Re: Is it possible to use templates to implement something like the `@show` macro from the Julia programming langauge in D?
On Sunday, 8 September 2024 at 22:01:10 UTC, WraithGlade wrote:
Basically, I want there to be a way to print both an expression
and its value but to only have to write the expression once
(which also aids refactoring). Such a feature is extremely
useful for faster print-based debugging.
[...]
I want to just be able to write this:
```
show!(1 + 2)
```
Try this:
```
import core.interpolation;
void show(Args...)(InterpolationHeader hdr, Args args,
InterpolationFooter ftr) {
import std.stdio;
foreach(arg; args) {
static if(is(typeof(arg) ==
InterpolatedExpression!code, string code))
write(code);
else static if(is(typeof(arg) ==
InterpolatedLiteral!str, string str))
write(str);
else
write(" = ", arg);
}
writeln();
}
```
Used like:
```
void main() {
int a = 5, b = 22;
show(i`$(a), $(b), $(a + b)`);
}
```
Output:
a = 5, b = 22, a + b = 27
You can show as many expressions as you want in there, each
$() thing is expanded to `code inside = result`.
So
show(i"$(1 + 2)"); // prints 1 + 2 = 3
The interpolated sequence syntax makes it a bit heavier: that
`i"$( )"` around it is required here, but it works anyway.
Re: Mixin Templates and Operators
On Wednesday, 6 April 2022 at 10:36:04 UTC, francesco.andreetto wrote: Am I doing something wrong or it is impossible to use mixin templates like that? mixin templates can't bring in operator overloads. The spec doesn't really say this I think, but that's the way it has been for a long time. It only checks for operator overloads on the direct thing itself, no UFCS, no mixin template.
Re: Mixin Templates and Operators
On Wednesday, 6 April 2022 at 17:33:28 UTC, Steven Schveighoffer wrote: As I mentioned elsewhere, it does work. But the situation I think must be that it's only one mixin template. Probably also you can't have any overloads in the type itself. ooh yeah there's multiple here so the names don't overload and one on the time itself would override the ones from mixin template. You'd have to alias them together on the type.
Re: Looking for a workaround
On Wednesday, 6 April 2022 at 18:10:32 UTC, Guillaume Piolat
wrote:
Any idea how to workaround that?
Works fine if you just use the language instead of the buggy
phobos wrappers:
---
struct MyUDA
{
}
class A
{
@MyUDA int a;
}
class B : A
{
@MyUDA int b;
}
void main()
{
foreach(memberName; __traits(allMembers, B))
foreach(attr; __traits(getAttributes, __traits(getMember,
B, memberName)))
static if(is(attr == MyUDA))
pragma(msg, memberName); // a, b
}
---
So make a function that does that and applies whatever it is you
need to apply and you're in business.
Note that it is `is(typeof(attr) == MyUDA)` if defined
`@MyUDA(args)`.
Re: arsd-minigui - couple of questions
On Monday, 11 April 2022 at 12:40:29 UTC, sai wrote: One more request, is it possible for you to do to ImageBox what you did to Button to show the transparent images (png)? Because Imagebox is showing black color for transparent pixels. oh yeah this one is different because the imagebox custom draws it, so it is really as simple as passing `true` to the opacity there too when it converts. Try this diff: https://github.com/adamdruppe/arsd/commit/912047ccdda7e7775f64431a631519e6024d2494 i think it fixes it, let me know.
Re: CTFE and BetterC compatibility
On Wednesday, 27 April 2022 at 14:21:15 UTC, Claude wrote:
The operation requiring the D-runtime is appending the array,
but it should **only** be done at compile-time.
In that case, you want to prove to the compiler it is only called
at compile time by encapsulating the function inside a template
or defining it immediately where it is called.
Delete the stand-alone function `parse` and instead call it like
this:
```
// define it
enum Data parsedData = function Data (string str) pure
{
Data data;
while (str.length != 0)
{
// Skip spaces
while (str[0] == ' ')
str = str[1 .. $];
// Parse single digit integer
data.digits ~= parseDigit(str[0]);
// Consume digit
str = str[1 .. $];
}
return data;
} ("5 4 2 6 9"); // and call it in the same place
```
Or if you want it to be independently defined still, you can
define it inside a helper template but you'd have to return a
basic type instead of Data, so I think calling it immediately is
what you want to do here.
There was going to be a ctfe-only thing you could put in the
function so the compiler doesn't try to generate the runtime
version, but this got killed due to internal D politics. A pity.
Re: Library for image editing and text insertion
On Wednesday, 27 April 2022 at 14:40:59 UTC, Alexander Zhirov wrote: Gorgeous! LDC has compressed my code at times! How small did it get? And with my libs if you import the other ones like `arsd.png` or `arsd.jpeg` directly instead of `arsd.image` that MIGHT help trim it down by removing support for other formats. I'm not sure though, none of them are especially big but it might add up.
Re: Library for image editing and text insertion
On Wednesday, 27 April 2022 at 17:07:54 UTC, matheus wrote: I know about Adam Ruppe's work, I already used his terminal.d, but I think that unfortunately most people don't and I think it should be announced more in these parts. tbh sometimes i just don't feel like answering messages. even this one, i was like "i can do that easily, but do i want to support another user?" but meh i had a few mins to kill anyway For me arsd is for D what stb is for C. Note that a few of those modules are stb ports over to D. I wrote the png and bmp modules myself, for example, but the jpeg is a port from C (that port done by ketmar on irc) and the ttf one is stb_ttf ported to D then with a little wrapper struct pasted on top. One thing I'm kinda proud of though is my OperatingSystemFont class in simpledisplay which can load a font and then pass it into the ttf thing and/or the nanovega module for all kinds of custom effects. You don't necessarily have to package your own ttf files!
Re: How do I get the screen resolution?
On Thursday, 28 April 2022 at 11:22:15 UTC, Alexander Zhirov
wrote:
Are there any methods to get the screen resolution?
Call DisplayWidth/DisplayHeight on the X connection... my
simpledisplay.d provides bindings (though not a high level helper
function since both X and Windows calls are trivial)
On C/C++ from under X11, it is not possible to do this on the
command line via SSH, since the display is not defined.
Just defined the display, that's easy.
import std.process;
enviornment["DISPLAY"] = ":0";
that can work with any lib, then connect.
OR, with my lib, it is all included:
---
import arsd.simpledisplay;
XDisplayConnection.setDisplayName(":0"); // set the local name
regardless of what is set on ssh
auto connection = XDisplayConnection.get(); // connection
import std.stdio;
writeln(DisplayWidth(connection, 0), " x ",
DisplayHeight(connection, 0)); // the 0 is the screen number
---
Though note with a multiple monitor system, this will give the
*full* size of the virtual screen, not individual screens.
simpledisplay has methods for this. but I marked it `private`
and it only loads the data when a window is created... you COULD
hack past this anyway but prolly not worth the hassle. Maybe I
will make it public officially in the next release.
