Re: Non-ugly ways to implement a 'static' class or namespace?
But in any case, it should be class private. There have now been three pages produced by three people all agreeing with each other. At what point does it start being spam? Having a discussion !== spam.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Sunday, 19 February 2023 at 00:21:42 UTC, ProtectAndHide wrote: On Saturday, 18 February 2023 at 21:23:24 UTC, ProtectAndHide wrote: The more I look at D, the more I like C++. I should correct that. The more I look at D, the more I like C++, C#, Java, Kotlin, Swift, Javascript .. and the list goes on.. All D needed to provide, was a way to let the programmer declare a private member inside a class. But that is too much for the language to handle, and so objectionable to many D users, that it will never happen. I have no problem with that, because, i really do have many other options - as do all the C++, C#, Java, Kotlin, Swift, Javascript .. and the list goes on..that you supposedly want to attract to D (although, I suspect nobody actually wants to attract them, since they'll expect to be able to declare a private member within a class. So.. good luck with the .. ummm.. D thing. Even if D did have the private feature, the ecosystem and community is too small for this language to be a viable option. Also D is not used on the job market, so good luck finding a D job.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Sunday, 19 February 2023 at 00:21:42 UTC, ProtectAndHide wrote: On Saturday, 18 February 2023 at 21:23:24 UTC, ProtectAndHide wrote: The more I look at D, the more I like C++. I should correct that. The more I look at D, the more I like C++, C#, Java, Kotlin, Swift, Javascript .. and the list goes on.. All D needed to provide, was a way to let the programmer declare a private member inside a class. But that is too much for the language to handle, and so objectionable to many D users, that it will never happen. I have no problem with that, because, i really do have many other options - as do all the C++, C#, Java, Kotlin, Swift, Javascript .. and the list goes on..that you supposedly want to attract to D (although, I suspect nobody actually wants to attract them, since they'll expect to be able to declare a private member within a class. So.. good luck with the .. ummm.. D thing. Based. I've already switched to TypeScript, Java, etc. Goodbye D.
Re: ELIZA Chatbot Implementation From C to D Lang
On Friday, 17 February 2023 at 17:03:34 UTC, ron77 wrote: Hello, I succeeded in converting an ELIZA code from C to D, and here are the results. although I'm sure there are better ways to code it or to convert it... this is nothing compared to chatgpt ;)
Re: Non-ugly ways to implement a 'static' class or namespace?
So let me just say: I think D does it right. D does not have class encapsulation; it has module encapsulation. This is by design, and the design is good. The design is terrible...
Re: Non-ugly ways to implement a 'static' class or namespace?
But at stop mispresenting what I'm saying. What I've stated above, is what I'm saying.. no more.. no less. Well said. Its not that hard to understand, folks.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Wednesday, 15 February 2023 at 20:06:18 UTC, bachmeier wrote: On Wednesday, 15 February 2023 at 07:13:41 UTC, thebluepandabear wrote: Time to move on to OCaml programmers telling us D doesn't have floating point arithmetic because there's no `+.` operator. that's not the same thing though, you've created a great false equivalence! Congrats. Only if you don't understand D's encapsulation. You're going on at length (apparently under multiple names in this thread) because you don't like D's implementation of encapsulation. That's no different from complaining that the `+` operator should be `+.`, and until D makes the change, it doesn't support floating point addition. There are reasonable arguments for changing and not changing D's implementation of encapsulation. Your claim that D doesn't support encapsulation is false. 'under multiple names'... You can clearly see I have the same name, simply different profile pictures.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Wednesday, 15 February 2023 at 02:14:30 UTC, Mike Parker wrote: On Wednesday, 15 February 2023 at 01:16:00 UTC, thebluepandabear wrote: I think what you could say is that D lacks _encapsulation_ which is also an OOP concept. So D is partially OOP but not fully OOP due to there being no encapsulation in the language. D does not lack encapsulation, it's just that the unit of encapsulation is the module. Everything private in a module is encapsulated from the perspective of the public API. If you really want to prevent anything inside a module from accessing the private parts of a class, you can put the class in its own module. Must we continue beating this horse? Why is the unit of encapsulation the module though? Makes no sense.
Re: Non-ugly ways to implement a 'static' class or namespace?
Time to move on to OCaml programmers telling us D doesn't have floating point arithmetic because there's no `+.` operator. that's not the same thing though, you've created a great false equivalence! Congrats.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Wednesday, 15 February 2023 at 01:15:09 UTC, thebluepandabear wrote: On Tuesday, 14 February 2023 at 15:34:17 UTC, bachmeier wrote: On Tuesday, 14 February 2023 at 10:16:47 UTC, ProtectAndHide wrote: In any case, there is nothing 'picky' about wanting to be able to explicately 'declare' a member of my class type as being private. That to me, is what a programmer should expect to be able to do in a language that says it supports OOP. What you are saying is that you want an implementation of a particular language that calls itself an OOP language. [There is a lot of controversy about the definition of OOP](https://wiki.c2.com/?NobodyAgreesOnWhatOoIs). I do not think the explicit ability to declare a member of a class private in a particular way has anything to do with it. You are certainly entitled to your opinion, but it doesn't help to say D is not an OOP language because you don't like some of the design decisions. D is still an OOP language, as long as it has classes, inheritance, and polymorphism, though it's certainly not a good one if any class can acccess private members from the module, that's just horrid. I think what you could say is that D lacks _encapsulation_ which is also an OOP concept. So D is partially OOP but not fully OOP due to there being no encapsulation in the language.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Tuesday, 14 February 2023 at 15:34:17 UTC, bachmeier wrote: On Tuesday, 14 February 2023 at 10:16:47 UTC, ProtectAndHide wrote: In any case, there is nothing 'picky' about wanting to be able to explicately 'declare' a member of my class type as being private. That to me, is what a programmer should expect to be able to do in a language that says it supports OOP. What you are saying is that you want an implementation of a particular language that calls itself an OOP language. [There is a lot of controversy about the definition of OOP](https://wiki.c2.com/?NobodyAgreesOnWhatOoIs). I do not think the explicit ability to declare a member of a class private in a particular way has anything to do with it. You are certainly entitled to your opinion, but it doesn't help to say D is not an OOP language because you don't like some of the design decisions. D is still an OOP language, as long as it has classes, inheritance, and polymorphism, though it's certainly not a good one if any class can acccess private members from the module, that's just horrid.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Tuesday, 14 February 2023 at 10:16:47 UTC, ProtectAndHide wrote: On Tuesday, 14 February 2023 at 08:15:37 UTC, Kagamin wrote: My point is you know you're just picky. Well.. it seems to me, that your 'point' is to just have a go at me. In any case, there is nothing 'picky' about wanting to be able to explicately 'declare' a member of my class type as being private. That to me, is what a programmer should expect to be able to do in a language that says it supports OOP. Further nonsense towards me will be ignored ;-) fight fight fight fight jk
Re: Non-ugly ways to implement a 'static' class or namespace?
For a language that claims to supprot OOP, and does public by default, and no way to declare type private... I mean... wow! agree, it should definitely be `private` by default... if `private` was implemented properly lmao
Re: Non-ugly ways to implement a 'static' class or namespace?
What attracts me to D, is the inability to program outside of a class in C#. I think they are trying to find ways to make this happen, but I wouldn't hold my breath. programming outside of a class is overrated though in my opinion. i've never seen a usecase for it in an object oriented language. Of course Kotlin can do this, which is good, but you can just create utility classes (i.e. `static class` in C#, `final class` in Java with a private ctor, or Kotlin `object`.)
Re: Non-ugly ways to implement a 'static' class or namespace?
That's not entirely correct. I don't use any Apple hardware products. Never have, and never will. I use Swift on Linux only. There are of course some library features of Swift tied to Apple products. But I have no need for those library features. As a standalone language, Swift can (IMO) already out compete D. Swift on Linux? Interesting... what is the use case?
Re: Non-ugly ways to implement a 'static' class or namespace?
I'm not an advocate of any style in particular. I'm happy to use any style that is clear to understand and use, suitable, and can provide reasonable guarantees around memory safety and correctness. But a language that claims to support OOP but doesn't even have type privacy, is a bit of joke IMO. agreed, the current behaviour of `private` is inexcusable, and it's something newcomers need to be warned about.
Re: Non-ugly ways to implement a 'static' class or namespace?
I think the 'real' problem, is that some core D people just refuse to allow D to provide such an option to the programmer. I think a lot of it has to do with the fact that heaps of D programmers write procedural code and don't care about any object oriented features, that's because they're 'old-school' programmers, whereas OOP is 'new-school'.
Re: Non-ugly ways to implement a 'static' class or namespace?
A good example of a language that does everything right is C#. If C# wasn't tied to Microsoft, it would honestly be pretty much the perfect language. Java is also pretty good, but it has its downsides.
