Re: how to call class' template constructor
On Sunday, 12 October 2014 at 19:46:41 UTC, ketmar via
Digitalmars-d-learn wrote:
Hello.
please, how to call template constructor of a class? it's
completely
escaped my mind. i.e. i have this class:
class A {
this(alias ent) (string name) {
...
}
}
and i want to do:
void foo () { ... }
auto a = new A!foo(xFn);
yet compiler tells me that
template instance A!foo A is not a template declaration, it is
a class
yes, i know that i can rewrite constructor to something like
this:
this(T) (string name, T fn) if (isCallable!T) {
...
}
and then use autodeduction, but i want the first form! ;-)
How about a static factory method? Or do you know there is a
syntax for invoking a templatized constructor and just can't
remember it?
Localizing a D application - best practices?
Coming from the C# world, all of localization we did was based on defining string resource files (XML-formatted source files which were translated into C# classes with named-string accessors by the build process) that would get included in the final application. For log messages, exception messages (because unhandled exceptions could make it to the user in the case of a bug) and format strings used for the above we would create a string table entry and this file would eventually get localized by the appropriate team. Is there a recommended pattern for applications in D that wish to do localization? Thanks.
Re: Object.factory from shared libraries
On Friday, 26 September 2014 at 15:45:11 UTC, Jacob Carlborg wrote: On 2014-09-26 16:24, krzaq wrote: That would be satisfactory to me, except for the linux-only part. In that case, I think I'll simply try to call filename() as the factory function in each library - that should work everywhere, right? Dynamic libraries only work properly on Linux. This has nothing to do with Object.factory. What is the nature of D's so/dll support? Or is there a page describing it?
Re: can't understand why code do not working
On Monday, 22 September 2014 at 20:12:28 UTC, Suliman wrote:
void worker()
{
int value = 0;
while (value =10)
{
value = receiveOnly!int();
writeln(value);
int result = value * 3;
ownerTid.send(result);
}
}
give me:
Running .\app1.exe
2
6
3
9
4
12
5
15
6
18
std.concurrency.OwnerTerminated@std\concurrency.d(234): Owner
terminated
0x00405777 in pure @safe void
std.concurrency.receiveOnly!(int).receiveOnly().__
lambda3(std.concurrency.OwnerTerminated) at
C:\DMD\dmd2\windows\bin\..\..\src\ph
obos\std\concurrency.d(730)
0x0040B88D in @safe void std.concurrency.Message.map!(pure
@safe void function(s
td.concurrency.OwnerTerminated)*).map(pure @safe void
function(std.concurrency.O
wnerTerminated)*) at
C:\DMD\dmd2\windows\bin\..\..\src\phobos\std\concurrency.d(
158)
0x0040B0B6 in
D3std11concurrency10MessageBox151__T3getTDFNbNfiZvTPFNaNfC3std11co
ncurrency14LinkTerminatedZvTP8047E12172B30CAF110369CD57C78A37
at C:\DMD\dmd2\win
dows\bin\..\..\src\phobos\std\concurrency.d(1159)
Is stdout threadsafe?
Re: can't understand why code do not working
On Monday, 22 September 2014 at 21:28:25 UTC, Cliff wrote: On Monday, 22 September 2014 at 21:24:58 UTC, monarch_dodra wrote: On Monday, 22 September 2014 at 21:19:37 UTC, Steven Schveighoffer wrote: On 9/22/14 4:37 PM, Cliff wrote: Is stdout threadsafe? Yes, stdout is thread safe, it's based on C's stdout which is thread safe. -Steve Techinallly, though thread safe, concurrent writes will create garbled text. D goes one step further in the sense that it prevents concurrent writes entirely. The reason I ask is that the first iteration of his loop does not show up in stdout as presented. I would expect 1 and 3 to be the first two lines of the output. For that matter I also don't expect the 6 and 18 - nevermind, there must be something else going on with that loop. He must have changed the loop limits.