But if you are desperate for the info now, here's how you can
bypass private and get at it anyway:
---
// use reflection to bypass `private`
alias MonitorInfo = __traits(getMember,
arsd.simpledisplay.SimpleWindow, "MonitorInfo");
// make a temporary window just to get the info
auto window = new SimpleWindow(1, 1, null, OpenGlOptions.no,
Resizability.fixedSize, WindowTypes.eventOnly);
// this is the function that actually loads the monitor info
window.actualDpi();
// make sure none waiting in a buffer
flushGui();
// and now get the data out
foreach(monitor; MonitorInfo.info) {
writeln(monitor.position.size);
}
window.close();
---
But since you're bypassing private and poking internals, if/when
I do decide to make this public instead of private, I'll probably
break this approach (when it is public though you can just simply
loop over the info).
Re: CTFE and BetterC compatibility
On Thursday, 28 April 2022 at 12:36:56 UTC, Dennis wrote: In this case, it was actually a trailing whitespace in the changelog entry making the test suite fail, but the PR author Stefan's own `assert(__ctfe);` approach was better anyway...
Re: What's a good way to disassemble Phobos?
On Saturday, 30 April 2022 at 18:18:02 UTC, Dukc wrote: I'm looking for something where I could search for the call to the DRuntime functions in question, from an already combined .o or .a. What do you suggest? I'm on Linux. objdump -d works on .o files
Re: How to get compatible symbol names and runtime typeid names for templated classes?
On Tuesday, 3 May 2022 at 09:42:45 UTC, cc wrote: something I can pass to `Object.factory`. Object.factory is useless and will hopefully be removed someday. Instead, make your own factory registration function. Put a static constructor in the class which appends a factory delegate to an array or something you can use later. Then you can use your own thing to construct registered objects.
Re: How to get compatible symbol names and runtime typeid names for templated classes?
On Tuesday, 3 May 2022 at 13:25:14 UTC, Arafel wrote:
I'd like to do a runtime registration system myself, using a
"template this" static constructor. A simple version supporting
only default constructors would be:
Yeah, you can't template this a static constructor, but you can
just use a static constructor. It will have to be mixed into each
child class though, and the compiler won't help to remind you.
But do something along the lines of:
```d
module factory.register;
private Object function()[string] factories;
Object construct(string name) {
if(auto f = name in factories)
return (*f)();
return null;
}
mixin template Register() {
static this() {
import factory.register;
alias This = typeof(this);
// bypassing private
__traits(getMember, factory.register, "factories")
[This.mangleof] = function Object() {
// you could even delegate to a static
// function if one is present, or pass
arguments
// etc. this impossible with
Object.factory
return new This();
};
}
}
```
That code is your library. Then, to use it:
```d
import factory.register;
class MyThing {
// you have to remember to do this in each child
mixin Register;
}
void main() {
auto t = new MyThing();
// I used the mangle instead of the FQN since it
// is easier.
Object o = construct(typeof(t).mangleof);
MyThing t2 = cast(MyThing) o;
assert(t2 !is null); // assert it actually worked
}
```
Now, you can extend this a little if you're willing to add an
interface too. And if you forget to register the base class, the
interface method being not implemented will remind user they did
something wrong, and you can runtime assert to check child
classes.
Check this out:
```d
module factory.register;
private Object function()[string] factories;
Object construct(string name) {
if(auto f = name in factories)
return (*f)();
return null;
}
// adding this for the assert
bool typeIsRegistered(string name) {
return (name in factories) !is null;
}
// this interface gives runtime access to the info we need
interface Serializable {
string typeCode() const;
}
mixin template Register() {
// interface implementation
override string typeCode() const {
// casting away const for more consistent names
alias no_const = typeof(cast() this);
auto name = no_const.mangleof;
// a runtime check to help remind you if
something not registered
import factory.register;
assert(typeIsRegistered(name), "Type
"~typeof(this).stringof~" not registered!");
// also making sure the child class was registered
// by ensuring the runtime type is the same as
the static type
assert(typeid(this) == typeid(no_const), "Child
class "~typeid(this).toString()~" was not registered!");
return name;
}
static this() {
import factory.register;
alias This = typeof(this);
// bypassing private
__traits(getMember, factory.register, "factories")
[This.mangleof] = function Object() {
// you could even delegate to a static
// function if one is present, or pass
arguments
// etc. this impossible with
Object.factory
return new This();
};
}
}
```
And the usage:
```d
import factory.register;
class MyThing : Serializable {
mixin Register;
}
class Child : MyThing {
// forgot to register uh oh
// mixin Register;
}
void main() {
auto t = new MyThing();
Object o = construct(typeof(t).mangleof);
MyThing t2 = cast(MyThing) o;
assert(t2 !is null);
auto child = new Child();
// if we called this in the serialize function or even
one of those constructors' contracts
// it can verify things work by triggering the asserts
back in the library implementation
child.typeCode();
}
```
So doing things yourself gives you some control.
Re: How to get compatible symbol names and runtime typeid names for templated classes?
On Tuesday, 3 May 2022 at 14:38:53 UTC, Arafel wrote: Actually, it would be cool to do it through an interface, although I don't think an interface's static constructors are invoked by the implementing classes... it would be cool, though. yeah interfaces can't have constructors. I'd try it myself, but I wouldn't know where to start. Compiler internals are way beyond my comfort zone... Believe it or not, you don't need to touch the compiler. Open your druntime's object.d and search for `RTInfo` http://druntime.dpldocs.info/object.RTInfo.html That is instantiated for every user defined type in the program and you have the compile time info. all druntime uses it for is a tiny bit of GC info and even then only sometimes. But it could do so so so much more. Including doing custom factories and runtime reflection buildups!
Re: How to get compatible symbol names and runtime typeid names for templated classes?
On Tuesday, 3 May 2022 at 16:38:23 UTC, cc wrote: This is really interesting syntax, I'm surprised that works! Can read a little more on my blog about it: http://dpldocs.info/this-week-in-d/Blog.Posted_2019_06_10.html#tip-of-the-week pretty cool little pattern.
Re: Google Code Jam 2022
On Friday, 6 May 2022 at 04:26:13 UTC, Siarhei Siamashka wrote: So it may seem that D should be a very good choice for programming competitions, but there's still no success. Programming competitions are a 100% waste of time. I'm too busy doing real work.
Re: What are (were) the most difficult parts of D?
On Thursday, 12 May 2022 at 01:06:02 UTC, Christopher Katko wrote: completely different semantics for a class vs a struct. Is it a reference? Is it a value? Look up the entire declaration and have the entire Dlang manual open to find out. As far as I remember, no automatic RAII support, even though it's insanely useful. class = virtual functions struct = RAII
Re: What are (were) the most difficult parts of D?
On Thursday, 12 May 2022 at 14:42:43 UTC, Anonymouse wrote: That said, one thing I cannot seem to firmly wrap my head around is `is` expressions. `is` does so many things. It is simpler than it looks, I wrote about it in my book and in a post here: https://forum.dlang.org/post/xklcgjaqggihvhctc...@forum.dlang.org ``` alias AA = long*[string]; static if (is(AA whatEvenGoesHere : VP[K], VP, K)) You don't have to put anything there. The is expression kinda parallels declarations, so that thing would be the name for the newly declared symbol. But you don't need to declare a new symbol there so you can leave it blank; most the pieces are optional. The one thing that has caused me most anguish and woe is hands-down https://issues.dlang.org/show_bug.cgi?id=18026 though. yeah bugs happen.
Re: What are (were) the most difficult parts of D?
