Why TypeTuple can be assigned to a variable
Hi!
I was just surprised when realized, that this code compiles and
runs:
import std.typetuple;
import std.stdio;
void main()
{
auto foo = TypeTuple!(foo,bar);
writeln(typeid(typeof(foo)));
writeln(foo);
}
If I were compiler expert,I'd say that it's a bug.But I am not)
So, can anybody explain why it's work?
Thank you.
Re: Why TypeTuple can be assigned to a variable
On Wednesday, 12 June 2013 at 08:14:06 UTC, Simen Kjaeraas wrote:
On Wed, 12 Jun 2013 10:01:59 +0200, Zhenya zh...@list.ru
wrote:
Hi!
I was just surprised when realized, that this code compiles
and runs:
import std.typetuple;
import std.stdio;
void main()
{
auto foo = TypeTuple!(foo,bar);
writeln(typeid(typeof(foo)));
writeln(foo);
}
If I were compiler expert,I'd say that it's a bug.But I am not)
So, can anybody explain why it's work?
It is the equivalent of:
TypeTuple!(string, string) foo;
foo[0] = foo;
foo[1] = bar;
The ability to have a tupetuple as a variable is very useful -
if that
had not been possible one would need something akin to this:
struct Tuple(T...) {
T[0] head;
static if (T.length) {
Tuple!(T[1..$]) tail;
}
}
And to access the third element of a tuple one'd need to write:
myTuple.tail.tail.head = foo;
Clearly this is suboptimal, so D has better ways of doing such
things.
OK,you say that TypeTuple!(foo,bar) is a cool value of type
TypeTuple!(string,string),right?
Then could you tell me what type has [TypeTuple!(foo,bar)]?
Currently it is evaluated to string[].And I think if TypeTuple
had value semantic, this type would be TypeTuple!(...)[].
This behaviour confuses me a bit.
And I just don't understand why do we need TypeTuple's value
semantic
to implement std.Tuple,because AFAIK it use variadic template
parameter pack
!= TypeTuple.
Sorry for my english.
Re: Why TypeTuple can be assigned to a variable
On Wednesday, 12 June 2013 at 10:09:07 UTC, Simen Kjaeraas wrote:
On Wed, 12 Jun 2013 11:44:19 +0200, Zhenya zh...@list.ru
wrote:
OK,you say that TypeTuple!(foo,bar) is a cool value of type
TypeTuple!(string,string),right?
Well, yes and no, not really. It's a bit magical. In your case,
it's assigned to an auto variable, and that variable gets that
type.
There are other ways to use a TypeTuple where it has other
semantics,
as you write yourself.
As explained below, a TypeTuple is just a bag of template
parameters,
and thus obeys the rules for a bag of template parameters.
This behaviour confuses me a bit.
Understandable. It's not entirely straightforward, because the
concerns of usability weigh heavier than those of consistency.
And I just don't understand why do we need TypeTuple's value
semantic
to implement std.Tuple,because AFAIK it use variadic template
parameter pack
!= TypeTuple.
The definition od std.typetuple.TypeTuple is:
template TypeTuple(T...){
alias TypeTuple = T;
}
So a TypeTuple is exactly the same as a variadic template
parameter pack.
Sorry for my english.
No need to be, your English is great.
Thank you for your explaination,I understand.
Re: issue 9122
On Sunday, 12 May 2013 at 10:49:40 UTC, Tofu Ninja wrote: http://d.puremagic.com/issues/show_bug.cgi?id=9122 Is anyone working on this or know of a work around, it is breaking my project and I can't move on until its fixed. see http://forum.dlang.org/thread/puqbpycvisbjrahao...@forum.dlang.org
Re: Collections
On Tuesday, 12 March 2013 at 11:57:29 UTC, ZILtoid1991 wrote: Is there any equaliaments of java collections in D? https://github.com/Domain/java/tree/master/java
Re: Collections
On Tuesday, 12 March 2013 at 12:02:03 UTC, Zhenya wrote: On Tuesday, 12 March 2013 at 11:57:29 UTC, ZILtoid1991 wrote: Is there any equaliaments of java collections in D? https://github.com/Domain/java/tree/master/java Oh sorry,it seems to be unfinished.
Re: question with compile-time reflection
And since alias can represent any symbol,i think that it's correct usage.
Re: question with compile-time reflection
On Monday, 11 March 2013 at 00:10:46 UTC, Rob T wrote: template NDimensionalArrayType(T,alias size) I'm wondering what alias size does? I can't find that form documented anywhere, but it seems to be valid. Thanks. --rt It's just a little hack for known bug - only string and integer value can be passed into template. size is array,and it's really size of n-dimensional array,every element matches its dimension.
question with compile-time reflection
Hi!
this code fails with message:NDimensionalArray.doIndex(Array) if
(is(Array _ : NDimensionalArrayType!(T,s),const(int[]) s)) cannot
deduce template function from argument types
!()(int[2u][2u],const(int[]))
Tell me please,am I wrong?
And if yes,what should I change to make it work?
template NDimensionalArrayType(T,alias size)
if(is(typeof(size) _ : const int[]) size.length 0)
{
static if(size.length 1)
alias NDimensionalArrayType!(T,size[1..$])[size[0]]
NDimensionalArrayType;
else
alias T[size[0]] NDimensionalArrayType;
}
struct NDimensionalArray(T,alias size)
{
private NDimensionalArrayType!(T,size) m_array;
static ref T doIndex(Array)(Array array,const int[] index) //HERE
if(is(Array _ : NDimensionalArrayType!(T,s),const int[] s))
{
assert(index.length == s.length);
if(index.length == 1)
return array[index[0]];
else
return doIndex(array[index[0]],index[1..$]);
}
ref T opIndex(const int[] index)
{
return doIndex(m_array,index);
}
alias m_array this;
}
void main()
{
NDimensionalArray!(int,[2,2]) array;
}
Re: question with compile-time reflection
On Saturday, 9 March 2013 at 23:05:56 UTC, Ivan Kazmenko wrote:
this code fails with message:NDimensionalArray.doIndex(Array)
if (is(Array _ : NDimensionalArrayType!(T,s),const(int[]) s))
cannot deduce template function from argument types
!()(int[2u][2u],const(int[]))
Tell me please,am I wrong?
And if yes,what should I change to make it work?
I'm no D expert, but here's what I got.
1. One problem is returning the wrong type from doIndex. When
the condition if(index.length == 1) is false, the subsequent
line is still compiled but fails to return a ref T since
array[index[0]] is an array of T, not a T.
The correct way (and better for performance, too) would be a
compile-time static if there, like in the code below. (I
don't quite get the syntax of the template constraint for
doIndex, so I've just commented that out for now.)
2. The next problem is that fixed-size arrays obey value
semantics, so they should be passed by reference and not by
value.
Here's what works for me (DMD 2.062):
-
import std.stdio;
template NDimensionalArrayType(T,alias size)
if(is(typeof(size) _ : const int[]) size.length 0)
{
static if(size.length 1)
alias NDimensionalArrayType!(T,size[1..$])[size[0]]
NDimensionalArrayType;
else
alias T[size[0]] NDimensionalArrayType;
}
struct NDimensionalArray(T,alias size)
{
private NDimensionalArrayType!(T,size) m_array;
static ref T doIndex(Array)(ref Array array,const int[] index)
//HERE
// if(is(Array _ : NDimensionalArrayType!(T,s),const int[] s))
{
// assert(index.length == s.length);
assert(index.length = size.length);
debug {writefln(doIndex (%s, %s = %s),
typeof(array).stringof,
typeof(index).stringof,
index);}
static if(is(Array : T[]))
{
assert(index.length == 1);
return array[index[0]];
}
else
{
assert(index.length 1);
return doIndex(array[index[0]],index[1..$]);
}
}
ref T opIndex(const int[] index)
{
return doIndex(m_array,index);
}
alias m_array this;
}
void main()
{
NDimensionalArray!(int,[5,2]) array;
array[[4,1]] = 1;
assert(array[[4,1]] == 1);
}
-
With the debug mode on, it successfully prints the following:
-
doIndex (int[2u][5u], const(int[]) = [4, 1])
doIndex (int[2u], const(int[]) = [1])
doIndex (int[2u][5u], const(int[]) = [4, 1])
doIndex (int[2u], const(int[]) = [1])
-
On a side note, this still looks like too much effort to do one
opIndex in terms of performance. I doubt that any current
compiler would optimize all that into a simple multiply +
bounds-check + add loop.
-
Ivan Kazmenko.
