Re: DlangUI Error
On Friday, 11 August 2017 at 02:25:51 UTC, Mike Parker wrote: On Thursday, 10 August 2017 at 23:38:42 UTC, Jiyan wrote: [...] Sounds like you used the script from the download page that installs the compiler per user. It's designed to allow you to have multiple versions installed in your user directory and requires you to specify which version you want to activate. You could probably configure your bash shell to activate dmd when you launch it, or you could install dmd via the .deb or .rpm, assuming you're on a Linux flavor. Ok thanks :)
DlangUI Error
Hey, i get the following errors when i try to use dlangui, by just importing the package i get a lot of errors which look like: function std.xml.Item.opEquals does not override any function, did you mean to override 'object.Object.opEquals'? What is happening there?
Re: DlangUI Error
On Thursday, 10 August 2017 at 22:27:44 UTC, HyperParrow wrote: On Thursday, 10 August 2017 at 20:48:23 UTC, Jiyan wrote: Hey, i get the following errors when i try to use dlangui, by just importing the package i get a lot of errors which look like: function std.xml.Item.opEquals does not override any function, did you mean to override 'object.Object.opEquals'? What is happening there? The error message is correct but the error is only recognized by the compiler since the latest release. To fix it requires intervention of the author: either "override" must be removed from the opEquals that's indicated or the opEquals parameters must be changed o match exactly the signature used on Object.opEquals. Until this is done in libdlangui you can use an older compiler, e.g last 2.074.x release should make the error disappearing (since it wasn't detected yet). Hey thank you for your reply :) So the strange thing is i had an older compiler (v2.074.1), so i started running the 2.075 version - with which it worked! The thing is i can start the 2.075 version only over the activate.sh script in a shell. Can you tell me how i can really use the 2.075 version (without having to run the script each time i open a shell, and why do i have to do that).
Vectorflow noob
Hey,
wanted to the following simple thing with vectorflow:
I want to develop a simple MLP, which has 2 input neurons and one
output neuron.
The network should simply add the input values together, so [1,2]
predicts [3] i guess.
I started in a newbish way to build the following code:
import vectorflow;
struct Obs // The represeneted data
{
float label; // Did i get that right that label would be the
DESIRED output (3=1+2)
float []features; // The features are the input i guess, so
features = f.e. [1,2]
}
void main()
{
auto net = NeuralNet()
.stack(DenseData(2))
.stack(Linear(10)); // Is this the right way to construct
the Net?
// The training data
Obs []data;
data.length = 10;
import std.random;
import std.algorithm;
foreach(ref Obs n; data)
{
// The features are getting fille with random numbers between
0.5 and 5
// The label becomes the sum of feature[0] and feature[1]
n.features.length = 2;
n.features[0] = uniform(0.5, 5);
n.features[1] = uniform(0.5, 5);
n.label = n.features.sum;
writeln(n.features[0], " ", n.features[1], " ", n.label);
assert (n.label == n.features[0] + n.features[1]);
}
net.learn(data, "logistic", AdaGrad(10, 0.1, 500), true, 3);
auto val = net.predict(data[0]); // is this wrong?
val.writeln;
}
Thanks :)
Re: Struct Constructor Lazy
On Wednesday, 12 July 2017 at 11:18:08 UTC, Biotronic wrote:
On Wednesday, 12 July 2017 at 11:00:54 UTC, Jiyan wrote:
[...]
The traditional solution is static opCall:
struct A {
int field;
static A opCall() {
A result;
result.field = getDataFromFile("file.txt");
return result;
}
}
A instance = A();
I believe I've heard this is frowned upon these days, but I
don't know of a better solution.
For optimal speed you might also want to skip default
initialization of result, by writing A result = void;.
I would be surprised if the optimizer wasn't able to optimize
away the useless parameter though - have you looked at the
generated assembly?
--
Biotronic
Hey,
yes i did but to be honest i used dmd in debug version.