On Thursday, 12 May 2022 at 15:18:34 UTC, jmh530 wrote: What's the difference between a Type and Type Identifier? The is expression roughly follows variable declaration style. You write int a; to declare a new symbol named `a` of type `int`. Similarly, static if(is(T a)) declares a new symbol of type `a` if `T` is a valid type. (Of course, in this case, a and T are aliases of each other, so it isn't super useful, but in the more complex matches using the == and : operators, it might be different.) The Identifier is optional.
Re: What are (were) the most difficult parts of D?
On Friday, 13 May 2022 at 18:23:58 UTC, H. S. Teoh wrote: On Thu, May 12, 2022 at 11:45:47PM +, Guillaume Piolat via It's a problem because it goes from solving "no accidental race condition" and you get "people forget to add shared or __gshared and their shared library silently fail" situation. You could have none of that with explicit TLS. Valid point. Yeah, I used to be pro-TLS by default, then got bit by it several times and moved to the fence, and now I'm anti. Data races aren't actually prevented by it (maybe forcing you to specify shared or tls would at least get you think about it though) and lots of things mysteriously fail if you forget about it. You can lock the variable and everything and it still null cuz it was tls the whole time. Oops. This a case where I think forcing explitness would be better than either default, but failing that, tls by default is the more-bad choice.
Re: D WebAssembly working differently than C++, Zig
I would suspect it is something to do with your memset... even if it needs to take the int (wtf but ldc is weird) you might want to reinterpret cast it to float to avoid any extra conversions.
Re: D WebAssembly working differently than C++, Zig
On Monday, 16 May 2022 at 18:17:03 UTC, Allen Garvey wrote: Thanks so much, that fixed the problem! You have no idea have long I have spent trying to debug this! Oh I should have checked my impl, where I did all this already! https://github.com/adamdruppe/webassembly/blob/master/arsd-webassembly/object.d#L263 And also might be able to just have the function forward to the ldc intrinsic: https://github.com/ldc-developers/druntime/blob/ldc/src/ldc/intrinsics.di#L160 might help speed up a lil too, i don't know though (I didn't do it here for me)
Re: D WebAssembly working differently than C++, Zig
On Tuesday, 17 May 2022 at 11:43:45 UTC, Siarhei Siamashka wrote: Looks like you forgot to increment the pointer and need "*d++ = cast(ubyte) c;" there. hahaha yup. And filling the buffer one byte at a time is likely slow. prolly but meh, that's where the intrinsics are nice.
Re: Why are structs and classes so different?
On Tuesday, 17 May 2022 at 14:40:48 UTC, Kevin Bailey wrote: Foo foo; is undefined behavior waiting to happen, that I can't detect at a glance. It is actually perfectly well defined - for the class, it will be null, and this will kill the program if you use it. You might not like that definition, but that's how it is defined. - A *secondary* goal would be for class objects to be able to have deterministic destructors like structs. they can with the `scope` keyword. The first looks trivial: Just have it allocate a Foo by default. Worth noting that D *never* calls a user defined function on variable declaration; there are no default constructors. Even if it is a struct, it never actually calls a constructor, it just copies over the default init value. This is different than classes, which have some kind of constructor call any time you make one. I think it is probably this default constructor stance that the rest flows from: a class is assumed to encapsulate some non-trivial state so it has a constructor, interfaces, object identities, etc. A struct is more of a plain collection of data. Of course, in practice the lines are more blurred than that, but I think that's where it comes from. Especially if you look at the older D versions when structs didn't support constructors at all.
Re: Error: undefined symbol: _WinMain@16 When try compile no console
On Thursday, 19 May 2022 at 19:29:25 UTC, Marcone wrote: Using -L/SUBSYSTEM:windows user32.lib you using a main() function right? Please note when compiling on Win64, you need to explicitly list -Lgdi32.lib -Luser32.lib on the build command. If you want the Windows subsystem too, use -L/subsystem:windows -L/entry:mainCRTStartup. If using ldc instead of dmd, use -L/entry:wmainCRTStartup instead of mainCRTStartup; note the "w". see some deets i wrote here http://arsd-official.dpldocs.info/arsd.simpledisplay.html#installation-instructions
Re: Error: undefined symbol: _WinMain@16 When try compile no console
On Thursday, 19 May 2022 at 20:20:49 UTC, Marcone wrote: I am using a main() function. I am compiling on Windows x86 32 bits. I am using DMD 2.100.0 This error is only in version 2.100.0 of DMD. Are you using the `-L/entry:mainCRTStartup` or the `L/entry:wmainCRTStartup` ?
Re: UI Library
On Friday, 20 May 2022 at 03:47:14 UTC, harakim wrote: Thank you. I will definitely give that a try. My minigui uses the normal Windows controls so it works well there. On linux it uses a custom thing of my own design so your mileage may vary. The docs don't have a lot of examples but hopefully one you do the first one the rest won't be too hard, the classes are relatively simple and the events are based on javascript so if you've used that before you can probably get to know it. But just ask me if something comes up since I can push fixes to master p quickly. The only files it needs from the repo are `minigui.d`, `simpledisplay.d` and `color.d`. There's other optional things in there that might be useful though. My recommended way to use it is to `git clone` the repo in your source dir then `dmd -i yourfile.d` so it is easy to update with a `git pull` and the compiler pulls what it needs (and nothing more) automatically when compiling. But you can also do it yourself or use the dub packages etc.
Re: template? mixin? template mixins? for modifying a struct setup
On Friday, 20 May 2022 at 14:54:31 UTC, Christopher Katko wrote: If the declarations are at module scope, `static` has no effect, and CTFE will be used for initialization. It won't use CTFE? Why is there a local module requirement? "module scope" just means at the top level in a module. so not inside a function.
Re: Sleep in a cycle
On Friday, 20 May 2022 at 14:59:07 UTC, Alexander Zhirov wrote: I have a loop spinning, I want to pause in it in order to repeat the next iteration. An error is displayed during compilation. The error has nothing to do with the sleep source/app.d(32,5): Warning: statement is not reachable Error: warnings are treated as errors Use -wi if you wish to treat warnings only as informational. this is saying the stuff after your `while(true)` is never reached because it is an infinite loop.
Re: Install DCD language server on Raspberrry PI4 (aarch64) requires rdmd , command not found.
On Saturday, 21 May 2022 at 22:44:55 UTC, Alain De Vos wrote: Can I compile rdmd from source ? Yes, rdmd is a trivial program. https://github.com/dlang/tools/blob/master/rdmd.d
Re: Allocate a string via the GC
On Monday, 23 May 2022 at 09:38:07 UTC, JG wrote: Hi, Is there any more standard way to achieve something to the effect of: ```d import std.experimental.allocator; string* name = theAllocator.make!string; ``` Why do you want that? Easiest way I know of is to just wrap it in a struct, then `new that_struct`, which is also a better way for all the use cases I know but those use cases are pretty rare so there's probably a better way to do what you're trying to do.
Re: Allocate a string via the GC
On Monday, 23 May 2022 at 12:20:11 UTC, JG wrote: I am writing an interpreter and I needed access to a string via a pointer of type void* I ended up wrapping it in a struct since I needed another value anyway. Seems odd that one can't do it in a less unusual way. OK yeah, that's the main use case I'd think of, and that's also exactly why I think doing the struct is the best thing anyway since you can bundle whatever you need in there instead of just a single value.
