4 ms·

> That you have to write them over and over again for every single class. You offer to do that with Python. Or with some other code generator. A mythical langu

> That you have to write them over and over again for every single class. You offer to do that with Python. Or with some other code generator. A mythical language with SoA/AoS transformation "built in" will do exactly the same under the covers. But it might not offer other features you are used to, or (your argument) a sufficiently rich library ecosystem. You might as well do it yourself and use a language you are otherwise familiar and happy with. > This is an argument of the "all languages that are Turing complete are essentially equivalent" kind. Is it? You can't do what I described in C, for instance. To be clear, what I meant when I wrote "as a library, 100% inside the language" was that, given the appropriate definitions in a library, not in an external tool you run before your build, you just write something like the following Python: class Ant: someField = ... someOtherField = ... @StructureOfArrays class AntColony: pass or something the following Java: class Ant { int someField; boolean someOtherField; } @StructureOfArrays class AntColony { } and get all the features you can dream of generated for you inside the AntColony class, which you then use exactly as if you had typed things out yourself. You can't do this in C. This isn't an "all Turing complete languages" argument as far as I can see. > You will be unable to use any other library without back-and-force adapters, for example. I don't understand what you mean. In the above example, the Ant class exists, so you don't need adapters. The arrays inside the AntColony class exist (once the annotation processor is done with them), so you don't need adapters.

beagle3 5y ago
> You might as well do it yourself and use a language you are otherwise familiar and happy with. Nim, Rust, D, Lisp support this already as compiled languages, without sacrificing anything - perhaps also Zig - at the macro level. Jai offers it as a language feature, but I don't think that's a particularly good idea - it's just that Jai tries to stay simple in such a way that doesn't let it be a user-level thing. > Is it? You can't do what I described in C, for instance. Not exactly, no, but you can with "X-macros", and I have - in fact - been doing that since 2005 or so, using only features from C89 ; I admit I have not used Java in the last 10 years, and then it was impossible - maybe some of the revisions in the last decade made it possible "inside the language" - what's the name of the feature I need to look up? > I don't understand what you mean. In the above example, the Ant class exists, so you don't need adapters. The arrays inside the AntColony class exist (once the annotation processor is done with them), so you don't need adapters. And now, you try to use the standard library "Sort" or "Find", it doesn't work without adapters, even if you have comparators defined for Ant -- and many other things that assume that objects are not part of a colony. It's hard to explain in a short post. I occasionally use a language called "K" of the APL family, which makes all of this incredibly trivial from the get go. It's not a new language - K itself IIRC predates Java by a couple of years, APL (of which K is often considered a dialect) was first specified in 1958 and implemented in 1962. It basically considers everything an array - one or multiple dimensional - and field access is nothing more than having one of the axes specified by symbols rather than numbers. This makes everything incredibly simple and uniform to an extent that is hard to describe to someone who has not experienced it. (And indeed, in the turing sense it makes no difference .... but if you implement your Java objects as "mapping from field to value" you may get some of the benefits but will not really be using Java or be able to use the ecosystem)
- tom_mellior 5y ago
  > Not exactly, no, but you can with "X-macros", I only gave this a passing thought before and was too quick to dismiss it. Yes, I see how it can be done. Which is just another argument that the whole thing is a non-issue, no? Languages with macro systems can do it. Languages with other build time code generation systems can do it as well. > what's the name of the feature I need to look up? Annotation processors. Here's the first thing I found with an example of code generation: https://cloudogu.com/en/blog/Java-Annotation-Processors_3-Generating-Code https://cloudogu.com/en/blog/Java-Annotation-Processors_3-Ge.... Yes, it's considerably more verbose than a macro system. But it's still a tiny, write-once (or completely off-the-shelf) part of your overall project. > And now, you try to use the standard library "Sort" or "Find", it doesn't work without adapters OK, but the same is true for all the macro based systems you mentioned above, isn't it? And if it isn't: whatever you can generate with macros you can also generate some other way. Edit: You won't like this, but looking at the docs for Java's Collections.sort method (https://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#sort(java.util.List) https://docs.oracle.com/javase/7/docs/api/java/util/Collecti...: "This implementation dumps the specified list into an array, sorts the array, and iterates over the list resetting each element from the corresponding position in the array." So you can use it just fine if the SoA implements the List interface. But yes, at the cost of temporarily materializing an array of structs.
  - beagle3 5y ago
    That what I refer to as the "Turing complete" argument. Yes, you can definitely do all of those. But almost no one does - and those that do, usually silo themselves from the ecosystem. Yes, if you like Java, you can definitely implement a Java compiler/interpreter in C and get everything you like about Java using C. But no one does. Thanks for the reference, I'll read about annotation processors later tonight.
    - tom_mellior 5y ago
      I appreciate the discussion, but I believe you're arguing in bad faith. > Yes, you can definitely do all of those. But almost no one does <shrug> That's what you say. What is this based on, considering that until a few hours ago you didn't even know that Java has this built-in code generation facility? When I search for "entity component sytem java", the first hit is this project: https://github.com/Rubentxu/Entitas-Java https://github.com/Rubentxu/Entitas-Java which uses a "code generator [that] generates classes and methods for you, so you can focus on getting the job done. Radically reduce the amount of code you have to write and improve readability. It makes more of a sea code less prone to errors to ensure the best performance." Sure, it's probably not as widely used as other frameworks in other languages. Java isn't necessarily the first thing on people's mind when it comes to implementing AAA games. > and those that do, usually silo themselves from the ecosystem. You have not shown this. And if you mean that your C macro implementations do this -- fine. But you still seem to find them useful enough to keep using them? > Yes, if you like Java, you can definitely implement a Java compiler/interpreter in C and get everything you like about Java using C. That is a Turing equivalence argument. But using a very simple code generator for a very simple problem is not the same thing. Given that Java syntax is very similar to C, I wouldn't be surprised if your existing macros could be used 1:1, with the hardest part being getting a Java build system to call the C preprocessor on a Java file. Not quite the same thing as implementing an interpreter. (Also, as far as I'm concerned this was never about Java per se.)

