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This is a strange article to me. I've not seen any class that teaches Prolog place these constraints (use recursion / don't add new predicates) or even accident

This is a strange article to me. I've not seen any class that teaches Prolog place these constraints (use recursion / don't add new predicates) or even accidentally have the outcome of "making prolog look tedious". What's the joke here? That aside, I wonder if getting the reverse solution (sum(?, 10)) is better served by the straightforward or the tedious approach. I suspect both would work just the same, but I'd be curious if anyone knows otherwise.

7thaccount 1y ago
I found the article to be hilarious. It's existence obviously means some professor didn't allow them to use the standard library and they tongue in cheek show how irritating that is. I'm sure it's possible they made it up, but we had similar restrictions where I could use an Arduino for my engineering Senior Design Project in college, but no Arduino or module libraries - just our own C. We passed, but barely. It also was weird as it didn't match how normal people would solve the problem.
- Jtsummers 1y ago
  Yeah, this line made it click: > Now this is starting to look like Professor of Programming Languages code! A lot of tier 2/3 CS schools with programming language courses (a survey of multiple languages across various paradigms) teach Prolog this way (and I've seen some fantastically terrible examples of Lisp code coming out of those same courses). It's unfortunate because, at these schools, this is often the only formal course where students branch out of C/Java/C++/C#/Python/JS (and they may only get 2-3 of those over the rest of their courses). It leaves the students with a gross misunderstanding of the languages and dread when they see them again.
- Blackthorn 1y ago
  There's nothing wrong with teaching like that. If the class is supposed to teach you something that isn't just "use the stdlib", then it makes sense to ban it.
  - deleted 1y ago
    [deleted]
  - 7thaccount 1y ago
    I'm guessing the author is aware and just venting. It doesn't make it less frustrating though. It's almost like someone asking you to dig a hole with chopsticks.
- seba_dos1 1y ago
  > It also was weird as it didn't match how normal people would solve the problem. If I can solve a problem by building from preexisting LEGO blocks then I'll probably do that, but it wouldn't be a valuable learning exercise. Students aren't being given problems in need of effective solution, these problems are tools to facilitate understanding. What you described could be pointless if it made you work on reimplementing trivial stuff that you'd already mastered long time ago instead of focusing on actual problem. Writing your 100th hashmap implementation or yet another I2C driver isn't particularly valuable. Since you mentioned "barely passing", I don't think that was the case though.
  - 7thaccount 1y ago
    It's one of those projects where you never have enough time throughout the year. Coding what we did from scratch wasn't very easy either. I could now probably do the coding in a weekend with the right library code. You learn something either way I guess.
- yuye 1y ago
  >I'm sure it's possible they made it up, but we had similar restrictions where I could use an Arduino for my engineering Senior Design Project in college, but no Arduino or module libraries - just our own C. When I started compsci, it was the first year of a all-new curriculum for CompSci. Literally the first week: We had to program an Arduino to play a song on a speaker by toggling GPIO, within a week. No assembly or any of that high-level mumbo-jumbo. We had to read the datasheet, look at the instructions and write the hex representation for each instruction in a txt file. We had a "linker" tool: It took a basic bootloader (containing some helper functions for GPIO), turned our hex-txt file into actual binary, then just copies that to a set address. The bootloader did nothing more than init the GPIO pins and jump into our code. We were given the locations of where these helper functions lived, nothing else. It was to give a quick and intimate understanding of how CPUs actually work and why we use compilers and stuff. It worked really well, but it was so much of a pain that they changed it to allow students to use asm a year or two after.
  - tengwar2 1y ago
    <Four Yorkshiremen accent> You were lucky! We had to design and build the computer out of Z80-family components first before we could play around in binary. There was actually a reason - this was back in '83/84 in a physics lab, and the idea was to be able to build your own logging / control device. PCs existed, but were terribly expensive.