Re: Non-ugly ways to implement a 'static' class or namespace?
I think the 'real' problem, is that some core D people just refuse to allow D to provide such an option to the programmer. For what reason, I cannot fathom, since Swift can do this just fine. I think it's some kind of bias against a particular style of programming that some don't want to see occuring when people use the D programming lanuguage. i.e. It has nothing at all to do with implementation, since it's already been demonstrated that it can be implemented, very easily. Again, in this particular area, Swift is way ahead of D. Sorry, but I do not believe Swift is near to the level of what D is, it's a language that's tied - like jail - to Apple's ecosystem, and its only real use is for iOS apps. They're two completely different languages in general.
Re: Non-ugly ways to implement a 'static' class or namespace?
In contrast, I use D every day and love its relaxed attitude towards private. the fact that private stuff is accessible from other classes in the same module is really really bad, and it's pretty detrimental to the language. let's actually think about what `private` means. when you come back from work, arrive home, and you close the curtains and want some alone, you want to be private to everyone. you wouldn't want your neighbours (the module) to peek at what you're doing. your neighbours aren't your friends in real life, and they (the module) aren't your friends in code -- just because they are in your vicinity doesn't mean they have a right to violate your privacy. tbh this whole private behaviour should be changed, it's just so weird
Re: Non-ugly ways to implement a 'static' class or namespace?
btw. When a newbie to D raises ideas, suggestions, etc... and you counter them with (in essence) 'we don't need that in D, but go write a dip if you think we do' attitude, is a real turn off. yeah it seems like the community is closed off for feedback, which is concerning. namespaces/static classes are a net positive for the language, and they've been shown to be an extremely good features, being implemented in Kotlin, C#, and C++. if the language wants to gain more people it needs to evolve
Re: Non-ugly ways to implement a 'static' class or namespace?
On Thursday, 9 February 2023 at 19:17:15 UTC, Adam D Ruppe wrote: On Thursday, 9 February 2023 at 13:00:04 UTC, thebluepandabear wrote: For my school I am commissioned to create many types of software. I tried to have a look at some of the gui kits in D but there was no tutorial for how to use them and they seemed as if they are lacking features in comparison to Qt/JavaFX. So your objection is one of newbie documentation. That's fair. Qt I always thought had nice docs, they're hard to beat. I've been slowly adding more to my stuff but it is a slow process. idk about features though, you saying "seemed" means you probably don't even actually know what they have so that's not as actionable. it's not anything personal, it's just that the current gui libraries for D are only around 1/100th of the size of other ones such as Qt/JavaFX, it's not really on the same wavelength, and there's nothing wrong with that specifically, it's very difficult to make an enterprise level gui library from scratch
Re: Non-ugly ways to implement a 'static' class or namespace?
On Wednesday, 8 February 2023 at 12:07:35 UTC, zjh wrote: On Friday, 20 January 2023 at 11:28:23 UTC, thebluepandabear wrote: Hi, In Java/C# you can create purely static classes. ... Last time, someone proposed to add `private` like `C++'s`, and then it was the same,they are always unwilling to add facilities useful to others, and then he left `D`. yeah the whole module behaviour with `private` is just a massive turn off tbh, it needs to be changed to match the Java style
Re: Non-ugly ways to implement a 'static' class or namespace?
On Thursday, 9 February 2023 at 12:55:41 UTC, Guillaume Piolat wrote: On Wednesday, 8 February 2023 at 12:10:59 UTC, zjh wrote: On Wednesday, 8 February 2023 at 12:07:35 UTC, zjh wrote: they are always unwilling to add facilities useful to others, `D`'s community is small, this is the reason! yeah right let's implement everything that people propose that's not the point of this thread here :P Of course you dont add stuff on the whim if one person says you should, I am just encouraging open ended discussion.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Thursday, 9 February 2023 at 12:50:48 UTC, Adam D Ruppe wrote: On Thursday, 9 February 2023 at 12:31:03 UTC, thebluepandabear wrote: I am actually taking a computer science class and I need to create desktop apps to pass and get through school. This is pretty easy in D. Like what specific kind of desktop app? For my school I am commissioned to create many types of software. I tried to have a look at some of the gui kits in D but there was no tutorial for how to use them and they seemed as if they are lacking features in comparison to Qt/JavaFX.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Wednesday, 8 February 2023 at 13:32:46 UTC, zjh wrote: On Wednesday, 8 February 2023 at 12:12:57 UTC, thebluepandabear wrote: but I still think the language has potential in the future I don't know if they have a sense of crisis. Now `D` in tiebo ranks `50`. I wouldn't say they have or should have a sense of crisis, the language itself is improving on a day-to-day basis but it isn't gaining popularity. I initially came in excited learning D because I thought that having a small ecosystem would just be a minor pain, but now I realize it's not minor -- it's pretty major. This is not to say D isn't a good language, it certainly is pretty good, but it just needs a bigger ecosystem. The community itself is great, no weirdos in it like Rust, but it just needs to be bigger. I am actually taking a computer science class and I need to create desktop apps to pass and get through school. I thought this would be possible with D, but it has turned out to be a massive pain, so this is why I am switching to Java. I think D may be one of those languages that eventually blows up like Rust because it's honestly great (it feels like a native Java some times), they just need to work on _marketing_ and _strengthening_ the ecosystem. Some corporate backing (RedHat, for example) would also be great since many people are working on it for free, and thus lacking in motivation. anyways I know nobody cares about my opinion, and hopefully this didn't come across disrespectful
Re: Non-ugly ways to implement a 'static' class or namespace?
On Wednesday, 8 February 2023 at 12:10:59 UTC, zjh wrote: On Wednesday, 8 February 2023 at 12:07:35 UTC, zjh wrote: they are always unwilling to add facilities useful to others, `D`'s community is small, this is the reason! yeah, I've already switched to Java because of this. but I still think the language has potential in the future
Re: Non-ugly ways to implement a 'static' class or namespace?
C# just makes it 'easy' for the programmer to define it as such, without all the nonsense other languages require. In addition, the C# compiler WILL prevent nonsense code, which is exactly what I want from a compiler ;-) Java as well.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Wednesday, 8 February 2023 at 09:00:40 UTC, thebluepandabear wrote: C# just makes it 'easy' for the programmer to define it as such, without all the nonsense other languages require. In addition, the C# compiler WILL prevent nonsense code, which is exactly what I want from a compiler ;-) Java as well. Wait nvm
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
Thanks. update: just set up a Manjaro vm and it seems to work, I guess I'll have no choice but to switch to Manjaro then if I want to use sfml
Re: Non-ugly ways to implement a 'static' class or namespace?
I do not agree, that a compiler that allows a programmer to misuse a type, should be seen as 'a feature'. If that's the kind of 'power' D programmers want, then D is not for me. Eh, I don't think I would _quit_ D because of this issue, but it's definitely something that bothers me (more so the lack of an ecosystem) especially since I come from a .NET/JVM background. I'm pretty shocked this isn't a feature tbh.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Sunday, 5 February 2023 at 23:53:35 UTC, Ali Çehreli wrote: On 2/5/23 14:40, ProtectAndHide wrote: > On Sunday, 5 February 2023 at 10:51:51 UTC, thebluepandabear wrote: >> >> It's not a terrible workaround to be honest. >> > > The 'terrible' part is this: > > - the compiler will allow you to declare a variable of type Algo > - the compiler will allow you to declare an array with elements of type > Algo > - the compiler will allow you to use Algo as a type argument > - the compiler will allow you to use Algo as a parameter > - the compiler will allow you to use Algo as a return type I understand disabling the programmer to do certain things are beneficial e.g. to prevent bugs but those above can all be seen as features. What is so terrible about giving the programmer those powers? Ali I don't see why you'd want to expose a static class/namespace as a variable, or any of such similar things. That would give no benefits to the programmer?
Re: Non-ugly ways to implement a 'static' class or namespace?
On Sunday, 5 February 2023 at 23:50:35 UTC, Ali Çehreli wrote: On 2/5/23 02:57, thebluepandabear wrote: > When dealing with contexts, or for when you want a clear context in your > codebase, namespaces can be a life saver Can you give an example of a D problem that namespaces could solve? I have been with D for 14 years and haven't missed namespaces from C++ ever. The reason I ask is, mentioning lack of features of other programming languages is not the right way to go. We have to understand what problem they were trying to solve with that feature and then see how D already tackels it. In this case, it is namespacing and D solves it with the following feature and perhaps others that I can't think of: - modules - structs - classes - templates I don't consider myself a maintainer of D but I don't agree that yet another feature for namespacing is needed. I feel that it would bring complications. I don't think it is practical to bring all features of all languages into D or any other language. > we've seen it used in the D > library, so there's no excuse for why this shouldn't be added, in my > opinion. If I'm not mistaken you've counted five such instances. Were they really necessary? Could they be coded in a different way? What is the cost of missing namespaces? I think you are the first person raising this issue. You must have a strong case for this feature; so, I recommend you write a DIP for it. It is likely that the mere act of doing that will expose hidden costs and usage problems. Ali I'm not going to create a DIP when I've hardly even touched the surface of the language, this is a beginners forum. I would need to wait 3-5 years until I'd feel comfortable doing so. Right now, it's not my place to be doing such things; this is just an observation from a beginner (aka me).
