Re: Assocative array lookup for object
On Wednesday, 12 April 2023 at 13:09:07 UTC, Ali Çehreli wrote:
Not every type is null'able but nullable. ;) So, a design may
use the following:
https://dlang.org/library/std/typecons/nullable.html
I implemented Handler into the Voldermort build, which Walter
loved so much. For convenience, I put an alias between the
template and the function. But Nullable didn't work, instead
it's returning T.init...
```d
template Handler(alias A)
{
alias T = typeof(A);
auto Handler()
{
struct Impl
{
T*[string] data;
void set(string key, ref T value)
{
data[key] =
}
auto opIndex(string key)
{
if (auto ret = key in data)
{
return **ret;
}
return T.init;/*
import std.typecons : Nullable;
return Nullable!T.init;//*/
}
auto opSlice()
{
T[] result;
foreach (ref value; data.values)
result ~= *value;
return result;
}
}
return Impl();
}
}
import std.stdio;
void main()
{
struct List { string product; float price; }
auto fruits = [ List("Manderin", 3.79),
List("Orange", 2.99),
List("Kiwi", 0.59),
];
auto handlers = Handler!fruits;
handlers.set("fruits", fruits);
// please try it: ^--v
foreach(h; handlers["fruit"])
{
h.product.write(": ");
h.price.writeln(" €");
}
auto handler = Handler!(List());
import std.conv : text;
foreach(i, ref fruit; fruits)
{
handler.set(i.text, fruit);
}
handler[].writeln;
} /* Prints:
Manderin: 3.79 €
Orange: 2.99 €
Kiwi: 0.59 €
[List("Kiwi", 0.59), List("Manderin", 3.79), List("Orange",
2.99)]
*/
```
SDB@79
Re: How can a function pointer required to be extern(C)?
On Wednesday, 12 April 2023 at 20:36:59 UTC, H. S. Teoh wrote:
---snip---
extern(C) void* abc(void*) {return null;}
alias FuncPtr = typeof();
You can also express it like this:
```d
extern(C) alias FuncPtr = void* function(void*);
```
Re: How can a function pointer required to be extern(C)?
On Wed, Apr 12, 2023 at 08:23:51PM +, rempas via Digitalmars-d-learn wrote:
> Sorry if the title doesn't make any sense, let me explain. So, I do have the
> following code that does not compile:
>
> ```d
> import core.sys.posix.pthread; /* The library */
>
> struct Thread {
> private:
> pthread_t thread_id;
>
> public:
> this(void* function(void*) func, void* arg = null, scope
> const(pthread_attr_t*) attr = null) {
> pthread_create(_id, attr, func, arg);
> }
>
> @property:
> pthread_t id() { return this.thread_id; }
> }
>
> ```
>
> Yes, I'm trying to "encapsulate" the Pthread (POSIX threads) API.
> Normally, the function pointer that is passed to "pthread_create" must
> be "extern(C)" and this is the complaining that the compile does. So,
> I'm thinking to replace the constructor to this:
>
> ```d
> this(extern(C) void* function(void*) func, void* arg = null,
> scope const(pthread_attr_t*) attr = null)
> { pthread_create(_id, attr, func, arg); }
> ```
>
> I just added "extern(C)" before the type. This is how it looks in the
> error message so it must work right? Well... it doesn't. And here I am
> wondering why. Any ideas?
IMO this is a bug either in D's syntax or in the parser. I'd file an
enhancement request.
In the meantime, you can use alias as a workaround:
---snip---
extern(C) void* abc(void*) {return null;}
alias FuncPtr = typeof();
pragma(msg, typeof(abc));
pragma(msg, typeof());
//void wrapper(extern(C) void* function(void*) callback) {} // NG
void wrapper(FuncPtr callback) {} // OK
pragma(msg, typeof(wrapper));
---snip---
T
--
A programming language should be a toolbox for the programmer to draw
upon, not a minefield of dangerous explosives that you have to very
carefully avoid touching in the wrong way.
How can a function pointer required to be extern(C)?
Sorry if the title doesn't make any sense, let me explain. So, I
do have the following code that does not compile:
```d
import core.sys.posix.pthread; /* The library */
struct Thread {
private:
pthread_t thread_id;
public:
this(void* function(void*) func, void* arg = null, scope
const(pthread_attr_t*) attr = null) {
pthread_create(_id, attr, func, arg);
}
@property:
pthread_t id() { return this.thread_id; }
}
```
Yes, I'm trying to "encapsulate" the Pthread (POSIX threads) API.
Normally, the function pointer that is passed to "pthread_create"
must be "extern(C)" and this is the complaining that the compile
does. So, I'm thinking to replace the constructor to this:
```d
this(extern(C) void* function(void*) func, void* arg = null,
scope const(pthread_attr_t*) attr = null)
{ pthread_create(_id, attr, func, arg); }
```
I just added "extern(C)" before the type. This is how it looks in
the error message so it must work right? Well... it doesn't. And
here I am wondering why. Any ideas?
