Re: How can I put the current value of a variable into a delegate?
On Monday, 6 May 2024 at 16:41:38 UTC, Steven Schveighoffer wrote: This is a very old issue: https://issues.dlang.org/show_bug.cgi?id=2043 since "moved" to https://issues.dlang.org/show_bug.cgi?id=23136 I would love to see a solution, but the workaround at least exists! -Steve Interestingly enough C# used to have the same behaviour but MS decided to go for a breaking change in C# 5; now it behaves as most people expect. Since it's an unsolved problem to keep links working for 10+ years I gave up looking for something official about the subject. Here's an SO question about it though: https://stackoverflow.com/questions/14184515/action-delegate-uses-the-last-values-of-variables-declared-outside-foreach-loop
Re: how can I load html files and not .dt or diet files in vibe.d
On Thursday, 1 February 2024 at 03:20:31 UTC, dunkelheit wrote: this is my code, I'm a begginer on vibe, and I want to use html and not diet files Take a look at the static file example, I think that's close to what you're looking for. https://github.com/vibe-d/vibe.d/blob/master/examples/http_static_server/source/app.d
Re: Error: none of the overloads of template `once.main.each!((l)
On Wednesday, 4 October 2023 at 08:11:12 UTC, Joel wrote:
What am I missing?
Splitter returns a forward range so you can't slice the result.
You can use take() and drop() instead. Also, converting a string
range to int[] doesn't seem to work, but I don't know if it
should. Here is a version that works:
```D
import std;
void main() {
struct DateRem {
Date date;
string rem;
string toString() const => text(date.toSimpleString, " ",
rem);
}
DateRem[] daterem;
data
.splitter('\n')
.filter!(l => l.length && l[0].isDigit)
.each!((l) {
auto parts=l
.splitter
.take(3)
.map!(to!int)
.array;
if (parts.length==3) {
daterem~=DateRem(Date(parts[2],parts[1],parts[0]),
l.splitter.drop(3).join(" "));
}
});
daterem.each!writeln;
}
auto data="04 10 2023 17:28, not much
30 9 2023 21:08, very little";
```
Re: Inheritance and arrays
On Monday, 3 July 2023 at 09:50:20 UTC, Arafel wrote:
Is this a conscious design decision (if so, why?), or just a
leak of some implementation detail, but that could eventually
be made to work?
Besides the pointer adjustment problem mentioned by
FeepingCreature, it's an unsound conversion even with just class
inheritance. Consider:
```
class A {}
class B : A {}
class C : A {}
void main()
{
auto bArr = [new B()];
A[] aArr = bArr; // If this was allowed..
aArr[0] = new C(); // This would be a problem, because bArray
would now contain a C.
}
```
Re: Union with bits ?
On Wednesday, 14 June 2023 at 00:59:30 UTC, Paul wrote:
I would like to have labeled bits in a union with a ubyte.
Something like this:
```d
struct MyStruct {
union {
ubyte status;
bit A, B, C…etc
}
}
```
Is something like this possible?
Thanks
You can do something like this if you don't mind compiling with
-preview=bitfields:
```d
union {
ubyte status;
struct {
bool A : 1, B : 1, C : 1, D : 1;
}
}
```
Re: iota where step is a function
On Wednesday, 24 May 2023 at 16:39:36 UTC, Ben Jones wrote: Is there a range like iota in phobos where step is a function? I want to specify begin/end and have the "step" be next = fun(prev). Should be easy to write, but don't want to reinvent the wheel. I think you’re looking for either recurrence() or sequence(), also defined in std.range.
Re: How to workaround assignment not allowed in a condition?
On Wednesday, 12 October 2022 at 02:15:55 UTC, Steven Schveighoffer wrote: Am I missing something? Perhaps I am, but why not turn it into a numeric comparison, like: ``` while((i = 5) == 0) ```
Re: Way to pass params to a function passed to a fiber?
On Monday, 3 October 2022 at 08:10:43 UTC, Bienlein wrote:
My question is whether someone has an idea for a better
solution.
You can pass a lambda to the fiber constructor. For example:
```
void fiberFunc(int i)
{
writeln(i);
}
void main()
{
auto fiber = new Fiber(() => fiberFunc(5));
fiber.call();
}
```
Re: How Stop Worker Thread if Owner Thread is Finished?
On Tuesday, 27 October 2020 at 11:36:42 UTC, Marcone wrote: I want to use isDaemon to automatic stop worker thread if ownner thread is finished Terminating threads without properly unwinding the stack is generally a very bad idea. Most importantly the destructors of stucts on the stack won't run which can cause problems like locks not being released. This isn't specific to D either. For example Raymond Chen writes about the TerminateThread function in Windows here: https://devblogs.microsoft.com/oldnewthing/20150814-00/?p=91811 You should signal the thread somehow that it's time to stop working
Re: How is this an "Access Violation"
On Tuesday, 27 October 2020 at 02:05:37 UTC, Ruby The Roobster
wrote:
void construct(string type,atom base,atom bonded)
{
base = new
atom(base.name.idup,base.mass,base.electro_negativity,base.valence_electrons,base.electrons,base.protons,base.neutrons,base.pos);
(...)
assert(this.base.valence >= 1 &&
this.bonded.valence >=1 && this.base.electro_negativity >= 0 &&
this.bonded.electro_negativity >= 0,"For a single bond, both
atoms need to have at least one free electron and have to have
electro negativity.");
Going by the assert this is a member function of a class or
struct with base and bonded members. I think you meant to assign
the newly created atoms to those fields instead of overwriting
your arguments.
Re: [windows] Can't delete a closed file?
On Thursday, 9 May 2019 at 12:33:37 UTC, Cym13 wrote: On Thursday, 9 May 2019 at 11:31:20 UTC, Cym13 wrote: ... To dismiss any doubt about AV or other processes coming into play I took the binary and ran it with wine on linux with the exact same end result. For reference my windows system is a 64b windows 10. You could try to use the find handle function in Process Explorer to figure out what process has the file open: https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer
Re: Memory reference that does not stop garbage collection.
On Friday, 8 February 2019 at 15:42:13 UTC, Jonathan Levi wrote: I should be able to use `core.memory.GC.removeRange` right? That would leave dangling references in the array. You may be interested in this, but I have not used it myself: https://repo.or.cz/w/iv.d.git/blob/HEAD:/weakref.d
Re: cas and interfaces
On Tuesday, 25 December 2018 at 22:07:07 UTC, Johannes Loher
wrote:
Thanks a lot for the info, that clarifies things a bit. But it
still leaves the question, why it works correctly when
inheriting from an abstract class instead of implementing an
interface... Any idea about why that?
Unlike interfaces, base class references don't need adjustment.
You can see this in action by printing addresses:
https://run.dlang.io/is/m6icVr
import std.stdio;
interface I {}
class Base : I {}
class Derived : Base { }
void main()
{
auto derived = new Derived;
Base base = derived;
I i = derived;
writeln(cast(void*)derived);
writeln(cast(void*)base);
writeln(cast(void*)i);
}
7FC1F96EE000
7FC1F96EE000
7FC1F96EE010
Re: How does calling function pointers work?
On Monday, 12 November 2018 at 16:29:24 UTC, helxi wrote:
On Monday, 12 November 2018 at 16:25:13 UTC, Rene Zwanenburg
wrote:
Idk where you got that syntax from, but there's no syntactic
difference between calling normal functions and function
pointers:
import std.stdio;
import std.concurrency;
import core.thread;
void worker(int firstNumber) {
foreach (i; 0 .. 4) {
Thread.sleep(500.msecs);
writeln(firstNumber + i);
}
}
void main() {
foreach (i; 1 .. 3) {
spawn(, i * 10);
}
}
Looks like worker needs an int and spawn(, i * 10) seems
to feed it's second arg to worker(?)