Re: Non-ugly ways to implement a 'static' class or namespace?
On Sunday, 5 February 2023 at 10:51:51 UTC, thebluepandabear
wrote:
{
@disable this();
static this()
{
Message = "Hello!";
}
static:
string Message;
void drawLine() {};
}
It's not a terrible workaround to be honest.
`static class` does have a use when it's nested, so it might
create some conflicts if such a feature (like C# `static
class`) were added.
Due to the mindset of the current maintainers of the language,
I doubt we will see such a thing. Maybe in 10-20 years
something will change and the language will add a static class
or namespace feature, for now we'll have to deal with modules
or using your way of creating a `static class`.
I don't like it when people see modules as a replacement for a
namespace/static class, when that's not the case.
Rust has modules. It also has namespaces.
C++ will be getting modules, it also has namespaces.
When dealing with contexts, or for when you want a clear context
in your codebase, namespaces can be a life saver, we've seen it
used in the D library, so there's no excuse for why this
shouldn't be added, in my opinion.
Re: Non-ugly ways to implement a 'static' class or namespace?
{
@disable this();
static this()
{
Message = "Hello!";
}
static:
string Message;
void drawLine() {};
}
It's not a terrible workaround to be honest.
`static class` does have a use when it's nested, so it might
create some conflicts if such a feature (like C# `static class`)
were added.
Due to the mindset of the current maintainers of the language, I
doubt we will see such a thing. Maybe in 10-20 years something
will change and the language will add a static class or namespace
feature, for now we'll have to deal with modules or using your
way of creating a `static class`.
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
On Sunday, 5 February 2023 at 03:19:43 UTC, bachmeier wrote: On Saturday, 4 February 2023 at 23:51:17 UTC, thebluepandabear wrote: "Error: Missing Symbol, Message: sfText_getLineSpacing", "Error: Missing Symbol, Message: sfText_getLineSpacing"] source/app.d:19 void app.loadDyn() [0x55d86edd1931] source/app.d:24 _Dmain [0x55d86edd1954] ``` Oh yeah, that's another bug I had. You would need to downgrade the version to SFML_240. Something of a puzzle that it works with Arch, though, but not Ubuntu/Mint. It doesn't sound like Arch has that problem. What problem doesn't Arch have, the missing symbol or the shared library one? If it's the missing symbol one, I suspect the reason Arch doesn't have that issue is because it has a more updated package on its repo (AUR). Ubuntu has CSFML 2.5.0, not CSFML 2.5.1, which makes everything much more of a pain. That's exactly why you are getting those missing symbol issues, I believe. I did speak to the bindbc team about it, and that was the conclusion that we came to. In order to fix the issue and not have to downgrade, you would have to manually compile CSFML 2.5.1, which is a pain. I'm wondering, after downgrading, do you get the shared library issue that I am currently dealing with? Thanks.
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
"Error: Missing Symbol, Message: sfText_getLineSpacing", "Error: Missing Symbol, Message: sfText_getLineSpacing"] source/app.d:19 void app.loadDyn() [0x55d86edd1931] source/app.d:24 _Dmain [0x55d86edd1954] ``` Oh yeah, that's another bug I had. You would need to downgrade the version to SFML_240.
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
I have tested on arch linux and everything works fine, i'll try to setup a linux mint / ubuntu VM tomorrow Thanks. It seems like an issue with my system then. I've been stuck on it for a week or so, but haven't been able to find the root cause of the issue.
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
Could someone (that uses Linux) perhaps try and emulate my bug to
see if it's an issue with the bindings or on my system? That
would be greatly appreciated!
Steps:
1. Open up the terminal and type in `sudo apt-get install
libcsfml-dev`
2. Create a new D project and add the following to `dub.json`:
```
"dependencies": {
"bindbc-sfml": "~>1.0.2",
"bindbc-loader": "~>1.0.1"
},
"versions": [
"SFML_Audio",
"SFML_Graphics",
"SFML_250"
],
```
3. Add the following code to `app.d`:
```D
import std.stdio;
import bindbc.sfml;
import std.string;
import std.exception;
import bindbc.loader;
import std.conv;
void loadDyn() {
if (!loadSFML()) {
string[] messages;
foreach (const(ErrorInfo) err; errors) {
string errorStr = to!string(err.error);
string messageStr = to!string(err.message);
messages ~= format("Error: %s, Message: %s", errorStr,
messageStr);
}
throw new Exception(format("Fatal error(s) encountered whilst
calling `loadSFML()` function: %s", messages));
}
}
void main() {
loadDyn();
sfRenderWindow* renderWindow =
sfRenderWindow_create(sfVideoMode(500, 500), "Snake Smooth
Dynamics", sfWindowStyle.sfDefaultStyle, null);
sfEvent event;
while (renderWindow.sfRenderWindow_isOpen()) {
while (renderWindow.sfRenderWindow_pollEvent()) {
if (event.type == sfEventType.sfEvtClosed) {
renderWindow.sfRenderWindow_close();
}
}
renderWindow.sfRenderWindow_clear(sfYellow);
renderWindow.sfRenderWindow_display();
}
}
```
It should only take around 2-3 minutes.
Regards,
thebluepandabear
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
On Friday, 3 February 2023 at 19:44:07 UTC, bachmeier wrote: On Friday, 3 February 2023 at 12:23:40 UTC, thebluepandabear wrote: On Friday, 3 February 2023 at 11:43:46 UTC, thebluepandabear wrote: On Friday, 3 February 2023 at 11:37:43 UTC, bachmeier wrote: On Friday, 3 February 2023 at 10:15:37 UTC, thebluepandabear wrote: I recently did a fresh install of CSFML and I am getting this errors when running my csfml D bindings program: ``` object.Exception@source/app.d(38): Fatal error(s) encountered whilst calling `loadSFML()` function: ["Error: libcsfml-system.so, Message: libsfml-system.so.2.5: cannot open shared object file: No such file or directory", "Error: libcsfml-system.so.2, Message: libcsfml-system.so.2: cannot open shared object file: No such file or directory", "Error: libcsfml-system.so.2.0, Message: libcsfml-system.so.2.0: cannot open shared object file: No such file or directory"] ``` We don't have the full compilation and loading details, but this part of the message seems unusual: "Error: libcsfml-system.so, Message: libsfml-system.so.2.5 One is `libcsfml` and the other is `libsfml`. Hi, It seems like it has changed since then, I am _no longer_ getting those conflicting errors, it's just 'libcsfml' for both instances. I am thinking of compiling CSFML from scratch to see if it will help, but I'd rather not since it seems complex. Furthermore, I would like to thank you for bringing up the compilation/loading details up. I'll send a snippet of that if I can figure out how to do so. nvm, im getting that error again It might be a bug in bindbc-sfml. The code is here: https://github.com/BindBC/bindbc-sfml/blob/master/source/bindbc/sfml/system.d#L231 Unbuntu stores the file in /usr/lib/x86_64-linux-gnu/libcsfml-system.so.2.5. Maybe the compiler doesn't know to look in /usr/lib/x86_64-linux-gnu. I sent an issue request to bindbc-sfml and they could not reproduce my bug or figure out why it was happening, but I wouldn't be surprised if it is a bug.