Re: @nogc and Phobos
On Tuesday, 14 March 2023 at 20:40:39 UTC, bomat wrote: Sounds intriguing. Anything I can look at yet? Or still all top secret? :) Oh, amazing! I let you on waiting for almost a month and I wouldn't had see it if I didn't came to post another question. I'm so so sorry for the waiting, I will not even use an excuse. So, if you are willing to make an account on [Codeberg](https://codeberg.org/), the repository is private but after making the account, follow [me](https://codeberg.org/rempas) and I will give you access! Tho, you may read something cringe! Be prepared, lol!
Re: Assocative array lookup for object
On 4/12/23 04:35, Salih Dincer wrote:
> I made a little mistake and I'll fix it before someone rub nose in it :)
You asked for it! :)
>auto opIndex(string key) {
> if(auto ret = key in data)
> {
>return *ret;
> }
> return null;
>}
Not every type is null'able but nullable. ;) So, a design may use the
following:
https://dlang.org/library/std/typecons/nullable.html
Ali
Re: Mir-ion:YAML Example
On Wednesday, 12 April 2023 at 12:00:14 UTC, Vino wrote:
Hi All,
Can some point me where i can find examples on how to use
mir-ion YAML
From,
Vino.B
documentation is very sparse, but essentially with mir-ion you
import the different ser/deser packages that you would like to
use. If you for example want to deserialize YAML to a custom
struct, you use
```d
import mir.deser.yaml;
struct CustomStruct
{
string foo;
uint bar;
}
void main()
{
string yamlString = `{foo: str, bar: 4}`;
CustomStruct s = yamlString.deserializeYaml!CustomStruct;
assert(s == S("str", 4));
}
```
If you want to deserialize arbitrary values and introspect them
at runtime, you use `YamlAlgebraic` instead of `CustomStruct`,
which you can think of like std.json : JSONValue, but utilizes
mir's algebraic structures, which work more like std.sumtype.
To convert algebraic values to custom structs later, you use
mir.ion.conv : serde, which basically just internally serializes
the data and deserializes it again (but a little more efficiently)
more deserialization examples in the unittests:
https://github.com/libmir/mir-ion/blob/62c476a6a00d0d5ddfb3585bdfbe520d825e872b/source/mir/deser/yaml.d
and for serialization you use `serializeYaml` from
`mir.ser.yaml`, see
https://github.com/libmir/mir-ion/blob/62c476a6a00d0d5ddfb3585bdfbe520d825e872b/source/mir/ser/yaml.d
Mir-ion:YAML Example
Hi All, Can some point me where i can find examples on how to use mir-ion YAML From, Vino.B
Re: Using DUB packages with Meson
On Wednesday, 12 April 2023 at 11:07:56 UTC, Richard (Rikki) Andrew Cattermole wrote: Did you compile the library with dub using ldc2? Yup, I do not have other compilers installed. -- Dmitry Olshansky
Re: Assocative array lookup for object
On Wednesday, 12 April 2023 at 04:57:58 UTC, Salih Dincer wrote:
I think you want to do an encapsulation like below.
```d
auto opIndex(string key)
=> *(key in data);
```
I made a little mistake and I'll fix it before someone rub nose
in it :)
```d
auto opIndex(string key) {
if(auto ret = key in data)
{
return *ret;
}
return null;
}
assert(handler["D Lang"] == );
assert(handler["null"] is null);
```
SDB@79
Re: Using DUB packages with Meson
Did you compile the library with dub using ldc2?
Re: Using DUB packages with Meson
On Wednesday, 12 April 2023 at 10:24:48 UTC, Richard (Rikki) Andrew Cattermole wrote: I'm going to guess that you need to use the version specifier in the package name. Because I'm not seeing anything there to handle it specifically. https://github.com/mesonbuild/meson/blob/master/mesonbuild/dependencies/dub.py i.e. ``dub build [[@]] []`` So use ``package:sub@1.0.2``. Also I just noticed meson doesn't support shared libraries from dub, so something to keep in mind. I'm getting closer. I'm stuck with this at the moment: Found DUB: /home/d.olshanskiy/bin/dub (DUB version 1.31.1, built on Mar 12 2023) ERROR: strand found but it wasn't compiled with ldc Run-time dependency strand found: NO src/meson.build:22:0: ERROR: Dependency "strand" not found -- Dmitry Olshansky
Re: Using DUB packages with Meson
On Wednesday, 12 April 2023 at 10:24:48 UTC, Richard (Rikki) Andrew Cattermole wrote: I'm going to guess that you need to use the version specifier in the package name. Because I'm not seeing anything there to handle it specifically. https://github.com/mesonbuild/meson/blob/master/mesonbuild/dependencies/dub.py i.e. ``dub build [[@]] []`` So use ``package:sub@1.0.2``. Also I just noticed meson doesn't support shared libraries from dub, so something to keep in mind. Oh, Rikki, you are so helpful. Thanks! -- Dmitry Olshansky
Re: Using DUB packages with Meson
I'm going to guess that you need to use the version specifier in the package name. Because I'm not seeing anything there to handle it specifically. https://github.com/mesonbuild/meson/blob/master/mesonbuild/dependencies/dub.py i.e. ``dub build [[@]] []`` So use ``package:sub@1.0.2``. Also I just noticed meson doesn't support shared libraries from dub, so something to keep in mind.