Thank you very much for your time)
Your answer is very useful.
Re: question with compile-time reflection
Although of course I would want to know what's wrong with constrait,because it protect doArray against incorrect using. I don't worry about effiency very much,I just wanted to right n-dimensional tree of intervals.And for doing it I needed n-dimensional array with opIndex like it.
Re: question with compile-time reflection
On Saturday, 9 March 2013 at 23:40:25 UTC, Zhenya wrote: Although of course I would want to know what's wrong with constrait,because it protect doArray against incorrect using. I don't worry about effiency very much,I just wanted to right n-dimensional tree of intervals.And for doing it I needed n-dimensional array with opIndex like it. sorry for my english(
typeof([2,2]) !=? int[2]
Hi!
Explain me please,what's wrong with this code:
struct NDimensionalArray(T,alias size)
if(is(typeof(size) _ == int[n],int n)
n 0)
{
static if(n 1)
NDimensionalArray!(T,n - 1,size[1..$]) m_array[size[0]];
else
T m_array[size[0]];
alias m_array this;
}
void main()
{
NDimensionalArray!(int,[2,2]) array;
array[0][1] = 1;
}
It fails with message:
Error: template instance NDimensionalArray!(int, [2, 2])
NDimensionalArray!(int, [2, 2]) does not match template
declaration NDimensionalArray(T, alias size) if (is(typeof(size)
_ == int[n],int n) n 0)
on dmd git-head.
Re: typeof([2,2]) !=? int[2]
On Friday, 8 March 2013 at 22:59:40 UTC, bearophile wrote: This is an answer to just your title question. A lot of time ago typeof([2,2]) was int[2]. This was efficient, but in most cases this was a source of troubles and bugs. So now a [2,2] is a heap-allocated dynamic array of type int[]. Some persons have askes for a fixed-sized array litera, like s[2,2] but nothing has happened on this so far. Bye, bearophile Thank you very much.
Re: typeof([2,2]) !=? int[2]
On Friday, 8 March 2013 at 23:03:47 UTC, Zhenya wrote: On Friday, 8 March 2013 at 22:59:40 UTC, bearophile wrote: This is an answer to just your title question. A lot of time ago typeof([2,2]) was int[2]. This was efficient, but in most cases this was a source of troubles and bugs. So now a [2,2] is a heap-allocated dynamic array of type int[]. Some persons have askes for a fixed-sized array litera, like s[2,2] but nothing has happened on this so far. Bye, bearophile Thank you very much. Although it's a bit strange,since we can always pass heap allocated array by using new.
Re: typeof([2,2]) !=? int[2]
On Friday, 8 March 2013 at 23:09:07 UTC, cal wrote: On Friday, 8 March 2013 at 23:03:47 UTC, Zhenya wrote: Your constraint could be: if(is(typeof(size) _ == int[]) size.length 0) Also it looks like you are passing 1 too many template args? static if(n 1) NDimensionalArray!(T,n - 1,size[1..$]) m_array[size[0]]; ^^ Yes,it's a typo.But it seems to be ugly pass dynamically allocated array through a template parameter,because it's size should be compile-time constant.
Re: typeof([2,2]) !=? int[2]
On Friday, 8 March 2013 at 23:18:52 UTC, cal wrote: On Friday, 8 March 2013 at 23:15:30 UTC, Zhenya wrote: Yes,it's a typo.But it seems to be ugly pass dynamically allocated array through a template parameter,because it's size should be compile-time constant. Its size is a compile-time constant because it is an array literal. The size is known inside the constraint. Yes,really. I thought that dynamic allocation is runtime operation
Re: Automatic dynamic dispatch
On Wednesday, 6 February 2013 at 04:37:17 UTC, Andrej Mitrovic
wrote:
Someone asked about how to invoke a function with the dynamic
type of
an object. Essentially the user wanted to implement functions
external
to a class without touching the class vtable (he might not have
access
to it if it's in another library), but he explicitly wanted to
work on
the derived type and not the base type, for example:
class A { }
class B : A { }
class C : B { }
void foo(B b) { } // requires B or derived from B, not A
void foo(C c) { } // requires C or derived from C, not A
Since all classes have a TypeInfo_Class associated with them,
we can
create a few helper templates which figure out the entire class
tree
from a set of leaf classes, and then tries to dynamically
dispatch to
the appropriate function at runtime.
Here's the code to do just that: http://dpaste.dzfl.pl/8338067b
And pasted here for convenience:
import std.stdio;
import std.typetuple;
import std.traits;
import std.string;
class A { }
class B : A { }
class C : B { }
class D : B { }
template ClassTreeImpl(Leaves...)
{
static if (Leaves.length 1)
{
alias TypeTuple!(Leaves[0],
BaseClassesTuple!(Leaves[0]),
ClassTreeImpl!(Leaves[1..$]))
ClassTreeImpl;
}
else
static if (Leaves.length == 1)
{
alias TypeTuple!(Leaves[0],
BaseClassesTuple!(Leaves[0])) ClassTreeImpl;
}
else
{
alias TypeTuple!() ClassTreeImpl;
}
}
template ClassTree(Leaves...)
{
alias
DerivedToFront!(NoDuplicates!(ClassTreeImpl!(Leaves)))
ClassTree;
}
void callFunc(alias func, Args...)(Args args)
if (Args.length = 1 is(Args[0] == class))
{
auto objInfo = typeid(args[0]);
foreach (Base; ClassTree!(C, D))
{
if (objInfo == Base.classinfo)
{
static if (__traits(compiles, // avoid CT errors
due to
unrolled static foreach
{ return func(cast(Base)(cast(void*)args[0]),
args[1..$]); }() ))
{
return func(cast(Base)(cast(void*)args[0]),
args[1..$]);
}
}
}
assert(0, format(function '%s' is not callable with object
of
dynamic type '%s',
__traits(identifier, func),
objInfo.toString()));
}
void foo(C c, int x) { writefln(foo(C) : received %s, x); }
void foo(D d, int x, int y) { writefln(foo(D) : received %s
%s, x, y); }
void main()
{
A c = new C;
A d = new D;
A a = new A;
callFunc!foo(c, 1);// ok
callFunc!foo(d, 2, 3); // ok
callFunc!foo(a, 3);// will assert at runtime
}
It would have been a good blog entry, but I don't blog so.. :)
Hi!
When I read your post I remembered,that some time ago I had
written in D
an n-dimensional dispatcher simular to the one,described by
Andrei in Modern C++ Design.But my dispatcher allow casting of
arguments:
import std.stdio;
class Foo {}
class Bar : Foo {}
class Gun {}
void main()
{
Dispatcher!2 d;
d.add((Foo f,Gun g) {writeln(FooXGun)});
d(new Bar,new Gun);//prints FooXGun,because Bar can be
converted to Foo
}
Maybe my code has more mixin's than needed,but it works,and it
has some disadvantages,but
I would be glad if it was useful:
http://dpaste.dzfl.pl/2ff50a12
Re: Building DFL
On Friday, 25 January 2013 at 09:07:44 UTC, SaltySugar wrote: On Friday, 25 January 2013 at 09:06:30 UTC, SaltySugar wrote: Hey guys. I have a problem when building DFL. My Console: C:\D\dmd2\packages\dfl\examples\d2dfl hello.d DFL lib files not found. Would you like to build the DFL lib files now? [Y/n] I press y. Then: Compiling debug DFL... C:\D\dmd2\import\dflC:\D\dmd2\windows\bin\dmd -c -debug -g -I.. all.d base.d application.d internal/dlib.d internal/clib.d internal/utf.d internal/com.d con trol.d form.d registry.d drawing.d menu.d notifyicon.d commondialog.d filedialog .d folderdialog.d panel.d textbox.d richtextbox.d picturebox.d listbox.d groupbo x.d splitter.d usercontrol.d button.d label.d collections.d internal/winapi.d in ternal/wincom.d event.d socket.d timer.d environment.d messagebox.d tooltip.d co mbobox.d treeview.d tabcontrol.d colordialog.d listview.d data.d clipboard.d fon tdialog.d progressbar.d resources.d statusbar.d imagelist.d toolbar.d application.d(1845): Deprecation: use of typedef is deprecated; use alias instea d application.d(1845): Deprecation: use of typedef is deprecated; use alias instea d internal\winapi.d(1726): Deprecation: use of typedef is deprecated; use alias in stead internal\winapi.d(1726): Deprecation: use of typedef is deprecated; use alias in stead socket.d(89): Error: module intrinsic is in file 'std\intrinsic.d' which cannot be read import path[0] = .. import path[1] = C:\D\dmd2\windows\bin\..\..\src\phobos import path[2] = C:\D\dmd2\windows\bin\..\..\src\druntime\import Failed. Done. Could Not Find C:\D\dmd2\import\dfl\*.obj DFL lib files not found. Error: dfl_debug.lib not found How to fix It? :( I'm using dmd 2.061 Maybe you tried to compile an old version of dfl.If yes,try this: https://github.com/Rayerd/dfl
Re: Building DFL
Which version of dmd are you using?
