I think that "It's what I'm used to." is the main reason - intellectual comfort zone.
Having learned BASIC, FORTRAN and Pascal, C seemed like line noise - at first. As did PERL. And then k.
Btw, COBOL seemed "too verbose".
Once I actually started writing many k programs and then reading even more of them, I was able to recalibrate for the abstraction/density. I moved my intellectual comfort zone. Ironically, I was already there with mathematics. However, programming languages were different :).
Now, as a result, every time I have to read Java, I suffer from a kind of fatigue - having to read way too much code to glean the writer's intent. I just want them to get to the F'ing point.
N.B. - Mathematical literature/writing went through this same transition during the Renaissance. Equations were described in natural language (not unlike COBOL). A simple polynomial could require a paragraph of text to describe.
I'm not sure -- I know that after the fourth or fifth time solving a problem on projecteuler.net in 20 lines of code and seeing someone post a 1-line J/K solution, I went and downloaded J. I even managed to solve a few euler problems with it, which I regard as a large accomplishment for a novice. I like to tell people I've written a whole twenty or so lines of code in J!
I do enjoy learning about such things, but, for most of the work I do, performance is nowhere near at the top of the list of things I care about. Also in the past I've been burned by code that's small/fast but is otherwise utterly unmaintainable. I'm not saying that's the case here, but... past experience, and all that tends to color perceptions.
I think with a language like k or q, which appears to be purpose-built for certain types of problems, people look at it and get easily confused and discouraged because it's so different from all the more mainstream general-purpose programming languages they're used to. And it's a lot easier to put down something you don't understand than to admit you don't get it, or to spend lots of time learning something that may not be of much use to you. Kinda sucks, but it's often human nature.
> I think with a language like k or q, which appears to be purpose-built for certain types of problems,
The thing is, it's not purpose built, and it doesn't even appear to be if you suspend your disbelief. The only reason you'd think it is purpose built is because "well, it can't be this short if it wasn't purpose built". But if you go over the manual, and find special built operators, please tell us what they are.
e.g., to compute an average, you can use the function avg:{(+/x)%#x} - with the exception of parentheses, every character has an orthogonal function. Similarly, the maximum subarray sum solution mss:|/0(0|+)\ ; and there are many others. And it's not just math stuff - http://nsl.com has lots of other examples of many kinds -- and most importantly -- is an operating system + GUI not general enough?
If you are really interested, http://nsl.com/ is a treasure trove - quite a few of the examples are extremely well documented, some or not, but there's a wealth of information there.
Thanks, I've missed the SCC one. I will try to understand it. (The reason I've asked about DFS in particular is that it is inherently sequential. This SCC algorithm probably encapsulates some kind of DFS.)
K has interesting sequential goodies as well: over ("fold" in Lisp/Haskell, "reduce" in python), and scan (same, with all intermediate results returned as well). But it also has the unary ("monadic" in APL terminology) counterparts to these essentially binary operators, which I don't remember from Lisp or Haskell (but I'm neither a Lisper or a Haskellite, they probably are there somewhere..)
Unary over is the "fixed point"/"converge" adverb, which does
x <- f(x)
until x stabilizes (to within floating point tolerance if it is a float), returns to its first value, or goes through a requested number of iterations.
The best example of this that I can think off is the K "flatten" idiom:
,//
read: "concat over, converge". That is, given a general list, it concatenates all its items promoting atoms to one-element lists - thus, flattening one level of the list; And then applies it again and again until there is no further change, thus flattening successive levels of the list.
Is this the most efficient way to do this? No! in fact, for an unbalanced one sided list it will do O(n^2) where n is the number of items, with a best (and idiomatic Lisp/Haskell) solution being O(n), although it's usually 100 chars rather than 3.
But the actual code orchestrated by these 3 chars behind the scenes is all tight C loops, so for small n it will beat complex solutions. And it is all of 3 self-describing, easily remembered, easily recognized, easily optimized (if Arthur ever cared ...) characters. If you care about worst case, you can easily code the standard Lisp/Haskell solution just as you would in those languages. See [0] for more.
The underlying computational model fits sequential, parallel, SIMD, and almost every other paradigm much better than all the popular programming languages. Unfortunately, there's a learning curve that puts of most people (and is perhaps insurmountable to some people who have no problem with Python, Java, C or PHP) - it's much more Math-oriented.
Numbers in arrays can be treated as pointers, into that same array, giving a graph. It's just a question of context. If you were storing RDF triples in K you'd simply have an array for subjects, one for objects, one for predicates, and one of the URIs/text. Simply store the index of the URI/text item in each of the subject, object and predicate columns. An individual triple would be formed by the same index applied to the subject, object and predicate arrays.
DFS is then a variation of the more familiar functional style of tackling the problem where you have your end condition (i.e. something that matches what you're looking for) and failing that do something else (typically recursion).
I can't recall enough of the K syntax these days to actually implement that right now though, or if K has TCO.
It all depends on how you define "small and fast".
Comments obviously are not code, so it's reasonable to complain about lack of comments.
You suggested wordcount, I think wordcount is good, so it's reasonable to complain about single letter words rather than descriptive words.
uberalex's suggestion for reformatting wouldn't change the algorithm or speed. It would simply spread operations across more lines. That also seems like a reasonable thing to ask, to me. They can learn your method either way.
Edit: I mean, I'm sure fitting more on the screen is valuable, but people already know how to fit many times as much code onto a screen. They avoid it on purpose for whatever reason.
>I mean, I'm sure fitting more on the screen is valuable, but people already know how to fit many times as much code onto a screen. They avoid it on purpose for whatever reason.
I think this reason (whatever it happens to be) is probably wrong.
I don't understand it either. But it happens everywhere, not just in code. Most people are only interested in the "truth" and "facts" as long as it fits within their existing world view.
Having learned BASIC, FORTRAN and Pascal, C seemed like line noise - at first. As did PERL. And then k.
Btw, COBOL seemed "too verbose".
Once I actually started writing many k programs and then reading even more of them, I was able to recalibrate for the abstraction/density. I moved my intellectual comfort zone. Ironically, I was already there with mathematics. However, programming languages were different :).
Now, as a result, every time I have to read Java, I suffer from a kind of fatigue - having to read way too much code to glean the writer's intent. I just want them to get to the F'ing point.
N.B. - Mathematical literature/writing went through this same transition during the Renaissance. Equations were described in natural language (not unlike COBOL). A simple polynomial could require a paragraph of text to describe.