Re: How to setup D with SFML? (using bindbc-sfml)
On Tuesday, 11 April 2023 at 10:24:09 UTC, Ki Rill wrote:
My `dub.json`:
```Json
{
"authors": [
"rillki"
],
"copyright": "Copyright © 2023, rillki",
"dependencies": {
"bindbc-sfml": "~>1.0.2"
},
"description": "D/SFML project template",
"license": "BSL",
"name": "d-sfml-project-template",
"targetPath": "bin",
"versions": [
"SFML_Audio",
"SFML_Graphics",
"SFML_Network",
"SFML_System",
"SFML_Window",
"SFML_250"
]
}
```
I will try to make it work... Meanwhile, if someones spots what
I am doing wrong, please reply to this post.
If I use your dub.json, my terminal screen says:
user@debian:~/Downloads$ cd dsfml
user@debian:~/Downloads/dsfml$ dub
Fetching bindbc-sfml 1.0.2 (getting selected version)
Fetching bindbc-loader 1.0.3 (getting selected version)
Starting Performing "debug" build using /usr/bin/dmd for
x86_64.
Building bindbc-loader 1.0.3: building configuration [noBC]
Building bindbc-sfml 1.0.2: building configuration
[dynamic]
Building d-sfml-project-template ~master: building
configuration [application]
Linking d-sfml-project-template
Running bin/d-sfml-project-template
Error Program exited with code -11
If I add "BindSFML_Static" to the DUB's version directive, I
switch to static, which I guess you don't want. But then I also
get a bunch of undefined errors:
/usr/bin/ld:
/home/user/.dub/cache/d-sfml-project-template/~master/build/application-debug-TGcRCxHHanKq_MbfWLee8g/d-sfml-project-template.o: in function `_Dmain':
/home/user/Downloads/dsfml/source/app.d:11: undefined reference
to `sfRenderWindow_create'
...
collect2: error: ld returned 1 exit status
Error: linker exited with status 1
Error /usr/bin/dmd failed with exit code 1.
If you wanted static I would add and run libraries easy, like
this:
```Json
"libs": [
"csfml-audio",
"csfml-graphics"
],
"versions": [
"SFML_Audio",
"SFML_Graphics",
"BindSFML_Static",
]
}
```
In summary, DUB takes care of everything for us. It should be
same in W$...
SDB@79
Using DUB packages with Meson
I'm trying to use my new DUB package from Photon, which is polyglot project and is built with Meson. Have anyone worked with DUB packages in Meson? I've found this bit of documentation: https://mesonbuild.com/Dependencies.html#dub And I did fetch & build but I do not understand how to introduce library dependency on a specific DUB package. -- Dmitry Olshansky
Re: learning D as your first language but having difficulty in making or logic building in order to make software
On Tuesday, 11 April 2023 at 14:13:17 UTC, slectr wrote: I want to make software like krita inkscape and my own language using D Although i previosly learned C and C++ i left it in the middle and for some reasons i dont want to learn those so i searched for alternatives and found D but there are not a lot of resources like cookbooks and videos as compared to C or C++ does anybody know any resources for making complex software in D for some practise ? Of course there are cookbooks - one even has explicitly that title! Have a look on forum.dlang.org under Resources/Books.
Re: Help with registering dub package
On Wednesday, 12 April 2023 at 08:25:54 UTC, Richard (Rikki) Andrew Cattermole wrote: Your branches + tag is all messed up. You have both ~master and ~main. ~main has dub.json (which is required), but the tag is based upon ~master which has your README. Between the two branches everything is there, its just that it needs to be all in one. Thanks, Rikki! — Dmitry Olshansky
Re: Help with registering dub package
Your branches + tag is all messed up. You have both ~master and ~main. ~main has dub.json (which is required), but the tag is based upon ~master which has your README. Between the two branches everything is there, its just that it needs to be all in one.
Help with registering dub package
Could someone walk me through the steps of publish my dub package? I'm stuck with this: https://code.dlang.org/packages/strand For some reason code.dlang.org cannot find my semver tag I guess. -- Dmitry Olshansky