Re: Building DFL
On Friday, 25 January 2013 at 10:17:48 UTC, SaltySugar wrote: On Friday, 25 January 2013 at 10:15:33 UTC, Zhenya wrote: Which version of dmd are you using? dmd 2.061. I tried building DFL on dmd 2.059 too. I am using dmd 2.060. I just have built it. Try to open ...\dfl-master\win32\dfl\makelib.bat
Re: Building DFL
On Friday, 25 January 2013 at 10:21:27 UTC, Zhenya wrote: On Friday, 25 January 2013 at 10:17:48 UTC, SaltySugar wrote: On Friday, 25 January 2013 at 10:15:33 UTC, Zhenya wrote: Which version of dmd are you using? dmd 2.061. I tried building DFL on dmd 2.059 too. I am using dmd 2.060. I just have built it. Try to open ...\dfl-master\win32\dfl\makelib.bat If the same error occur,you should edit the file environment.d
Re: Building DFL
On Friday, 25 January 2013 at 10:28:26 UTC, SaltySugar wrote: On Friday, 25 January 2013 at 10:21:27 UTC, Zhenya wrote: On Friday, 25 January 2013 at 10:17:48 UTC, SaltySugar wrote: On Friday, 25 January 2013 at 10:15:33 UTC, Zhenya wrote: Which version of dmd are you using? dmd 2.061. I tried building DFL on dmd 2.059 too. I am using dmd 2.060. I just have built it. Try to open ...\dfl-master\win32\dfl\makelib.bat Maybe I don't know how to install it? I replaced C:\D\dmd2\import\dfl with dfl_master\win_32\dfl Then copied dfl_master\win_32\dflexe to C:\D\dmd2\import I installed it correctly? Sorry I am not very familiar with that. But I build it succefuly by only executing ...\dfl-master\win32\dfl\makelib.bat. Your errors may be caused by new dmd In that case you should manually change the file environment.d and everything will be allright.
Re: Building DFL
On Friday, 25 January 2013 at 10:37:00 UTC, SaltySugar wrote:
On Friday, 25 January 2013 at 10:33:42 UTC, Zhenya wrote:
On Friday, 25 January 2013 at 10:28:26 UTC, SaltySugar wrote:
On Friday, 25 January 2013 at 10:21:27 UTC, Zhenya wrote:
On Friday, 25 January 2013 at 10:17:48 UTC, SaltySugar wrote:
On Friday, 25 January 2013 at 10:15:33 UTC, Zhenya wrote:
Which version of dmd are you using?
dmd 2.061. I tried building DFL on dmd 2.059 too.
I am using dmd 2.060.
I just have built it.
Try to open
...\dfl-master\win32\dfl\makelib.bat
Maybe I don't know how to install it? I replaced
C:\D\dmd2\import\dfl with dfl_master\win_32\dfl
Then copied dfl_master\win_32\dflexe to C:\D\dmd2\import
I installed it correctly?
Sorry I am not very familiar with that.
But I build it succefuly
by only executing ...\dfl-master\win32\dfl\makelib.bat.
Your errors may be caused by new dmd
In that case you should manually change the file environment.d
and everything will be allright.
maybe you can send me yours environment.d file?
My is the same.I just use dmd 2.060.
But it is quite simple to edit it.
I think you should just add goto statements:
int a = 1;
switch(a)
{
case 1:
goto case 2;
case 2:
{}
goto default;
default:
{}
}
Sorry if I am useless(
Re: D popularity
Oh? What's so unreliable about delegates? I find that they work quite well in general. This for example: http://d.puremagic.com/issues/show_bug.cgi?id=5710
enum function can't be passed into template?
Hi!
Am I doing something wrong?
import std.stdio;
template gun(alias f)
{
void gun()
{
f();
}
}
void main()
{
auto str = hello;
enum fun = (){writeln(str);};//replace enum - auto to compile
gun!fun();
}
Error:delegate c634.main.__lambda1 is a nested function and
cannot be accessed from c634.gun!(delegate @system void()
{
writeln(str);
}
).gun
Re: enum function can't be passed into template?
On Sunday, 20 January 2013 at 14:51:51 UTC, Philippe Sigaud wrote:
On Sun, Jan 20, 2013 at 3:21 PM, Zhenya zh...@list.ru wrote:
Hi!
Am I doing something wrong?
import std.stdio;
template gun(alias f)
{
void gun()
{
f();
}
}
void main()
{
auto str = hello;
enum fun = (){writeln(str);};//replace enum - auto to
compile
gun!fun();
}
fun depends on str, which is a runtime value. Either make str
an enum
or put them in the module scope (which will make the auto's
enum's)
Thank you!
Re: does alias this work correctly?
On Sunday, 13 January 2013 at 22:36:03 UTC, Jonathan M Davis wrote: On Sunday, January 13, 2013 20:41:48 Zhenya wrote: On Sunday, 13 January 2013 at 19:35:08 UTC, Maxim Fomin wrote: According to spec http://dlang.org/class.html#AliasThis undefined lookups are forwarded to AliasThis member. But in your case Foo struct has bar member, so no further resolution is performed. Rename the member and the code compiles. Note, this seems to come from neighbor thread http://forum.dlang.org/thread/uelmpwwckcveimpbd...@forum.dlang.org. I think it is simpler to rename functions than create bunch of structs just to be able to have eponymous non-static and static functions. I just want very much avoid renaming function,it's principle for me. So I would like to know is my sample right or no. It functions exactly like it's supposed to. As Maxim said, undefined lookups go to the alias this member. If Foo already has a bar and you try and call it, it doesn't matter what Foo is aliased to, it's Foo's bar that's going to be used. - Jonathan M Davis Now it's clear for me,thank you.
Re: does alias this work correctly?
On Sunday, 13 January 2013 at 23:21:20 UTC, Andrey wrote:
I just want very much avoid renaming function,it's principle
for me.
So I would like to know is my sample right or no.
I think that the main overall principle here is that is it
impossible to have two functions which differ only by static
attribute. I even do not imagine the use case of this.
Well, here is the most natural way to achieve similar effect, I
suppose:
struct MyStruct {
struct Static {
static void myfun() {
writeln(static myfun);
}
}
void myfun() {
writeln(myfun);
}
static Static opCall() {
return Static();
}
}
MyStruct obj;
obj.myfun(); //dynamic;
MyStruct().myfun(); //static;
I do not agree with you, static attribute is not a small detail.
this reference is the same argument, like all the others. And
despite the fact that
function signatures are the same, the actual list of arguments
are different.
Re: does alias this work correctly?
On Sunday, 13 January 2013 at 22:36:03 UTC, Jonathan M Davis
wrote:
On Sunday, January 13, 2013 20:41:48 Zhenya wrote:
On Sunday, 13 January 2013 at 19:35:08 UTC, Maxim Fomin wrote:
According to spec http://dlang.org/class.html#AliasThis
undefined lookups are forwarded to AliasThis member. But in
your case Foo struct has bar member, so no further resolution
is performed. Rename the member and the code compiles.
Note, this seems to come from neighbor thread
http://forum.dlang.org/thread/uelmpwwckcveimpbd...@forum.dlang.org.
I think it is simpler to rename functions than create bunch
of
structs just to be able to have eponymous non-static and
static
functions.
I just want very much avoid renaming function,it's principle
for
me.
So I would like to know is my sample right or no.
It functions exactly like it's supposed to. As Maxim said,
undefined lookups go
to the alias this member. If Foo already has a bar and you try
and call it, it
doesn't matter what Foo is aliased to, it's Foo's bar that's
going to be used.
- Jonathan M Davis
import std.stdio;
struct Bar
{
void opDispatch(string op)()
if(op == bar)
{
if(this !is m_init)
writeln(non-static);
else
writeln(maybe static);
}
static @property Bar m_init()
{
return Bar.init;
}
alias m_init this;
}
void main()
{
Bar b;
Bar.bar();
readln;
}
If I understood you correctly, it must be compiled since there
isn't some 'bar' that is going to be used, right?
