5 ms·

Hah! That is how the code is really written. It's... a unique style, shared amongst the APL languages. I'm pretty sure there are about two people that can read

Hah! That is how the code is really written. It's... a unique style, shared amongst the APL languages. I'm pretty sure there are about two people that can read and write that fluently: Roger Hui and Arthur Whitney.

swah 16y ago
Btw, is this related in anyway to Arthur?
- kragen 16y ago
  Apparently Arthur Whitney wrote a one-page interpreter of an APL dialect in C (in the same style!) which inspired Ken Iverson to write J. http://keiapl.org/rhui/remember.htm#40 http://keiapl.org/rhui/remember.htm#40
  - swah 16y ago
    He is also the author of the K language.
jfager 16y ago
As a wholly unaffiliated, self-selected, and entirely unofficial spokesperson, I'm happy to bestow this lifetime achievement award on behalf of the IOCCC.
- narrator 16y ago
  People who like APL do not often code with readability as their number 1 priority. In fact, to code in APL one must have an outright disdain for the idea that someone else could easily understand their code.
  - gnosis 16y ago
    With that kind of attitude, they might enjoy programming in Brainfuck or Malbolge even more.
  - silentbicycle 16y ago
    No, we just have a different idea of what's readable. APL was created to have a mathematical notation that made problem solving easier. Don't believe me? See Iverson's Turing Award lecture,"Notation as a Tool of Thought" (http://www.jsoftware.com/papers/tot.htm http://www.jsoftware.com/papers/tot.htm). "I did pure mathematics in school, but later I was a teaching assistant for a graduate course in computer algorithms. I could see that the professor was getting killed by the notation. He was trying to express the idea of different kinds of matrix inner products, saying if you have a directed graph and you're looking at connections, then you write this triple nested loop in Fortran or Algol. It took him an hour to express it. What he really wanted to show was that for a connected graph it was an or-dot-and. If it's a graph of pipe capacities, then maybe it's a plus-dot-min. If he'd had APL or K as a notation, he could have covered that in a few seconds or maybe a minute, but because of the notation he couldn't do it." - "A Conversation with Arthur Whitney" (http://queue.acm.org/detail.cfm?id=1531242 http://queue.acm.org/detail.cfm?id=1531242)
  - gchpaco 16y ago
    APL is actually not inherently so bad, because at least the operators have some vague relationship to what they're doing and are all distinct. I can't read J at all because in attempting to embed the APL operator space in ASCII they went in for multiple token operators that can be modified (so =, =., and =: are all different, and actually quite different IIRC). A better way of doing this is Fortress, which tries to use mathematical notation when possible but doesn't try to compress it as small as possible.
- gruseom 16y ago
  Begging your pardon, you're doing so out of ignorance. An entire programming ecosystem -- a brilliant one, one of the very most impressive -- has been built on top of what you are denigrating. Scour through searchyc looking for past threads on APL/K/J and you'll find the arguments all repeated on multiple occasions, including many instances of the same but-this-isn't-what-I'm-used-to rush to judgment that always, unfortunately, comes up in droves.
  - akkartik 16y ago
    I've seen some threads on APL, but I've never seen other languages used with APL-level compression. Are there really other threads about this? I'm not sure what to search for on searchyc.
    - silentbicycle 16y ago
      Try any of these: apl iverson k kona whitney j hui incunabulum (That one-page J interpreter is sometimes called the "J Incunabulum".) See e.g. http://news.ycombinator.com/item?id=1458016 http://news.ycombinator.com/item?id=1458016 http://news.ycombinator.com/item?id=266982 http://news.ycombinator.com/item?id=266982 http://news.ycombinator.com/item?id=697501 http://news.ycombinator.com/item?id=697501 http://news.ycombinator.com/item?id=2176980 http://news.ycombinator.com/item?id=2176980
