23 ms·

I'll sometimes gauge code complexity by comparing the number of lines of code against the output of tar -cf - . | gzip | base64 | wc -l IE "how much does it

by cduzz 2y ago

I'll sometimes gauge code complexity by comparing the number of lines of code against the output of tar -cf - . | gzip | base64 | wc -l IE "how much does it compress?" Looking at APL -- I'm reminded of what happens if I accidentally send the gzipped output to my tty... I'm impressed that there's anyone who can follow along (can you find the bug?) to code like p←{(↑⍵)∘{(⍺∨.=⍵)/⍳n×n∘}¨,⍵},(n*÷2){⍵,⍺⊥⌊⍵÷⍺}'⍳n n←⍴⍵ It really feels like compressed binary data where everyone's got a copy of the dictionary already...

rak1507 2y ago
I'm not sure why it would be any more impressive or surprising than the billions of people who read and write in non English alphabets
- cduzz 2y ago
  That's a really good point... But -- (and forgive me if I'm totally wrong) -- this isn't just "non-english" but "non-phonetic" which is a smaller set of written languages, and the underlying language is ... math.... so understanding the underlying grammer itself relies on having decades of math education to really make it jive. If this code is just a final result of "learn math for 2-3 decades, and spend years learning this specific programming language" -- my statement stands. Interacting with this kinda binary blob as a programming language is impressive. I think I read somewhere that seymour cray's wife knew he was working too hard when he started balancing the checkbook in hex...
  - rak1507 2y ago
    The underlying language isn't really very mathematical, at most there's a bit of linear algebra in the primitives but that's it. You certainly don't need any sort of formal maths education to learn APL. There are about 50 or so new symbols, which is not a big ask, with any sort of focus the majority of the syntax etc can be learned very quickly. The "bugs" in your original code stand out very clearly because things like "∘}" don't make sense, ∘ being "dyadic" (infix).
    - RodgerTheGreat 2y ago
      and it bears mention that a decent chunk of those symbols are things nearly everyone is familiar with from other languages (+, -, =, etc), symbols you've probably seen in math class or on your graphing calculators (÷, ×, ≠, ⌈, ←, etc), and symbols with very strong mnemonic associations once you've seen them explained (≢, ⍋, ⍳, ⌽, etc).
bryancoxwell 2y ago
Legitimately curious how APL programmers think about maintainability and readability. Is code just thoroughly commented or otherwise documented?
- deleted 2y ago
  [deleted]
- shawn_w 2y ago
  I suspect that if you're fluent in the language, understanding an expression written in it comes just as easily and quickly as reading a sentence in a book does to me.
  - andylynch 2y ago
    That’s exactly what they say. Though most kdb I’ve see in business looks more like Python.
  - campbel 2y ago
    Information density is studied in linguistics. It could likely apply to programming languages similarly.
- genewitch 2y ago
  i've only seen these style of languages commented after a contest is over on stack programming challenges. I have no idea how one would learn all this stuff from code in the wild (like i learned most of python, for example). then again, i don't go searching github for k, apl, or perl for that matter. I'm sure each of those languages makes some guarantee about the sorts of errors that can be introduced - as opposed to C (let me pick on it) where the errors you know you can introduce, and the errors that are introduced aren't a large union. However i have a hard enough time typing english consistently, so the various "symbol-y" languages just glaze my eyes, unfortunately. It almost "feels" like these languages are an overreaction to the chestnut "they must get paid by LoC".
- t-3 2y ago
  You don't really have to worry about keeping track of tons of functions, variables, structs, classes, etc., and trying to keep all the names straight in your head - all you need is to know the symbols, so it's in some ways easier than reading a complex function in more verbose languages where you might need to lookup stuff from several libraries just to understand what's going on. Also, that one line is ~100 characters, each of which probably covers ~0.5-1 lines in other languages, so you should expect to set aside a similar amount of time to reading and understanding it.
xelxebar 2y ago
Late to the game here but... > can you find the bug? Several stand out immediately: - Two syntax errors: unclosed single quote in '⍳n n←⍴⍵ and no right operand in the second use of Jot (∘). It's not clear how those could have snuk in naturally by accident, but I'll just assume cosmic rays and that they should be simply elided. - n n←⍴⍵ is setting n twice, which is a bit surprising, though it signals that you probably expect ⍵ to have rank 2. In such cases _ n←⍴⍵ or n←⊃⌽⍴⍵ may be more natural, depending on intent. - However, Decode (⊥) will error if ⍴⍵ returns anything other than a single integer (or an empty vector), so n n←⍴⍵ is equivalent to just n←⍴⍵ and doubly confusing. - Which means that (n*÷2){⍵,⍺⊥⌊⍵÷⍺}⍳n n←⍴⍵ can only return a vector, i.e. 1..n with a number tacked on the end: the value of (1-x^n)/(1-x) evaluated at sqrt(n), which is a bit of a strange data structure IMHO. Something to do with geometric series of n^2? - The second use of Ravel (,) in ,⍵ is redundant, and given the constraints we know above, so is the first use: ,(n*÷2)... - It also means that (↑⍵) is the same as just ⍵ - But then (⍺∨.=⍵) is always just 1 - Meaning that the whole code is essentially equivalent to p←(n+1)⍴⊂⍳n×n←⍴⍵. I.e. it just outputs n+1 vectors of the integers 1 to n^2. - Which, without context, is hard to guess intent, but that data structure feels a bit strange. Instead of a vector of uniform-length vectors, a matrix would be more efficient: (n+1)(n*2)⍴⍳n×n←⍴⍵. But that's just a matrix with rows that are all the same, so maybe we could just use the single vector (⍳2*⍨⍴⍵) directly? Really, despite looking strange, once you learn the symbols and basic operations, APL is surprisingly straightforward. If you're on HN, then you're already smart enough to learn the basics easily enough. Admittedly, though, becoming proficient in APL does take some time and learning pains. Once there, though, it does feel like a superpower.