The thing about the static one, is that it creates a local object
A isnt that a performance issue itself - or am i wrong - im
confused actually :P?
Re: Struct Constructor Lazy
Thank you, one last question: If i declare the parameter as ref i, then there shouldnt be any overhead wouldnt it? Thanks :)
Struct Constructor Lazy
Hey there:)
i want to know whether the following is somehow possible:
structs dont have default constructors, i know so:
struct A
{
int field;
this(int i){field = getDataFromFile("file.txt");}
}
A instance = A(0);
Here comes my issue:
when A(0) is called I would want here optimal performance, so
there doesnt even need to be a value pushed on the stack (i=0),
what would be like having a constructor with zero arguments (i is
never used!).
Im pretty new to D, can somebody tell me how i would do this?
Is this(lazy int i){ ... a solution?
Struct Postblit Void Initialization
Hey,
just wanted to know whether something like this would be possible
sowmehow:
struct S
{
int m;
int n;
this(this)
{
m = void;
n = n;
}
}
So not the whole struct is moved everytime f.e. a function is
called, but only n has to be "filled"
Re: Struct Postblit Void Initialization
On Sunday, 30 July 2017 at 19:32:48 UTC, Eugene Wissner wrote:
On Sunday, 30 July 2017 at 19:22:07 UTC, Jiyan wrote:
Hey,
just wanted to know whether something like this would be
possible sowmehow:
struct S
{
int m;
int n;
this(this)
{
m = void;
n = n;
}
}
So not the whole struct is moved everytime f.e. a function is
called, but only n has to be "filled"
this(this) is called after the struct is copied. Doing
something in the postblit constructor is too late. The second
thing is that the struct is copied with memcpy. What you
propose would require 2 memcpy calls to copy the first part of
the struct and then the second part. Besides it is difficult to
implement, it may reduce the performance of the copying since
memcpy is optimized to copy memory chunks.
Ok thank you :)
Imports
Hey, as i see it the -Ipath command for dmd just imports the files within a directory but it doesnt work for sub directories, so i can write something like: import subdirectoryFromPath.file; Also with dub this doesnt seem possible (sourcePaths seems to work as the -I command). Is there a way to do what i want? Or am i doing something wrong? And by the way what is the difference from sourcePaths to importPaths?
Re: Imports
On Thursday, 5 October 2017 at 00:28:32 UTC, Mike Parker wrote: On Wednesday, 4 October 2017 at 16:31:35 UTC, Jiyan wrote: [...] If you have this directory tree: - mylib -- pack1 --- a.d --- b.d pack2 - c.d [...] Thank you, i think i kinda got that :) But as i see it with sourcePaths the directories are not influencing the module names(in the directories except "source"), so "dir.sub" will just have the name "sub" is there a way around that, except naming every module like: module dir.sub;
Re: Imports
On Thursday, 5 October 2017 at 12:35:26 UTC, Mike Parker wrote: On Thursday, 5 October 2017 at 12:25:27 UTC, Mike Parker wrote: [...] Right. I had to go back and look at what I wrote in Learning D, which is the last (and only) time I played around with the default module behavior. I always use module statements (and you should too). [...] Thank you :) PS: is it spam to say thank you?
Re: Anonymous nogc class
On Friday, 8 September 2017 at 06:37:54 UTC, Biotronic wrote: On Thursday, 7 September 2017 at 23:40:11 UTC, Jiyan wrote: [...] Sadly, even std.typecons.scoped isn't currently @nogc: https://issues.dlang.org/show_bug.cgi?id=13972 https://issues.dlang.org/show_bug.cgi?id=17592 [...] First thanks :) i understand the part with scopedAnon, but can you explain what the ~this is referring to? Is it the Modul destructor? And in general is it just that scoped is just not marked @nogc or is it that it would really need to use the gc?