Re: can't understand why code do not working
On Monday, 22 September 2014 at 21:24:58 UTC, monarch_dodra wrote: On Monday, 22 September 2014 at 21:19:37 UTC, Steven Schveighoffer wrote: On 9/22/14 4:37 PM, Cliff wrote: Is stdout threadsafe? Yes, stdout is thread safe, it's based on C's stdout which is thread safe. -Steve Techinallly, though thread safe, concurrent writes will create garbled text. D goes one step further in the sense that it prevents concurrent writes entirely. The reason I ask is that the first iteration of his loop does not show up in stdout as presented. I would expect 1 and 3 to be the first two lines of the output.
Re: Interop with C++ library - what toolchain do you use?
On Thursday, 18 September 2014 at 08:27:07 UTC, Szymon Gatner wrote: On Wednesday, 17 September 2014 at 22:28:44 UTC, Cliff wrote: So I am trying to use a C++ library with D. My toolchain is currently Visual Studio 2013 with Visual D, using the DMD compiler. When trying to link, I obviously ran into the OMF vs. COFF issue, which makes using the C++ library a bit of a trial to say the least (I played around with some lib format converters but perhaps unsurprisingly this led to somewhat unpredictable behavior.) I'd like to fix up my toolchain to avoid having this issue. For those of you who are on Windows and who do D and C++ interop, what toolchain have you had success with? Additionally, I have heard tell that D now allows calling C++ non-virtual class methods but I have not found documentation on how to make this work (how do I define the C++ class layout in D - I know how to do it for vtable entries but not non-virtual methods.) Pointers to docs or samples would be much appreciated. Thanks! I am using Visual Studio 2012 (in x64 bit mode that is). Binary D distribution also comes with phobos64.lib that C++ executable has to link. With VisualD plugin you can just add D static library project to the solution and the link C++ exe to it. It is very easy to make back-and-forth function calls between C++/D. I recommend Adam Ruppe's excellent D Cookbook Integration chapter on the details on how to expose this for cross-lang usage. It does not all work correctly tho. I reported my issues on learn subforum but didn't get much help. In short: it seems not everything in D run-time (Phobos) gets properly initialized even after successful rt_init() call. In my case simple call to writeln() causes a crash because stdout is not properly initialized on D'd side. Happy hybridizing! Thanks guys. I do have that book, but I was unaware of the COFF capabilities of the 64-bit DMD, I'll take a look at it.
Re: Code doesn't work - why?
On Wednesday, 17 September 2014 at 21:33:01 UTC, Robin wrote:
Here is the fully working code for everyone experiencing
similar bugs or problems with pointers and value types. =)
struct DeterministicState {
public:
this(string name, bool isFinal, DeterministicState *[char]
transits...) {
this.name = name;
this.finalState = isFinal;
this.addTransits(transits);
}
this(string name, bool isFinal) {
this.name = name;
this.finalState = isFinal;
}
this(bool isFinal, DeterministicState *[char] transits...) {
this(, isFinal, transits);
}
this(DeterministicState *[char] transits...) {
this(, false, transits);
}
void addTransits(DeterministicState *[char] newTransits) {
foreach (immutable key; newTransits.keys) {
transits[key] = newTransits[key];
}
}
string getName() const {
return name;
}
bool isFinalState() const {
return finalState;
}
bool hasNext(char input) const {
return (input in transits) ? true : false;
}
DeterministicState * getNext(char input) {
return transits[input];
}
string toString() const {
return name;
}
private:
string name;
DeterministicState *[char] transits;
bool finalState;
}
struct DeterministicFiniteAutomaton {
public:
DeterministicState *[] input(char[] input) {
DeterministicState *[] trace = [ start ];
auto currentState = trace[0];
foreach (immutable c; input) {
if (!currentState.hasNext(c)) {
writeln(currentState.toString() ~ has no next for ~
to!string(c));
break;
} else {
writeln(currentState.toString() ~ has next for ~
to!string(c));
}
currentState = currentState.getNext(c);
trace ~= currentState;
}
return trace;
}
this(DeterministicState * start) {
this.start = start;
}
private:
DeterministicState * start;
}
void main()
{
auto s0 = DeterministicState(s0, false);
auto s1 = DeterministicState(s1, false);
auto s2 = DeterministicState(s2, true);
s0.addTransits(['0' : s1, '1' : s2]);
s1.addTransits(['0' : s0, '1' : s2]);
s2.addTransits(['0' : s2, '1' : s2]);
auto dfa = DeterministicFiniteAutomaton( s0);
auto trace = dfa.input(0001.dup);
foreach (t; trace) {
writeln(t.toString());
}
writeln(Trace Length = ~ to!string(trace.length));
}
Regards,
Rob
Out of curiosity, why did you decide to stick with structs
instead of simply using classes? To avoid heap allocations?