Re: How are delegate attributes in fn signature inferred?
On Monday, 23 May 2022 at 13:44:53 UTC, wjoe wrote:
i.construct((ulong i) {return cast(int)(i+i);}).print;
You can actually make this work with `construct!(int[])` rather
than plain `construct`. This is a (really annoying) deficiency in
dmd's implementation. (that sdc solved btw proving it can be done
just dmd never bothered)
Where's **pure nothrow @nogc @safe** coming from?
That's because it is a delegate literal, so it automatically
figured out the tightest thing that works (this is also why it
came as `function` instead of `delegate`, since it doesn't use
any local variables from the enclosing function, it doesn't need
the delegate pointer either).
But all those implicitly convert away so it doesn't really
matter. The type system allows this, just the crappy
implementation can't handle inferring that R when it is mentioned
both as R r *and* ElementType!R - the stupid compiler sees
ElementType!R and bails out.
Thus why you have to help it by telling the type when
instantiating it
i.construct!(int[])((ulong i) {return cast(int)(i+i);}).print;
Re: Cannot check function address
On Tuesday, 24 May 2022 at 22:10:21 UTC, frame wrote: To also anwser to Adam: no, this symbol is unique. The first line of the error says: ``` Error: function `a.fun(string param)` is not callable using argument types `()`. ``` There's a big difference between a function and a function pointer. This error message says "function". But the code you showed as a function pointer. If it were a function pointer, the error would be: ``` Error: function pointer `a()` is not callable using argument types (int)` ``` So there is clearly some kind of mix up here. The point is, it shouldn't be called in this line anyway? If it is a function, you get its address with the & operator. But if it is supposed to be a function pointer, something is wrong with the declaration...
Re: gdc 12.1: undefined references when linking separately compiled files
On Saturday, 28 May 2022 at 13:12:46 UTC, kdevel wrote: gdc -o ppinsta ppinsta.o esah.o evaluate.o jsr.o jsw.o parser.o ptvr.o stack.o testdatagenerator.o You might need to add -lgphobos or -lgphobos2 or whatever it is called too explicitly.
Re: gdc 12.1: undefined references when linking separately compiled files
On Saturday, 28 May 2022 at 14:16:51 UTC, kdevel wrote: $ gdc -o ppinsta ppinsta.d parser.d Compiling together is faster anyway this is prolly what you want most the time. But I know what's going on now, it is the template emission thing, the compiler thinks, since it is from std, it was already compiled somewhere else and skips it but it isn't actually there so the linker errors. Using gdc -fall-instantiations -c parser.d Might generate it in that parser.o getting it to link. Might need to be used in all builds but I *think* just here, hard to say without a test.
Re: Basic SQLite Application
On Wednesday, 1 June 2022 at 03:46:38 UTC, harakim wrote: I started trying to get it to compile in another directory structure but since I've switched to dub It should work the way you have it, just with dub you can also the dub version instead of copying the files: https://code.dlang.org/packages/arsd-official%3Asqlite both are supposed to work. anyway it compiles and runs and returns some large negative number as an error without printing what's in the writeln. What is the number? My guess is you might have gotten the wrong sqlite3.dll (it should come from the same source as the .lib file you used) or it is in the wrong place. I won't rule out that my lib file is the wrong file as I don't know how to tell or find the right one. That's possible too but it would normally fail to link entirely if this was it. My money is on the dll, especially since the main() doesn't even try to open the database, it must be a loading issue. Where did you get the .lib file anyway? BTW: "copyFiles":["lib/sqlite3.lib"] You don't need that, the .lib is only used while building. You might need to copyFiles the .dll though.
Re: Basic SQLite Application
On Wednesday, 1 June 2022 at 15:40:43 UTC, harakim wrote: It's been a long time since I did any C development, and I have never done any on windows, but I thought I could statically link to the .lib at compile time and then I wouldn't need a dll. You sometimes can, it depends on how the library is built. If it was built as a dll, you need to use it that way unless you recompile the library itself.
Re: Dynamic Arrays Capacity
On Friday, 3 June 2022 at 12:49:07 UTC, bauss wrote: I believe it's only true in unicode for utf-32 since all characters do fit in the 4 byte space they have Depends how you define "character".
Re: Comparing Exceptions and Errors
On Sunday, 5 June 2022 at 10:38:44 UTC, Ola Fosheim Grøstad wrote: That is a workaround that makes other languages more attractive. It is what a lot of real world things do since it provides additional layers of protection while still being pretty easy to use. *Correctness **is** probabilistic.* Even in the case of 100% verified code, as there is a possibility that the spec is wrong. I'm of the opinion that the nothrow implementation right now is misguided. It is a relatively recent change to dmd (merged December 2017). My code did and still does simply catch Error and proceed. Most Errors are completely harmless; RangeError, for example, is thrown *before* the out-of-bounds write, meaning it prevented the damage, not just notified you of it. It was fully recoverable in practice before that silly Dec '17 dmd change, and tbh still is after it in a lot of code. If it was up to me, that patch would be reverted and the spec modified to codify the old status quo. Or perhaps redefine RangeError into RangeException, OutOfMemoryError as OutOfMemoryException, and such for the other preventative cases and carry on with joy, productivity, and correctness.
Re: How to map machine instctions in memory and execute them? (Aka, how to create a loader)
On Monday, 6 June 2022 at 15:13:45 UTC, rempas wrote: void* code = mmap(null, cast(ulong)500, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0); On a lot of systems, it can't be executable and writable at the same time, it is a security measure. see https://en.wikipedia.org/wiki/W%5EX so you might have to mprotect it to remove the write permission before trying to execute it. idk though
Re: 'each' can take static arrays
On Friday, 10 June 2022 at 16:59:04 UTC, Ali Çehreli wrote: Why the inconsistency? Phobos has dozens of random special cases throughout. I'd prefer if these were all removed, but right now there's just some functions that special case to allow it and others that don't. Apparently each is one that does.
Re: UI Library
On Saturday, 11 June 2022 at 01:20:17 UTC, harakim wrote: The issue I'm having is that I don't understand how to assign bounds in the nested widget. I'm sure there's a very clean solution. I basically want a paintContent method but with the bounds dynamically assigned by the parent. Well the bounds given to paintContent just define your content area boundaries, relative to the nested widget. The content area is inside its own border. The actual position is assigned by the parent (the virtual function there is recomputeChildLayout, you can override that to arrange instead of letting it automatically fill the space). I don't really know what exactly you have in mind for the bounds, but anything outside your widget area is going to be clipped anyway, so I think you really want to change that child layout computation.
Re: UI Library
On Saturday, 11 June 2022 at 21:44:17 UTC, harakim wrote: I tried the solution I suggested and it did not work because the child would occlude the parent (which is in the comments now that I see it.) yeah minigui's model is to tile the widgets; they aren't supposed to overlap (except their parent, but then they cover the parent) I decided to stick to simpledisplay strictly and forgo using the minigui library for the time being, and that is working well. Yeah, nested widgets are something i sometimes use btu more often then not, i'll make the whole display for a thing - say a graph - just be a single widget and paint it in there. A simpledisplay window's paint code can generally be pasted into a single minigui widget's paint code without much modification (the minigui WidgetPainter actually is a subclass of simpledisplay's ScreenPainter)
Re: Creating DLL
On Thursday, 16 June 2022 at 13:57:48 UTC, Sergeant wrote: export int my(int a, int b) the name here is going to be mangled, so like "_D5mydll2myiiZi" or something like that. You might want to add `extern(C)` to it so it keeps the simple name "my", that might help.