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
On Friday, 3 February 2023 at 11:43:46 UTC, thebluepandabear wrote: On Friday, 3 February 2023 at 11:37:43 UTC, bachmeier wrote: On Friday, 3 February 2023 at 10:15:37 UTC, thebluepandabear wrote: I recently did a fresh install of CSFML and I am getting this errors when running my csfml D bindings program: ``` object.Exception@source/app.d(38): Fatal error(s) encountered whilst calling `loadSFML()` function: ["Error: libcsfml-system.so, Message: libsfml-system.so.2.5: cannot open shared object file: No such file or directory", "Error: libcsfml-system.so.2, Message: libcsfml-system.so.2: cannot open shared object file: No such file or directory", "Error: libcsfml-system.so.2.0, Message: libcsfml-system.so.2.0: cannot open shared object file: No such file or directory"] ``` We don't have the full compilation and loading details, but this part of the message seems unusual: "Error: libcsfml-system.so, Message: libsfml-system.so.2.5 One is `libcsfml` and the other is `libsfml`. Hi, It seems like it has changed since then, I am _no longer_ getting those conflicting errors, it's just 'libcsfml' for both instances. I am thinking of compiling CSFML from scratch to see if it will help, but I'd rather not since it seems complex. Furthermore, I would like to thank you for bringing up the compilation/loading details up. I'll send a snippet of that if I can figure out how to do so. nvm, im getting that error again
Re: SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
On Friday, 3 February 2023 at 11:37:43 UTC, bachmeier wrote: On Friday, 3 February 2023 at 10:15:37 UTC, thebluepandabear wrote: I recently did a fresh install of CSFML and I am getting this errors when running my csfml D bindings program: ``` object.Exception@source/app.d(38): Fatal error(s) encountered whilst calling `loadSFML()` function: ["Error: libcsfml-system.so, Message: libsfml-system.so.2.5: cannot open shared object file: No such file or directory", "Error: libcsfml-system.so.2, Message: libcsfml-system.so.2: cannot open shared object file: No such file or directory", "Error: libcsfml-system.so.2.0, Message: libcsfml-system.so.2.0: cannot open shared object file: No such file or directory"] ``` We don't have the full compilation and loading details, but this part of the message seems unusual: "Error: libcsfml-system.so, Message: libsfml-system.so.2.5 One is `libcsfml` and the other is `libsfml`. Hi, It seems like it has changed since then, I am _no longer_ getting those conflicting errors, it's just 'libcsfml' for both instances. I am thinking of compiling CSFML from scratch to see if it will help, but I'd rather not since it seems complex. Furthermore, I would like to thank you for bringing up the compilation/loading details up. I'll send a snippet of that if I can figure out how to do so.
SFML D bindings: libsfml-system.so.2.5: cannot open shared object file:
I recently did a fresh install of CSFML and I am getting this
errors when running my csfml D bindings program:
```
object.Exception@source/app.d(38): Fatal error(s) encountered
whilst calling `loadSFML()` function:
["Error: libcsfml-system.so, Message: libsfml-system.so.2.5:
cannot open shared object file: No such file or directory",
"Error: libcsfml-system.so.2, Message: libcsfml-system.so.2:
cannot open shared object file: No such file or directory",
"Error: libcsfml-system.so.2.0, Message: libcsfml-system.so.2.0:
cannot open shared object file: No such file or directory"]
```
I am using SFML D bindings
(https://github.com/BindBC/bindbc-sfml):
```D
void loadDyn() {
if (!loadSFML()) {
string[] messages;
foreach (const(ErrorInfo) err; errors) {
string errorStr = to!string(err.error);
string messageStr = to!string(err.message);
messages ~= format("Error: %s, Message: %s", errorStr,
messageStr);
}
throw new Exception(format("Fatal error(s) encountered whilst
calling `loadSFML()` function: %s", messages));
}
}
void main() {
loadDyn();
sfRenderWindow* renderWindow =
sfRenderWindow_create(sfVideoMode(500, 500), "Snake Smooth
Dynamics", sfWindowStyle.sfDefaultStyle, null);
sfEvent event;
while (renderWindow.sfRenderWindow_isOpen()) {
while (renderWindow.sfRenderWindow_pollEvent()) {
if (event.type == sfEventType.sfEvtClosed) {
renderWindow.sfRenderWindow_close();
}
}
renderWindow.sfRenderWindow_clear(sfYellow);
renderWindow.sfRenderWindow_drawSprite(snakeHeadSprite, null);
renderWindow.sfRenderWindow_display();
}
}
```
Things I've tried:
- I found someone with a similar question:
https://stackoverflow.com/questions/41516065/linux-sfml-cannot-open-shared-object-file, tried out some answers but to no avail
- I tried to `sudo apt purge` every CSFML dependency (graphics,
audo, etc) and reinstall each component (`csfml-audio`,
`csfml-graphics`) manually etc, to no avail.
- I tried to run `sudo ldconfig`... didn't work
- As a last ditch effort I tried to manually move the shared
object files to the `/usr/local/lib` directory (to try and
perhaps trick the compiler to run the program?) but to no avail.
- I tried to run on a new VM and still didn't work
- I tried to set `LD_LIBRARY_PATH` environment variable
The amount of layers I depend on make it impossible to find where
the bug is from, there are a lot of separate things going on and
it's very multilayered, I don't know where the issue is
specifically coming from as it used to work just fine I ran the
exact same commands to install CSFML previously, now when I do
it it just refuses to run.
The weird thing is when I ran a brand new virtual machine,
installed those packages, still same issue.
I am running Linux Mint 21.1, Ubuntu based. Relatively new PC.
Help would be appreciated.
Re: Non-ugly ways to implement a 'static' class or namespace?
Why do you want a type? I want a type because it gives clear context as to what family the method(s) belongs to, and helps make the code more idiomatic and easy to understand.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Monday, 30 January 2023 at 21:50:03 UTC, thebluepandabear
wrote:
Use a struct and put `static:` after the opening brace. That's
what GC is in core.memory.
Using a `struct` for a purely static type would still allow the
user to create instances of that `struct`. To bypass that,
you'd have to disable the default constructor -- that then
becomes ugly, hackish code.
Looking at the GC code found @
https://github.com/dlang/dmd/blob/master/druntime/src/core/memory.d, it seems like they have disabled the default constructor:
```D
struct GC
{
@disable this();
...
}
```
Interesting, so maybe there is a use case for a purely static
type or namespace?
The standard library as well uses `final abstract class` a couple
of times, which can also be thought as a type of namespace.
All these 'hacks' to workaround a namespace-like feature are ...
interesting... So maybe such a feature would help the language?
Just askin questions!
Re: Non-ugly ways to implement a 'static' class or namespace?
Use a struct and put `static:` after the opening brace. That's what GC is in core.memory. Using a `struct` for a purely static type would still allow the user to create instances of that `struct`. To bypass that, you'd have to disable the default constructor -- that then becomes ugly, hackish code.
Re: Non-ugly ways to implement a 'static' class or namespace?
I hate a world with the classes. I can do almost anything I want without the classes. The software world soared above C without classes. SDB@79 As I said in my email to you -- each to their own. There's no point in arguing about whether OOP is the best method of doing things or procedural is, it's up to the person's personal preferences. Personally, I like interfaces, I like abstract classes, I like inheritance, I like polymorphism. A lot of things can be done with pure structs, but sometimes that extra OOP stuff is needed too.
Re: How to a link to a C library to create static bindings?
When I do run with dub I just get: ``` Program exited with code -11 ```
How to a link to a C library to create static bindings?
Hello, I am wanting to create my own C bindings to CSFML, and I have been extremely struggling with this. There is no resources or tutorials for how to do this so I am basically on my own. First thing I looked at was `dstep` which helps translate C header files to D language, so I ran `dstep` and translated the C header files to D language. This went well. I ended up wrapping all the code in an `extern(C)` call. Now, I am trying to 'link' CSFML to my bindings but have been struggling to do so. I tried to add the following to `dub.json`: ``` "libs": ["csfml-audio", "csfml-graphics"] ``` But it came back with an error: ``` /usr/bin/ld: /home/tom/Desktop/sfmld-backend/out/production/sfmld-backend/obj/sfmld-backend.o: in function `_Dmain': /home/tom/Desktop/sfmld-backend/source/graphics.d:(.text._Dmain[_Dmain]+0x3a): undefined reference to `sfRenderWindow_create' /usr/bin/ld: /home/tom/Desktop/sfmld-backend/source/graphics.d:(.text._Dmain[_Dmain]+0x58): undefined reference to `sfRenderWindow_isOpen' /usr/bin/ld: /home/tom/Desktop/sfmld-backend/source/graphics.d:(.text._Dmain[_Dmain]+0x69): undefined reference to `sfRenderWindow_pollEvent' /usr/bin/ld: /home/tom/Desktop/sfmld-backend/source/graphics.d:(.text._Dmain[_Dmain]+0x7c): undefined reference to `sfRenderWindow_close' /usr/bin/ld: /home/tom/Desktop/sfmld-backend/source/graphics.d:(.text._Dmain[_Dmain]+0x90): undefined reference to `sfRenderWindow_clear' /usr/bin/ld: /home/tom/Desktop/sfmld-backend/source/graphics.d:(.text._Dmain[_Dmain]+0x99): undefined reference to `sfRenderWindow_display' collect2: error: ld returned 1 exit status Error: linker exited with status 1 ``` I am really confused as to how I even am supposed to get the library name in the first place, which is another thing that is confusing me. Any help with this would be appreciated.
