4 ms·

This is definitely the most interesting part of the article for me: Incidentally, this problem set the scene for a wizard duel between two computer scientists

by Shorel 6y ago

This is definitely the most interesting part of the article for me: Incidentally, this problem set the scene for a wizard duel between two computer scientists several decades ago. In 1986, Jon Bentley asked Donald Knuth to show off “literate programming” with a solution to this problem, and he came up with an exquisite, ten-page Knuthian masterpiece. Then Doug McIlroy (the inventor of Unix pipelines) replied with a one-liner Unix shell version using tr, sort, and uniq. http://www.leancrew.com/all-this/2011/12/more-shell-less-egg/ http://www.leancrew.com/all-this/2011/12/more-shell-less-egg...

felixr 6y ago
If you want to read the " ten-page Knuthian masterpiece": https://homepages.cwi.nl/~storm/teaching/reader/BentleyEtAl86.pdf https://homepages.cwi.nl/~storm/teaching/reader/BentleyEtAl8... I don't think it was linked from the article
jerf 6y ago
I have seen it observed that while the tr/sort/uniq approach has practical value, that if the question is how would you implement the features that tr/sort/uniq provide simply invoking them is not much of an answer. I don't think Knuth was unaware that there were existing tools that could solve the problem, the whole point was to demonstrate his literate programming approach at some semi-reasonable scale on a problem everyone could recognize. It's kinda like how pretty much every interview-sized question has some sort of off-the-shelf solution somewhere, because anything that fits into an interview has been solved thousands of times over... but that's not the point of interviews. In modern terms, it would be something like complaining that $LANGUAGE's web server implementation is a grotesque bloated mess (and therefore $LANGUAGE isn't very good) because in shell all I have to do is run "nginx". There is a true and useful sense in which that is true, but there is also a true and useful sense in which that is utterly missing the point.
35fbe7d3d5b9 6y ago
I've always personally disliked McIlroy's oft-quoted conclusion (emph. mine): > Knuth has shown us here how to program intelligibly, but not wisely. I buy the discipline. I do not buy the result. He has fashioned a sort of industrial-strength Fabergé egg—intricate, wonderfully worked, refined beyond all ordinary desires, a museum piece from the start. Well, yes – absolutely. If you read the initial column[1] pre-McIlroy's response, you'll see that Knuth is not presenting a word-counting solution, but instead the concept of literate programming and how intertwining code and prose can be better for the programmer. Knuth isn't trying to count words, he's trying to teach you a different way to develop, and he's doing it by showing an example that has been simplified so the average person can chew on it. I'm not sure if the popular interpretation of "ivory tower Knuth versus tactical genius McIlroy" is a modern take or if that was how it was received when the column was published, but it feels very unfair to present it as such today. [1]: https://doi.org/10.1145/5689.315644 https://doi.org/10.1145/5689.315644
taeric 6y ago
Sorta. That incident is also famous for being easy to misrepresent. That said, if you are new to that, Programmer Pearls is a great series. And literate programming is neat to at least know of.
henrik_w 6y ago
Also interesting is that this problem is used as the example in the book "Exercises in Programming Style" by Cristina Videira Lopes. It shows this problem solved in 33 different programming styles, for example historical, function composition, data-centric etc. I have written more about it here: https://henrikwarne.com/2018/03/13/exercises-in-programming-style/ https://henrikwarne.com/2018/03/13/exercises-in-programming-...
- taeric 6y ago
  There is a new version of that book. Thanks for bringing it to my attention, looks great!
ngngngng 6y ago
Last summer I was looking for a program that would tell me which shell commands last used in a specific directory. Because I had been reading "The Unix Programming Environment" it quickly occurred to me that the program I was looking for could easily be made from several existing commands. Only after I wrote the small script did I find that the solution already existed except it was >1000 lines of code, 20 github contributors, and utilized a sqlite database. My one line has less features, but I'll take it.
- themantri 6y ago
  Could you please share the one-liner? Thanks!
  - ngngngng 6y ago
    https://github.com/natethinks/jog/ https://github.com/natethinks/jog/

by Shorel 6y ago

felixr 6y ago

If you want to read the " ten-page Knuthian masterpiece": https://homepages.cwi.nl/~storm/teaching/reader/BentleyEtAl86.pdf https://homepages.cwi.nl/~storm/teaching/reader/BentleyEtAl8... I don't think it was linked from the article

jerf 6y ago

I have seen it observed that while the tr/sort/uniq approach has practical value, that if the question is how would you implement the features that tr/sort/uniq provide simply invoking them is not much of an answer. I don't think Knuth was unaware that there were existing tools that could solve the problem, the whole point was to demonstrate his literate programming approach at some semi-reasonable scale on a problem everyone could recognize. It's kinda like how pretty much every interview-sized question has some sort of off-the-shelf solution somewhere, because anything that fits into an interview has been solved thousands of times over... but that's not the point of interviews. In modern terms, it would be something like complaining that $LANGUAGE's web server implementation is a grotesque bloated mess (and therefore $LANGUAGE isn't very good) because in shell all I have to do is run "nginx". There is a true and useful sense in which that is true, but there is also a true and useful sense in which that is utterly missing the point.

35fbe7d3d5b9 6y ago

I've always personally disliked McIlroy's oft-quoted conclusion (emph. mine): > Knuth has shown us here how to program intelligibly, but not wisely. I buy the discipline. I do not buy the result. He has fashioned a sort of industrial-strength Fabergé egg—intricate, wonderfully worked, refined beyond all ordinary desires, a museum piece from the start. Well, yes – absolutely. If you read the initial column[1] pre-McIlroy's response, you'll see that Knuth is not presenting a word-counting solution, but instead the concept of literate programming and how intertwining code and prose can be better for the programmer. Knuth isn't trying to count words, he's trying to teach you a different way to develop, and he's doing it by showing an example that has been simplified so the average person can chew on it. I'm not sure if the popular interpretation of "ivory tower Knuth versus tactical genius McIlroy" is a modern take or if that was how it was received when the column was published, but it feels very unfair to present it as such today. [1]: https://doi.org/10.1145/5689.315644 https://doi.org/10.1145/5689.315644

taeric 6y ago

Sorta. That incident is also famous for being easy to misrepresent. That said, if you are new to that, Programmer Pearls is a great series. And literate programming is neat to at least know of.

henrik_w 6y ago

Also interesting is that this problem is used as the example in the book "Exercises in Programming Style" by Cristina Videira Lopes. It shows this problem solved in 33 different programming styles, for example historical, function composition, data-centric etc. I have written more about it here: https://henrikwarne.com/2018/03/13/exercises-in-programming-style/ https://henrikwarne.com/2018/03/13/exercises-in-programming-...

taeric 6y ago
There is a new version of that book. Thanks for bringing it to my attention, looks great!

ngngngng 6y ago

Last summer I was looking for a program that would tell me which shell commands last used in a specific directory. Because I had been reading "The Unix Programming Environment" it quickly occurred to me that the program I was looking for could easily be made from several existing commands. Only after I wrote the small script did I find that the solution already existed except it was >1000 lines of code, 20 github contributors, and utilized a sqlite database. My one line has less features, but I'll take it.

themantri 6y ago
Could you please share the one-liner? Thanks!
- ngngngng 6y ago
  https://github.com/natethinks/jog/ https://github.com/natethinks/jog/