Re: Creating DLL
On Thursday, 16 June 2022 at 16:07:41 UTC, Sergeant wrote:
May I ask one more question: why a code like this would work in
D-application but not in D-DLL? (also I notice some other D
functions don't work in DLL):
Probably because the runtime not initialized properly. Export an
Initialize() and Terminate() functions and call them from your
application loading the dll.
Inside those functions:
export extern(C) void Initialize() {
import core.runtime;
Runtime.initialize();
}
export extern(C) void Terminate() {
import core.runtime;
Runtime.terminate();
}
If you call those the other functions should start working.
(this is a fairly common thing libraries need to do, but it might
be tricky if you are loading the dll into an uncooperative
application, there's other hacks for that, but having your
functions like this and the app calling them are the right way to
do it)
Re: Creating DLL
On Thursday, 16 June 2022 at 16:19:22 UTC, Ali Çehreli wrote: pragma (crt_constructor) You have to be pretty careful about this since it might not run in the order you expect. If there's two things in the program with a equal-priority crt constructor, they are run in arbitrary order. In a shared lib, there's also the possibility that loader locks are in place, and if it runs rt_init specifically, that can run D module constructors... which might load other libraries. Similar concerns apply to doing rt_init in DllMain. This is why an explicit initialization call is the preferred method - there, the time it is called is well-defined by the user after initial loading is complete.
Re: Creating DLL
On Thursday, 16 June 2022 at 16:37:34 UTC, Ali Çehreli wrote:
Agreed but that excludes using the D runtime in 'static this'
(and shared) blocks, right?
It is runtime.initialize that calls those `static this` blocks.
If my explicit call to Initialize is in a 'shared static this'
This is backward - the explicit call to Initalize is in the exe.
It'd look like:
// this code is in the exe! pretend it is C++ or whatever
HANDLE lib = LoadLibrary("my_d_lib.dll");
if(lib !is null) {
auto fn = cast(typeof(init_func))
GetProcAddress("Initialize");
if(fn !is null) {
fn(); // this now calls runtime.initialize which calls
the static this blocks etc
// you're now good to call any D functions
}
}
Re: multidim array with enum
On Saturday, 18 June 2022 at 17:19:24 UTC, Chris Katko wrote: I'm having difficulty figuring out exactly what signature D is expecting. BITMAP*[2][DIR] bmps; I'm actually not sure if that [DIR] is an associative array or DIR's base type or a static array of DIR's size. I *think* it is an assoc array... let's test it using the `in` operator: auto a = DIR.UP in bmps; That compiled. So this must be an associative array! Try this instead: BITMAP*[2][DIR.max] bmps; That's a static array of directions and I think that's what you intended and the other things should work as you want too with this.
Re: can you initialize a array of POD structs?
On Saturday, 18 June 2022 at 17:37:44 UTC, Chris Katko wrote:
D
struct pair { float x, y;}
pair p[] = [[0, 0], [255, 255], [25,-25]]; //nope
An array of pair is `pair[]`, keep the brackets with the type.
Then a struct literal is either:
pair(0, 0) // using constructor syntax
or in some select contexts (including this one):
{0, 0} // using named literal syntax
Therefore:
pair[] p = [{0, 0}, {255, 255}, {25,-25}];
compiles here.
Re: destroy and @safe
On Tuesday, 21 June 2022 at 15:13:36 UTC, Paul Backus wrote: `destroy` should be `@safe` as long as the destructor it's calling is `@safe`. For classes, the current dmd+druntime implementation makes it impossible to determine statically if the destructor is safe or not. Structs I'm not sure about, the implementation might block it there too but idk.
Re: dlang bug - accessing module variable from method segfaults only when using module reference directly
On Friday, 1 July 2022 at 12:57:01 UTC, Chris Katko wrote: Cannot access memory at address 0x10 Looks like an ordinary null pointer. How did you create the variable?
Re: How to check if something can be null
On Friday, 1 July 2022 at 13:48:25 UTC, Antonio wrote: I has been using this pattern each time something needs special treatment when it can be null: i'd prolly check `static if(is(typeof(null) : T))` which means if the null literal implicitly converts to type T. there's also the bludgeon __traits(compiles, v is null) too lol
Re: How to call a function from a dll created with d ?
On Friday, 1 July 2022 at 22:32:24 UTC, Vinod K Chandran wrote: So using a `def` file is a must I think. no it is not. you just need to mark things export and make sure names match (including module name)
Re: How to obtain Variant underlying type?
On Saturday, 9 July 2022 at 14:36:44 UTC, anonymouse wrote: auto vb = v.base; // what should I put here to achieve the following: typeof(vb); // int[][] Impossible; Variant's type is only known at runtime, and this would require compile time knowledge.
Re: How can I convert a file encode by CP936 to a file with UTF-8 encoding
On Wednesday, 13 July 2022 at 11:47:56 UTC, rocex wrote: How can I convert a file encode by CP936 to a file with UTF-8 encoding My lib doesn't have it included but the basic idea is to take this table: https://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WINDOWS/CP936.TXT and do the conversions. So loop through it, if it is < 128, it stays the same, if it == 128 it is 0x20AC, and greater than that you need to read the second byte too and look it up in that table. It looks like for many of the bytes, they increase in sequence, so you might only need part of the actual lookup table, and the rest you can do with some addition. Looks like from lead byte 83 it is a almost sequential offset. Probably safest to just copy the whole table.
Re: File.write introduces \r regardless of presence
On Saturday, 16 July 2022 at 19:54:08 UTC, HuskyNator wrote:
File("test.txt", "w").write(a);
The default here is write in text mode, change the "w" to "wb"
and it won't molest your line endings any more.
Re: mixin template bug with opBinary?
On Friday, 22 July 2022 at 12:33:37 UTC, Anthony Quizon wrote:
Is this a bug or am I doing something wrong?
I think this is a bug. The compiler must not take well to this
pattern, maybe the assoc array template argument, but idk. It
looks like the first type used gets cached and reused even if it
is supposed to change.
I vaguely recall seeing this before but yeah smells buggy
anyway.
An alternative you might consider is dropping some of the type
and using typeof(this):
```
module foo;
mixin template opBi(
alias f0
) {
static foreach (k, f; f0) { typeof(this) opBinary(string op:
k)(typeof(this) r) { return f(this, r); } }
}
struct A {
mixin opBi!(
[ "+": (A a, A b) => a],
);
}
struct B {
mixin opBi!(
[ "+": (B a, B b) => a],
);
}
```
That sidesteps the bug though it just trusts you pass the right
type to `f0`.
Re: Using "%s" with inputting numberic values
On Sunday, 24 July 2022 at 23:12:46 UTC, pascal111 wrote:
In the next code, we used "%s" format with receiving an integer
value, while from C experience, we know that we use "%d" or
"%i" formats, so what "%s" stands for here, I guess it's for
receiving string data type?
The D things in std.stdio, writef and readf, use %s to just mean
default for the given type. Since you passed it an int, the
function knows it got an int (this is different than C, where the
function only knows the format string so it requires you to get
it right) and just automatically picks a default representation
to scan.