But it doesn't compile.
Re: does alias this work correctly?
On Tuesday, 15 January 2013 at 00:04:15 UTC, Jonathan M Davis
wrote:
On Monday, January 14, 2013 17:57:03 Zhenya wrote:
import std.stdio;
struct Bar
{
void opDispatch(string op)()
if(op == bar)
{
if(this !is m_init)
writeln(non-static);
else
writeln(maybe static);
}
static @property Bar m_init()
{
return Bar.init;
}
alias m_init this;
}
void main()
{
Bar b;
Bar.bar();
readln;
}
If I understood you correctly, it must be compiled since there
isn't some 'bar' that is going to be used, right?
But it doesn't compile.
I honestly have no idea how opDispatch and alias this are
supposed to
interact. They're both used as fallbacks when the type doesn't
directly define
a function. That being said The reason that your code doesn't
work here is the
fact that you'r ecalling bar is if it were a static function,
but your
opDispatch isn't static. opDispatch would have to be static for
it to be used
as a static function (it can't be both static and non-static),
and in that
case, the if condition that you have in it wouldn't compile.
- Jonathan M Davis
:( If compiler tried alias this before opDispatch all would be OK.
Maybe I'm going to give up.
Thank you for comprehensive explanation.
static vs non-static
Hi!
Sorry,if it already was discussed,but
import std.stdio;
struct Foo
{
static void bar()
{
writeln(static);
}
void bar()
{
writeln(non-static);
}
}
int main()
{
Foo gun;
gun.bar();//fails here
}
Is it all right,that compiler dosn't prefer non-static function
in ths case?
Re: static vs non-static
On Sunday, 13 January 2013 at 16:39:22 UTC, bearophile wrote: Maxim Fomin: dmd allows to call static functions on instance. I think that's a D design mistake (and I think Jonathan Davis agrees with me), but Walter prefers the current behavour. Bye, bearophile Maybe you could suggest some workaround? for example I tried to use global function,but in that case it never will be executed...
Re: static vs non-static
On Sunday, 13 January 2013 at 17:17:54 UTC, Maxim Fomin wrote: On Sunday, 13 January 2013 at 16:23:27 UTC, Zhenya wrote: On Sunday, 13 January 2013 at 16:18:36 UTC, Maxim Fomin wrote: Yes, it is a problem - dmd allows to call static functions on instance. When both match, it issues ambiguity error. Hmmm...So it will remain as it is? It hurts me a little bit( Frankly speaking I do not know - I keep an eye on D project for some period of time and remember how some features I considered stable were easily changed. If Walter is for current behavior - than it will remain as it is (unless Walter is overpersuaded). What I would do is not writing code which is looking for problems. BTW, take look at this thread http://forum.dlang.org/thread/pkodcsxwwehumhtkr...@forum.dlang.org (posts 1-3). Thank you.
Re: static vs non-static
On Sunday, 13 January 2013 at 17:59:28 UTC, Andrey wrote:
Don't know if this will be useful in any manner, but it came
this silly way:
class MyClass {
struct _static {
static void myfun() {
writeln(static myfun);
}
}
void myfun() {
writeln(myfun);
}
}
void main() {
auto obj = new MyClass();
obj.myfun(); //myfun
obj._static.myfun(); //static
MyClass._static.myfun(); //static
}
Aha...Thank you,very interesting idea to hide function in struct:
struct Foo
{
static struct bar
{
static void opCall()
{
writeln(static);
}
void bar()
{
writeln(non-static);
}
}
}
This is the workaround I looked for.
Re: static vs non-static
On Sunday, 13 January 2013 at 18:16:40 UTC, Zhenya wrote:
On Sunday, 13 January 2013 at 17:59:28 UTC, Andrey wrote:
Don't know if this will be useful in any manner, but it came
this silly way:
class MyClass {
struct _static {
static void myfun() {
writeln(static myfun);
}
}
void myfun() {
writeln(myfun);
}
}
void main() {
auto obj = new MyClass();
obj.myfun(); //myfun
obj._static.myfun(); //static
MyClass._static.myfun(); //static
}
Aha...Thank you,very interesting idea to hide function in
struct:
struct Foo
{
static struct bar
{
static void opCall()
{
writeln(static);
}
void bar()
{
writeln(non-static);
}
}
}
This is the workaround I looked for.
Oops...I made mistake:struct and function with the same name
isn't allowed.
Okay, I will try to get around it somehow...
does alias this work correctly?
Hi!
Is it all right with it:
struct Foo
{
struct Bar
{
void opCall()
{
writeln(non-static);
}
}
Bar bar;
static struct Anotherbar
{
static void bar()
{
writeln(static);
}
}
alias Anotherbar this;
}
void main()
{
Foo f;
f.bar();
Foo.bar();//fils with message:type Bar is not an expression
Foo.Bar b;
b();//this works however
}
?
Re: does alias this work correctly?
On Sunday, 13 January 2013 at 19:35:08 UTC, Maxim Fomin wrote:
On Sunday, 13 January 2013 at 19:16:36 UTC, Zhenya wrote:
Hi!
Is it all right with it:
struct Foo
{
struct Bar
{
void opCall()
{
writeln(non-static);
}
}
Bar bar;
static struct Anotherbar
{
static void bar()
{
writeln(static);
}
}
alias Anotherbar this;
}
void main()
{
Foo f;
f.bar();
Foo.bar();//fils with message:type Bar is not an expression
Foo.Bar b;
b();//this works however
}
?
According to spec http://dlang.org/class.html#AliasThis
undefined lookups are forwarded to AliasThis member. But in
your case Foo struct has bar member, so no further resolution
is performed. Rename the member and the code compiles.
Note, this seems to come from neighbor thread
http://forum.dlang.org/thread/uelmpwwckcveimpbd...@forum.dlang.org.
I think it is simpler to rename functions than create bunch of
structs just to be able to have eponymous non-static and static
functions.
I just want very much avoid renaming function,it's principle for
me.
So I would like to know is my sample right or no.
Passing member-function to template
Hi!
Tell me please,is there any way to pass member-function to
template?
I need something like that:
template execute(alias obj,alias mfun)
{
void execute()
{
obj.mfun();
}
}
struct Foo
{
void nothing()
{
}
}
void main()
{
Foo f;
execute!(f,Foo.nothing)();
}
I could pass mfun by string,but I think it's a little bit ugly.
Re: Passing member-function to template
On Saturday, 12 January 2013 at 19:06:27 UTC, Maxim Fomin wrote:
On Saturday, 12 January 2013 at 18:17:47 UTC, Zhenya wrote:
Hi!
Tell me please,is there any way to pass member-function to
template?
Probably this can help: (you can manually construct a delegate
combining function and context pointers)
import std.stdio;
template execute(alias func)
{
void execute(void* ptr)
{
void delegate() dg;
dg.funcptr = func;
dg.ptr = ptr;
dg();
}
}
struct Foo
{
void nothing()
{
writeln(reached);
}
}
void main()
{
Foo f;
execute!(Foo.nothing)(f);
}
Thank you,it really can help me.
But I would like to handle not only member-function,but global
function too(by UFCS) if it's possible.
Re: Passing member-function to template
On Saturday, 12 January 2013 at 19:24:04 UTC, Maxim Fomin wrote: On Saturday, 12 January 2013 at 19:16:02 UTC, Zhenya wrote: But I would like to handle not only member-function,but global function too(by UFCS) if it's possible. Global functions rewritten as UFCS functions are not delegates, they are still functions, so they can be handled just as other functions. In such case it is enough to supply null to void* parameter. Understood,thank you.
Re: is(...) with alias this
On Saturday, 5 January 2013 at 22:17:08 UTC, monarch_dodra wrote: On Saturday, 5 January 2013 at 22:09:45 UTC, Philippe Sigaud wrote: I think the alias this transformation is done 'before' any usual conversion. I guess it's a real replacement inside the code (I'm not sure how to explain my feeling). But in any case, since OhWhy!(float) type is ... OhWhy!(float), I agree this should fail. Agreed. This warrants a ticket in bugzilla. http://d.puremagic.com/issues/show_bug.cgi?id=9274
is(...) with alias this
Hi!
I just read the David's post
http://forum.dlang.org/thread/kc9e74$bg7$1...@digitalmars.com
This code worked with dmd 2.060:
import std.stdio;
import std.traits;
struct OhWhy(S) {
S[] arr;
alias arr this;
}
void main() {
static assert(isArray!(OhWhy!(float)));
}
But fails with dmd 2.061:
ss.d(10): Error: static assert (isArray!(OhWhy!(float))) is false
(same happens with alias this to static arrays and
isArray/isStaticArray)
Is this intended or a regression? If latter, I'll submit a
bug-ticket.