Re: Code doesn't work - why?
On Wednesday, 17 September 2014 at 21:45:01 UTC, Robin wrote: This is actually a good question as this code isn't really complex or doesn't require the best possible performance. But in case I will ever need optimum performance I should have learned how to handle tasks with value types which is the main reason why I chose them instead of reference types - for learning purposes. - can't hurt! ;) Regards, Rob Probably also has applicability when creating compile-time data structures that have scope-limited lifetimes.
Interop with C++ library - what toolchain do you use?
So I am trying to use a C++ library with D. My toolchain is currently Visual Studio 2013 with Visual D, using the DMD compiler. When trying to link, I obviously ran into the OMF vs. COFF issue, which makes using the C++ library a bit of a trial to say the least (I played around with some lib format converters but perhaps unsurprisingly this led to somewhat unpredictable behavior.) I'd like to fix up my toolchain to avoid having this issue. For those of you who are on Windows and who do D and C++ interop, what toolchain have you had success with? Additionally, I have heard tell that D now allows calling C++ non-virtual class methods but I have not found documentation on how to make this work (how do I define the C++ class layout in D - I know how to do it for vtable entries but not non-virtual methods.) Pointers to docs or samples would be much appreciated. Thanks!
Re: compile automation, makefile, or whatever?
On Tuesday, 16 September 2014 at 19:00:05 UTC, K.K. wrote: Hey I have a quick question: Does D have it's own version of makefiles or anything (preferably simpler)? So instead of typing in PowerShell dmd file1.d file2.d lib\foo.lib -Isrc\ . I could just type most of that into a file and then just type dmd file.X I've seen some people make really complex .d files that have a lot of interchangeability but at the moment I wouldn't really need something of that scale. Also, I'm not using DUB; I'd prefer to just use the command line. ..Can pragma's help with this, aside from linking just the libs? I want to say somewhere on the forums are some descriptions of using CMake for this. Might try searching for that.
Re: compile automation, makefile, or whatever?
On Tuesday, 16 September 2014 at 20:29:12 UTC, K.K. wrote: On Tuesday, 16 September 2014 at 19:26:29 UTC, Cliff wrote: I want to say somewhere on the forums are some descriptions of using CMake for this. Might try searching for that. Yeah I just looked up the CMake thing. It definitely seems worth playing with, though I'm not really sure how extensive it's D support currently is :S Out of curiosity, why are you not using dub (on the command-line)?
Re: compile automation, makefile, or whatever?
On Tuesday, 16 September 2014 at 20:45:29 UTC, K.K. wrote: On Tuesday, 16 September 2014 at 20:31:33 UTC, Cliff wrote: Out of curiosity, why are you not using dub (on the command-line)? I'm not against using it or anything, but I've found that it didn't help me significantly nor did I have the patience to figure out it's whole set of issues, D by itself is already enough trouble xD Plus with my spastic work style, it kinda slowed me down. However, it is something I may consider when I have an actually organized project with a final goal. A lot of what I'm doing right now is just experiments. Though, if Cmake + D does the trick then I might not use DUB in the end. Hard to say atm. Would you be willing to provide some more detail on what about it you didn't like (errors, missing features, etc.)? I ask because build systems are a particular interest of mine and I have projects in this area which can always use more user data.