by cduzz 2y ago

rak1507 2y ago

I'm not sure why it would be any more impressive or surprising than the billions of people who read and write in non English alphabets

cduzz 2y ago
That's a really good point... But -- (and forgive me if I'm totally wrong) -- this isn't just "non-english" but "non-phonetic" which is a smaller set of written languages, and the underlying language is ... math.... so understanding the underlying grammer itself relies on having decades of math education to really make it jive. If this code is just a final result of "learn math for 2-3 decades, and spend years learning this specific programming language" -- my statement stands. Interacting with this kinda binary blob as a programming language is impressive. I think I read somewhere that seymour cray's wife knew he was working too hard when he started balancing the checkbook in hex...
- rak1507 2y ago
  The underlying language isn't really very mathematical, at most there's a bit of linear algebra in the primitives but that's it. You certainly don't need any sort of formal maths education to learn APL. There are about 50 or so new symbols, which is not a big ask, with any sort of focus the majority of the syntax etc can be learned very quickly. The "bugs" in your original code stand out very clearly because things like "∘}" don't make sense, ∘ being "dyadic" (infix).
  - RodgerTheGreat 2y ago
    and it bears mention that a decent chunk of those symbols are things nearly everyone is familiar with from other languages (+, -, =, etc), symbols you've probably seen in math class or on your graphing calculators (÷, ×, ≠, ⌈, ←, etc), and symbols with very strong mnemonic associations once you've seen them explained (≢, ⍋, ⍳, ⌽, etc).

bryancoxwell 2y ago

Legitimately curious how APL programmers think about maintainability and readability. Is code just thoroughly commented or otherwise documented?

deleted 2y ago
[deleted]
shawn_w 2y ago
I suspect that if you're fluent in the language, understanding an expression written in it comes just as easily and quickly as reading a sentence in a book does to me.
- andylynch 2y ago
  That’s exactly what they say. Though most kdb I’ve see in business looks more like Python.
- campbel 2y ago
  Information density is studied in linguistics. It could likely apply to programming languages similarly.
genewitch 2y ago
i've only seen these style of languages commented after a contest is over on stack programming challenges. I have no idea how one would learn all this stuff from code in the wild (like i learned most of python, for example). then again, i don't go searching github for k, apl, or perl for that matter. I'm sure each of those languages makes some guarantee about the sorts of errors that can be introduced - as opposed to C (let me pick on it) where the errors you know you can introduce, and the errors that are introduced aren't a large union. However i have a hard enough time typing english consistently, so the various "symbol-y" languages just glaze my eyes, unfortunately. It almost "feels" like these languages are an overreaction to the chestnut "they must get paid by LoC".
t-3 2y ago
You don't really have to worry about keeping track of tons of functions, variables, structs, classes, etc., and trying to keep all the names straight in your head - all you need is to know the symbols, so it's in some ways easier than reading a complex function in more verbose languages where you might need to lookup stuff from several libraries just to understand what's going on. Also, that one line is ~100 characters, each of which probably covers ~0.5-1 lines in other languages, so you should expect to set aside a similar amount of time to reading and understanding it.

xelxebar 2y ago

Late to the game here but... > can you find the bug? Several stand out immediately: - Two syntax errors: unclosed single quote in '⍳n n←⍴⍵ and no right operand in the second use of Jot (∘). It's not clear how those could have snuk in naturally by accident, but I'll just assume cosmic rays and that they should be simply elided. - n n←⍴⍵ is setting n twice, which is a bit surprising, though it signals that you probably expect ⍵ to have rank 2. In such cases _ n←⍴⍵ or n←⊃⌽⍴⍵ may be more natural, depending on intent. - However, Decode (⊥) will error if ⍴⍵ returns anything other than a single integer (or an empty vector), so n n←⍴⍵ is equivalent to just n←⍴⍵ and doubly confusing. - Which means that (n*÷2){⍵,⍺⊥⌊⍵÷⍺}⍳n n←⍴⍵ can only return a vector, i.e. 1..n with a number tacked on the end: the value of (1-x^n)/(1-x) evaluated at sqrt(n), which is a bit of a strange data structure IMHO. Something to do with geometric series of n^2? - The second use of Ravel (,) in ,⍵ is redundant, and given the constraints we know above, so is the first use: ,(n*÷2)... - It also means that (↑⍵) is the same as just ⍵ - But then (⍺∨.=⍵) is always just 1 - Meaning that the whole code is essentially equivalent to p←(n+1)⍴⊂⍳n×n←⍴⍵. I.e. it just outputs n+1 vectors of the integers 1 to n^2. - Which, without context, is hard to guess intent, but that data structure feels a bit strange. Instead of a vector of uniform-length vectors, a matrix would be more efficient: (n+1)(n*2)⍴⍳n×n←⍴⍵. But that's just a matrix with rows that are all the same, so maybe we could just use the single vector (⍳2*⍨⍴⍵) directly? Really, despite looking strange, once you learn the symbols and basic operations, APL is surprisingly straightforward. If you're on HN, then you're already smart enough to learn the basics easily enough. Admittedly, though, becoming proficient in APL does take some time and learning pains. Once there, though, it does feel like a superpower.