floxy 1y ago
>getting the reverse solution (sum(?, 10)) Doing an "all modes" predicate: sum_list(List,Sum) ...where... sum_list([1,2,3], 6) ...is "True" as expected would probably be a pretty interesting exercise if you wanted to be able to get all of the lists. You'd probably need to do an "enumerate the rationals" type of thing, since you need to go to infinity in a couple of different directions at the same time. That is, you can't do nested loops/recursing: for(x=-∞; x<∞; ++x) { for(y=-∞; y<∞; ++y) { i.e. sum_list([],0). sum_list([L|Ls],BigSum) :- sum_list(Ls, LittleSum), add(L,LittleSum,BigSum). ...with an all-modes "add/3". Since there are an infinite supply of pairs that add up to, say 10: ⋮ [12,-2] [11,-1] [10, 0] [ 9, 1] [ 8, 2] ⋮ [ 0,10] [-1,11] [-2,12] ⋮ ...and you can also go to arbitrary list lengths: [10] [1,9] [1,1,8] [1,1,1,7] ⋮ [1,1,1,1,1,1,1,1,1,1] ⋮ [0,1,1,1,1,1,1,1,1,1,1] [1,0,1,1,1,1,1,1,1,1,1] ⋮ [1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0] ⋮ [-100,-99,-98,...,-12,-11,-9,-8,...,0,1,2,3,4,5,6,7,8,9,10,11,...,99,100] ...your life probably gets easier if you limit the domain to positive integers (without zero) since then the list length doesn't diverge. Then a declarative looking solution probably just has a all-modes equivalent to "sort" somewhere within? Certainly interesting to think about. https://www.cs.ox.ac.uk/people/jeremy.gibbons/publications/rationals.pdf https://www.cs.ox.ac.uk/people/jeremy.gibbons/publications/r... https://prolog-lang.org/ImplementersForum/0103-modes.html https://prolog-lang.org/ImplementersForum/0103-modes.html https://www.swi-prolog.org/pldoc/man?predicate=permutation%2f2 https://www.swi-prolog.org/pldoc/man?predicate=permutation%2...
ebolyen 1y ago
It's been a long time since I took a class like this, but I definitely had a similar experience to the author. Ideas like fold and map where _never_ mentioned in lisp (to exaggerate, every function had to have the recursive implementation with 5 state variables and then a simpler form for the initial call), at no point did higher-order functions or closures make an appearance while rotating a list by 1 and then 2 positions. The treatment of Prolog was somehow worse. Often the code only made any sense once you reversed what the lecturer was saying, realizing the arrow meant "X given Y" not "X implies Y", at which point, if you could imagine the variables ran "backwards" (unification was not explained) the outcome might start to seem _possible_. I expect the lecturer was as baffled by their presentation as we were. In general, it left the rest of the class believing quite strongly that languages other than Java were impossible to use and generally a bad move. I may have been relatively bitter in the course evaluation by the end.
- Y_Y 1y ago
  Thie irony is palpable. I had the (misfortune) of only being (mis)taught procedural languages by professors who thought computers were big calculators who could never be understood, but could be bent to your will by writing more code and maybe by getting a weird grad student to help. Patterns might appear to the enlighted on the zeroth or first instance, but even the mortal must notice them after several goes. The magic of lisp is that if you notice yourself doing anything more than once you can go ahead and abstract it out. Not everything needs to be lifted to functional valhalla of course, but not factoring out e.g. map and filter requires (imho) a wilful ignorance of the sort that no teacher should countenance. I think it's bad professional practise, bad pedagogy, and a bad time overall. I will die on this hill.
  - eru 1y ago
    If you are only used to Java (the bad, old, ancient version), you don't even notice that you can factor out map and filter.
- kstrauser 1y ago
  Ah, yes. Like in the class where we learned Moscow ML, where loops don’t and variables ain’t, and Godspeed!
smadge 1y ago
It reminds me of a satirical post called “Evolution of a Haskell Programmer” in which a nice simple implementation of the Fibonacci function becomes more and more convoluted, abstract, and academic [1]. [1] https://people.willamette.edu/~fruehr/haskell/evolution.html https://people.willamette.edu/~fruehr/haskell/evolution.html
- smadge 1y ago
  *factorial function
  - JadeNB 1y ago
    Or maybe just a very bad implementation of the Fibonnaci sequence.
  - widforss 1y ago
    I was extremely confused for a moment and pondered returning my MSc.