When I read this I understood that I don't know what should return
is(OhWhy!float unused == T[],T)
Of course OhWhy!float implicit convertable into float[].But on
the other hand
is with == (not :) should check the type without conversions.
What do you think?
DMD 2.060 HEAD evaluate is(OhWhy!float unused == T[],T) - true
Re: Visual D 0.3.35 released - semantic analysis considered stable
On Tuesday, 1 January 2013 at 17:11:31 UTC, thedeemon wrote: After switching to this version it started to build my windows app as a console one. It seems to ignore the subsystem choice, I don't see any mention of -L/SUBSYSTEM: in generated build scripts anymore. Previously I had 0.3.33, I guess, which compiled and linked in one go, not in separate steps, it worked fine. +1 I have the same problem.But it was alright when I used 0.3.34.
Re: typeid + toString = runtime error
On Sunday, 30 December 2012 at 16:04:48 UTC, Ali Çehreli wrote:
On 12/30/2012 07:32 AM, Zhenya wrote:
Hi!
Explain me please why this code fails in runtime:
import std.stdio;
class Foo
{
~this() {writeln(typeid(this).toString ~ is dead);}
}
void main()
{
new Foo;
}
Application error:
core.exception.InvalidMemoryOperationError
My guess is that by the time that destructor is executed, the
runtime has been shut down sufficiently that the ~ operator
cannot work. The following has the same error:
import std.stdio;
string foo()
{
return abc;
}
class Foo
{
~this() {writeln(foo() ~ xyz);}
}
void main()
{
new Foo;
}
Ali
Thank you,now all is clear for me.
DList!(Tuple!(TypeInfo_Class)) causes compilation error
Hi! I just need DList!(Tuple!(TypeInfo_Class)) for my n-dimensional dispatcher, but compiler says: Error: function std.typecons.Tuple!(TypeInfo_Class).Tuple.opEquals!(const(Tuple!(TypeInfo_Class))).opEquals (const(Tuple!(TypeInfo_Class)) rhs) is not callable using argument types (const(Tuple!(TypeInfo_Class))) const Could you give me some advice/workaround for this?
Re: DList!(Tuple!(TypeInfo_Class)) causes compilation error
On Sunday, 30 December 2012 at 20:09:57 UTC, Zhenya wrote:
Hi!
I just need DList!(Tuple!(TypeInfo_Class)) for my n-dimensional
dispatcher,
but compiler says:
Error: function
std.typecons.Tuple!(TypeInfo_Class).Tuple.opEquals!(const(Tuple!(TypeInfo_Class))).opEquals
(const(Tuple!(TypeInfo_Class)) rhs) is not callable using
argument types (const(Tuple!(TypeInfo_Class))) const
Could you give me some advice/workaround for this?
Used
struct Wrapper(T)
{
T t;
this(T a)
{
t = a;
}
alias t this;
}
Ugly a little bit,but works.
Could anyone explain me please what's wrong with
Tuple!TypeInfo_Class opEquals?
Re: DList!(Tuple!(TypeInfo_Class)) causes compilation error
On Sunday, 30 December 2012 at 21:30:04 UTC, monarch_dodra wrote: On Sunday, 30 December 2012 at 20:09:57 UTC, Zhenya wrote: Hi! I just need DList!(Tuple!(TypeInfo_Class)) for my n-dimensional dispatcher, but compiler says: Error: function std.typecons.Tuple!(TypeInfo_Class).Tuple.opEquals!(const(Tuple!(TypeInfo_Class))).opEquals (const(Tuple!(TypeInfo_Class)) rhs) is not callable using argument types (const(Tuple!(TypeInfo_Class))) const Could you give me some advice/workaround for this? Sounds like a bug in Tuple.opEqual: It, and its arguments, should be const qualified, but aren't. I'll try and get it fixed for 2.061. In the mean time, you *could* try changing std.typecons.Tuple's opEqual: From: bool opEquals(R)(R rhs) if (isTuple!R) To: bool opEquals(R)(const R rhs) const if (isTuple!R) But I have not thoroughly tested this, so use at your own risk. Thank you,that works.
checking whether the number is NaN
Hi! Tell me please,are there any way to check whether number is NaN?
Re: checking whether the number is NaN
On Friday, 28 December 2012 at 15:59:35 UTC, bearophile wrote: Zhenya: Tell me please,are there any way to check whether number is NaN? http://dlang.org/phobos/std_math.html#isNaN Bye, bearophile Thank you!
Re: private with alias this
On Tuesday, 25 December 2012 at 07:21:12 UTC, evilrat wrote: On Tuesday, 25 December 2012 at 05:28:54 UTC, Zhenya wrote: On Tuesday, 25 December 2012 at 02:43:52 UTC, r_m_r wrote: On 12/25/2012 07:42 AM, r_m_r wrote: assert(!__traits(compiles, b._bar)); sorry, i made a typo: it should be bar_ instead of _bar. Interestingly, the below assertion fails at run time: assert(!__traits(compiles, b.bar_)); but this won't compile (as expected): assert(b.bar_ == 20); //main.d(15): Error: undefined identifier 'bar_' regards, r_m_r So,should I file a new bug?Or it's alright and I don't understand something? i don't think it's a bug, because you are just setting alias for a member. if you remove private from field it would work. i'm just wonder why do you want do something like this? After your explaination I understood that it's really meaningless.Thank you)
Re: auto ref and non-templated functions
On Tuesday, 25 December 2012 at 01:40:16 UTC, Peter Alexander wrote: On Tuesday, 25 December 2012 at 00:56:44 UTC, Peter Alexander wrote: On Monday, 24 December 2012 at 17:40:54 UTC, Jonathan M Davis wrote: And if that doesn't work, can we simply make it so that the compiler automatically creates a variable when you pass an rvalue to a non-templated auto ref function? I don't see any problems with this, but I admittedly haven't thought too much about it. If there are no problems with this way, then what I want to know is why the template version of auto ref wasn't implemented this way. The way auto ref is currently implemented for templates is a bit of a mess. Maybe it's difficult to generate both versions because for the function like this void foo(auto ref S s1,auto ref S s2,...,auto ref s10) compiler should generate 2^10 versions of function foo.
Re: private with alias this
On Tuesday, 25 December 2012 at 02:43:52 UTC, r_m_r wrote: On 12/25/2012 07:42 AM, r_m_r wrote: assert(!__traits(compiles, b._bar)); sorry, i made a typo: it should be bar_ instead of _bar. Interestingly, the below assertion fails at run time: assert(!__traits(compiles, b.bar_)); but this won't compile (as expected): assert(b.bar_ == 20); //main.d(15): Error: undefined identifier 'bar_' regards, r_m_r So,should I file a new bug?Or it's alright and I don't understand something?
const property don't wont return const reference to value
Hi!
Explain me please what's wrong with this code:
module main;
struct foo
{
int m_bar;
@property const ref int bar() const
{
return m_bar;
}
}
void main()
{
}
Error: cast(int)this.m_bar is not an lvalue
Re: const property don't wont return const reference to value
On Sunday, 23 December 2012 at 13:37:33 UTC, Rainer Schuetze wrote: On 23.12.2012 14:20, Zhenya wrote: @property const ref int bar() const The first const does not bind to the return type, but to the whole declaration, so it does the same as the const at the end. You should use @property ref const(int) bar() const Thank you very much!
opDispatch bug?
Hi!
Is it a bug?
class Foo
{
int m_bar;
char m_gun;
@property auto ref opDispatch(string s)()
{
return mixin(m_~s);
}
this(int i,char c)
{
bar = i;//Error: undefined identifier bar, did you mean
variable m_bar?
this.gun = c;
}
}
Re: opDispatch bug?
On Saturday, 15 December 2012 at 18:09:00 UTC, Ali Çehreli wrote: On 12/15/2012 10:07 AM, Ali Çehreli wrote: Otherwise any type would go to opDispatch. Wow. I made a typo in typo. :) That should be: Otherwise any _typo_ would go to opDispatch. Ali It's pretty reasonable,thank you.
Re: Type value
On Tuesday, 11 December 2012 at 07:50:10 UTC, js.mdnq wrote:
On Tuesday, 11 December 2012 at 07:15:38 UTC, Zhenya wrote:
I'm sorry for my english.