That's right. spawn() is a function in the standard library that
takes a function pointer, and all the arguments to pass to that
function. It's a bit unusual in that regard: normally when using
function pointers the arguments are provided by the code that
receives the function pointer. Internally, spawn will call the
function pointer just like I did in my example, but on another
thread.
Here's an example where a function pointer is passed around with
the arguments provided by the callee:
https://run.dlang.io/is/ArCN5t
Re: How does calling function pointers work?
On Monday, 12 November 2018 at 16:08:28 UTC, helxi wrote: As far as I understand, calling a function pointer with an argument in D looks like: call(, argTofn0, argTofn1, argTofn3); Idk where you got that syntax from, but there's no syntactic difference between calling normal functions and function pointers: https://run.dlang.io/is/I6u0rg
Re: Test if variable has void value
On Wednesday, 22 August 2018 at 13:50:07 UTC, Andrey wrote:
Hello,
How to test if variable has void value?
string text = void;
if(text == void)
{
writeln("Is void");
}
Tried this:
if(is(text == void))
but doesn't work.
You can't. When using a void initializer the actual value is
garbage until initialized properly, and that garbage can look
like anything including a valid instance.
So if the flow of your program can't guarantee that the value has
been initialized at a certain point, you'll have to track it
yourself some way. Nullable may be of help:
https://dlang.org/phobos/std_typecons.html#Nullable
Re: Coreect way to create delegate for struct method.
On Tuesday, 21 August 2018 at 21:29:38 UTC, Andrey wrote: Hello, This is a code: (...) test.handler = That's an internal pointer, and internal pointers are not allowed in structs precisely because of the issues you're running into: the pointer will be invalid after a move. You may be able to get it kind of working, but I'd recommend looking for another solution to your problem. This is one of those things that will come back to bite you later.
Re: asdf json library moved to libmir
On Wednesday, 11 July 2018 at 21:42:45 UTC, yannick wrote: Hi All, Since i'll be leaving Tamedia (who sponsored development of Asdf) and it's not under active use anymore here we decided to donate it to libmir. ... cheers, y Thanks for keeping it alive. I've used asdf at work last week to build a json plugin for logparser: https://en.wikipedia.org/wiki/Logparser I have yet to ask permission to open source it, but I'll make an announcement if the boss agrees.
Memory corruption with COM object
I've been staring at this problem the past few hours without making any progress. But I feel like I'm overlooking something obvious.. Using Adam's comhelpers, I've made a JSON plugin for LogParser. However after running for a bit it'll crash with signs of memory corruption. My guess was the GC was collecting things still in use, and disabling the GC does indeed 'fix' the problem. Looking through comhelpers, the code doesn't add a GC root for a created object before handing it off to the C side. I've added root adding and removing, expecting that to fix the problem. However it didn't help. The DLL uses the helper functions like dll_process_attach in DllMain, so druntime is initialized. What would be a good way to figure out why the GC decides to collect objects I'm still holding on to?
Re: Configuring DerelictGL3
On Wednesday, 6 June 2018 at 23:26:23 UTC, Entity325 wrote: I can't imagine things like "glEnable/DisableClientState" are deprecated. They are. All the missing symbols are indeed deprecated. attempting to load the deprecated functions according to the documentation page did a whole lot of nothing Could you post the exact code you used? I'm not using the old functions, but that should work.
Re: D Library Breakage
On Friday, 13 April 2018 at 05:31:25 UTC, Jesse Phillips wrote: Well if DIP1000 isn't on by default I don't think Phobos should be compiled with it. I think that the version issue is not unique to D and would be good to address, but I don't see the compiler reading the object file to determine how it should built the import files. More importantly, it can be perfectly valid to link object files compiled with different options. Things like parts of the program that shouldn't be optimized, or have their logging calls added/removed.
Re: Aggressive conditional inlining with ldc only, not dmd
On Sunday, 25 March 2018 at 22:09:43 UTC, Nordlöw wrote: eventhough I compile with -release -inline -nobounds flags. Just to make sure: are you passing -O as well?
Re: How to make AA key a pointer
On Monday, 19 February 2018 at 14:57:47 UTC, Clinton wrote: On Monday, 19 February 2018 at 14:55:01 UTC, Clinton wrote: Hi all, I need advice from better developers on this concern. I'm using an AA to reference another array for quicker access: [...] Sorry, on second look my explanation isn't very clear. I want to know if: bool[string] myAA; myAA[contact.id] = true; // Does this copy contact.id or is this a pointer to contact.id? It's a pointer. In D, string is an alias to immutable(char)[] (Slice of immutable characters). A slice is a combination of pointer and length.
Re: Debugging on Windows
On Thursday, 8 February 2018 at 21:09:33 UTC, JN wrote: Hi, is there any way to debug binaries on Windows? I'd at least like to know which line of code made it crash. If it's D code, I get a call trace usually, but if it's a call to a C library, I get a crash and that's it. I am using VSCode and I'd prefer to debug in it if possible, but using other IDEs is a possibility for me if that will help. You can debug D programs from VS Code using the C++ plugin: https://marketplace.visualstudio.com/items?itemName=ms-vscode.cpptools It requires some configuring, but from what I remember it was all very straightforward.
Re: SegFault with HibernateD
On Friday, 12 January 2018 at 07:33:37 UTC, Mike Parker wrote: On Friday, 12 January 2018 at 05:24:52 UTC, Venkat wrote: I get a SegFault with the main method below which uses HibernateD . The second main method which uses ddbc just works fine. What is wrong with the first main method ? I have attached the error at the bottom although I don't think it says much. This is the error. object.Exception@source/dub/generators/build.d(530): Program It says enough to know that the exception is being thrown from dub and not your program. You program is never executed because dub throws the exception before it gets that far. You should report this at the dub repository: https://github.com/dlang/dub/issues It looks to me like the program is being run through dub, and dub is just reporting the program's exit code. Hard to guess what the issue is, I'd attach a debugger to see where it crashes.
Re: High-resolution thread sleep
On Friday, 15 December 2017 at 01:49:56 UTC, Steven Schveighoffer wrote: So... you plan on rendering more than 1000 frames per second? I think in any case, even if the API allows it, you are probably not getting much better resolution on your non-windows systems. Have you tried it anyway and see how it works? I think it might actually work just fine. -Steve The higher precision would be needed b/c updating and rendering takes time, so the sleep time would be timePerFrame - timeSpendOnRendering. Problem is you'll need vsync anyway to avoid tearing. Applications that use their own timing to limit the framerate without using vsync are easy to recognise: they have a tear slowly moving around on the screen. It's visually even more annoying than regular tearing.
Re: High-resolution thread sleep
On Thursday, 14 December 2017 at 23:45:18 UTC, Ivan Trombley
wrote:
Something along the lines of this:
while (render)
{
immutable auto startTime = MonoTime.currTime;
// Render the frame...
immutable auto remain = m_frameDuration - (startTime -
MonoTime.currTime);
if (remain > Duration.zero)
Thread.sleep(remain);
}
In that case, the best thing you can do is use vsync as the
waiting mechanism ;)
Re: High-resolution thread sleep
On Thursday, 14 December 2017 at 21:11:34 UTC, Ivan Trombley wrote: I need to be able to put a thread to sleep for some amount of time. I was looking at using Thread.sleep but it appears that on Windows, it's limited to millisecond resolution. Is there a way to do this in a cross-platform way that is higher resolution? Sleeping for very short periods is usually a bad idea for various reasons. What do you need it for? If you really need this, go for a loop with a high resolution timer.