beagle3 5y ago

> You might as well do it yourself and use a language you are otherwise familiar and happy with. Nim, Rust, D, Lisp support this already as compiled languages, without sacrificing anything - perhaps also Zig - at the macro level. Jai offers it as a language feature, but I don't think that's a particularly good idea - it's just that Jai tries to stay simple in such a way that doesn't let it be a user-level thing. > Is it? You can't do what I described in C, for instance. Not exactly, no, but you can with "X-macros", and I have - in fact - been doing that since 2005 or so, using only features from C89 ; I admit I have not used Java in the last 10 years, and then it was impossible - maybe some of the revisions in the last decade made it possible "inside the language" - what's the name of the feature I need to look up? > I don't understand what you mean. In the above example, the Ant class exists, so you don't need adapters. The arrays inside the AntColony class exist (once the annotation processor is done with them), so you don't need adapters. And now, you try to use the standard library "Sort" or "Find", it doesn't work without adapters, even if you have comparators defined for Ant -- and many other things that assume that objects are not part of a colony. It's hard to explain in a short post. I occasionally use a language called "K" of the APL family, which makes all of this incredibly trivial from the get go. It's not a new language - K itself IIRC predates Java by a couple of years, APL (of which K is often considered a dialect) was first specified in 1958 and implemented in 1962. It basically considers everything an array - one or multiple dimensional - and field access is nothing more than having one of the axes specified by symbols rather than numbers. This makes everything incredibly simple and uniform to an extent that is hard to describe to someone who has not experienced it. (And indeed, in the turing sense it makes no difference .... but if you implement your Java objects as "mapping from field to value" you may get some of the benefits but will not really be using Java or be able to use the ecosystem)

tom_mellior 5y ago
> Not exactly, no, but you can with "X-macros", I only gave this a passing thought before and was too quick to dismiss it. Yes, I see how it can be done. Which is just another argument that the whole thing is a non-issue, no? Languages with macro systems can do it. Languages with other build time code generation systems can do it as well. > what's the name of the feature I need to look up? Annotation processors. Here's the first thing I found with an example of code generation: https://cloudogu.com/en/blog/Java-Annotation-Processors_3-Generating-Code https://cloudogu.com/en/blog/Java-Annotation-Processors_3-Ge.... Yes, it's considerably more verbose than a macro system. But it's still a tiny, write-once (or completely off-the-shelf) part of your overall project. > And now, you try to use the standard library "Sort" or "Find", it doesn't work without adapters OK, but the same is true for all the macro based systems you mentioned above, isn't it? And if it isn't: whatever you can generate with macros you can also generate some other way. Edit: You won't like this, but looking at the docs for Java's Collections.sort method (https://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#sort(java.util.List) https://docs.oracle.com/javase/7/docs/api/java/util/Collecti...: "This implementation dumps the specified list into an array, sorts the array, and iterates over the list resetting each element from the corresponding position in the array." So you can use it just fine if the SoA implements the List interface. But yes, at the cost of temporarily materializing an array of structs.
- beagle3 5y ago
  That what I refer to as the "Turing complete" argument. Yes, you can definitely do all of those. But almost no one does - and those that do, usually silo themselves from the ecosystem. Yes, if you like Java, you can definitely implement a Java compiler/interpreter in C and get everything you like about Java using C. But no one does. Thanks for the reference, I'll read about annotation processors later tonight.
  - tom_mellior 5y ago
    I appreciate the discussion, but I believe you're arguing in bad faith. > Yes, you can definitely do all of those. But almost no one does <shrug> That's what you say. What is this based on, considering that until a few hours ago you didn't even know that Java has this built-in code generation facility? When I search for "entity component sytem java", the first hit is this project: https://github.com/Rubentxu/Entitas-Java https://github.com/Rubentxu/Entitas-Java which uses a "code generator [that] generates classes and methods for you, so you can focus on getting the job done. Radically reduce the amount of code you have to write and improve readability. It makes more of a sea code less prone to errors to ensure the best performance." Sure, it's probably not as widely used as other frameworks in other languages. Java isn't necessarily the first thing on people's mind when it comes to implementing AAA games. > and those that do, usually silo themselves from the ecosystem. You have not shown this. And if you mean that your C macro implementations do this -- fine. But you still seem to find them useful enough to keep using them? > Yes, if you like Java, you can definitely implement a Java compiler/interpreter in C and get everything you like about Java using C. That is a Turing equivalence argument. But using a very simple code generator for a very simple problem is not the same thing. Given that Java syntax is very similar to C, I wouldn't be surprised if your existing macros could be used 1:1, with the hardest part being getting a Java build system to call the C preprocessor on a Java file. Not quite the same thing as implementing an interpreter. (Also, as far as I'm concerned this was never about Java per se.)