You can writef("%s %s", "foo", 5); and it will see "foo" is a
string and thus do it as a regular %s then see 5 is an int and
since it knows, and you asked for just the default as-string
representation, it will convert just like %d would.
Re: "string" data type with readln
On Monday, 25 July 2022 at 19:55:40 UTC, pascal111 wrote: I tried to type small program, and tried to use "string" data type with "readln", but the compiler refused it, and I had to use "char[]". the overload you used modifies the array you give it try string s = readln();
Re: BASIC "sgn" function equivalent
On Thursday, 28 July 2022 at 12:02:54 UTC, pascal111 wrote: I'm making an equivalent of "sgn" function of BASIC language, and I used "(T)" in its definition, but the function can receive wrong data by passing string data to it, how we can solve it? There's no need to do the complication of a template, just do a normal function taking a `double`. You can add overloads if you want like one taking a `long` and/or `int` but those would cover all types that have signs.
Re: Write binary data as a file
On Tuesday, 2 August 2022 at 11:10:27 UTC, Alexander Zhirov wrote: As a result, I get only a set of text data. my database layer is doing to!string(that_ubyte) which is wrong. gonna see about pushing a fix
Re: How to find all modules in a package?
On Wednesday, 3 August 2022 at 03:36:55 UTC, Domain wrote: I want to find out all public functions in all modules in a package. Can I do that at compile time? No, D packages are not closed; anyone can add new modules to them at any time.
Re: curses/ncurses liberary in D
On Thursday, 4 August 2022 at 21:15:39 UTC, pascal111 wrote: https://github.com/adamdruppe/arsd/blob/master/terminal.d How can I use this terminal module? Is there a document for it? http://arsd-official.dpldocs.info/arsd.terminal.html
Re: curses/ncurses liberary in D
On Friday, 5 August 2022 at 04:14:22 UTC, H. S. Teoh wrote: including cursorX, cursorY Worth noting these are not initialized in linear mode, only in fullscreen/cellular. I might change that soon, it is on my todo list. (Granted, though, the main page could be expanded to include examples of how to use these functions.. take that up with Adam. :-P) Email me a patch.
Re: curses/ncurses liberary in D
On Friday, 5 August 2022 at 18:20:36 UTC, pascal111 wrote: But I'll need help to understand some functions like how we can use "readf" equivalent, I don't see it. http://arsd-official.dpldocs.info/arsd.terminal.html#get-line get a line then strip it and convert to whatever numbers you want etc
Re: My programs issues
On Wednesday, 10 August 2022 at 12:36:42 UTC, pascal111 wrote: 1) I used "exit()" from "core.stdc.stdlib;" module, but someone can say this isn't the D way to exit the program. It is better to simply return a value from main instead. 2) I used "goto", I heard from someone before that using "goto" isn't good programming feature. Don't listen to people who are wrong.
Re: How to use exceptions
You might find my recent blog post interesting too: http://dpldocs.info/this-week-in-d/Blog.Posted_2022_08_01.html#exception-template-concept and a draft of some more concepts: http://arsd-official.dpldocs.info/source/arsd.exception.d.html I also find the lack of information disturbing, but I also hate formatting it all into strings, so I wanted to experiment with other options there that avoid the strings.
Re: How to use exceptions
On Thursday, 11 August 2022 at 23:50:58 UTC, H. S. Teoh wrote: I think the OP's idea is somewhat different: adding contextual information to a propagating exception that the throwing code may not have access to. Yeah, but you can use the mechanism again: you'd catch the one then throw a new one with the old one tacked on the back. The OP's idea of wrapping throwing code with a function that tacks on extra information is a good idea. Yeah, that is good. I also kinda wish that scope(failure) could do it so you could tack on info with a more convenient syntax... i have some more wild ideas brewing now lol
Re: How to use exceptions
On Friday, 12 August 2022 at 00:40:48 UTC, H. S. Teoh wrote:
Hmm! That gets me thinking. Maybe something like this?
aye. and scopes share dtors which means we can do it in the lib
today:
---
struct AdditionalInfo {
static string[] info;
this(string info) {
AdditionalInfo.info ~= info;
}
~this() {
AdditionalInfo.info = AdditionalInfo.info[0 .. $
- 1];
}
@disable this(this);
}
class AdditionalInfoException : Exception {
this(string t) {
import std.string;
super(t ~ "\n" ~ AdditionalInfo.info.join(" "));
}
}
void bar() {
with(AdditionalInfo("zone 1")) {
with(AdditionalInfo("zone 2")) {
}
throw new AdditionalInfoException("info");
}
}
void main() {
bar();
}
---
the throw site needs to cooperate with this but you could still
try/catch an operation as a whole too and attach the original
exception in a new one.
needs a bit more thought but this might work. biggest problem is
still being stringly typed, ugh.
with compiler help tho we could possibly attach info on function
levels right in the EH metadata, so it looks it up as it does the
stack trace generation. but that would be limited to per-function
i believe... but eh there's nested functions.
tbh i think op's delegate is a better plan at this point but
still my brain is running some concepts.
Re: Recommendation for parallelism with nested for loops?
On Friday, 19 August 2022 at 01:49:43 UTC, Shriramana Sharma wrote: Also, what is the best way to do parallelism in such a situation? If the inner loops are about the same size for each pass of the outer loop, you can just simply parallel on the outer loop and get the same benefit. Even if they aren't equal, you'll get decent benefit from parallel on the outer one alone, but not as good since the work won't be balanced. Still, that's what I'd try.
Re: Best practice for dub registry package and module names
On Sunday, 4 September 2022 at 01:52:11 UTC, Ali Çehreli wrote: Should the package be the author's name: acehreli.a, acehreli.b, and acehreli.c? This is what I'd suggest. You want something that nobody else is likely to step on throughout the entirety of the D ecosystem. It doesn't have to literally be your name, but it should be something unique and probably arbitrary at the top level. This way you can use it as much as you want without worrying about conflicting with someone else. Then you have the more descriptive name as the module. Your dub package name is then a combination of these to make that unique too. So you might have dub package `acehreli-a` which has the D module `acehreli.a`. What about module names? If the type is 'struct MyCache', should the module name be mycache, or my_cache, or my-cache? Module names must be valid D identifiers, so no dash there. Whether you use _ or squeeze the words together is up to you, I'd say pick whichever one is easier to read. I usually squeeze words together.
Re: Best practice for dub registry package and module names
On Sunday, 4 September 2022 at 03:50:56 UTC, Ali Çehreli wrote: For example, there is fixedsizearray, which does not belong to any package: Yeah, this is bad design since two separate people might reuse the name and then end users - even if it comes through a couple layers of dependencies they didn't even know about - can see conflicts when they try to link the program. You really need globally unique D names. On the other hand, arsd-official:minigui does have a package. (And that answers a question: Dash character is acceptable in package and module names.) dub allows dash. D does not. The dub name and the D name do not have to match (I personally consider this yet another design flaw in dub, but it is what it is). The reason mine is called "arsd-official" on dub is because someone else registered "arsd" before me, but they didn't keep up with changes, so I had to do it myself but the name was already taken. But remember, the dub package name and the D package/module names are completely separate. D knows absolutely nothing about dub and dub knows very little about D. You should have them match when you can for user convenience, but it doesn't actually check it. How does that work? When the following dependency added to a user's project, "arsd-official:minigui": "~>10.9.1" does dub pull the entirety of arsd-official and then use minigui module from it? Yes, dub always pulls its top level thing in full. Then I had to specify a long list of subpackages in dub.json to let it understand the independent modules. Dub is unbelievably and embarrassingly bad. It really is a disappointment, but you can make it somewhat work if you repeat yourself enough times. Downloading a few extra kilobytes of D code is the least of its problems.