I know that D != Python and my example don't need
any RTTI.
D has alias this feature.My example shows that we can use
alias this with types.
And I just want use this:
struct Type(T)
{
alias T m_type;
alias m_type this;
}
int main()
{
Type!int Int;
Int i;//should compile by definition of alias this
}
My I ask, why not just use int directly?
I'm not proficient enough with D yet but it seems to me that
the example does not make sense.
alias T m_type;
alias m_type this;
should be equivalent to
alias T this;
which, in some sense makes struct Type(T) equal to T... which
is what you are thinking, I think.
But! I also believe that structs are meant as value types and
are addressable.
So when you do
Int i; you are essentially doing something like
int x;
x i;
which makes no sense.
If you do this instead,
alias Type!int Int;
Int i;
then it will compile, of course.
But your way, when you do Int x; you are specifically trying to
create a instance of an object. Yet you are not wanting it to
be an object and I'm not sure what you are wanting x to be.
(another type? a type of a type?)
In my example Int is value of Type!int.
When I write
Int i;
If Int had not alias this it really would not have sense,because
type expected
instead of 'Int'.But Int have alias this 'int',and can be
replaced by it.
My reason is simple:
Operators are functions.But if I want declare some struct like
std.TypeTuple
I will need opSlice that return type.
It is impossible.
But if my example compiled,I could return value,that can be used
as type.
It's something like Andrei's Type2Type.
Re: Type value
On Tuesday, 11 December 2012 at 09:40:08 UTC, Ali Çehreli wrote:
On 12/11/2012 01:05 AM, Ali Çehreli wrote:
/* Fundamental types must be made differently; probably due
to syntax
* issues. I would have expected for the following to work:
*
* return Type!index(args); // -- compilation error
*/
My mind must have been in C++ mode there. :) The following is
not legal in D:
int foo()
{
return int(42);// not D syntax!
}
But of course the simpler code below works:
/* A generic function that can make an object of any type. */
Type!index make(size_t index, T...)(T args)
{
// ...
} else {
return args[0];// simply return the argument
}
}
Ali
Thank you for you example,I understand.
But how do you think does it make sense to open enhancement
allow alias this with types?
Or it is completely useless?
Type value
Hi!
In some previous post I asked about possibility of declar
opIndex,that return type.
I thoght about it,and I understood that code like this is legal:
struct Type(T)
{
alias T m_type;
alias m_type this;
}
void main()
{
Type!int Int;
// Int a;
}
Is it hard to implement possibility of using Int as a type?
It would allow functions,that return types:)
Re: Type value
I'm sorry for my english.
I know that D != Python and my example don't need
any RTTI.
D has alias this feature.My example shows that we can use alias
this with types.
And I just want use this:
struct Type(T)
{
alias T m_type;
alias m_type this;
}
int main()
{
Type!int Int;
Int i;//should compile by definition of alias this
}
VisualD solution configuration
Hi! I'm sorry,maybe it is a little bit stupid question,but how to configure VisualD project to get it compile not only main.d but all files in project?
Re: VisualD solution configuration
On Sunday, 2 December 2012 at 14:52:24 UTC, Lubos Pintes wrote: Not sure if I understand what you ask here, but you probably need to add all files you want to compile to the project. Thus not only the main.d, but all modules. Dňa 2. 12. 2012 11:56 Zhenya wrote / napísal(a): Hi! I'm sorry,maybe it is a little bit stupid question,but how to configure VisualD project to get it compile not only main.d but all files in project? I added 2 modules in project.But compiled only one.
Re: VisualD solution configuration
On Sunday, 2 December 2012 at 14:58:24 UTC, Zhenya wrote: On Sunday, 2 December 2012 at 14:52:24 UTC, Lubos Pintes wrote: Not sure if I understand what you ask here, but you probably need to add all files you want to compile to the project. Thus not only the main.d, but all modules. Dňa 2. 12. 2012 11:56 Zhenya wrote / napísal(a): Hi! I'm sorry,maybe it is a little bit stupid question,but how to configure VisualD project to get it compile not only main.d but all files in project? I added 2 modules in project.But compiled only one. I have the following errors: Error 42: Symbol Undefined _D10dispatcher7__arrayZ Debug\space.obj(space) Error 42: Symbol Undefined _D10dispatcher12__ModuleInfoZ
Re: VisualD solution configuration
On Sunday, 2 December 2012 at 15:03:26 UTC, Zhenya wrote: On Sunday, 2 December 2012 at 14:58:24 UTC, Zhenya wrote: On Sunday, 2 December 2012 at 14:52:24 UTC, Lubos Pintes wrote: Not sure if I understand what you ask here, but you probably need to add all files you want to compile to the project. Thus not only the main.d, but all modules. Dňa 2. 12. 2012 11:56 Zhenya wrote / napísal(a): Hi! I'm sorry,maybe it is a little bit stupid question,but how to configure VisualD project to get it compile not only main.d but all files in project? I added 2 modules in project.But compiled only one. I have the following errors: Error 42: Symbol Undefined _D10dispatcher7__arrayZ Debug\space.obj(space) Error 42: Symbol Undefined _D10dispatcher12__ModuleInfoZ I added line module dispatcher; in file dispatcher.d and all compiled. Strange,I thought module name inferred from filename.
Re: VisualD solution configuration
On Sunday, 2 December 2012 at 20:12:08 UTC, Regan Heath wrote: On Sun, 02 Dec 2012 15:08:51 -, Zhenya zh...@list.ru wrote: On Sunday, 2 December 2012 at 15:03:26 UTC, Zhenya wrote: On Sunday, 2 December 2012 at 14:58:24 UTC, Zhenya wrote: On Sunday, 2 December 2012 at 14:52:24 UTC, Lubos Pintes wrote: Not sure if I understand what you ask here, but you probably need to add all files you want to compile to the project. Thus not only the main.d, but all modules. Dňa 2. 12. 2012 11:56 Zhenya wrote / napísal(a): Hi! I'm sorry,maybe it is a little bit stupid question,but how to configure VisualD project to get it compile not only main.d but all files in project? I added 2 modules in project.But compiled only one. I have the following errors: Error 42: Symbol Undefined _D10dispatcher7__arrayZ Debug\space.obj(space) Error 42: Symbol Undefined _D10dispatcher12__ModuleInfoZ I added line module dispatcher; in file dispatcher.d and all compiled. Strange,I thought module name inferred from filename. What folder was main.d in, and what folder was dispatcher.d in? R These are in the same folder
Can operators return type?
Hi! It would useful for some my project,if operators could be a template,that return type.Something like alias TypeTuple!(int,char) types; static assert(types[1] == char) //opIndex So can I define something like that?
Re: Can operators return type?
On Thursday, 29 November 2012 at 16:55:01 UTC, bearophile wrote:
Zhenya:
It would useful for some my project,if operators could be a
template,that return
type.
D operators are functions, and D functions return values. And
in D types are not values (unlike Python and several other
languages), unless you use a Typeinfo or something.
Maybe if you explain better what you are trying to do someone
will be able to suggest you an alternative solution. D is not
as flexible as Lisp, but it doesn't lack
meta-programming/type-processing capabilities.
Bye,
bearophile
Of course I understand,that type is not value in D.I meant that
maybe we can declare non-function template operators.For example:
struct MyIntType
{
alias int type;
template opSlice()
{
alias type opSlice;
}
Re: Can operators return type?
On Thursday, 29 November 2012 at 21:53:20 UTC, bearophile wrote:
Zhenya:
For example:
struct MyIntType
{
alias int type;
template opSlice()
{
alias type opSlice;
}
As you guess, this is not supported in D.
Bye,
bearophile
Thank you,understood(
Re: SList/DList ranges
On Tuesday, 27 November 2012 at 07:51:16 UTC, Jonathan M Davis
wrote:
On Monday, November 26, 2012 19:49:51 Zhenya wrote:
Hi!
I read the spec,but I didn't find any function,that removes
concrete element from
list.I am not familiar with D's ranges,so could you help me
please?