Re: Email validation
On Tuesday, 28 November 2017 at 18:47:06 UTC, Vino wrote: Hi All, You can do this easily using the std.net.isemail module: https://dlang.org/phobos/std_net_isemail.html
Re: opAssign for most struct assignment calls not executed
On Thursday, 23 November 2017 at 15:26:03 UTC, Timoses wrote:
A aaa = a;
That's initialization, not assignment, which is subtly different.
It will call the postblit on aaa instead of opAssign. A postblit
can be defined this way:
this(this)
{
}
There is no way to access the original a from the postblit. All
fields have already been copied, you can use it to duplicate
reference types, increment reference counts, and other things
like that.
Re: DateTime trying to do it at compile time.
On Thursday, 26 October 2017 at 17:55:05 UTC, Mr. Jonse wrote:
when calling Clock.currTime() in a this() in a class. I have no
idea why it is trying to do it at compile time and failing. I
thought if ctfe couldn't compile it would do it at run time
anyways? Seems like a bug.
I suspect you're trying to instantiate your class in a static
context, which causes it to be constructed at compile time. For
example:
class A
{
this() {
// Do sth. with datetime
}
}
class B
{
// This will construct A at compile time. This also
// means a single A instance is shared between all
// B instances. This is different from most langs!
A a = new A;
}
// This will also construct at compile time.
A moduleScopedA = new A;
The solution is to new A in your class or module constructor.
Re: How to modify process environment variables
On Tuesday, 17 October 2017 at 05:57:50 UTC, Ky-Anh Huynh wrote: On Tuesday, 17 October 2017 at 04:56:23 UTC, ketmar wrote: you can use libc's `putenv()` in D too, it is ok. just import `core.sys.posix.stdlib`, it is there. D is not antagonistic to C, and doesn't try to replace the whole libc with it's own libraries. so if you see something that libc has and you'd like to use -- just do it! ;-) I see :) I have always tried to avoid C if possible :D As an alternative, a search on code.dlang.org turned up this lib: http://code.dlang.org/packages/dotenv
Re: code.dlang.org is offline?
On Friday, 22 September 2017 at 08:14:43 UTC, Szabo Bogdan wrote: Hi, Is there a reason why code.dlang.org is offline? Thanks, Bogdan It works fine for me. Can you verify?
Re: Making a repo of downloaded dub package
On Tuesday, 5 September 2017 at 06:23:26 UTC, Dukc wrote: On Monday, 4 September 2017 at 20:31:35 UTC, Igor wrote: Search for word "local" here: https://code.dlang.org/docs/commandline. Maybe some of those can help you. If not you could make a pull request for dub that would support such a thing :) That will make a Dub package out of a Git package, but I'm trying to do it vice-versa (And so that it is able to use the same histoy as the repository). I think it will require Git commands, but what commands exactly? I was unable to figure that out myself. When you go to the package's page on code.dlang, look for the github repository link in the top right corner. You can fork from there.
Re: Remove all blank lines from a file
On Thursday, 31 August 2017 at 14:44:07 UTC, vino wrote:
Hi All,
Can some provide me a example of how to remove all blank
lines from a file.
From,
Vino.B
This one doesn't read the entire file into memory:
import std.stdio;
import std.array;
import std.algorithm;
import std.uni;
void main(string[] args)
{
auto inputFile = File(args[1]);
auto outputFile = File(args[2], "wb");
inputFile
.byLine
.filter!(line => !line.all!isWhite)
.copy(outputFile.lockingTextWriter);
}
But if you want to replace the input file, you'd have to write to
a temp file, remove the original, then move the temp file.
Re: Import modules too verbose in some cases
On Wednesday, 9 August 2017 at 23:57:19 UTC, Johnson Jones wrote: Sometimes one doesn't want to import either the whole module nor specify a single function to import. It seems that basically D has all the info to import the function implicitly because it usually gives a nice error message tells us which module to import for the function. It doesn't have that information available, and that's unlikely to change due to the compilation model. Rather, a few very common cases have been hardcoded in the compiler: https://github.com/dlang/dmd/blob/4d86fcba2fd2ef86cc85738cd2ac2b059dbb5800/src/ddmd/imphint.d
Re: Getting enum from value
On Saturday, 5 August 2017 at 15:33:57 UTC, Matthew Remmel wrote:
Any ideas?
You can use to! in std.conv:
import std.stdio;
import std.conv;
enum Foo
{
A = "A",
B = "B"
}
void main()
{
writeln("A".to!Foo);
}
Re: [OT] - A hacker stole $31M of Ether — how it happened, and what it means for Ethereum
On Friday, 4 August 2017 at 08:33:42 UTC, RazvanN wrote:
On Friday, 4 August 2017 at 05:57:00 UTC, Nick B wrote:
See -
https://medium.freecodecamp.org/a-hacker-stole-31m-of-ether-how-it-happened-and-what-it-means-for-ethereum-9e5dc29e33ce
[...]
I don't think the problem was with the blockchain here. It is
usually a bad idea to have turing-complete scripts over
blockchains. From what I've seen the bug was that there was
issued a library call based on a user-provided string. That
could have never happened if they would have used D with @safe
D's OpDispatch is very similar to what caused this bug ;)
struct Library
{
void doSomethingUseful(){}
void doSomethingNice(){}
void resetSecurity(){}
}
struct BuggyContract
{
private void customizedBehaviour(){}
void opDispatch(string f)()
{
if(f == "doSomethingUseful")
{
customizedBehaviour();
}
else
{
mixin("Library.init." ~ f ~ "();";
}
}
}
Re: Function with static array as parameter
On Wednesday, 12 July 2017 at 12:57:19 UTC, Rene Zwanenburg wrote:
On Wednesday, 12 July 2017 at 12:20:11 UTC, Miguel L wrote:
What is the best way in D to create a function that receives a
static array of any length?
Templatize the array length:
void foo(size_t length)(int[length] arr)
{
}
That being said, this may lead to template bloat and excessive
copying. What are you trying to do? Is there a reason you can't
use a slice?
Re: Function with static array as parameter
On Wednesday, 12 July 2017 at 12:20:11 UTC, Miguel L wrote:
What is the best way in D to create a function that receives a
static array of any length?
Templatize the array length:
void foo(size_t length)(int[length] arr)
{
}
Re: D and memory mapped devices
On Wednesday, 14 June 2017 at 08:10:57 UTC, Russel Winder wrote: but the bitfields mixin template appears to do more than add all the bit twiddling functions to emulate the bitfields. This would appear a priori to not allow for actual memory mapped devices using it, or am I missing something? I've casted void buffers to structs containing bitfields to read pre-existing binary files, and that worked just fine. I don't see why it would be different for memory mapped devices. What do yo mean by 'do more'?
Re: purity question
On Tuesday, 30 May 2017 at 11:34:52 UTC, ketmar wrote: If malloc were marked as pure, wouldn't that mean it must return the same pointer every time you call it with the same size? of course. but D "pure" is not what other world knows as "pure". we love to mess with words. Well, there's the ability to modify non-const reference parameters from a pure function, but that's not applicable to malloc. Are there any other special rules?