Re: Need some technical help an object oriented wrapper I am creating for bindbc.sfml
On Thursday, 26 January 2023 at 11:46:07 UTC, matheus wrote: On Tuesday, 24 January 2023 at 03:42:34 UTC, thebluepandabear wrote: ... if not please tell me and I will remove this... How you would do that? Matheus. The forums don't have a delete feature. I am used to most forums having a delete feature which is why I said that, I now realize I cannot remove posts on This forum.
Re: Non-ugly ways to implement a 'static' class or namespace?
symbols. So let the users use them that way. There's no need to force them to type out the namespace all the time. It's certainly not an OOP vs. procedural issue, as namespaces have nothing to do with OOP. Thanks, appreciate your perspective.
Re: Need some technical help an object oriented wrapper I am creating for bindbc.sfml
The example shows calls to `update()` in the setters and in the
constructor. The D method for binding this looks like `void
sfShape_update(sfShape* shape);`.
Ur a legend bro...
It fixed it...
Calling this in the `Rectangle` constructor:
```D
class RectangleShape : Shape {
this(Vector2f size) {
_size = size;
setSize(_size);
ptr.sfShape_update();
}
```
It is my fault on this one.
Thank u sir.
Re: Need some technical help an object oriented wrapper I am creating for bindbc.sfml
On Tuesday, 24 January 2023 at 06:32:35 UTC, Christian Köstlin wrote: On 24.01.23 04:59, thebluepandabear wrote: Regards, thebluepandabear Btw I understand this question is extremely complex, don't want to pressure anyone to help me because of that... but any sort of assistance or leads would be greatly... greatly apprecaited... I do not know anything about sfml, but could you try a simpler shape, e.g. circle (that is a primitive on the native side). perhaps the winding order of your vertices is wrong? Kind regards, Christian thanks for the reply That also - unfortunately - doesn't seem to work. I would love to see some proper examples for creating shapes but the docs for bind-bc didn't have any :|
Re: Need some technical help an object oriented wrapper I am creating for bindbc.sfml
Regards, thebluepandabear Btw I understand this question is extremely complex, don't want to pressure anyone to help me because of that... but any sort of assistance or leads would be greatly... greatly apprecaited...
Need some technical help an object oriented wrapper I am creating for bindbc.sfml
Hello everyone , hope everyone is having a good day.
Hopefully I am allowed to ask technical questions here, if not
please tell me and I will remove this.
I am trying to create object oriented wrappers around
`bindbc.sfml`, this is because I don't like the C-style syntax of
CSFML.
The C-style syntax is not right -- in my opinion -- for an object
oriented language. Dealing with pointers all the time is also
unsafe.
This is not to say that CSFML isn't good -- it's great, and I've
made some apps using `bindbc-sfml`. I just want to extend it to
my liking with object oriented wrappers that can more closely
match the C++ SFML syntax.
For the wrappers, I created a `Shape` class. This `Shape` class
is seen in the original C++ SFML implementation:
```D
class Shape : Transformable, Drawable {
void setTexture(sfTexture* texture, bool resetRect) {
ptr.sfShape_setTexture(texture, resetRect);
}
void setTextureRect(IntRect rect) {
ptr.sfShape_setTextureRect(rect.to_sfIntRect());
}
void setFillColor(Color color) {
ptr.sfShape_setFillColor(color.to_sfColor());
}
void setOutlineColor(Color color) {
ptr.sfShape_setOutlineColor(color.to_sfColor());
}
void setOutlineThickness(float thickness) {
ptr.sfShape_setOutlineThickness(thickness);
}
const(sfTexture)* getTexture() {
return ptr.sfShape_getTexture();
}
IntRect getTextureRect() {
return ptr.sfShape_getTextureRect().toIntRect();
}
Color getFillColor() {
return ptr.sfShape_getFillColor().toColor();
}
Color getOutlineColor() {
return ptr.sfShape_getOutlineColor().toColor();
}
float getOutlineThickness() {
return ptr.sfShape_getOutlineThickness();
}
size_t getPointCount() nothrow {
return ptr.sfShape_getPointCount();
}
Vector2f getPoint(size_t index) nothrow {
return ptr.sfShape_getPoint(index).toVector2f_noThrow();
}
FloatRect getLocalBounds() {
return ptr.sfShape_getLocalBounds().toFloatRect();
}
FloatRect getGlobalBounds() {
return ptr.sfShape_getGlobalBounds().toFloatRect();
}
private sfShape* ptr;
}
```
The `sfShape` pointer isn't currently initialized, I'll get to
that issue soon.
As you can see, `Shape` extends the `Transformable` class and the
`Drawable` interface. This again roughly matches what's seen in
SFML. SFML.NET also did a similar wrapper for their CSFML C#
bindings. What's great about SFML.NET is that you don't even know
that you're using CSFML, this is because it feels just like C++
SFML.
Now, I will create a `RectangleShape` which will be a subclass of
the `Shape` class:
(Btw I took a lot of inspiration from SFML.NET when it comes to
these wrappers.)
```D
class RectangleShape : Shape {
this(Vector2f size) {
_size = size;
setSize(_size);
}
Vector2f getSize() {
return _size;
}
void setSize(Vector2f size) {
_size = size;
}
override {
size_t getPointCount() {
return 4;
}
Vector2f getPoint(size_t index) {
final switch (index) {
case 0:
return Vector2f(0, 0);
case 1:
return Vector2f(_size.x, 0);
case 2:
return Vector2f(_size.x, _size.y);
case 3:
return Vector2f(0, _size.y);
}
}
}
private Vector2f _size;
}
```
As you can see, the `Rectangle` class only overrides the
`getPointCount` and `getPoint` methods.
**These are the methods that the superclass - `Shape` - will use
to construct the shape object for it to actually be drawable.**
Now, let us add the following code to the `Shape` class so that
we can construct a `Shape` via these two methods, which we assume
that the child provides us a good implementation for:
```D
class Shape : Transformable, Drawable {
this() {
ptr = sfShape_create(, ,
cast(void*)this);
}
extern(C) private static ulong getPointCount(void* data)
nothrow {
return (cast(Shape)data).getPointCount();
}
extern(C) private static sfVector2f getPoint(size_t index,
void* data) nothrow {
return
(cast(Shape)data).getPoint(index).to_sfVector2f_noThrow();
}
```
I hear you asking, what's going on here?
We are providing two callbacks to the `getPointCount` and
`getPoint` methods via function pointers, and we're passing in
the current object to the `data` `void*` pointer. It's kind of
hard to understand, but if you read through it carefully you
should get a rough idea of what's going on.
Now, when we create a new instance of `Rectangle`, I will assume
that the constructor will be called, the `sf_shape` ptr will be
initialized correctly (as it will be utilizing the crucial
`getPoint` and `getPointCount` methods) and everything
Re: Non-ugly ways to implement a 'static' class or namespace?
On Monday, 23 January 2023 at 00:27:29 UTC, Adam D Ruppe wrote: On Monday, 23 January 2023 at 00:21:12 UTC, thebluepandabear wrote: there's nothing in the language currently that would 'force' the user Why do you hate freedom? It's not a freedom issue, it's a library-design issue. Some libraries want to incorporate a namespace-like design to force the user to be more 'explicit' with what they want. SFML has a `Keyboard` namespace which has a `Key` enum. The user is 'forced' (although I am not sure if this is the case since it's C++) to use the `Keyboard.` declaration before using the `Key` enum. Looking at code block 1 and 2, which makes more sense? ```C++ Keyboard::Key.A ``` ```C++ Key.A ``` The first one does, because looking at the second one, the person who will read the code might be confused what 'Key' means, is it a car key, a set of keys for unlocking something, etc? Now, the user doesn't have to use the library if they don't want to. There will be plenty of libraries out there that don't have namespaces. I haven't been programming for a long time, but most of the other languages I used had such a namespace feature. Kotlin has something called an `object` which is essentially a namespace and it is great. The benefits of adding a namespace-like feature outweigh its costs, imo.
Re: Non-ugly ways to implement a 'static' class or namespace?
That way of naming a global function is essentially a poor man's^W^Wexcuse me, I mean, C's way of working around the lack of a proper namespacing / module system. In D, we do have a proper module system, so you could just call the function `drawLine` and put it in a file named Algo.d, then you can just use D's symbol resolution rules to disambiguate between Algo.drawLine and PersonalSpace.drawLine, for example. :-P T Again, stuffing it into a module is not the same thing as a namespace. The user can just bypass this by writing `drawLine`, there's nothing in the language currently that would 'force' the user to write in a namespace-like/static-class-like fashion, and that's the biggest problem.
Re: Non-ugly ways to implement a 'static' class or namespace?
Something interesting. I know that D has C++ SFML bindings, although they are unmaintained. I was interested to see how they would 'implement' the C++ namespaces of SFML, and - boy was I surprised. Reading through `DSFML`, I see `final abstract class` getting used to implement SFML's `Keyboard` namespace: `final abstract class Keyboard` at https://github.com/Jebbs/DSFML/blob/master/src/dsfml/window/keyboard.d It seems like using `final abstract` is the best solution.