  - scott_s 16y ago
    You're conflating the implementation of an environment with the value of the environment itself. Did you read the C code? It is terribly difficult to follow, does not follow C formatting idioms, and makes frequent use of macros that further obfuscate what is going on. Example: #define DECLG V*sv=VAV(self);A gs=sv->g; \ AF g1=gs?VAV(gs)->f1:0,g2=gs?VAV(gs)->f2:0 Judging the quality of this code says nothing about the language and environment that this code provides.
    - silentbicycle 16y ago
      From the coding conventions for Kona (http://github.com/kevinlawler/kona/wiki/Coding-Guidelines http://github.com/kevinlawler/kona/wiki/Coding-Guidelines), an open-source implementation of K 3.2 that I've been contributing to lately: This is a very unusual style of C "The unusual appearance is a side effect of writing C as concisely as possible. There are great benefits to writing code as concisely as possible. Someone familiar with the style can read and comprehend the code much faster than they would be able to with traditional code. It also creates a discipline that reduces bugs. Some of the benefits will not be apparent until you try it. Some of the downsides of the style are inaccessibility and a steep learning curve." You get used to code like that, and often, doing it that way makes sense. I first encountered it learning to read this short prototype interpreter (http://nsl.com/papers/origins.htm http://nsl.com/papers/origins.htm) by Arthur Whitney, which very strongly influenced the programming style in the J codebase. As gruesom notes, this discussion has already happened numerous times in the HN archives. Your reaction is the APL equivalent of going, "OMG! Parens!!!!1!" when introduced to Lisp code.
robinhouston 16y ago
It looks as though Kevin Lawler can hold his own in that style, too. https://github.com/kevinlawler/kona/blob/master/k.c https://github.com/kevinlawler/kona/blob/master/k.c
Locke1689 16y ago
That is one of the most frustratingly idiotic things I have ever seen. Any incentive I had to try this language is now gone and I want to erase the memory of its construction from my mind.
- sofuture 16y ago
  How could you look at an APL-family language and then be totally outraged that the implementation took quite a bit stylistically from the language itself?
  - billswift 16y ago
    Conventional C style is there to improve its readability and maintainability. Applying APL style to C code is sort of like trying to use Russian grammar with English vocabulary, you might be able to puzzle out the meaning, but it is a stupid waste of time.
    - silentbicycle 16y ago
      Actually, given that a substantial part of the codebase involves looping simple operators over vectors, it makes sense to use macros to make the looping implicit. Code like this needs to be read more slowly than usual, because unlike much C code, the information level isn't low enough that you can read it lines at a time. Math papers have all these weird sigma symbols and stuff, too; you can't read just them as fast as you would read "for (i=0; i<N; i++) {" for the millionth time. Likewise, rather than writing "for (i=0; i<N; i++) {" yet again, K just calls that ' and moves on. In the source, there's a macro called DO, which is used extensively. DO(N, Blk) -> for(i=0, int _n=N; i<_n; i++) { Blk } . The APLs are about having a notation that doesn't constantly get in the way of thinking about your actual problem.
      - Locke1689 16y ago
        In practical implementations we call this code write-only. It's funny that you bring up mathematical notation because mathematical notation is completely optimized for write-only. Mathematics is so obsessed with one letter variable names that they had to gather letters from other alphabets to continue their opaque tradition.