Re: Anonymous nogc class
On Friday, 8 September 2017 at 16:10:55 UTC, Biotronic wrote: On Friday, 8 September 2017 at 12:32:35 UTC, Jiyan wrote: [...] It's scoped!T's destructor. If you decide to use that workaround, you should probably copy scoped!T from std.typecons and have your own version. It's not safe in all cases, and the next standard library update might break it. [...] In your case, scoped!T is can be safely called from @nogc code, and thus could be marked @nogc. However, when a class C has a destructor that allocates, scoped!C could not be @nogc. So in order to be safe in all cases, it can't be @nogc in the general case. -- Biotronic Thank you very much :)
Anonymous nogc class
Hey,
wanted to know whether it is possible to make anonymous nogc
classes:
interface I
{
public void ap();
}
void exec(I i)
{
i.ap;
}
// now execute, but with something like `scope`
exec( new class I
{
int tr = 43;
override void ap(){tr.writeln;}
});
Thanks :)
Re: Template Question
With working i mean that Text X; Doesnt compile!
Re: Template Question
On Sunday, 19 November 2017 at 19:42:02 UTC, Jonathan M Davis wrote: On Sunday, November 19, 2017 19:25:40 Jiyan via Digitalmars-d-learn wrote: [...] Okay. For starters, [...] Ah ok thanks very much, this helped me a lot :)
Template Question
Hello,
i wanted to ask why this isnt working:
struct Text(T : char)
{
size_t _len;
T* _ptr;
}
Thanks :)
Re: Template Question
On Sunday, 19 November 2017 at 19:28:37 UTC, Jonathan M Davis
wrote:
On Sunday, November 19, 2017 19:22:51 Jiyan via
Digitalmars-d-learn wrote:
Hello,
i wanted to ask why this isnt working:
struct Text(T : char)
{
size_t _len;
T* _ptr;
}
Thanks :)
What about it isn't working? I think that you need to explain
what you're trying to do and what you think that this code
should be doing but isn't.
- Jonathan M Davis
Text X;
Here X would be an Object from type Text with T being char when
i'm right.
But this doesn't compile!
Thanks :)
Rvalue references
Sry i know i asked it already in IRC: Are rvalue references already solved with auto ref? https://p0nce.github.io/d-idioms/#Rvalue-references:-Understanding-auto-ref-and-then-not-using-it Says rvalues are moved! The other solution seems not so practical. Is any solution to them intended, or was all the talk about rvalue references simply discarded? Thanks :)
Trait compiles
Hello,
is there anyway to do something like this:
mixin template foo( exp)
{
static if(__traits(compiles, exp))exp;
}
Thanks :)
Implicit conversion
Hello,
I want to convert from ints implicit to a struct type, so for
example:
struct use
{
int x;
int toInt()
{
return x;
}
use fromInt(int v)
{
return use(v);
}
alias toInt this; // implicit conversion to int value
this(int v)
{x = v;}
}
void useP(int v)
{
v.writeln;
}
void useV(use v)
{
v.writeln;
}
void main(string[] args)
{
use a = use(2);
//useP(a);
useV(2); // how can i let this work?
}
Thanks :)
Re: Interactive Interpreter
On Tuesday, 6 February 2018 at 01:23:57 UTC, Stefan Koch wrote: On Monday, 5 February 2018 at 19:54:09 UTC, Jiyan wrote: Is there any work for an interactive interpreter for D -maybe just for ctfe-able expressions? It shouldnt be too hard to implement it regarding the fact, that ctfe is kinda doing what an interpreter should do i guess. There is https://github.com/dlang-community/drepl which should give you what you want. As the person who builds newCTFE I can tell you that it is rather tricky :) Thank you very much :)
Interactive Interpreter
Is there any work for an interactive interpreter for D -maybe just for ctfe-able expressions? It shouldnt be too hard to implement it regarding the fact, that ctfe is kinda doing what an interpreter should do i guess.