Re: purity question
On Monday, 29 May 2017 at 01:36:24 UTC, Jonathan M Davis wrote: A simple example: anything that has a malloc/free pair. Yeah, if you do it right, you should be fine, but you have to do it right, and it's very easy to miss some detail that makes it wrong to insist to the compiler that what you're doing is pure. If malloc were marked as pure, wouldn't that mean it must return the same pointer every time you call it with the same size?
Re: See you soon at dconf
On Wednesday, 3 May 2017 at 15:05:02 UTC, Bastiaan Veelo wrote: On Wednesday, 3 May 2017 at 14:38:41 UTC, Rene Zwanenburg wrote: On Wednesday, 3 May 2017 at 13:36:45 UTC, Steven Schveighoffer wrote: I am at the Ludwig van Beethoven hotel. Just had a 2 hour nap, couldn't sleep on the plane. So a few beers will do me well (first of which I'm having now ;). Where were you thinking to meet? -Steve Are you still at the hotel bar? I just went down there but saw no-one. Sorry I lost cellular connection. Steve an I took the U7 to Ibis, 6 stops. We are 9 chaps atm. "Kurzstreckefahrkarte" is enough, the cheap ticket. Ah great, I'll go there as well.
Re: See you soon at dconf
On Wednesday, 3 May 2017 at 13:36:45 UTC, Steven Schveighoffer wrote: I am at the Ludwig van Beethoven hotel. Just had a 2 hour nap, couldn't sleep on the plane. So a few beers will do me well (first of which I'm having now ;). Where were you thinking to meet? -Steve Are you still at the hotel bar? I just went down there but saw no-one.
Re: See you soon at dconf
On Wednesday, 3 May 2017 at 13:50:53 UTC, Bastiaan Veelo wrote: On Wednesday, 3 May 2017 at 13:36:45 UTC, Steven Schveighoffer wrote: (first of which I'm having now ;). Where were you thinking to meet? If there's beer where you are, I can get to you. 20 min. I'm also staying at the Beethoven. First I've got to finish something up, then I'll join you as well.
Re: Why map return [] ?
On Friday, 14 April 2017 at 15:49:00 UTC, Suliman wrote: I found problem! ResultRange should be converted to array before it can be `map`ed That shouldn't be necessary. Can you post your complete code?
Re: Can't build simple project. Very strange errors
On Friday, 14 April 2017 at 15:42:33 UTC, Suliman wrote: On Friday, 14 April 2017 at 15:40:18 UTC, Rene Zwanenburg wrote: On Friday, 14 April 2017 at 15:31:21 UTC, Suliman wrote: On Friday, 14 April 2017 at 15:22:49 UTC, Rene Zwanenburg wrote: On Friday, 14 April 2017 at 09:49:09 UTC, Suliman wrote: on: dub build --compiler=ldc2 link OPTLINK (R) for Win32 Release 8.00.17 Optlink isn't able to link object files produced by ldc. Could you try an x64_86 build? You'll need the Microsoft linker. I do not have VS on my PC :( You don't need VS, the Windows SDK should be fine too. It's a free download :) How to check if it's installed and how to use linker from it? If it's installed you can find it in the programs and features list as 'Windows Software Development Kit for Windows X'. The DMD installer will look for it during installation, so reinstalling DMD after installing the SDK should work. I'm not sure how LDC does it, but last time I installed LDC it also just worked.
Re: Can't build simple project. Very strange errors
On Friday, 14 April 2017 at 15:31:21 UTC, Suliman wrote: On Friday, 14 April 2017 at 15:22:49 UTC, Rene Zwanenburg wrote: On Friday, 14 April 2017 at 09:49:09 UTC, Suliman wrote: on: dub build --compiler=ldc2 link OPTLINK (R) for Win32 Release 8.00.17 Optlink isn't able to link object files produced by ldc. Could you try an x64_86 build? You'll need the Microsoft linker. I do not have VS on my PC :( You don't need VS, the Windows SDK should be fine too. It's a free download :)
Re: Can't build simple project. Very strange errors
On Friday, 14 April 2017 at 09:49:09 UTC, Suliman wrote: on: dub build --compiler=ldc2 link OPTLINK (R) for Win32 Release 8.00.17 Optlink isn't able to link object files produced by ldc. Could you try an x64_86 build? You'll need the Microsoft linker.
Re: DUB mismatch between project structure and dub.json contents
On Monday, 10 April 2017 at 12:56:49 UTC, Nordlöw wrote: src/knet/traversal.d(20,8): Error: module factixs from file src/knet/factixs.d must be imported with 'import factixs;' What am I doing wrong? My first guess would be that the module declaration in that file is incorrect. Are you sure it's set to knet.factixs? The module declaration needs to be present or it will be put in the root package.
Re: delegate with optional parameters
On Monday, 3 April 2017 at 05:00:15 UTC, Inquie wrote: Yes, but they are really not any different. They only look different. A field can be a function just like a method because they look exactly the same except on is in a vtable and the other is in the fields memory. But both point functions. It should be possible to create a wrapper struct around your 'overloads' with an opDispatch which selects the right delegate.
Re: Registering for DConf, PayPal appears to be broken.
On Saturday, 1 April 2017 at 23:54:45 UTC, Walter Bright wrote: On 4/1/2017 12:38 PM, Rene Zwanenburg wrote: I just tried to register for DConf, but PayPal is borken at the moment. (Not the link on the DConf website, PayPal itself is throwing errors) In case it's still not working tomorrow, would it be possible to register some other way? I don't have a credit card. You can mail the D Foundation a check: D Language Foundation 6830 NE Bothell Way Ste C-162 Kenmore, WA 98028 Let me know when you do, and I'll reserve your ticket for you. For credit cards, eventbrite will work, too: https://www.eventbrite.com/e/dconf-2017-berlin-tickets-31277455712 I learned the hard way years ago to have more than one service for ticket purchases, as one or the other always goes down :-( Thanks, but luckily PayPal works now. It turned out that their service agreement had been updated some time ago and I needed to login to my account and accept it. Instead of telling me that, it showed a generic 'something is not working right now, try again later' during checkout. Anyway, see you at DConf!
Registering for DConf, PayPal appears to be broken.
Hi, I just tried to register for DConf, but PayPal is borken at the moment. (Not the link on the DConf website, PayPal itself is throwing errors) In case it's still not working tomorrow, would it be possible to register some other way? I don't have a credit card.
Re: Why is [0] @safer than array.ptr?
On Tuesday, 24 January 2017 at 11:38:16 UTC, Jonathan M Davis
wrote:
Likely because it does bounds checking, so you at least know
that it's not null. But I don't see why that would really
improve much considering that the odds are that you're really
going to be accessing far more than just the first element with
the pointer. It seems _slightly_ better from a safety
perspective but only slightly. So, I don't know what the point
is in suggesting it as an alternative.
- Jonathan M Davis
Pointer arithmetic is forbidden in @safe code so that's not a
problem. The reason this was introduced was indeed bounds
checking. For example:
@safe:
int parse(ref char[] input)
{
// Pop all numeric characters from the front of the input slice
and convert to int
}
void main()
{
auto input = "123".dup;
parse(input);
// Since all numeric chars have been popped, input is now
effectively input[$ .. $].