Re: Is there a way to
On Saturday, 10 September 2022 at 23:37:30 UTC, Kyle Ingraham wrote: How can I write a type that is strict for the first two parameters but tolerant of any other parameter following those? That's not a type per se, but you can assign wrapper at the assignment thing. Like your_delegate = (a,b) => func_with_three_args(a, b, "some default"); that kind of thing. if you have a delegate in an object, you can use a property setter to accept more things and wrap it like that.
Re: Is there a way to
On Sunday, 11 September 2022 at 00:32:18 UTC, Kyle Ingraham wrote: I can't use default parameters because I want to be able to call the delegate with arguments extracted from a URL path at runtime Some kind of wrapper might not only be your best option, it might be your only option. Your delegate would be like string callWith(string[][string] webArgs) and you can generate a wrapper to convert arguments and call the original function. I'm mucking about with a custom router for vibe-d and trying to setup the ability for handlers to have different parameter signatures. I'd be surprised if vibe doesn't already have this built in, my web frameworks have since before vibe was born. (my implementation btw does the wrapper thing like described above)
Re: Is it valid in D to write an opSlice overload that takes no arguments?
On Sunday, 11 September 2022 at 09:47:34 UTC, solidstate1991 wrote: Here's this code: This should be allowed, but also the way you're supposed to write it now is a no-argument opIndex.
Re: Is this a new bug ?
On Saturday, 24 September 2022 at 06:13:55 UTC, test123 wrote:
If so please report it for me to bugs platform.
This isn't a bug, the effect of keyword: things stop at the
matching }.
(static if and version don't introduce a namespace scope, but
they still follow this rule for the { colon: ... } blocks)
You need to duplicate your uint test2 variable inside those
branches.
Re: Detect uninitialized class var access
On Saturday, 24 September 2022 at 13:17:19 UTC, rassoc wrote: just crashes with `Error: program killed by signal 11` on linux and nothing else. gdb --args ./your_program and then it will tell you all the details you want to know about when this happens. strangly sometimes adding the -O option will cause dmd to catch simple cases at compile time but gdb is the general solution to track these down.
Re: Template function alias that leaves out the last type parameter
On Tuesday, 27 September 2022 at 22:39:52 UTC, torhu wrote:
How would I achieve something like this, do I have to turn the
aliases into functions?
You can write it out long-form with two steps like this:
---
template _messageBox(string title, int style)
{
void _messageBox(T...)(T args)
{
import std.format;
string s = format("%s", args);
/* etc... */
}
}
alias _messageBox!("lol", 4) info;
alias _messageBox!("Warning", 4) warning;
alias _messageBox!("Error", 4) error;
void main() {
info(4, "ok");
}
---
Re: Way to pass params to a function passed to a fiber?
On Monday, 3 October 2022 at 08:10:43 UTC, Bienlein wrote: Hello, I'm looking for a way to pass parameters to a function called by a fiber. Starting a fiber works like this: You can also make a subclass of fiber that stores them with the object.
Re: DateTime resetting
On Tuesday, 11 October 2022 at 22:09:34 UTC, Joel wrote: I've been working on a diary program (ChronoLog). but lately my date and time variable keeps resetting. I've spent hours trying to fix it. I'm wondering if there's a known issue. An ordinary DateTime variable? Those are pretty simple and won't reset unless something else is wrong around it. Do you have the code online? Or can at least show some of the context around its use?
Re: DateTime resetting
I'm just eyeballing the code, is it the g_dateTimeCursor you're
concerned about? That's the only one I really see there.
A few things that might explain it:
1) as a global variable, it is thread local. I don't see any use
of threads in here, but if you do, each one has a separate copy
and other threads won't see the same value. I do see a `new Task`
in places though so maybe it is this... I don't know where that's
coming from or what it actually does but possible the different
tasks are running in different threads, and thus seeing a
different variable. If it is this, you can make the variable
`shared` (then handle the cross thread safety so they don't
overwrite each other) and maybe fix it.
2) there's a bunch of places it might be modified from so
possible you just overwrite it somewhere
I also see a _dateTime in there. This is a member of the Control
struct and since it is a struct, remember it is an
independent value whenever you use it, just like an int.
int a = 5;
int getA() { return a; }
int b = getA();
b += 5;
// but a is still 5 here! Because ints are values, when it is
returned by the function, it gets an independent copy.
Structs work the same way. So that `getControl` in base.d returns
an independent copy of the control, and this has an independent
copy of the _dateTime variable too. Changes to one will not
affect the original.
So this might cause your problem too, with the info being lost.
It is possible that changing getControl to return `ref` will help
here, but hard to be sure when just eyeballing the code like I am.
Let me know if this helps.
Re: Can someone tell me what the compiler thought I was trying to do?
On Wednesday, 19 October 2022 at 00:57:31 UTC, H. S. Teoh wrote: Has it really been implemented? I tested the latest git master, the following code doesn't compile: it only applies to types, not to functions.
Re: Can someone tell me what the compiler thought I was trying to do?
On Wednesday, 19 October 2022 at 01:34:54 UTC, mw wrote: Is there any (design) doc about this? scroll up, click the link from this very thread. https://github.com/dlang/DIPs/blob/master/DIPs/accepted/DIP1038.md#design-goals-and-possible-alternatives
Re: Is "auto t=T();" not the same as "T t;"?
On Tuesday, 25 October 2022 at 13:51:30 UTC, Andrey Zherikov wrote: A[] a = [A.init]; This is a problem - this is referring to a static array instance, shared across all copies of B. You almost certainly don't want this. That B.a[0] is the *same object* across different default-constructed Bs... unless the optimizer hits it or something. But just don't do this. Only basic values and immutable strings are good to initialize this way. With the array or class objects, you're liable to get some shared thing. If you change this to be initialized in a constructor (which will require an argument in D) or factory function, you'll get far more consistent behavior as each instance will have its own array. As for why B() and B.init are different here... i don't know, probably some subtly of the compiler's implementation.
Re: Importing modules under DUB on Windows
On Wednesday, 26 October 2022 at 16:20:01 UTC, DLearner wrote: Wanted to use a function stored in a module outside the main source. easiest thing to do with dub is to add it as a sourcePath or a sourceFile. Well, actually, easiest is to just copy the module right into your default src folder, but second easiest is to add the other thing as the sourcePath/sourceFile. Messing with lib compiles and import paths rarely worth the hassle. (and without dub btw you can make a generic lib directory, add it to your -I path, then just `dmd -I/path/to/libs -i yourmainfile.d` and it automatically picks up things from import paths. that's how i do it myself) Also later i see you are using the arsd terminal.d, which you can also use through dub's dependency system by adding `arsd-official:terminal` to its list.
