[valenterry]

> Whether due to unfamiliarity or genuine opacity, some of the shorter solutions will be incomprehensible to some (most?) people. So while technically more expressive, what good is that if you can't read the solution, let alone write it?

How many people can read advanced math formulas? Mostly none. So what good is it that they are used?

The answer is, it doesn't really matter if outsiders can't read it. Yes, it increases the hurdle to enter the field, but the benefits drastically outweight the initial learning in the long term.

Same is true (even more so, I would say) for programming languages.

[coldtea]

>How many people can read advanced math formulas? Mostly none. So what good is it that they are used? The answer is, it doesn't really matter if outsiders can't read it. Yes, it increases the hurdle to enter the field, but the benefits drastically outweight the initial learning in the long term.

Do they? I feel like a "citation needed" is in order.

There's a target for math formulas, and it's mathematicians. Those can read math formulas, even advanced ones. If outsiders (that is, laymen) can't read them, it's ok: they aren't supposed to be working with math most of the time.

The target for programming languages is programmers. But unlike math formulas, the outsiders that can't read some language J isn't laymen, but still programmers. The problem is not that non-programmer Joe Sixpack can't read J. The problem is that programmers can't read it, or find it unyieldly.

You could argue that, 'that's ok, the target for J is people who comprehend and are productive with something like J'. Sure, but that's precisely what we call out here. That some languages, even though expressive technically, put off not just outsiders from programming, but also programmers.

[valenterry]

I don't think every mathematician can read any formula, no matter of the field and how advanced it is.

And for developers it's the same. However, I'll grant that PLs are evolving faster than math does, so there is more catchup-required for sure. But without that there would be much more limited progress. Think lambdas: before they were an "elite feature" and now they are everywhere and languages have adopted them and people had to learn new syntax.

[gcanyon]

Experts in J say something like, "If you think through the problem, you've solved the problem in J"

I definitely agree that "can outsiders, or even less experienced coders, understand it?" is orthogonal to "expressiveness." I went a little harder than I intended listing that as a drawback to expressiveness, although it's certainly a complementary feature: given two languages of equal expressiveness, the one that encapsulates that range in more comprehensible terms is "better" (there are many other factors to consider, hence the mitigation quotes).

I love the fact that in J:

    mean =: +/%#

Meaning that you can express, from primitives, calculating the mean average with just four characters. And even with my very weak J, that's clear. But then I look at something I wrote over ten years ago:

    candidates =:,/((_4]\4#"3 (_1 + 2 * #:i.2^9) (* &. |:)" 1 _ list)  * (>rowSigns))

and I have zero clue how to interpret that. It's almost certainly not idiomatic J, so it's possible (likely) that it looks like garbage to a J expert as well. Certainly J's terseness doesn't lend itself to commentation. :-)