7thaccount 1y ago

I found the article to be hilarious. It's existence obviously means some professor didn't allow them to use the standard library and they tongue in cheek show how irritating that is. I'm sure it's possible they made it up, but we had similar restrictions where I could use an Arduino for my engineering Senior Design Project in college, but no Arduino or module libraries - just our own C. We passed, but barely. It also was weird as it didn't match how normal people would solve the problem.

Jtsummers 1y ago
Yeah, this line made it click: > Now this is starting to look like Professor of Programming Languages code! A lot of tier 2/3 CS schools with programming language courses (a survey of multiple languages across various paradigms) teach Prolog this way (and I've seen some fantastically terrible examples of Lisp code coming out of those same courses). It's unfortunate because, at these schools, this is often the only formal course where students branch out of C/Java/C++/C#/Python/JS (and they may only get 2-3 of those over the rest of their courses). It leaves the students with a gross misunderstanding of the languages and dread when they see them again.
Blackthorn 1y ago
There's nothing wrong with teaching like that. If the class is supposed to teach you something that isn't just "use the stdlib", then it makes sense to ban it.
- deleted 1y ago
  [deleted]
- 7thaccount 1y ago
  I'm guessing the author is aware and just venting. It doesn't make it less frustrating though. It's almost like someone asking you to dig a hole with chopsticks.
seba_dos1 1y ago
> It also was weird as it didn't match how normal people would solve the problem. If I can solve a problem by building from preexisting LEGO blocks then I'll probably do that, but it wouldn't be a valuable learning exercise. Students aren't being given problems in need of effective solution, these problems are tools to facilitate understanding. What you described could be pointless if it made you work on reimplementing trivial stuff that you'd already mastered long time ago instead of focusing on actual problem. Writing your 100th hashmap implementation or yet another I2C driver isn't particularly valuable. Since you mentioned "barely passing", I don't think that was the case though.
- 7thaccount 1y ago
  It's one of those projects where you never have enough time throughout the year. Coding what we did from scratch wasn't very easy either. I could now probably do the coding in a weekend with the right library code. You learn something either way I guess.
yuye 1y ago
>I'm sure it's possible they made it up, but we had similar restrictions where I could use an Arduino for my engineering Senior Design Project in college, but no Arduino or module libraries - just our own C. When I started compsci, it was the first year of a all-new curriculum for CompSci. Literally the first week: We had to program an Arduino to play a song on a speaker by toggling GPIO, within a week. No assembly or any of that high-level mumbo-jumbo. We had to read the datasheet, look at the instructions and write the hex representation for each instruction in a txt file. We had a "linker" tool: It took a basic bootloader (containing some helper functions for GPIO), turned our hex-txt file into actual binary, then just copies that to a set address. The bootloader did nothing more than init the GPIO pins and jump into our code. We were given the locations of where these helper functions lived, nothing else. It was to give a quick and intimate understanding of how CPUs actually work and why we use compilers and stuff. It worked really well, but it was so much of a pain that they changed it to allow students to use asm a year or two after.
- tengwar2 1y ago
  <Four Yorkshiremen accent> You were lucky! We had to design and build the computer out of Z80-family components first before we could play around in binary. There was actually a reason - this was back in '83/84 in a physics lab, and the idea was to be able to build your own logging / control device. PCs existed, but were terribly expensive.