Re: Importing modules under DUB on Windows
On Friday, 28 October 2022 at 15:15:04 UTC, DLearner wrote:
Took suggestion, dub run then produced:
`Linking...
lld-link: error: subsystem must be defined
Error: linker exited with status 1`
That means the linker didn't see a `main` function. Make sure you
have a `void main() {}` somewhere (and of course if you want the
application to do something, make main do something)
Re: overloading main
On Sunday, 30 October 2022 at 16:09:54 UTC, NonNull wrote:
I am linking to a C project with some C already automatically
translated into D including the C main function `int main(int
argc, char** argv){/* ... */}` which I wanted to call from a D
main function in a new module.
did you put extern(C) on that thing? im p sure it'd allow it then
but then it'd be the entry point instead of the D main so i
don't think it'd let you get ahead.
So it seems that main cannot be overloaded with a prototype
that is not a valid entry point in D. Is this restriction
essential? And if not, why make it?
it prolly just to keep newbs from making confusing mistakes and
getting weird behavior at startup. If there's two mains, which
one is the expected entry? Perhaps it could just be the one that
matches the permitted signature, and if there isn't one it
complains. But how does it know if there is one? Suppose there's
module A:
module a;
int main(int argc, char** argv) {}
And module B:
module b;
void main() {}
They are compiled separately:
dmd -c a.d
dmd -c b.d
dmd a.o b.o
Which one is the main you want to use? What if you just did `dmd
a.d`, should it error that the prototype is wrong, or just give
the user the linker error "could not find D main" when they think
they have it right there? (remember the linker doesn't know what
D signatures are so it can't print a helpful message to correct
the mistake).
Re: Make IN Dlang
I don't have specific answers to your questions but your goal sounds similar to Atila's reggae project so it might be good for you to take a look at: https://code.dlang.org/packages/reggae
Re: What's the correct way of creating an instance of class in D?
On Thursday, 3 November 2022 at 15:40:02 UTC, H. S. Teoh wrote: D does not have the equivalent of C++'s allocating a class instance on the stack. In D, all class instances are allocated on the heap and class variables are references to them. well there is scope Object o = new Object; which is stack allocated but still a reference of course
Re: Hipreme's #4 Tip of the day - Don't use package.d
On Friday, 4 November 2022 at 14:11:55 UTC, bauss wrote: Having used D for like a decade at this point, I've never experienced any issues with it. Lucky you, lots of other people have. Broken phobos updates, impossible to transition to it without code breakages (which is the only reason it exists), random inconsistencies with the rest of the language leading to link errors. package.d is absolutely essential in some cases. Which cases?
Re: Hipreme's #4 Tip of the day - Don't use package.d
On Friday, 4 November 2022 at 19:10:33 UTC, jmh530 wrote: If you don't plan to use private(package_name), then I don't know what the point of it is. This works fine without the package.d anyway.
Re: Hipreme's #4 Tip of the day - Don't use package.d
On Friday, 4 November 2022 at 19:34:58 UTC, jmh530 wrote: Oh really, then what's the point of package.d? It was originally added because Phobos had `std.algorithm` and `std.datetime` and some people wanted to break them up into pieces, but not break user code that still said `import std.algorithm` instead of `import std.algorithm.sorting` (or whatever). One alternative was to call the new things like `std.algorithm_parts.sorted` but this name a little ugly and people would be less likely to transition to it. The failure of this scheme though is that the package.d design is braindead and broke things anyway as people updated and it brought about other various bugs down the line. It was possible to do it well but it wasn't.
Re: Hipreme's #4 Tip of the day - Don't use package.d
On Friday, 4 November 2022 at 19:40:09 UTC, H. S. Teoh wrote: So that you can import abc.def separately from abc.def.ghi and abc.def.jkl. This isn't that hard; in the old days you'd have `pkg.foo` then `import pkg.all` instead of `import pkg;`. The specific thing that led to the package.d thing is the desire to transition Phobos in addition to some flawed ideology. (One of the other constraints was that you should be able to zip up the directory of the package and have it all together, hence using dir/package.d instead of just dir.d. But this would have worked anyway if not for the inconsistent design flaw of requiring the file to be called package.d in the first place! And with this if you compile it separately vs compiling it together you get totally different results. It really is just a *terrible* design.)
Re: My new programming book ...
On Monday, 7 November 2022 at 00:55:33 UTC, zjh wrote: Is there a second edition? After all, it has been many years. No, but not that much has changed and you can always post here with questions.
Re: Passing a string by reference
On Tuesday, 8 November 2022 at 12:30:50 UTC, Alexander Zhirov wrote: Do I understand correctly that in order for me to pass a string when creating an object, I must pass it by value? You should almost never use `ref string`. Just use plain `string`. In fact, ref in general in D is a lot more rare than in languages like C++. The main reason to use it for arrays is when you need changes to the length to be visible to the caller... which is fairly rare. In the case of the variable `c`, a drop occurs. Why? An object is not being created on the stack? nope, an object isn't created there at all. you should use `new C`.
Re: My new programming book ...
On Monday, 7 November 2022 at 04:54:05 UTC, ikelaiah wrote: I'm aware of the publication date. However, I find the content still highly relevant to many day-to-day tasks (my use case). Yeah, I tried to focus more on the ideas behind it than the specifics of a library. My thought is if you understand what it is trying to do, the adjustments to bring it up to date shouldn't be too hard. It took some effort to avoid talking more about my libraries though lol. I did do a few small examples near the end of the book, and some of those have had minor changes, like I've since renamed "import simpledisplay" to "import arsd.simpledisplay". But the rest of it should still work, i try to keep things pretty stable in my libs. BTW one of the things in chapter 2 i found surprisingly popular was the talk about std.socket. I did write a follow-up to that in my blog here: http://dpldocs.info/this-week-in-d/Blog.Posted_2019_11_11.html#sockets-tutorial Since the socket api is the same as C, I assumed people would know it from other sources, but the C api isn't as common knowledge as it used to be. So this tries to explain (tho even there I didn't go into ipv6 fallbacks and whatnot but it still lays the foundation). And of course always feel free to ask here or whatever about anything, if I'm online I try to answer things pretty quickly.
Re: My new programming book ...
On Monday, 7 November 2022 at 06:10:46 UTC, zjh wrote: How is your `minigui`? Please write an `introduction` when you have time. It is on my list but minigui is a pretty simple class collection of basic widgets. It works pretty well now. I don't have too many intro examples yet though. My blog has one thing but it uses an experimental piece (http://dpldocs.info/this-week-in-d/Blog.Posted_2020_11_02.html) that isn't really representative of the average program. But if I make it to the dconf online I'll probably show off a minigui application there this year.
Re: Using glibc headers with ImportC
On Saturday, 12 November 2022 at 13:46:27 UTC, qua wrote: This is supposed to work, right? No, it isn't. And it probably never will. importC looks for a .c file in the current directory. It is that .c file's responsibility to #include whatever .h files you want.
Re: Using glibc headers with ImportC
On Saturday, 12 November 2022 at 14:39:14 UTC, qua wrote: Do I have to do anything else? I've read that importc doesn't have a preprocessor and I assume it is related to that, however "ImportC can automatically run the C preprocessor associated with the Associated C Compiler". I still don't think that's been released yet, so if you aren't on the git master or at least the latest beta build it isn't going to work. Which dmd version are you running?