Re: Non-ugly ways to implement a 'static' class or namespace?
// app.d
import API = api;
void main()
{
API.draw();
}
```
Another thing that I don't like about that solution, is that it
doesn't 'force' the user to write in a namespace-like style.
C++ `namespaces` force you to (I believe), and so does `static
class` from Java/C#.
D is both an object oriented and procedural language, I would
honestly love to see some sort of `namespace` or `static class`
feature come into the language. I know that it's controversial
here, but I would honestly think it would help develop the
language in a good way. But that's just my opinion.
Re: Non-ugly ways to implement a 'static' class or namespace?
On Sunday, 22 January 2023 at 18:30:59 UTC, ryuukk_ wrote:
On Friday, 20 January 2023 at 11:28:23 UTC, thebluepandabear
wrote:
D is not java/C#, it's better than that!
```D
// api.d
void draw(){}
// app.d
import API = api;
void main()
{
API.draw();
}
```
Sorry don't like that solution specifically. That's because it is
a procedural implementation, not an OOP-style one. I don't know
how much of the D community writes procedurally but I'm
personally an OOP-type of guy.
Re: Non-ugly ways to implement a 'static' class or namespace?
ll a function without instantiating said class, as functions act on the class object. Ok, thanks. I think D should implement something similar to `static class` but I doubt it will happen.
Non-ugly ways to implement a 'static' class or namespace?
Hi,
In Java/C# you can create purely static classes.
These are classes whose methods are all static, the classes
cannot be derived from or instantiated:
```
static class Algo {
void drawLine(Canvas c, Pos from, Pos to) { .. };
}
```
Class in use:
```
Algo.drawLine(new Canvas(), new Pos(5, 3), new Pos(7, 9));
```
This type of semantics is not possible in D, which sucks.
After scouring the forums, the only workaround seems to be the
following:
```
final abstract class Algo {
void drawLine(Canvas c, Pos from, Pos to) { .. };
}
```
This solution seems like a bit of a hack, which is why I don't
like it.
Alternatively you could create a module, but then it would just
be a function without a clear type.
Is anyone aware of a non-ugly way to implement a 'static' class
or namespace?
Regards,
thebluepandabear
Re: Are there more up-to-date D template tutorials?
roduct/learning-d/9781783552481?_ga=2.241359490.1811075590.1674153096-1605518740.1674153096 or Adam's book https://www.packtpub.com/product/d-cookbook/9781783287215?_ga=2.198287279.1811075590.1674153096-1605518740.1674153096 They're older than 2019, but I don't think much of the material they've covered is in any sense obsolete. Mike's one is more of a learning one. I'll check out Adam's as it seems to be more geared toward learning the advanced stuff of the language, thanks!
Re: Are there more up-to-date D template tutorials?
Help would be appreciated. Regards, thebluepandabear A bit off topic/ranty but I did find the book by Ali on D extremely useful, but it was good as an 'introduction'. I feel like when it comes to more advanced features (such as templates, mixins, ranges, concurrency, etc) there are no resources out there, but I guess that's the 'cost' of picking a lesser-known language. Hopefully in the future there will be more books written on this language, if there was a book on the advanced features of D I'd happily purchase it :)
Are there more up-to-date D template tutorials?
Hello, The GitHub repo which helps introduce new users about D templates (https://github.com/PhilippeSigaud/D-templates-tutorial) seems to be quite outdated. As a beginner to D I have been struggling to learn about D templates, I haven't been able to find any up-to-date D template resources so I can learn this concept, which sucks. Is anyone on this forums aware of any up-to-date (preferably 2019+) D template books/resources? I know C++ has many books on this topic, but less so for D. Help would be appreciated. Regards, thebluepandabear
Re: How to access private variable of outer class from an inner struct
On Sunday, 15 January 2023 at 13:23:20 UTC, matheus wrote:
On Sunday, 15 January 2023 at 12:44:51 UTC, thebluepandabear
wrote:
...
How will the variable `outer` become the reference to the
current `X` object (if that makes sense?). Does the compiler
do it automatically?
I think you'll need to do this:
class X {
private int num;
struct Y {
X outer;
int fun() { return outer.num; }
}
Y y;
this(){
y = Y(this);
}
}
void main(){
import std.stdio : writeln;
auto x = new X();
x.num = 10;
writeln(x.num);
writeln(x.y.fun());
}
Prints:
10
10
Matheus.
ah, that's annoying, but I guess it's the only solution as it
stands.
Re: How to access private variable of outer class from an inner struct
On Sunday, 15 January 2023 at 12:37:43 UTC, Paul Backus wrote:
On Sunday, 15 January 2023 at 12:26:15 UTC, thebluepandabear
wrote:
If I have the following code:
```D
class X {
private int num;
struct Y {
// how to access num?
}
}
```
How would I access `num` from `Y`?
Whenever I try to I get a compilation error.
I believe that it's possible for nested/inner classes, but I
don't know if it's possible for structs.
Help would be apprciated.
I don't think this works for structs. As a workaround, you give
your struct an explicit reference to the outer class, like this:
```D
class X {
private int num;
struct Y {
X outer;
int fun() { return outer.num; }
}
}
```
Thanks.
How will the variable `outer` become the reference to the current
`X` object (if that makes sense?). Does the compiler do it
automatically?
How to access private variable of outer class from an inner struct
If I have the following code:
```D
class X {
private int num;
struct Y {
// how to access num?
}
}
```
How would I access `num` from `Y`?
Whenever I try to I get a compilation error.
I believe that it's possible for nested/inner classes, but I
don't know if it's possible for structs.
Help would be apprciated.
(Noob question) Should subclasses be defined in separate modules?
(Sorry if this is a duplicate.)
If I have the following code inside of a module:
```D
class Obj {
private {
string name = "Hi";
}
}
class ObjDerived : Obj {
}
```
Is it best practice to define `ObjDerived` inside another module,
since `ObjDerived` can still access the members of `Obj` (since
`private` is only applied to modules), or does this go against
the intended use of the language?
As a beginner, I am having an extremely tough time understanding
why you would want to place these two classes in the same module
or even have this intended behavior of `private`. I am coming
from Java/Kotlin which are both strictly OO language and have
different ways of encapsulation.
Re: Coding Challenges - Dlang or Generic
I know. Someone's going to say why don't YOU do it:) regards, The official book on D by Ali has many coding challenges. There isn't any need to create a website for D coding challenges or incorporate it into an existing website since D has under 1% of the market share.
Re: How to avoid variable capturing in `foreach` loop with lambdas?
: create a copy of the value that is currently present in one particular iteration of the `foreach` by creating a function literal that takes your `struct` as a paramter. This works because structs are value types, so passing it to the function creates a copy. Thanks, your solution seems to be the most elegant one yet, I recently came across the similar problem and I realized that the other answer was too long and verbose.
Re: How to avoid variable capturing in `foreach` loop with lambdas?
Fixing this will improve the quality of the language for newcomers such as myself greatly. This not only confuses newcomers but it gave a false illusion of a bug within the code :/
Re: How to avoid variable capturing in `foreach` loop with lambdas?
A nested function (or perhaps an inline lambda) is needed to force the allocation of a dynamic context for the capture. This is an embarrassment. Why hasn't this been fixed yet? :-( T I agree that this needs to get fixed immediately, it seems to be bugging me another time as well. I believe I saw a similar StackOverflow post about this issue for C#, and Microsoft did fix it, hopefully D can do the same. Fixing this will improve the quality of the language for newcomers such as myself greatly.
Re: Why does this code only work with `std.conv.to` whilst not with `cast`?
On Sunday, 8 January 2023 at 12:35:38 UTC, matheus wrote:
On Sunday, 8 January 2023 at 11:29:10 UTC, thebluepandabear
wrote:
...
There is an explanation here:
https://forum.dlang.org/post/tqukutfzeaxedunuv...@forum.dlang.org
But in any case I'd like to point it out that I think you could
do that foreach without casting or std.conv by just omitting
the type of the variable you're iterating:
import std.stdio, std.conv;
interface IDog {
void bark();
}
class Dog: IDog{
string s;
this(string _s){s = _s;}
void bark(){writeln(s);}
}
class List{
IDog[] dogs;
void add(T)(T d){ dogs ~= d; }
}
void main(){
auto d1 = new Dog("meaw!");
auto d2 = new Dog("wof!");
auto l = new List();
l.add(d1);
l.add(d2);
foreach(d; l.dogs){ // No type informed for "d"
d.bark();
}
}
Prints:
meaw!
wof!
Matheus.
The `foreach` worked for that case since `bark` is a method of
`IDog`. `update` is not so a conversion to `Button[]` is needed.
