[acqq]

How would you feel if somebody would present the “six steps clicks in Excel and SQL Server” that eventually produce the same result? The starting goal was simply not “show how to use and combine external programs.” Even if you need some kind of skill to combine them. It’s exactly the same kind of missed fullfilment of the given starting task.

[mschaef]

The reason I asked about a literate programming version of the shell script is that it speaks directly to Knuth's original stated goal: "I’ll try to prove the merits of literate programming by finding the best possible solution to whatever problem you pose"

In the context of that requirement, the it's the use of literate programming that's more of a concern than the specific implementation. (Which is why I asked about a literate version of the shell pipeline.)

Earlier in the thread, you also mention this concern around data volumes:

> If you have hundreds of gigabytes of input, you'd have to have at least that much more just to sort it. McIlroy's approach is a good one for one-off program or not too big input processing,

There, your concern is not justified by the stated requirements of the problem: "I did impose an efficiency constraint: a user should be able to find the 100 most frequent words in a twenty-page technical paper"

I do think McIlroy failed to solve the problem of demonstrating the value of literate programming, but I'm not sympathetic to arguments that he should've used more complex algorithms or relied on less library code. This is particularly the case when the additional complexity is only relevant in cases that don't fall into the given requirements.

(A literate program that uses SQL server or Excel might be an interesting read....)

[acqq]

> The reason I asked about a literate programming version of the shell script is that it speaks directly to Knuth's original stated goal: "I’ll try to prove the merits of literate programming by finding the best possible solution to whatever problem you pose" In the context of that requirement, the it's the use of literate programming that's more of a concern than the specific implementation.

And McIlroy's "solution" is provably not the "best possible solution" if you are interested in the algorithms, algorithmic complexity, the resources used, you know, all the topics studied by people doing computer science. All these topics are still relevant today.

That is the domain that was of interest to both Bentley and Knuth, and McIlroy "sabotaged" the whole by presenting effectively only a list of calls to the stand-alone programs which he hasn't developed himself, which he avoided to present, and even without looking at them, just by analyzing what are the best possible implementations of these, every student of computer science can prove that McIlroy's solution is worse.

If you carefully read the original text (and if you understand the topics of computer science), you can recognize that McIlroy was aware of the algorithmic superiority of Knuth's solution.

Knuth definitely and provably won.

[svat]

While I have been watching this subthread with increasing dread, I feel I should point out it was not a competition or contest to be "won" -- Knuth wrote an interesting program, and McIlroy wrote an interesting review of it.

[acqq]

> it was not a competition or contest to be "won"

Sure, it wasn't a competition. The fact remains: McIlroy criticized Knuth's presentation of complete algorithms which effectively solved specified problem, by presenting just a sequence of calls which provably have to call the implementations that must implement provably worse algorithms. In the column in ACM whose topic were... algorithms, edited by Jon Bentley.

So if you consider that two sides presented their arguments regarding the algorithms related to the specific problem, we can still say that Knuth "won" that "dispute."

[mschaef]

> presenting just a sequence of calls ... that must implement provably worse algorithms.

You've never really established why this matters given that the goal of the challenge was to present the value of literate programming.

The goal wasn't an optimal algorithm or minimal resource consumption - the goal was to demonstrate the value of literate programming on a small data processing problem.

This is a very different problem than writing an optimal or highly scalable algorithm.

[acqq]

> The goal wasn't an optimal algorithm or minimal resource consumption - the goal was to demonstrate the value of literate programming on a small data processing problem.

No. You obviously still haven't read the column and the article that explained what the goal actually was. The actual goal was to demonstrate Knuth's WEB system, which was explicitly made only for Pascal in 1986. That was what Bentley asked Knuth to do (quoting from the article "Programming pearls: literate programming", Communications of the ACM, Volume 29 Issue 5, May 1986 Pages 384-369):

"for the first time, somebody was proud enough of a substantial piece of code to publish it for public viewing, in a way that is inviting to read. I was so fascinated that I wrote Knuth a letter, asking whether he had any spare programs handy that I might publish as a “Programming Pearl.” But that was too easy for Knuth. He responded, “Why should you let me choose the program? My claim is that programming is an artistic endeavor and that the WEB system gives me the best way to write beautiful programs. Therefore I should be able to meet a stiffer test: I should be able to write a superliterate program that will be noticeably better than an ordinary one, whatever the topic. So how about this: You tell me what sort of program you want me to write, Crin d I’ll try to prove the merits of literate programming by finding the best possible solution to whatever problem you pose’--at least the best by current standards.”"

So, in the context of demonstrating Knuth's WEB on the substantial piece of code, the modification of the request was only that Knuth wasn't allowed to use the program he already wrote, but that he had to write a new one! (So the starting goal was in effectively all the premises exactly the opposite of what McIlroy then showed!)

So the goal was to write and present a wholly new program in Knuth's WEB, which, under the standards of evaluation of the quality of the solution as widely accepted by computer scientists, would be "the best solution." Which is exactly about the optimality of the algorithms, resources use etc.

If you still don't fully appreciate the context of the Knuth's program, do search for all the other columns and computer science books written by both Bentley and Knuth -- the topics of both were never "how to use existing programs" but how to develop/use the best algorithms.

[mschaef]

Well put.

I think it's possible and desirable to simultaneously respect both approaches for their respective merits. Maybe ironically for this profession, the choice isn't either/or.