Re: compile automation, makefile, or whatever?
On Tuesday, 16 September 2014 at 21:05:18 UTC, K.K. wrote: On Tuesday, 16 September 2014 at 20:53:08 UTC, Cliff wrote: Would you be willing to provide some more detail on what about it you didn't like (errors, missing features, etc.)? I ask because build systems are a particular interest of mine and I have projects in this area which can always use more user data. I'll try, but I haven't used it at all since maybe.. April? One of the main things that annoyed me about it was how sensitive it could be. The best comparison I can give is that it reminded me ALOT of Haxe. Both are very flimsy, and very poorly documented. (Nothing beats a good manual as far as I'm concerned!) The other thing, as I briefly mentioned, was it really didn't speed anything up, unless maybe you were working on a larger project. Obviously I'm not a master of any sort, but the main point I'd take from this is it wasn't inviting. Hope that helps a bit :3 Yep, that's useful information to me. Over the years I have found that build systems *generally* tend to be uninviting. My suspicion is that comes down to a few reasons: 1. Builds end up being a LOT more complicated that you would expect as soon as you step out of a single project with a few source files and default options 2. Build tooling is typically built and maintained by people who end up being relatively specialist - either they are part of the small cabal of people who know the tooling intimately, or they have been forced into it and know just enough to get by for their organization. 3. Most build tooling is designed to solve a particular subset of actual build-related problems, with much less though given to how it fits holistically into the entire developer workflow. 4. Build tooling is almost never treated like an actual product - documentation is written for wizards, not lay-people. As a result, the casual user is a bit SOL. (NOTE: This is not a rant specifically aimed at DUB, but my general observation on the state of build tooling.)
Re: Idiomatic async programming like C# async/await
On Sunday, 14 September 2014 at 09:19:11 UTC, Kagamin wrote:
On Friday, 12 September 2014 at 03:59:58 UTC, Cliff wrote:
...but std.parallelism.Task requires parameterization on the
function which the task would execute - that is clearly an
implementation detail of the store.
I think, you can wrap the Task in a class.
abstract class CTask
{
abstract void wait();
}
abstract class CTask(TResult)
{
abstract TResult result();
}
class CTTask(TTask): CTask(TResult)
{
TTask task; //std.parallelism.Task
override void wait(){ ... }
override TResult result(){ ... }
}
Yep, that's what I figured. Thanks :)
Re: Idiomatic async programming like C# async/await
On Friday, 12 September 2014 at 07:15:33 UTC, Kagamin wrote: async/await is not so much about futures/promises, but optimization of IO-bound operations, i.e. when you wait on network/disk, you don't consume stack, threads and similar resources, an analog in D is vibe.d I should have been more clear - it's not the async/await bit I am interested in so much as the Task behavior - that I have some object which represents the (future) completed state of a task without the recipient of that object having to know what the type of the task function is as they are only interested in the task result. I'll take a closer look at vibe.d and see if they already have a system representing this before I cook up my own.
Idiomatic async programming like C# async/await
(New to D, old hand at software engineering...)
I come from .NET and have made heavy use of the async/await
programming paradigm there. In particular, the Task mechanism
(futures/promises) lets one encapsulate the future result of some
work and pass that around. D seems to have something similar in
std.parallelism.Task, but this seems to additionally encapsulate
and expose the actual work to do.
What I want to do is be able to define an interface that performs
certain possibly-slow operations and presents a Task-based
interface. Example in C#:
interface MyStore
{
TaskKey Store(byte[] content);
Taskbyte[] Retrieve(Key key);
}
What I feel like I *want* to do in D is something roughly similar:
interface MyDStore
{
Task!Key Store(InputRange!ubyte content);
Task!(InputRange!ubyte) Retrieve(Key key);
}
...but std.parallelism.Task requires parameterization on the
function which the task would execute - that is clearly an
implementation detail of the store.
What is the correct D idiom to use in this case?