I will look at your resource, thanks.
Why does this code only work with `std.conv.to` whilst not with `cast`?
I've been writing some code and I have been experimenting with
casting. I've found that sometimes only `std.conv.to!` does the
job over casting, and I am unsure why this is the case as I
assumed that they are both the same.
I have the following interface:
```D
interface ICustomDrawable {
void render(sfRenderWindow* renderWindow);
}
```
And the following class that implements that interface:
```D
class Button : ICustomDrawable {
...
override void render(sfRenderWindow* renderWindow) {
...
}
}
```
And this class which uses `ICustomDrawable`:
```D
class StackLayout : ICustomDrawable {
...
void addChild(T)(T child) {
static assert(is(T : ICustomDrawable), "Invalid type T
for child");
...
}
...
ICustomDrawable[] _children;
}
```
For some reason, when I want to cast the `children` (property),
only the second example works:
1.
```D
foreach (Button button; cast(Button[])(_boardSizeRow.children)) {
button.update(event, _renderWindow);
}
```
2.
```D
foreach (Button button; to!(Button[])(_boardSizeRow.children)) {
button.update(event, _renderWindow);
}
```
When I run the first code example I get a black screen, whilst
with the second I do not. I find this very strange as when I
write to the console the 'type', it is the same for both
scenarios.
Help would be appreciated as to why this is happening so I can
better understand how D works.
Re: Is there a way to enforce UFCS?
them or remove them. I agree, forbidding function call syntax would be a great usecase for `@property`. It will probably never get implemented though.
Re: How to avoid variable capturing in `foreach` loop with lambdas?
``` These two solutions should compile to approximately the same runtime code, with optimizations enabled. So, it's really down to personal preference; the former is more explicit about what the computer is to do, while the latter is more concise. Thanks! Works great.
Re: How to avoid variable capturing in `foreach` loop with lambdas?
Have fun reading this : https://issues.dlang.org/show_bug.cgi?id=21929 Thanks for the code suggestion although it still doesn't fix the bug. I am curious as to what those brackets do as well.
Re: How to avoid variable capturing in `foreach` loop with lambdas?
On Thursday, 5 January 2023 at 17:36:55 UTC, H. S. Teoh wrote:
On Thu, Jan 05, 2023 at 11:55:33AM +, thebluepandabear via
Digitalmars-d-learn wrote: [...]
```D
foreach (BoardSize boardSize; arr) {
Button button = new Button();
button.text = format("%sx%s", boardSize[0], boardSize[1]);
button.onButtonClick = {
eventHandler.settingsWindow_onBoardSizeButtonClick(boardSize);
};
button.onButtonClick();
_boardSizeRow.addChild(button);
}
```
This is a classic D trap: the loop variable is only allocated
once, and the closure captures the single location where the
loop variable resides, thus every delegate from every loop
iteration will see the same value when they are run later,
i.e., the last value of the loop index. Do this instead:
```D
foreach (BoardSize boardSize; arr) {
Button button = new Button();
button.text = format("%sx%s", boardSize[0], boardSize[1]);
BoardSize size = boardSize; // force separate capture
button.onButtonClick = {
eventHandler.settingsWindow_onBoardSizeButtonClick(size);
};
button.onButtonClick();
_boardSizeRow.addChild(button);
}
```
This is arguably a language bug (I can't imagine any sane use
case where somebody would actually want the current semantics).
But we have not be successful in convincing Walter about
this...
T
Your code with the variable capture doesn't seem to work.
Re: How to avoid variable capturing in `foreach` loop with lambdas?
Update some time later: the only way (oof!) around this seems to
be using a `static foreach` with arrays:
```D
Button[3] b;
static foreach (indx, BoardSize boardSize; arr) {
b[indx] = new Button();
b[indx].text = format("%sx%s", boardSize[0], boardSize[1]);
b[indx].onButtonClick = {
eventHandler.settingsWindow_onBoardSizeButtonClick(boardSize);
};
_boardSizeRow.addChild(b[indx]);
}
```
Any other ways of fixing this annoying issue?
How to avoid variable capturing in `foreach` loop with lambdas?
I am using CSFML D bindings and I have created my own sort of UI
library for drawing elements onto the screen.
One of the classes I've created is a `Button` class, which
contains a delegate called `onButtonClick` which is called when
the button is clicked on by the user.
Up until now, everything has worked fine.
I want to add a couple of buttons side by side to represent an
element of a list and assign them each a unique lambda expression
for that particular element in the list, this is the current code
I have:
```D
foreach (BoardSize boardSize; arr) {
Button button = new Button();
button.text = format("%sx%s", boardSize[0], boardSize[1]);
button.onButtonClick = {
eventHandler.settingsWindow_onBoardSizeButtonClick(boardSize);
};
button.onButtonClick();
_boardSizeRow.addChild(button);
}
```
Running this code, I had expected that everything would work
fine. Unfortunately upon running the code, tapping each of the
buttons returned only the largest `boardSize` value, the one
which is gets iterated last.
Note that I am still not totally sure why this is the case. At
first, I was confused, but then I suspected that after the
variable gets sent as a parameter to the
`settingsWindow_onBoardSizeButtonClick` function, it gets changed
again in the next iteration creating a sort of chain effect -- I
may be wrong, but this is my suspicion.
Some of the things I tried was creating a new object each time,
although it didn't work. I might have not done this properly as I
am a beginner to D language. I saw someone else ask a similar
question as to why this is happening but that was for C#, not D,
so it wasn't that much of a use to me.
Help would be appreciated!
Re: Is there a way to enforce UFCS?
On Wednesday, 4 January 2023 at 14:21:46 UTC, bauss wrote:
On Wednesday, 4 January 2023 at 03:42:28 UTC, thebluepandabear
wrote:
...
My question is: is there a way to enforce UFCS-syntax?
None of your code actually uses UFCS.
This is UFCS:
```
class Foo {
int bar;
}
void setBar(Foo foo, int value) {
foo.bar = value;
}
void main() {
foo.setBar(100); // UFCS
setBar(foo, 100); // Non-UFCS (Above expands to this)
}
```
This is not UFCS but just class method calling:
```
class Foo {
int bar;
void setBar(Foo foo, int value) {
foo.bar = value;
}
}
void main() {
foo.setBar(100); // Not UFCS - just method call to the class
foo.setBar = 100; // Not UFCS - simply a setter function call
(equal to the above)
setBar(foo, 100); // Error
}
```
Also note that @property doesn't really do anything now and
there's even talk about deprecating it. Althought I personally
still use it, then it doesn't have much of a function and none
of your code is affected if you remove it.
Yeah I got mixed up.
I think a good use of `@property` is for code clarity, it makes
it clear which parts of your code should be treated as properties.
Re: Why does this code only work with `T` and not `typeof(T)`?
On Wednesday, 4 January 2023 at 04:42:08 UTC, Ali Çehreli wrote:
On 1/3/23 20:11, thebluepandabear wrote:
> if I replace the `isDrawable` template with the
> following (using `typeof`), the code does not compile:
It must be because T is already a type. It's the same reason
why the following code fails to compile:
void main() {
alias T = int;
alias TT = typeof(T);
}
Error: type `int` is not an expression
And the error message tells us typeof requires an expression.
What you can do is to use T.init and the code should now work
like the following does:
alias TT = typeof(T.init);
Ali
Ok, that makes sense now, my mistake. I seem to have gotten the
wrong impression that typeof is more flexible than it is.
Why does this code only work with `T` and not `typeof(T)`?
I am using the CSFML D bindings, and I am creating my own `draw`
template function.
I first check that the object passed in is of the appropriate
type, and if it is, I call the appropriate function:
```D
template isDrawable(T) {
enum isDrawable = is(T == sfCircleShape*) || is(T ==
sfRectangleShape*) || is(T == sfText*) || is(T == sfSprite*);
}
void sfRenderWindowExt_draw(T)(sfRenderWindow* renderWindow, T
obj) {
static assert(isDrawable!T, format("Cannot call any draw
method on type %s", T.stringof));
if (is(T == sfCircleShape*)) {
renderWindow.sfRenderWindow_drawCircleShape(cast(sfCircleShape*)obj, null);
} else if (is(T == sfRectangleShape*)) {
renderWindow.sfRenderWindow_drawRectangleShape(cast(sfRectangleShape*)obj, null);
} else if (is(T == sfText*)) {
renderWindow.sfRenderWindow_drawText(cast(sfText*)obj,
null);
} else if (is(T == sfSprite*)) {
renderWindow.sfRenderWindow_drawSprite(cast(sfSprite*)obj, null);
}
}
```
For some reason, if I replace the `isDrawable` template with the
following (using `typeof`), the code does not compile:
```D
template isDrawable(T) {
enum isDrawable = is(typeof(T) == sfCircleShape*) ||
is(typeof(T) == sfRectangleShape*) || is(typeof(T) == sfText*) ||
is(typeof(T) == sfSprite*);
}
```
This is really strange, as I assumed that the two pieces of code
were essentially the same.