What do you mean by removing concrete elements? How is that any
different from
any other element in the list? If you want to remove elements
from the list,
then use one of the *remove functions. [] on the list to get a
range over all
of the elements in the list, find to find the element that you
want, and then
take to get a range with just the elements from the front of
the range that
you want to remove. Hopefully this will enlighten you somewhat:
import std.algorithm;
import std.container;
import std.range;
import std.stdio;
void main()
{
auto list = make!(SList!int)(4, 5, 6, 7, 22, 9, 5, 4);
assert(equal(list[], [4, 5, 6, 7, 22, 9, 5, 4]));
auto found = find(list[], 6);
assert(equal(found.save, [6, 7, 22, 9, 5, 4]));
list.linearRemove(take(found, 3));
assert(equal(list[], [4, 5, 9, 5, 4]));
list.linearRemove(take(find(list[], 5), 1));
assert(equal(list[], [4, 9, 5, 4]));
}
Unfortunately, std.container needs a fair bit of work in terms
of some of the
details - particularly with its functions which accept and/or
return ranges,
so it doesn't always work like it should yet. It's very much a
work in
progress right now. But the above should give you the basic
idea.
As for ranges in general, the best resource on them at this
point would be
this chapter from an online book on D:
http://ddili.org/ders/d.en/ranges.html
If you're going to be using Phobos much (which is likely if
you're using D),
then you're going to need to understand ranges, because Phobos
uses them quite
heavily.
- Jonathan M Davis
Thank you,understood.I just want a container with fast
insert/remove.Something like C++ std::list.But when I look at you
example I understand that remove is linear,so maybe I need
assosiative array or RedBlackTree.
And thank you for a link,I will learn ranges surely.
SList/DList ranges
Hi! I read the spec,but I didn't find any function,that removes concrete element from list.I am not familiar with D's ranges,so could you help me please?
Re: std.signals2 proposal
On Monday, 5 November 2012 at 13:35:26 UTC, Robert wrote:
Hi there!
I just developed a proof-of-concept implementation of an
improved
std.signals.
Things I did not like about the current implementation:
1. Passing a delegate to connect, which basically is an
extended (void*)
and assuming it is an object delegate, does not feel quite
right in D,
where we usually try to guarantee correctness by the compiler
wherever
possible.
2. The restriction that only objects can be connected.
Point 2 does not really bother me, because from my little
experience I
never really had connected anything else than objects to a
signal. But
the restriction that the connected delegate must not be some
wrapper, is
quite a restriction I came to dislike about Qt and even more so
with
this implementation because unlike Qt the signatures have to
match
exactly, you can't omit parameters, like:
// Qt code
connect(button, SIGNAL(clicked(bool)), this,
SLOT(buttonClicked());
- In the current implementation buttonClicked would have to
take a
bool.
In addition boost::signals together with boost::bind offered
even more
comfort like passing additional parameters to a slot, which is
really
very, very useful:
for(int i=0; ibuttons.length(); i++) {
buttons[i].clicked.connect(boost::bind(MyObj::addNumber, this,
i));
}
So I tried to improve std.signals, code:
(warning at least one bug is remaining, explained below)
https://github.com/eskimor/phobos/tree/new_signal
You can easily connect to an object's method with:
obj.signal.connect!someMethod(obj);
instead of the old implementation:
obj.signal.connect(obj.someMethod);
- The interface is clean and type safe, all the ugly details
are hidden
from the user. And it is just one character more typing. Simple
things
stay simple.
In addition a method allowing wrapper delegates was added:
class Observer {
void addNumber(int i) {
sum+=i;
}
int sum;
}
class Button {
Signal!(bool) clicked;
// ...
}
void main() {
auto b=new Button;
auto o=new Observer;
// Ignore boolean parameter and pass some int:
b.connect!Observer(o, (o, p) { o.addNumber(7); });
// or even:
b.connect!Observer(o, (o, p) = o.addNumber(7));
// For some reason the compiler is not able to deduce o being
// Observer, so the !Observer is needed, but it is still very
// neat and readable.
}
Thanks to D's lamdas the syntax is even more concise as
boost::bind and
far more powerful.
By passing the object explicitly to the delegate, it is
possible to
maintain the 'weak ref' semantics to the target object, while
ensuring
that the delegates context won't be freed.
As a side effect it is now even possible to use struct
delegates or even
any non object delegate. Simply pass null for the obj
parameter. It is
completely safe, the only drawback is that the struct won't be
deleted
until the Button gets destroyed. (Because it holds a reference
to the
struct, by means of the delegate.) But for long lived structs
this
usually is perfectly acceptable.
Implementation:
In my implementation I changed the Signal mixin to be a simple
template
struct, because I hit strange compiler errors with it being a
mixin. The
most prominent:
std/signals.d(443): Error: no overload matches for
connect(string
method,T2) if (is(T2 : Object))
You can find the version triggering these errors at:
https://github.com/eskimor/phobos/tree/new_signal_mixin
Also I did not really get the point why a mixin was used in the
first
place, it does not really gain us anything? What was the
reasoning about
it?
I almost thought I found the reason, because my implementations
suffers
from unhook not being called, although it was properly
registered with
rt_attachDisposeEvent(obj, unhook);, thus causing a
segmentation
fault when the observer gets deleted. I did not really find any
difference from the original version that could explain this
behavior,
despite the original implementation being a mixin. So I
thought, well
maybe the delegate passed to rt_attachDisposeEvent(obj,
unhook); must
be an object delegate (that's would be why the mixin was
needed), but
after digging in object_.d I did not find any code assuming
that the
delegate was an object delegate. Any ideas on this?
Another thing I'd like to ask Walter, is what the L1: label
is for in
connect(), is it just some left over or has it some special
internal
compiler thing meaning?
What do you think?
Best regards,
Robert
Hi!Could you write some examples for struct and non-object
delegates?
Re: std.signals2 proposal
On Monday, 5 November 2012 at 19:07:13 UTC, Robert wrote:
Hi!Could you write some examples for struct and non-object
delegates?
Sure!
Something like:
struct Observer {
void observe(int a, int b) {
// ...
}
}
void main() {
Signal!(int, int) s1;
Signal!int s2
Observer o;
s1.connect!Object(null, (null_object, a, b) = o.observe(a,
b));
s2.connect!Object(null, (null_object, a) = o.observe(7, a));
}
Having the delegate accept a null parameter might not be
pretty, but I
consider this a good thing, because of the changed semantics:
The signal
will keep a reference to the struct now, so the signals weak
reference
semantics are no longer in place. (If struct is allocated on
the heap,
it won't be freed as long as the signal is alive.)
But it is possible and safe. And if you know what you are doing
also
very reasonable.
But the main benefit is not that you can connect to structs
(which is a
side effect), but that you can use wrapping delegates which do
parameter
adoptions. That's the killer feature that proved to be so
indispensable
and neat for me and others.
If really required it would not be to hard to provide an
overload of
connect() which takes a struct pointer directly, just like the
one
taking an object, but because of the changed semantics and the
rare uses
I'd expect, probably not worthwhile. But comments are
appreciated.
I am embarrassed a little that a member function of the structure
looks like a static function,maybe it would be better if connect
took struct pointer directly.I think if struct become immortal it
will not be a big trouble,in other
case we have disconnect,that will help us.
Sorry for my awful english
Re: Unexpected OPTLINK Termination while building dwt helloworld
On Wednesday, 31 October 2012 at 18:05:07 UTC, Jacob Carlborg wrote: On 2012-10-31 16:08, Zhenya wrote: Thank you) Maybe I will try it,although I do not know how. 1. Create a new folder, dlang 2. In the dlang folder clone DMD, druntime and Phobos using this command git clone address where address is one of the git addresses below 3. Install DVM 4. From dlang run dvm compile . 5. You will have a compiled binary in dlang\dmd\bin32\dmd DMD: git://github.com/D-Programming-Language/dmd.git druntime: git://github.com/D-Programming-Language/druntime.git Phobos: git://github.com/D-Programming-Language/phobos.git DVM: https://bitbucket.org/doob/dvm/wiki/Home Thank you very much:)
Re: Unexpected OPTLINK Termination while building dwt helloworld
On Wednesday, 31 October 2012 at 18:48:20 UTC, Zhenya wrote: On Wednesday, 31 October 2012 at 18:05:07 UTC, Jacob Carlborg wrote: On 2012-10-31 16:08, Zhenya wrote: Thank you) Maybe I will try it,although I do not know how. 1. Create a new folder, dlang 2. In the dlang folder clone DMD, druntime and Phobos using this command git clone address where address is one of the git addresses below 3. Install DVM 4. From dlang run dvm compile . 5. You will have a compiled binary in dlang\dmd\bin32\dmd DMD: git://github.com/D-Programming-Language/dmd.git druntime: git://github.com/D-Programming-Language/druntime.git Phobos: git://github.com/D-Programming-Language/phobos.git DVM: https://bitbucket.org/doob/dvm/wiki/Home Thank you very much:) Unfortunally this don't help.If anybody build dwt heloworld under windows succesfully,write please short howto.