// This means input.ptr is pointing past the end of the array.
writeln(input.ptr); // Out of bounds access
}
Re: Strange Bug
On Friday, 20 January 2017 at 08:19:57 UTC, Chris M. wrote: I have no idea if this is an issue with D, or OpenSSL, or if I'm just doing something completely wrong. I'm writing a program that will either encrypt or decrypt a string using AES in ECB mode (for a school assignment) and it's giving me a very strange bug. [...] auto encOut = new ubyte[inputStr.length]; // Encrypt and convert to base64 AES_set_encrypt_key(aesKey.ptr, aesKey.sizeof * 8, ); AES_ecb_encrypt(inputStr.ptr, encOut.ptr, , AES_ENCRYPT); Here's the problem. I tried running this without the if-else statements (i.e. encrypting and decrypting all in one run of the program, code below). If I leave in the base64 encoding and decoding, and use decB64 as the input to decrypt, it still doesn't work. However, if I decrypt with encOut directly, or assign encOut to decB64, it somehow works. My guess: The encrypted output will be a bit longer than your input. You're not getting an out of bounds exception during encryption since OpenSSL only has the pointer to write to, not a buffer length it can check. The memory behind your buffer is apparently committed, and will be written to by OpenSSL. This is why using the same buffer to decrypt works: it continues to read after the end of the buffer. (In case it's not clear, writing and reading past the end of the buffer is really bad) I expect OpenSSL to have a helper function to calculate the required buffer size for a given input length. Use that to allocate the buffer.
Re: Phobos: Determining number of hours or minutes or seconds till now
On Friday, 20 January 2017 at 03:48:14 UTC, rikki cattermole wrote: As per the documentation this is wrong for anything beyond a few weeks. Although I have no idea if that's the case implementation wise. I think the documentation is talking about the units used, not length of the duration. The reason Duration makes this distinction is because months and everything larger have a variable length. I'm not sure though.
Re: Phobos: Determining number of hours or minutes or seconds till now
On Thursday, 19 January 2017 at 14:04:36 UTC, aberba wrote: Using the standard library, how do a get number of hours or seconds or minutes or days or months or years till current time from a past timestamp (like "2 mins ago")? Not with manual calculations but from Phobos functions. You can get a duration by subtracting two timestamps. For example: auto delta = (Clock.currTime - timeStamp).total!"seconds";
Re: Thread will get garbage collected?
On Tuesday, 17 January 2017 at 08:58:33 UTC, Arun Chandrasekaran wrote: Interesting. Why doesn't the thread get GC'd in this case even without any reference still active? There will be a reference to it in druntime itself: http://dlang.org/phobos/core_thread.html#.Thread.getThis
Re: Changing template parameters
On Monday, 16 January 2017 at 15:56:16 UTC, Jack Stouffer wrote:
Same way you use any template parameters,
auto i = uniform!("(]")(0, 1000);
Also, if the template parameter consists of a single token you
can omit the parens:
auto i = uniform!"(]"(0, 1000);
Re: Alias variable from another class
On Tuesday, 13 December 2016 at 19:13:24 UTC, Begah wrote: Any ideas? Closest you can get is wrapping it in a property. If you need to do this often you may be able to generate them, check the recent "Getters/Setters generator" thread in Announce for some inspiration.
Re: Updated D then undefined symbols in vibed
On Thursday, 24 November 2016 at 16:17:19 UTC, Jot wrote: Any more ideas? Obviously something isn't getting linked in in the VS project. This is definitely a stale object file problem. From that error message it appears to use the .dub directory to store object files of your dependencies. Try nuking it, then run dub to recreate it.
Re: Updated D then undefined symbols in vibed
On Thursday, 24 November 2016 at 09:52:32 UTC, Jot wrote: Seems like someone decided to screw up a lot of people by removing a lot of stuff ;/ I guess I should learn my lesson about assuming a "stable" dmd release won't completely kill my project. There are still some old object files or libs hanging around. MSBuild doesn't know you've updated DMD and reuses them. Dub shouldn't have this problem. If you've generated the solution from a dub file, try a rebuild with Dub first. I suspect MSbuild will work after that.
Re: Why don't Function Lambdas Cast to Delegate?
On Monday, 21 November 2016 at 16:24:38 UTC, Q. Schroll wrote: Why don't lambdas cast to a delegate if they are of type R function(Args)? I don't see any reason to that; a lambda should be a delegate type by default, and a function only as a special guarantee/optimization. It just makes them cumbersome to use with toDelegate. Probably there is a good reason why R function(Args) does not implicitly cast to R delegate(Args); I can imagine something internally (memory layout etc.) causes that. I'd just like to know. A delegate has the hidden context pointer as parameter in addition to the 'visible' parameters. That causes functions and delegates with the same declared params to look different on the ABI level.
Re: D Lang installation on Windows, dependency on Visual Studio?
On Tuesday, 15 November 2016 at 16:20:53 UTC, AB wrote: Hopefully, future releases of DMD will fix this inconsistency by requiring Visual Studio for 32-bit D programs as well. You already do, if you compile with -m32mscoff.
Re: DMD 64-bit Windows
On Thursday, 10 November 2016 at 09:35:00 UTC, Mario Silva wrote: I haven't tried it yet, but I would want to avoid changing the compiler at this point, since we already have all our tooling build around DMD. That is why I'm asking specifically about the state of the 64-bit windows version of DMD. There is no official 64 bit build of DMD, but it's quite easy to make one yourself using Digger: https://github.com/CyberShadow/Digger Since the 64 bit build is not automatically tested master will sometimes fail to compile, but sticking to releases always works for me so far.
Re: [vibe.d] showing images
On Wednesday, 26 October 2016 at 12:42:09 UTC, Nicholas Wilson
wrote:
doctype html
html
body
-foreach(s; images)
// it doesn't seem to like #{s} or !{s}
img(src=s)
--
shared static this()
{
auto router = new URLRouter;
router.registerWebInterface(new CamController);
auto settings = new HTTPServerSettings;
settings.port = 8081;
settings.bindAddresses = ["::1", "127.0.0.1"];
listenHTTP(settings, router);
}
class Controller
{
void index(HTTPServerRequest req, HTTPServerResponse res)
{
auto images =
dirEntries("public/images",SpanMode.breadth)
.map!(f=> f.name).array;
writeln(images); // ["public/images/testprog.jpg"]
res.render!("index.dt",images);
}
}
What am I missing? I just get a 404 for the image.
You need to make the images accessible over HTTP. Note the use of
staticFileServer in the following example:
http://vibed.org/docs#http-routing
Re: File.write write extra CR character if a string has CRLF on windows
On Thursday, 6 October 2016 at 15:00:00 UTC, Pham wrote:
string s is multi-lines (CRLF as line break)
The write function will write extra CR character for each CRLF
pair -> why (bug?)
import std.file;
import std.stdio;
string s = ...;
auto fHandle = File("f:\\text.txt", "w"); // open for writing
fHandle.write(s);
fHandle.close();
Take a look at this thread:
http://forum.dlang.org/post/ehdnboaufaadgiaah...@forum.dlang.org
Re: The XML and JSON library
On Friday, 30 September 2016 at 03:27:36 UTC, Nick Sabalausky wrote: You don't have to USE the web framework stuff to the use json part. This sort of question has come up before, but I've really never understood the problem. Sounds more ideologic than anything real to me. Since Vibe has been split into subpackages it's not an issue anymore, but before that I copied Vibe's Json code into my project so I didn't need to depend on the entire Vibe codebase. DMD ICE's are much, much less frequent than they were a few years ago, but with largish projects I still regularly run into them, which is a reason for me to not include more code than necessary.
Re: Member not accessible in delegate body
On Friday, 23 September 2016 at 07:54:15 UTC, John C wrote:
How is it possible that "onTextChanged" isn't accessible but
the private method "changeSize" *is*?
Smells like an oversight. I guess the compiler doesn't see the
delegate as a member of a Control subclass, so it can't access
protected members. Private works because private in D means
module private.