Any help as to why this is the case would be appreciated.
Is there a way to enforce UFCS?
Say you have the following class which represents a dog :
```D
class Dog {
@property {
string name();
void name(string name) {
_name = name;
}
}
private {
string _name;
}
}
```
And you have the following code with constructs a `Dog` object:
```D
void main() {
Dog d = new Dog();
d.name = "Poodle";
writeln(d.name);
}
```
In the code we can see that we have utilized UFCS (universal
function call syntax) to set the properties for the object. This
feature is great. We have also used D's `@property` annotation
which gives us some other advantages that you can see in the
documentation.
The issue I have is that UFCS is not enforced, which I thought
would be a rather good use for the `@property` annotation. This
means that we can do the following in our code:
```D
void main() {
Dog d = new Dog();
d.name("poodle");
writeln(d.name());
}
```
I prefer the UFCS version over the non-UFCS version since it is
more clear that it is a property and it matches closely with the
official D style guide.
I am disappointed that `@property` does not enforce UFCS, as I
believe that it would add to its usefulness. Sometimes throughout
my codebase I get confused and write properties in non-UFCS
syntax, which bugs me a bit.
My question is: is there a way to enforce UFCS-syntax?
Re: Is there such a JSON parser?
On Sunday, 1 January 2023 at 23:28:12 UTC, torhu wrote: I need to parse some JSON data into various data structures, so I'm looking for a parser based on events or ranges. One that doesn't just load the file and build a data structure that represents the whole thing. So not std.json, at least. I'm new to D and also haven't found any solid JSON libraries. Unfortunately a massive downside for D is the fact that the ecosystem is very small when compared to other languages such as Java. You might want to try the following: https://github.com/libmir/asdf
Re: Compile time vs run time -- what is the difference?
On Wednesday, 28 December 2022 at 09:10:38 UTC,
areYouSureAboutThat wrote:
On Wednesday, 28 December 2022 at 02:31:45 UTC,
thebluepandabear wrote:
..
Other errors are only able to be spotted during run time such
as exceptions, dividing by zero, assert blocks.
With regards to the 'assert blocks' you mention, D (like C++)
has both static assert and runtime assert.
// ---
module test;
@safe:
import std;
void main()
{
string val = "some string";
static assert(is(typeof(x) : int)); // assertion fails at
compile time.
assert(val == "some other string"); // assertion fails at
runtime.
}
// ---
Before even running the code I get an IDE warning (IntelliJ).
Does IntelliJ compile the code in the background?
Compile time vs run time -- what is the difference?
I am reading through the free book on learning D by Ali Çehreli and I am having difficulties understanding the difference between compile time execution and run time execution in D language. What I do understand is that compile time and run time are the two processes that your code goes through to be executed natively. Compile time is the first stage. During compile time, the compiler checks for basic syntax errors such as a missing semicolon, typos throughout the codebase. Then the run time stage begins. Other errors are only able to be spotted during run time such as exceptions, dividing by zero, assert blocks. In Java and some other languages, during compile time the code gets executed into Java bytecode. This also happens for C#. I don't know if there is an equivalent 'intermediate' language for D that your code gets translated to. In general, I have a very vague understanding of these concept.s I don't understand the basics of how compile time and run time works in D language, it wasn't really explained in the book so when I see terms like 'compile time' and 'run time' I only have a very vague idea of what these things mean and how the process works for D language when compared to other high level languages. Any help would be appreciated.
Does 'ref' turn into a pointer during compile time?
Say you have the following function that takes in a `ref`
parameter:
```D
void modify(ref int num) {
num += 5;
}
```
Does the compiler turn that into the code below?
```D
void modify(int* num) {
num += 5;
}
```
I was just wondering whether or not this is the case because I
don't think this was touched in the book about D I am reading.
Re: Is there such concept of a list in D?
No worries, hopefully a mod will explain why. I don't like when posts get removed for no reason :|
Re: Is there such concept of a list in D?
On Monday, 19 December 2022 at 22:07:15 UTC, Ali Çehreli wrote: On 12/19/22 13:45, thebluepandabear wrote: > On Monday, 19 December 2022 at 21:41:45 UTC, thebluepandabear wrote: >> Why did my replies here to someone else get deleted? > > Myself and this other person's reply to this thread randomly got removed > for no reason, I would appreciate an explanation Are you sure it was this thread? What were in those posts? Perhaps they were posted on another thread? I follow these newsgroups with ThunderBird, which naturally keeps local copies of the posts. I've just gone through all posts in this thread and I see no difference between ThunderBird's cache and the forum interface's cache. Note that ThunderBird does not delete any post even if a moderator removes a posting from the newsgroup. For example, when a spam gets posted, my ThunderBird will show the post even after it's been deleted from the newsgroup server. Ali Yeah I am sure it was on this thread. One of the posts was at https://forum.dlang.org/post/kzvnajixjdnlcupsl...@forum.dlang.org, it now shows 'Not Found'. I just replied to this person who was asking whether or not I was talking about C's `union` type (I was not), and his post and my reply seems to have magically disappeared.
Re: Is there such concept of a list in D?
On Monday, 19 December 2022 at 21:41:45 UTC, thebluepandabear wrote: Why did my replies here to someone else get deleted? Myself and this other person's reply to this thread randomly got removed for no reason, I would appreciate an explanation
Re: Is there such concept of a list in D?
Why did my replies here to someone else get deleted?
Re: Is there such concept of a list in D?
On Sunday, 18 December 2022 at 22:17:04 UTC, j wrote: On Saturday, 10 December 2022 at 05:46:26 UTC, thebluepandabear wrote: In most languages there is some sort of `List` type, is that the same for D? What you're probably talking about is called a union in the C world. There is a nice (free) book by Ali that every Dlang beginner should probably read. I am reading that exact book (halfway through), it's great. I wasn't talking about the `union` type (I am familiar with it), I was talking about Java's `ArrayList` / C++'s `std::vector` / Rust's `vec!`.
Re: How is this code invalid?
T
Thanks, I've tried to mark it with `@safe` and it did give me a
warning.
I was also wondering, why is this code valid?
```D
int[] numbersForLaterUse;
@safe void foo(int[] numbers) {
numbersForLaterUse = numbers;
}
```
How is this code invalid?
I am reading the fantastic book about D by Ali Çehreli, and he
gives the following example when he talks about variadic
functions:
```D
int[] numbersForLaterUse;
void foo(int[] numbers...) {
numbersForLaterUse = numbers;
}
struct S {
string[] namesForLaterUse;
void foo(string[] names...) {
namesForLaterUse = names;
}
}
```
He says that the code above is a bug because:
"Both the free-standing function foo() and the member function
S.foo() are in
error because they store slices to automatically-generated
temporary arrays that
live on the program stack. Those arrays are valid only during the
execution of the
variadic functions."
The thing is, when I run the code I get absolutely no error, so
how is this exactly a 'bug' if the code runs properly? That's
what I am confused about. What is the D compiler doing behind the
scenes?
Re: Graphical progressive fill
On Sunday, 11 December 2022 at 06:50:44 UTC, Joel wrote: I've been trying to fill in areas with a colour but can't work it out. I want something like the effect where it fills with diamonds. Not all at once but building up in the main program loop. # # # # # # # # # # # # # # # # # #### # # # # # ## # # #### # # # # ### # ## # There should be some ANSI sequences that allow you to do such a thing (as in clearing the console and refreshing), not familiar with any though from the top of my head.
Why can't rvalues be passed to a 'ref' parameter?
Hello, I am not really understanding why rvalues cannot be passed to a 'ref' parameter, the explanation in the book about D I am reading was not clear: "The main reason for this limitation is the fact that a function taking a ref parameter can hold on to that reference for later use, at a time when the rvalue would not be available." I didn't really understand what Ali meant by this statement, any help would be appreciated so this can be clarified. Regards, thebluepandabear
Re: Is there such concept of a list in D?
On Saturday, 10 December 2022 at 05:54:09 UTC, Steven Schveighoffer wrote: On 12/10/22 12:46 AM, thebluepandabear wrote: In most languages there is some sort of `List` type, is that the same for D? D doesn't focus on interfaces, we have concepts, like ranges. Sorry, it's hard to answer your question without asking more questions: are you looking for a linked list? A list API? A specific list interface? -Steve I was wondering more if there is an object oriented way of creating arrays, like in Java there is an `ArrayList`, in C++ there is `std::vector`, etc.
Is there such concept of a list in D?
In most languages there is some sort of `List` type, is that the same for D?