floxy 1y ago

>getting the reverse solution (sum(?, 10)) Doing an "all modes" predicate: sum_list(List,Sum) ...where... sum_list([1,2,3], 6) ...is "True" as expected would probably be a pretty interesting exercise if you wanted to be able to get all of the lists. You'd probably need to do an "enumerate the rationals" type of thing, since you need to go to infinity in a couple of different directions at the same time. That is, you can't do nested loops/recursing: for(x=-∞; x<∞; ++x) { for(y=-∞; y<∞; ++y) { i.e. sum_list([],0). sum_list([L|Ls],BigSum) :- sum_list(Ls, LittleSum), add(L,LittleSum,BigSum). ...with an all-modes "add/3". Since there are an infinite supply of pairs that add up to, say 10: ⋮ [12,-2] [11,-1] [10, 0] [ 9, 1] [ 8, 2] ⋮ [ 0,10] [-1,11] [-2,12] ⋮ ...and you can also go to arbitrary list lengths: [10] [1,9] [1,1,8] [1,1,1,7] ⋮ [1,1,1,1,1,1,1,1,1,1] ⋮ [0,1,1,1,1,1,1,1,1,1,1] [1,0,1,1,1,1,1,1,1,1,1] ⋮ [1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0] ⋮ [-100,-99,-98,...,-12,-11,-9,-8,...,0,1,2,3,4,5,6,7,8,9,10,11,...,99,100] ...your life probably gets easier if you limit the domain to positive integers (without zero) since then the list length doesn't diverge. Then a declarative looking solution probably just has a all-modes equivalent to "sort" somewhere within? Certainly interesting to think about. https://www.cs.ox.ac.uk/people/jeremy.gibbons/publications/rationals.pdf https://www.cs.ox.ac.uk/people/jeremy.gibbons/publications/r... https://prolog-lang.org/ImplementersForum/0103-modes.html https://prolog-lang.org/ImplementersForum/0103-modes.html https://www.swi-prolog.org/pldoc/man?predicate=permutation%2f2 https://www.swi-prolog.org/pldoc/man?predicate=permutation%2...

ebolyen 1y ago

It's been a long time since I took a class like this, but I definitely had a similar experience to the author. Ideas like fold and map where _never_ mentioned in lisp (to exaggerate, every function had to have the recursive implementation with 5 state variables and then a simpler form for the initial call), at no point did higher-order functions or closures make an appearance while rotating a list by 1 and then 2 positions. The treatment of Prolog was somehow worse. Often the code only made any sense once you reversed what the lecturer was saying, realizing the arrow meant "X given Y" not "X implies Y", at which point, if you could imagine the variables ran "backwards" (unification was not explained) the outcome might start to seem _possible_. I expect the lecturer was as baffled by their presentation as we were. In general, it left the rest of the class believing quite strongly that languages other than Java were impossible to use and generally a bad move. I may have been relatively bitter in the course evaluation by the end.

Y_Y 1y ago
Thie irony is palpable. I had the (misfortune) of only being (mis)taught procedural languages by professors who thought computers were big calculators who could never be understood, but could be bent to your will by writing more code and maybe by getting a weird grad student to help. Patterns might appear to the enlighted on the zeroth or first instance, but even the mortal must notice them after several goes. The magic of lisp is that if you notice yourself doing anything more than once you can go ahead and abstract it out. Not everything needs to be lifted to functional valhalla of course, but not factoring out e.g. map and filter requires (imho) a wilful ignorance of the sort that no teacher should countenance. I think it's bad professional practise, bad pedagogy, and a bad time overall. I will die on this hill.
- eru 1y ago
  If you are only used to Java (the bad, old, ancient version), you don't even notice that you can factor out map and filter.
kstrauser 1y ago
Ah, yes. Like in the class where we learned Moscow ML, where loops don’t and variables ain’t, and Godspeed!

smadge 1y ago

It reminds me of a satirical post called “Evolution of a Haskell Programmer” in which a nice simple implementation of the Fibonacci function becomes more and more convoluted, abstract, and academic [1]. [1] https://people.willamette.edu/~fruehr/haskell/evolution.html https://people.willamette.edu/~fruehr/haskell/evolution.html

smadge 1y ago
*factorial function
- JadeNB 1y ago
  Or maybe just a very bad implementation of the Fibonnaci sequence.
- widforss 1y ago
  I was extremely confused for a moment and pondered returning my MSc.