Please file an issue. As a workaround you can try to take the
address of the method in the closure (untested):
void delegate() foo()
{
auto func =
return () => func(); // I think this will work
}
Re: Vibe.d compilation error: backend/cgelem.c 5018 dmd failed with exit code 1.
On Friday, 23 September 2016 at 08:39:44 UTC, llaine wrote: Okay I tried yesterday, after 4hours of process, I never went through the end of minification. At the beginning I enter YES should I enter NO instead? Hmm that's strange. I don't get any yes or no questions. What is the exact message you get? I've been looking into using dustmite with dub a bit, and running dub dustmite "../DustmiteResult" --compiler-regex=".*backend/cgelem\.c 501.*" --build=release in your project directory should just work..
Re: Vibe.d compilation error: backend/cgelem.c 5018 dmd failed with exit code 1.
On Wednesday, 21 September 2016 at 20:22:42 UTC, llaine wrote: The project is pretty big, DustMite would handle this? Yes, but it may take some time. For large projects, running it on a server is advisable. 3K LOC should be doable on a desktop machine. Dub has built-in support for running Dustmite. I'm not very familiar with it, but it looks like you'll want to use 'dub dustmite' with the --compiler-regex switch with a regex matching the ICE assert message.
Re: Copy a struct and its context
On Sunday, 11 September 2016 at 05:44:13 UTC, Yuxuan Shui wrote: I recently noticed nested struct capture its context by reference (which, BTW, is not mentioned at all here: https://dlang.org/spec/struct.html#nested). And bliting a struct obviously doesn't do a deep copy of its context. So my question is, is there a way to deep copy the context of a struct? I've tried a few things, but I don't think you can. The root issue is that the context pointer is void*, so you can't do meaningful reflection on it.
Re: Storing a reference
On Thursday, 1 September 2016 at 20:38:13 UTC, Yuxuan Shui wrote:
I think my approach is probably better, because I believe
(correct me if I'm wrong): 1) it will never refer to a null
object.
That's true, but you can ensure the same thing for the wrapper:
struct Ref()
{
@disable this();
this(T* value)
{
assert(value !is null);
this.value = value;
}
// rest same as before
}
2) after DIP1000 is implemented we will be able to make sure
there will be no dangling reference.
I'm not very familiar with the details of DIP1000, so I can't
comment on that.
Re: Storing a reference
On Thursday, 1 September 2016 at 19:37:25 UTC, Yuxuan Shui wrote:
I just figured out how to store a reference:
@safe:
auto x(ref int a) {
struct A {
ref int xa() { return a; }
}
return A();
}
void main() {
import std.stdio;
int b = 10;
auto a = x(b);
a.xa = 20;
writeln(b); //Prints 20
}
I have no idea if this is a right thing to do. Can someone tell
me if this is idiomatic D, and whether there're any catches to
this method or not?
Thanks.
This will allocate a closure. A struct definition inside a
function has a hidden context / closure pointer, unless it's a
static struct.
There is nothing like a ref variable in D. If you want to refer
to something someplace else, use a pointer. You can create a
pointer wrapper which acts like a reference (untested):
auto toRef(ref T value)
{
return Ref!T();
}
struct Ref(T)
{
private T* value;
@property ref T _value() { return *value; }
alias _value this;
}
Note that D's pointer syntax is a bit friendlier than C++'s: the
dot operator works fine on pointers. A good reason to use the Ref
wrapper is to forward arithmetic operations to the wrapped value.
Re: Checking all elements are unique.
On Wednesday, 31 August 2016 at 08:38:11 UTC, Andrea Fontana wrote: Something like this: https://dpaste.dzfl.pl/9fa55b2a7927 ? Andrea Or use findAdjacent: auto idsAreUnique = ids.array.sort.findAdjacent.empty; http://dlang.org/phobos/std_algorithm_searching.html#.findAdjacent
Re: DerelictGL3.reload with specified path question.
On Wednesday, 17 August 2016 at 22:59:31 UTC, WhatMeWorry wrote: I want to store all my shared/dynamic libraries within a special directory relative to where the application directory is. All of the derelictXX.loads(path) compiles except DerelictGL3.reload(lib); which doesn't seem to be implemented. Don't ever ship OpenGL.dll with your application: it's provided by the graphics driver. The only exception to this rule that I can think of is if you want to use a software implementation for some reason.
Re: randomIO, std.file, core.stdc.stdio
On Wednesday, 27 July 2016 at 02:20:57 UTC, Charles Hixson wrote: O, dear. It was sounding like such an excellent approach until this last paragraph, but growing the file is going to be one of the common operations. (Certainly at first.) (...) So I'm probably better off sticking to using a seek based i/o system. Not necessarily. The usual approach is to over-allocate your file so you don't need to grow it that often. This is the exact same strategy used by D's dynamic arrays and grow-able array-backed lists in other languages - the difference between list length and capacity. There is no built-in support for this in std.mmfile afaik. But it's not hard to do yourself.
Re: DConf 2016 on YouTube
On Thursday, 21 July 2016 at 16:35:44 UTC, Ali Çehreli wrote: Stealing the opportunity to announce this news... :) https://www.youtube.com/playlist?list=PL3jwVPmk_PRyTWWtTAZyvmjDF4pm6EX6z Reddit: https://www.reddit.com/r/programming/comments/4txf9w/dconf_2016_video_playlist/ Ali This is great, my thanks to everyone involved!
Re: Battle-plan for CTFE
On Friday, 8 July 2016 at 11:32:10 UTC, Stefan Koch wrote: I forgot to mention I posted a short article about the CTFE design on my blog. https://codesoldier.blogspot.com Feel free to comment or give suggestions. Thanks! Posts like these are always interesting to read. I noticed a few mistakes: I have been working a rewrite -> I have been working on a rewrite complicated corer-case -> complicated corner-case that have to handled correctly -> that have to be handled correctly a cononical from -> a canonical from
Re: Dynamic arrays, emplace and GC
On Tuesday, 5 July 2016 at 13:48:46 UTC, Claude wrote: Ah ok. I tried using void[size] static array and it seems to work without having to use GC.addRange(). Correct. void[] means the type of the data is unknown, so the GC has to assume it can contain pointers. This also means that _everything_ in any void buffer has to be treated as a potential pointer. In other words, if you allocate a void buffer and fill it with ints, and one of those ints happens to have a value equal to the address of a GC-allocated object, the GC will assume the int is a pointer to that object and not free it.
Re: Initializing static array with contents of (static and dynamic) arrays
On Tuesday, 5 July 2016 at 12:34:20 UTC, Johannes Loher wrote: I tried this, but it does not work correctly with slices. The length of a slice is a runtime value, which is why it can't be used to set static array size. What were you trying to achieve? Avoid copying the input arrays, or accepting any slice? In case of the first, you can put ref in front of the Args: auto combineArrays(Args...)(ref Args args) The second case will be a bit harder to solve nicely..
Re: Initializing static array with contents of (static and dynamic) arrays
On Monday, 4 July 2016 at 19:22:52 UTC, Johannes Loher wrote: This looks really nice, but I have several occurences of this, with different arrays (and lengths), so i would need to create several of those structs. But it looks really clean :) You can use a template to remove the boilerplate. Here's a quick example: https://dpaste.dzfl.pl/43b379992648
Re: Commit size and Page fault's very large for simple program
On Monday, 4 July 2016 at 11:42:40 UTC, Rene Zwanenburg wrote: ... I forgot to mention: If you're on Windows compilation defaults to 32 bit, false pointers can be a problem with D's current GC in 32 bit applications. This isn't an issue for the sample application though, since you're not putting random numbers in the allocated arrays. 64 bit doesn't suffer from this. There's also a GSoC project underway, aimed at improving the GC. I'm not sure what the exact goals are, but IIRC work on making the GC precise is being done, which would eliminate the false pointer issue.