swah 16y ago

Btw, is this related in anyway to Arthur?

kragen 16y ago
Apparently Arthur Whitney wrote a one-page interpreter of an APL dialect in C (in the same style!) which inspired Ken Iverson to write J. http://keiapl.org/rhui/remember.htm#40 http://keiapl.org/rhui/remember.htm#40
- swah 16y ago
  He is also the author of the K language.

jfager 16y ago

As a wholly unaffiliated, self-selected, and entirely unofficial spokesperson, I'm happy to bestow this lifetime achievement award on behalf of the IOCCC.

narrator 16y ago
People who like APL do not often code with readability as their number 1 priority. In fact, to code in APL one must have an outright disdain for the idea that someone else could easily understand their code.
- gnosis 16y ago
  With that kind of attitude, they might enjoy programming in Brainfuck or Malbolge even more.
- silentbicycle 16y ago
  No, we just have a different idea of what's readable. APL was created to have a mathematical notation that made problem solving easier. Don't believe me? See Iverson's Turing Award lecture,"Notation as a Tool of Thought" (http://www.jsoftware.com/papers/tot.htm http://www.jsoftware.com/papers/tot.htm). "I did pure mathematics in school, but later I was a teaching assistant for a graduate course in computer algorithms. I could see that the professor was getting killed by the notation. He was trying to express the idea of different kinds of matrix inner products, saying if you have a directed graph and you're looking at connections, then you write this triple nested loop in Fortran or Algol. It took him an hour to express it. What he really wanted to show was that for a connected graph it was an or-dot-and. If it's a graph of pipe capacities, then maybe it's a plus-dot-min. If he'd had APL or K as a notation, he could have covered that in a few seconds or maybe a minute, but because of the notation he couldn't do it." - "A Conversation with Arthur Whitney" (http://queue.acm.org/detail.cfm?id=1531242 http://queue.acm.org/detail.cfm?id=1531242)
- gchpaco 16y ago
  APL is actually not inherently so bad, because at least the operators have some vague relationship to what they're doing and are all distinct. I can't read J at all because in attempting to embed the APL operator space in ASCII they went in for multiple token operators that can be modified (so =, =., and =: are all different, and actually quite different IIRC). A better way of doing this is Fortress, which tries to use mathematical notation when possible but doesn't try to compress it as small as possible.
gruseom 16y ago
Begging your pardon, you're doing so out of ignorance. An entire programming ecosystem -- a brilliant one, one of the very most impressive -- has been built on top of what you are denigrating. Scour through searchyc looking for past threads on APL/K/J and you'll find the arguments all repeated on multiple occasions, including many instances of the same but-this-isn't-what-I'm-used-to rush to judgment that always, unfortunately, comes up in droves.
- akkartik 16y ago
  I've seen some threads on APL, but I've never seen other languages used with APL-level compression. Are there really other threads about this? I'm not sure what to search for on searchyc.
  - silentbicycle 16y ago
    Try any of these: apl iverson k kona whitney j hui incunabulum (That one-page J interpreter is sometimes called the "J Incunabulum".) See e.g. http://news.ycombinator.com/item?id=1458016 http://news.ycombinator.com/item?id=1458016 http://news.ycombinator.com/item?id=266982 http://news.ycombinator.com/item?id=266982 http://news.ycombinator.com/item?id=697501 http://news.ycombinator.com/item?id=697501 http://news.ycombinator.com/item?id=2176980 http://news.ycombinator.com/item?id=2176980
- scott_s 16y ago
  You're conflating the implementation of an environment with the value of the environment itself. Did you read the C code? It is terribly difficult to follow, does not follow C formatting idioms, and makes frequent use of macros that further obfuscate what is going on. Example: #define DECLG V*sv=VAV(self);A gs=sv->g; \ AF g1=gs?VAV(gs)->f1:0,g2=gs?VAV(gs)->f2:0 Judging the quality of this code says nothing about the language and environment that this code provides.
  - silentbicycle 16y ago
    From the coding conventions for Kona (http://github.com/kevinlawler/kona/wiki/Coding-Guidelines http://github.com/kevinlawler/kona/wiki/Coding-Guidelines), an open-source implementation of K 3.2 that I've been contributing to lately: This is a very unusual style of C "The unusual appearance is a side effect of writing C as concisely as possible. There are great benefits to writing code as concisely as possible. Someone familiar with the style can read and comprehend the code much faster than they would be able to with traditional code. It also creates a discipline that reduces bugs. Some of the benefits will not be apparent until you try it. Some of the downsides of the style are inaccessibility and a steep learning curve." You get used to code like that, and often, doing it that way makes sense. I first encountered it learning to read this short prototype interpreter (http://nsl.com/papers/origins.htm http://nsl.com/papers/origins.htm) by Arthur Whitney, which very strongly influenced the programming style in the J codebase. As gruesom notes, this discussion has already happened numerous times in the HN archives. Your reaction is the APL equivalent of going, "OMG! Parens!!!!1!" when introduced to Lisp code.

robinhouston 16y ago

It looks as though Kevin Lawler can hold his own in that style, too. https://github.com/kevinlawler/kona/blob/master/k.c https://github.com/kevinlawler/kona/blob/master/k.c

Locke1689 16y ago

That is one of the most frustratingly idiotic things I have ever seen. Any incentive I had to try this language is now gone and I want to erase the memory of its construction from my mind.

sofuture 16y ago
How could you look at an APL-family language and then be totally outraged that the implementation took quite a bit stylistically from the language itself?
- billswift 16y ago
  Conventional C style is there to improve its readability and maintainability. Applying APL style to C code is sort of like trying to use Russian grammar with English vocabulary, you might be able to puzzle out the meaning, but it is a stupid waste of time.
  - silentbicycle 16y ago
    Actually, given that a substantial part of the codebase involves looping simple operators over vectors, it makes sense to use macros to make the looping implicit. Code like this needs to be read more slowly than usual, because unlike much C code, the information level isn't low enough that you can read it lines at a time. Math papers have all these weird sigma symbols and stuff, too; you can't read just them as fast as you would read "for (i=0; i<N; i++) {" for the millionth time. Likewise, rather than writing "for (i=0; i<N; i++) {" yet again, K just calls that ' and moves on. In the source, there's a macro called DO, which is used extensively. DO(N, Blk) -> for(i=0, int _n=N; i<_n; i++) { Blk } . The APLs are about having a notation that doesn't constantly get in the way of thinking about your actual problem.
    - Locke1689 16y ago
      In practical implementations we call this code write-only. It's funny that you bring up mathematical notation because mathematical notation is completely optimized for write-only. Mathematics is so obsessed with one letter variable names that they had to gather letters from other alphabets to continue their opaque tradition.