Destructing Struct
Hi :),
What i thought was that when i create a struct dynamically i can
just deconstruct it with __dtor lets say:
struct U {...}
struct S {... private U _member;}
S* p;
p = cast(S*)malloc(S.sizeof);
// just run that if it compiles, for simplicity
// we dont use __traits(compiles, ...)
p.__dtor;
The thing here is that this doesn't work because of when S has an
element that that is private and has a __dtor itself, the __dtor
from U doesnt get called before the call of __dtor from S - or
after.
Is there any way with traits or sth to do that?
Are delete, destroy or any other functions the standard library
working here?
I would prefer a solution that can be build by myself - so
without the standard library for example with traits.
Thanks :)
Re: Destructing Struct
On Wednesday, 21 February 2018 at 11:12:01 UTC, Jiyan wrote:
Hi :),
What i thought was that when i create a struct dynamically i
can just deconstruct it with __dtor lets say:
struct U {...}
struct S {... private U _member;}
S* p;
p = cast(S*)malloc(S.sizeof);
// just run that if it compiles, for simplicity
// we dont use __traits(compiles, ...)
p.__dtor;
The thing here is that this doesn't work because of when S has
an element that that is private and has a __dtor itself, the
__dtor from U doesnt get called before the call of __dtor from
S - or after.
Is there any way with traits or sth to do that?
Are delete, destroy or any other functions the standard library
working here?
I would prefer a solution that can be build by myself - so
without the standard library for example with traits.
Thanks :)
I think i found my solution: is it __xdtor? :P
Forward references
Hi,
is there any document or text describing forward references?
It is kinda strange, i implemented a list structure which is
kinda like this:
struct list(T)
{
private:
struct node
{
T val;
node* next;
node* prev;
}
node* head;
node* last;
size_t size;
.
}
The thing is when i implement following struct:
struct Tre
{
list!Tre a;
}
theoretically it should be constructable. But it gives me out a
compiler error about Forward reference. Ok maybe the compiler at
this point cant do that but ...
The strange thing is i somehow managed earlier without knowing to
do exactly this in a much more complicated struct.
Can somebody enlighten me about this?
Re: Forward references
On Sunday, 25 February 2018 at 22:20:13 UTC, Steven Schveighoffer wrote: On 2/25/18 4:25 PM, Jiyan wrote: [...] Looks like this was fixed in 2.064. What version of the compiler are you using? -Steve 2.077.0 It is really strange, it works now but there still seems to be some strangeness about forward references. Thanks till now i guess :P
Postblit constructor
Hey,
i thought i had understood postblit, but in my Code the following
is happening (simplified):
struct C
{
this(this){/*Do sth*/}
list!C;
void opAssign(const C c)
{
"Postlbit from C called".writeln;
// Do sth
}
}
struct list(T)
{
node* head;
node* last;
size_t size;
struct node
{
T val;
node* next;
node* prev;
void deleteNode()
{
static if(!isPointer!T){
static if(__traits(compiles,val.__xdtor))val.__xdtor;
}
}
void constructNodeFrom(ref const T op)
{
static if(isPointer!T)
{
val = cast(T) op;
}
else
{
val.opAssign(op);
}
}
~this(){this.erase}
/// Methods Add, Remove, erase are implemented here ...
}
The nodes are only allocated over malloc(). So i have to take
care of the initioalisation myself.
The problem is, that i found out by debugging, that it seems that
when i call val.opAssign(op) in constructNodeFrom(), there isnt
any postblit constructor called in there, the struct seems just
to get copied by a memcpy, can that be? Or is it a bug? Shouldnt
the postblit constructor get called there?
Greetings
Re: Postblit constructor
On Wednesday, 28 February 2018 at 18:23:04 UTC, Jiyan wrote:
Hey,
i thought i had understood postblit, but in my Code the
following is happening (simplified):
struct C
{
this(this){/*Do sth*/}
list!C;
void opAssign(const C c)
{
"Postlbit from C called".writeln;
// Do sth
}
}
Sry of course it is
"Postlbit from C called".writeln; in this(this)
and the c from opAssign should get constructed via postblit.
Doesnt it?