Re: Commit size and Page fault's very large for simple program
On Monday, 4 July 2016 at 01:57:19 UTC, Hiemlick Hiemlicker wrote:
version(Windows)
void main()
{
import std.random;
while(getchar() != EOF)
{
auto x = new int[std.random.uniform(100, 1000)];
writeln("");
bThread.Now();
}
}
more or less, ends up with a huge amount of page faults and a
several hundred MB commit size(hold enter down a bit). I'm
trying to understand this. Is that normal behavior for normal
programs(haven't tried it with a similar C++ example though).
The PF's are most likely due to default initialization, so you
may not see those in a C++ equivalent (or, actually, the exact
equivalent would be to initialize the array as well, in that case
you'd get PF's too). If you've determined default initialization
is causing performance problems in a hot piece of code, D
provides facilities to disable it.
I realize the GC has to do some work and all that but the
program only has a working set of a few MB yet a commit of 10
times that.
Is commit size essentially "touched" memory but really doesn't
mean much to overall free ram?(can other programs use it at
some point)?
Strictly speaking there's no relation between commit size and
RAM, from your application's POV there's only the virtual address
space. Committed memory can be paged to disk if the OS determines
your application isn't actively using certain pages.
We know the program is not using more than 10MB
It's an array of ints, so you'll have to multiply that by four ;)
of extra memory(since x is local)... so I'd only expect the
footprint to be a max of around 15-20MB. not 150MB+(depends on
how fast and long you hit enter).
Keeping memory usage to an absolute minimum would mean the GC has
to do a collection on every allocation. As a very coarse rule of
thumb, expect a GC heap (not just the D GC) to be about 1.5 to 2
times as large as strictly necessary. This is to reduce the
amount of collections. Since your example is doing nothing but
hammering the GC I'm not surprised the heap is a bit larger than
that.
Re: Range non-emptyness assertions and opIndex
On Friday, 1 July 2016 at 10:35:04 UTC, Nordlöw wrote:
I think this is a important issue since asserts are not
optimized away in release mode and D is very much about
performance.
Asserts are removed in release mode, enforce isn't. Here's an
example:
=
void main(string[] args)
{
assert(args.length >= 1);
}
=
dmd testfile.d
This calls the assert function as expected:
=
_Dmain:
: 55 pushrbp
0001: 48 8B EC mov rbp,rsp
0004: 48 83 39 01cmp qword ptr
[rcx],1
0008: 73 0E jae
0018
000A: B9 03 00 00 00 mov ecx,3
000F: 48 83 EC 20sub rsp,20h
0013: E8 00 00 00 00 call
_D5test28__assertFiZv
0018: 31 C0 xor eax,eax
001A: 5D pop rbp
001B: C3 ret
=
Now compiling in release mode:
dmd -release testfile.d
No assert in sight:
=
_Dmain:
: 55 pushrbp
0001: 48 8B EC mov rbp,rsp
0004: 31 C0 xor eax,eax
0006: 5D pop rbp
0007: C3 ret
=
Re: How to use a char[] buffer in D
On Thursday, 23 June 2016 at 05:59:10 UTC, Andrew Chapman wrote:
Perfect, thank you! :-) Works like a charm.
On Wednesday, 22 June 2016 at 22:41:24 UTC, H. S. Teoh wrote:
On Wed, Jun 22, 2016 at 09:57:04PM +, Andrew Chapman via
Digitalmars-d-learn wrote:
Maybe try:
if (buffer[] in myHash) { ... }
? Does that make a difference?
T
If the keys are fixed-length, you may want to consider using
immutable(char[4]) as key. That way there is no GC allocation for
the strings at all, the only allocations are done by the AA.
Re: Templated class defaults and inheritence
On Saturday, 18 June 2016 at 17:48:47 UTC, Joerg Joergonson wrote:
class foo(T) if (is(T : subfoo)) X;
FYI this can also be done in the template parameter list:
class foo(T : subfoo){}
Re: Weird compiler
On Sunday, 19 June 2016 at 14:45:29 UTC, mogu wrote: Moreover, I wonder if D is really a cross-platform programming language?! The official dmd only supports x86 structure. You can never build a project with third party static library in windows independently. Back when DMD on windows exclusively used the OMF object format and optlink, a common complaint was that DMD didn't use the microsoft tools. I guess the DMD installer could ask to install the SDK when VS isn't present though. And how I can build an android program? LDC2? So what dmd is? Only for a bit faster compiling time? Yeah, use LDC or GDC for the fastest executables and widest platform support. Don't underestimate the value of fast compilation, it's incredibly useful while writing code. After a whole day struggled in dmd and static library， I rewrote the demo GUI tool in Nim. Only in ten minutes, all works. Sigh. You can always post in the forums if you're stuck. The learn forum is quite active most of the day.
Re: Weird compiler
On Sunday, 19 June 2016 at 14:05:22 UTC, mogu wrote: Today, I'm working on a private GUI tool which must be run at linux and windows. It's awful that I compile a little 64bit program(or -m32mscoff) in windows must have visual studio which has tremendous size installed even though I only need a linker. It's weird that a compiler compiles to binary targets needs another compiler or tools. Sigh. There's no need to install VS if you don't use it otherwise, the windows platform SDK should suffice; it comes with the microsoft linker and all the lib files, and the DMD installer should detect it just fine.
Re: Out of order execution
On Thursday, 16 June 2016 at 01:57:19 UTC, Joerg Joergonson wrote: Is there an efficient lazy way to make this happen? No, I don't see how that would work. Suppose I can't run the loop twice for performance reasons(there is other stuff in it) and I don't want to store the state and call info then sort them out afterwards. Storing the state is your best bet. Based on your recent post about OpenGL I assume this is for the same project? If so, you can reuse the storage buffer between frames. Generally speaking it's the allocations that are slow, copying some state to a buffer shouldn't be expensive. Use separate buffers for the Do1 and Do2 calls so you don't have to sort.
Re: GTKD - Application crashes - or not? [Coedit]
On Wednesday, 15 June 2016 at 10:31:18 UTC, TheDGuy wrote: Thanks a lot for your answer, getcwd() returns the path where coedit is located on my harddrive: C:\Program Files (x86)\Coedit_32\coedit.2update6.win32 How can i change that? I'm not familiar with Coedit, but the run options seem to contain a field for setting it: https://github.com/BBasile/Coedit/wiki#run-options You may be able to use the symbolic strings there: https://github.com/BBasile/Coedit/wiki#symbolic-strings
Re: GTKD - Application crashes - or not? [Coedit]
On Wednesday, 15 June 2016 at 09:48:19 UTC, TheDGuy wrote: But if i execute the app my hand (in the windows command window or my double click) it works as expected (so no error)? Why is that? My first guess would be that Coedit does not use the directory where the executable is located as working directory. You can check what getcwd returns: https://dlang.org/phobos/std_file.html#.getcwd
Re: What's up with GDC?
On Monday, 13 June 2016 at 20:21:28 UTC, Joerg Joergonson wrote: Are you running some other program that might be sending a lot of broadcast messages? Not that I know of. I haven't tried running it outside VS though so it might be doing something weird. I'll investigate further when I get a chance and get further down the road. It's often useful to attach a sampling profiler when the process is eating CPU. It should tell you what's going on at a glance. I believe VS has a sampling profiler built in, but it most likely won't demangle D symbols, so the function names will be a bit hard to read.
