x%i>0 for i in range(2,x)),range(2,R)) - is this really that much better?

You don't need to know Python. Filter is probably doing a filter, "lambda x: ... " looks like a lambda function, for looks like a loop... I am 100% sure that, without any language knowledge, the Python version is far more easy to understand.

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Ah, that code was added to the wiki page in 2006 apparently. A modern version is basically the same anyway.

I will (maybe) agree that the python is easier to understand without any language knowledge - but that does not mean the K is not understandable. If you know K, it is understandable, and knowing a language seems like a pretty low bar for understanding it.

I mean, by the same measure, spaghetti code is not spaghetti code if it makes sense in your head. But we all understand that there are certain qualities of code that make it “spaghetti” or not independently of your understanding of it. Similarly there are features of languages (such as terseness, use of symbols, dependency on context) that makes them harder to read

If you don’t know a language but are hoping to read it, for what purpose are you intending to read it? Is it a casual understanding? If you’re talking about maintaining the code it’s probably better to stipulate that people already know the language. If you want to maintain code in a language you don’t know, I’m not sure you’d be a great hire.

Unless you have perfect memory and perfect recall, it’s very possible you’ll forget what a certain symbol meant. Specially if you read the code at a time you’re not being specially bright (say, Friday noon after an stressful week). Much harder to forget what the word “filter” means. Also much easier to recognize words than symbols where differences might be small.

It's really unlikely (imo impossible) you'll forget what a symbol means in APL or K etc if you program in it reasonably often. There aren't many symbols, and most of them are used pretty frequently. If you do forget, there's plenty of resources to jog your memory though. The Dyalog RIDE has a language bar at the top, and hovering over a symbol gives a brief description with examples. https://janiczek.github.io/tryapl-elm/ replicates this if you want to see for yourself. I disagree that it's easier to recognise words than symbols if there are small differences, the symbols are distinctive anyway so that's not really a real problem.

> It's really unlikely (imo impossible) you'll forget what a symbol means in APL or K etc if you program in it reasonably often.

Well, of course, if you’re always practicing the same thing you’re unlikely to forget it. That’s not always the case, though.

> the symbols are distinctive anyway so that's not really a real problem.

Really? From that toolbar alone I’m seeing empty circle vs slightly smaller empty circle, a lot of symbols with/without a dash or umlaut, dot and comma… seems pretty easy to get a lot of those confused or misread.

Um, yeah. Knowing a language generally involves putting time into learning and the benefit is not forgetting stuff. You seem to not want to own the fact that your entire impression is predicated on it being not practical for someone not interested in investing any time into it. But I’m not sure that the input from such people is ever valuable.

It seems like it might be easy to confuse things, but from experience, it isn't.

I feel like in general, you're making a lot of (fairly reasonable) assumptions about what programming in an array language is like, but they aren't really the case (as lots of other people have tried to explain). Without really trying it out, I'm not sure how someone could convince you otherwise, so there's a bit of an impasse.

I think you should listen to what people are saying and have said in the past though (https://news.ycombinator.com/item?id=33640275, https://news.ycombinator.com/item?id=22524918) and trust that for some people who do learn array languages, they do find it useful + productive, and a lot of the things you've raised are not issues in practice.

I have listened and to me it always seems to come down to “you make reasonable points but it’s not a problem for me so it’s not a problem”.

And I think there’s a lot of implicit bias when people who like APL say it’s perfectly readable. Given how readability hits you in the face first thing when you see APL and how it’s not a widely used language, only the people enthusiastic about it and willing to overlook the readability issues will end up learning it. Of course they don’t find issues in practice, if they had issues with that they’d have probably abandoned the language quickly.

> and trust that for some people who do learn array languages, they do find it useful + productive, and a lot of the things you've raised are not issues in practice.

I’m not saying it isn’t useful or productive. That’s not the discussion. The point is that they’re languages that they’re hard to use and hard to read. I don’t see how it’s such a controversial point.

For example, I like LaTeX a lot. I’ve done quite a lot of things with it, it’s been very useful and I’ve been very productive with it. I have no problem reading that code. But the fact that I have no problems doesn’t mean there aren’t actual problems with LaTeX. LaTeX will always be hard to read and quite a bit messy no matter how used I get to it.

Yes - the first thing you notice when you see APL is 'this looks weird'. Most people then assume 'this is complicated, hard to read, and hard to use', and move on with their lives. Some people decide to learn it anyway, and quickly (within under a day) realise it is actually simple, readable, and easy to use!

It's not like some people are magically born with the ability to read APL (or anything else), and learning it isn't a matter of 'overlooking the readability issues', but rather realising the 'readability issues' are a false assumption. There's not 'bias', there's just experience.

That is why "they’re hard to use and hard to read" is 'controversial', because it is just not true.

> Some people decide to learn it anyway, and quickly (within under a day) realise it is actually simple, readable, and easy to use!

Do you think all people who decide to learn it anyway end up with the same conclusions?

> That is why "they’re hard to use and hard to read" is 'controversial', because it is just not true.

So things like symbols having different meanings depending on number of arguments, prefix notation making the arguments of functions/operators stand out less, making it reading right-to-left (which is different from what you usually read - that brings the fun question of whether APL is left-to-right in Arabic countries), or having to know extra symbols that aren't used in other contexts... All of those things are not real?

I come back to the LaTeX example because to me that's very similar. I get when you say "I don't find APL hard to read/understand/work with" because I feel the same with LaTeX (even though it's not as obscure and "alien-looking" as APL is). I write slides in LaTeX faster and better than what I could do with Powerpoint. But that doesn't deny that there are a lot of things in LaTeX that make things harder, even when those are part of the core and when removing them would mean removing good things about the language too.

I think all people who try to learn APL for more than about 5 minutes end up realising most of their assumptions were completely wrong. Maybe they don't reach exactly the same conclusions (a lot of people do), but they reach similar ones.

> So things like <APL things> are not real?

They are real, but they are not issues for anyone who has tried APL at all.

Advent of code is starting soon, I'd recommend that you pick an array language and give the first couple of problems a go in it - even if you don't like it, at least it would save you from making yet more uninformed comments next time an array language article is on HN (and save array language programmers worldwide the pain of reading them).

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