Re: Range and poolTask
On Monday, 6 June 2016 at 10:26:11 UTC, moechofe wrote: The functions passed to map or amap take the type of the element of the range as argument, but not a range itself. Right. I don't think I understand what the semantics of your example would be though.. Could you elaborate a bit?
Re: Range and poolTask
On Monday, 6 June 2016 at 09:32:30 UTC, moechofe wrote:
I wonder if it is possible to write something like this:
---
// taskPool.distribute -- take a range and distribute entries
to different threads.
dirEntries().distribute(function(R1,R2)(R1 from,R2 to){
from
.filter!xxx
.map!yyy
.tee!zzz(to);
})
.each!www;
---
This would be great.
This might be useful:
http://dlang.org/phobos/std_parallelism.html#.TaskPool
Or, more specifically,
http://dlang.org/phobos/std_parallelism.html#.TaskPool.amap
http://dlang.org/phobos/std_parallelism.html#.TaskPool.map
Re: Creating a "fixed-range int" with opDispatch and/or alias this?
On Wednesday, 1 June 2016 at 19:59:51 UTC, Mark Isaacson wrote: FWIW, the fixed range int part of this question is just an example, I'm mostly just interested in whether this idea is possible without a lot of bloat/duplication. I suspect not.. Here's how std.typecons.Proxy is doing it: https://github.com/dlang/phobos/blob/master/std/typecons.d#L5109
Re: Using referenceCounters
On Wednesday, 1 June 2016 at 18:14:33 UTC, Begah wrote:
I started using reference counters for my assets in my
application :
- Images
- Models
-
For my resource manager I started out with something similar to
what you're describing, but I eventually changed the design which
turned out to be an immense improvement so I'll just describe
that ^^
- Differentiate between the type implementing a resource, and
handles to a resource.
- Split up the resource manager, which stores the 'real' resource
for a given handle, and the cache where you look up resources by
name.
A stripped down version of the resource manager looks something
like this:
template ResourceManager(ResourceType)
{
struct HandleImpl
{
~this()
{
// Destroy the resource, make sure you mark the
corresponding slot in the array as free
}
size_t slot;
}
alias Handle = RefCounted!HandleImpl;
private ResourceType[] resources;
// When creating a resource add it to the manager and pass
around the opaque handle instead.
Handle add(ResourceType resource)
{
// Find an empty slot in the resources array, put the
resource there, and return a handle pointing to that slot.
}
// This should be used sparingly. Most code shouldn't care
about resource implementation. The parts that do can get at it
via this function, but shouldn't hold on to the reference longer
than necessary.
ResourceType getActualResource(Handle handle) { ... }
// This allows you to hot-swap resources while keeping the
resource implementation logically const. Hot-swapping is
extremely valuable, I've always found myself wanting to support
it sooner or later. I've tried to do it in different ways, but it
always ended up in a mess. Using handles on the other hand turned
out to be clean and easy.
void update(Handle handle, ResourceType newResource) { ... }
}
Note that it doesn't allow you to search for resource by name or
anything, this is just a simple mapping between handles and the
resource implementation. It doesn't store instances of the
RefCounted handles itself, so there are no issues with resources
not being cleaned up.
Now when you have this in place you can build a caching mechanism
on top of it:
template ResourceCache(ResourceType, alias loadByName)
{
alias Manager = ResourceManager!ResourceType;
Manager.Handle[string] cache;
Manager.Handle get(string name)
{
// Check if the resource is already in the cache, if not load
it using the loadByName function and store it.
}
void purge()
{
// the keys property allocates a new array with the AA keys,
which is important since we're modifying the AA.
foreach(key; cache.keys)
{
// This is the part you were actually interested in. It's
important to take a pointer to the handle here, and not reference
it directly. I had some issues with that in the past, I'm not
sure if that's still the case.
auto ptr = key in cache;
if(ptr.refCountedStore.refCount == 1) // If this is the
last reference
{
destroy(*ptr); // I'm not sure if this is still
necessary, there was some issue with AAs in the past. It may be
fixed today. Destroying the handle doesn't hurt either way so I
left it in.
cache.remove(key);
}
}
}
}
So cached resources don't get cleaned automatically if you don't
call purge, but that's usually the right thing to do anyways. For
example when you're changing scenes (I assume this is for some
kind of game?) you can simply destroy the current scene, load
another, then purge the cache, without having to reload resources
used by both scene 1 and 2.
Another upside is that this doesn't require every resource to be
named / backed by file. Resources can be dynamically generated at
runtime without special casing anywhere.
Re: Base64 of String without casting
On Wednesday, 1 June 2016 at 09:31:51 UTC, tcak wrote:
I understand that Base64 uses Ranges, and since String is seen
and used as unicode by Ranges (please tell me if I am wrong).
I am guessing, for this reason, auto btoa =
std.base64.Base64.encode("Blah"); doesn't work. You need to be
casting the string to ubyte[] to make it work which doesn't
look and feel nice at all.
Can/shall we add another alias into the module for encode
method, so it accepts a string, and casts it to ubyte[] by
itself?
This should do the trick:
https://dlang.org/phobos/std_string.html#.representation
Re: Preferred method of creating objects, structs, and arrays with deterministic memory management
I was wondering: what's the preferred method for deterministic
memory management?
You may be interested in RefCounted. It only works for structs,
not classes, but it's still useful.
- Classes/Structs have constructors and destructors. I am
unconfident with my knowledge as to how this works with malloc
and free.
malloc() and free() operate on a lower level, they only care
about raw memory. When you malloc() some space, you can construct
an object there using emplace(), and it can be destructed by
using detroy().
- Many features and types use the GC such as exceptions, the
new keyword, and all arrays except statics.
It's important to differentiate static arrays, and slices with
static storage. For example:
class C
{
static int[] someSlice; // This is a slice with static storage.
The memory it is referring to may be GC allocated, but it doesn't
have to (this is true for all slices btw).
int[4] someStaticArray; // This is a static array, i.e. an
array with a fixed length. In D static arrays are value types, so
it's allocated in its enclosing scope and copied when you pass it
around.
}
- std.container.array can be used for deterministic arrays,
but has the issue of dangling pointers. There is probably a
good solution to this, but I don't know it.
I don't know of any dangling pointer issues with Array. It's
possible to create cycles resulting in a leak, but that's only
likely to happen if you heavily rely on refcounting everything.
- There seems to be no way to completely turn off the GC. That
is, never have the runtime allocate the memory used by the GC.
Like Rikki said, if you really want to the GC can be replaced
with an asserting stub. This isn't as hard as it sounds, just add
something like the file he linked to to your project. Since all
declarations are extern(C) there is no name mangling, and the
linker will prefer your own definitions over the ones in
druntime. I don't recommend you do this though unless you really
know what you're doing.
This are the pieces I've gathered, but I don't really know
what's true or how to use this knowledge. Some ideas I've
gleaned may also be outdated. Does anyone know the "correct"
way one would go about a non-GC program, and if a program can
be ran without ever instantiating a GC? Has there been any
progress on reducing the std library's usage of the GC?
You can annotate your functions as @nogc. The compiler will
disallow any potential GC use, including calling other functions
that are not @nogc.
P0nce is doing real time audio stuff, iirc he's using a thread
with a @nogc entry point for the strictly real-time parts, and
regular GC-using code in another thread for everything else.