DFL Button.backColor
Hi!
Explain me please,why this code doesn't work
import dfl.all;
void main()
{
auto form = new Form;
auto button = new Button;
button.backColor = Color(0,0,0);
button.foreColor = Color(0,0,0);
form.controls.add(button);
Application.run(form);
}
It displays usualy button in system style,but should display
black button
Re: DFL Button.backColor
On Tuesday, 30 October 2012 at 13:34:21 UTC, Zhenya wrote:
Hi!
Explain me please,why this code doesn't work
import dfl.all;
void main()
{
auto form = new Form;
auto button = new Button;
button.backColor = Color(0,0,0);
button.foreColor = Color(0,0,0);
form.controls.add(button);
Application.run(form);
}
It displays usualy button in system style,but should display
black button
Oh,sorry,I should check it
http://wiki.dprogramming.com/Dfl/BugList
Thank you:)
__traits(compiles,...) = ? is(typeof(...))
Hi!
Tell me please,in this code first and second static if,are these
equivalent?
with arg = 1, __traits(compiles,check(arg);) = true,
is(typeof(check(arg))) = false.
template ArgType(alias arg)
{
void check(T)(ref T t) {};
// static if(__traits(compiles,check(arg);))
static if(is(typeof(check(arg
{
struct ArgType
{
typeof(arg)* m_ptr;
this(ref typeof(arg) r)
{
m_ptr = r;
}
@property ref typeof(arg) get()
{
return *m_ptr;
}
alias get this;
}
}
else
alias typeof(arg) ArgType;
}
Re: __traits(compiles,...) = ? is(typeof(...))
On Monday, 29 October 2012 at 10:58:51 UTC, Philippe Sigaud wrote:
Tell me please,in this code first and second static if,are
these equivalent?
with arg = 1, __traits(compiles,check(arg);) = true,
is(typeof(check(arg))) = false.
__traits(compiles, ...) takes an expression, not a string. From
the
spec: The arguments can be symbols, types, or expressions that
are
syntactically correct. The arguments cannot be statements or
declarations.
(http://dlang.org/traits.html#compiles)
So, in your case, that would be:
__traits(compiles, {check(arg);})
Note that you can also use the type of arg:
__traits(compiles, {check(typeof(arg).init);})
or
is(typeof({ check(typeof(arg).init);})
Thank you,understood.
Re: TypeInfo manipulation
On Friday, 26 October 2012 at 19:57:14 UTC, Zhenya wrote: On Thursday, 25 October 2012 at 15:05:05 UTC, Zhenya wrote: Hi! Tell me please,are any TypeInfo/typeid/classinfo manipulations possible? For example I need a struct that overload typeid, or something like that? Some time ago I tried to write some smart pointer that overlad classinfo property in accordance with the real type of hold object,but I failed to do this becouse of not having possibility to declar static and non-static version of the one function.Maybe there are better ways to do this? Or maybe there are a possibility to parametrize class by TypeInfo? Is my question is so meaningless, that no one even say why? :(
Re: TypeInfo manipulation
What do you mean: to parametrize class by Typeinfo?
class A { }
A!TypeInfo var;
If you mean this, than how it can help?
It would be well if I could create object that inherits class
with this typeinfo.
Re: TypeInfo manipulation
I have double dispatcher:
template Dispatcher(R)
{
R execute(Left,Right)(R delegate(Left,Right) f,Object
left,Object right)
{
return f(cast(Left)left,cast(Right)right);
}
struct Dispatcher
{
private R
delegate(Object,Object)[Tuple!(TypeInfo_Class,TypeInfo_Class)]
m_callbacks;
void add(Left,Right)(R delegate(Left,Right) f)
{
m_callbacks[tuple(Left.classinfo,Right.classinfo)] = (Object
l,Object r){return execute!(Left,Right)(f,l,r);};
}
void remove(Left,Right)()
{
m_callbacks.remove(tuple(Left.classinfo,Right.classinfo));
}
R opCall(Object l,Object r)
{
R delegate(Object,Object)* callback =
tuple(l.classinfo,r.classinfo) in m_callbacks;
return (*callback)(l,r);
}
}
}
And I have some class ierarhy:
class GameObject
{
}
class Foo : GameObject
{
}
class Bar : GameObject
{
}
problem is to create some wrapper to this classes
struct GameHandle(Type)
and this code work
void main()
{
Dispatcher!void d;
d.add!(GameHandle!Foo,GameHandle!Bar)((GameHandle!Foo,GameHandle!Bar){writeln(haha);});
GameHandle!GameObject a;a.m_hold = new Foo;
GameHandle!GameObject b;b.m_hold = new Bar;
d(a,c);
readln();
}
Re: TypeInfo manipulation
On Thursday, 25 October 2012 at 15:05:05 UTC, Zhenya wrote: Hi! Tell me please,are any TypeInfo/typeid/classinfo manipulations possible? For example I need a struct that overload typeid, or something like that? Some time ago I tried to write some smart pointer that overlad classinfo property in accordance with the real type of hold object,but I failed to do this becouse of not having possibility to declar static and non-static version of the one function.Maybe there are better ways to do this? Or maybe there are a possibility to parametrize class by TypeInfo?
TypeInfo manipulation
Hi! Tell me please,are any TypeInfo/typeid/classinfo manipulations possible? For example I need a struct that overload typeid, or something like that? Some time ago I tried to write some smart pointer that overlad classinfo property in accordance with the real type of hold object,but I failed to do this becouse of not having possibility to declar static and non-static version of the one function.Maybe there are better ways to do this?
static and non-static version of the one function
Hi! Tell me please,are there any way to declare two versions of one member function, something like this: int a; int.init //static version a.init //non-static version
Re: static and non-static version of the one function
On Wednesday, 24 October 2012 at 20:02:20 UTC, Jacob Carlborg wrote: On 2012-10-24 21:32, Zhenya wrote: Hi! Tell me please,are there any way to declare two versions of one member function, something like this: int a; int.init //static version a.init //non-static version No, not currently. http://d.puremagic.com/issues/show_bug.cgi?id=3345 Thank you,understood.
Re: SFML-D working example
On Sunday, 21 October 2012 at 03:37:20 UTC, Ellery Newcomer wrote: On Saturday, 20 October 2012 at 20:25:09 UTC, Zhenya wrote: Hi!I have a little problem with building example.I downloaded SFML-D working example at this adress https://github.com/krzat/SFML-D/downloads.But then I tried to build it myself,I received many errors like that: Symbol Undefined _D2sf8graphics7Texture6__ctorMFPxaPS2sf8graphics7IntRectZC2sf8graphics7Texture I don't understand why compiler isn't satisfied,becouse I include all .lib files,that is in example.Can anybody help my? dmd_build.bat works for me. Are you using it? No,but I created VisualD solution,and configured its import path and lib path.
Re: SFML-D working example
On Sunday, 21 October 2012 at 07:34:29 UTC, Zhenya wrote: On Sunday, 21 October 2012 at 03:37:20 UTC, Ellery Newcomer wrote: On Saturday, 20 October 2012 at 20:25:09 UTC, Zhenya wrote: Hi!I have a little problem with building example.I downloaded SFML-D working example at this adress https://github.com/krzat/SFML-D/downloads.But then I tried to build it myself,I received many errors like that: Symbol Undefined _D2sf8graphics7Texture6__ctorMFPxaPS2sf8graphics7IntRectZC2sf8graphics7Texture I don't understand why compiler isn't satisfied,becouse I include all .lib files,that is in example.Can anybody help my? dmd_build.bat works for me. Are you using it? No,but I created VisualD solution,and configured its import path and lib path. Oh,I'm sorry I made some mistakes. Thank you for your answer)
SFML-D working example
Hi!I have a little problem with building example.I downloaded SFML-D working example at this adress https://github.com/krzat/SFML-D/downloads.But then I tried to build it myself,I received many errors like that: Symbol Undefined _D2sf8graphics7Texture6__ctorMFPxaPS2sf8graphics7IntRectZC2sf8graphics7Texture I don't understand why compiler isn't satisfied,becouse I include all .lib files,that is in example.Can anybody help my?
non-const reference to const instance of class
Hi!
I thought that this should compile:
class Foo{}
const(Foo) foo = new Foo;// the same that const Foo foo?
foo = new Foo;
but compiler say that foo is const reference and it can't modify
it.
It is normally?If yes,how can I declare non-const reference to
const instance of class?
Re: non-const reference to const instance of class
On Wednesday, 10 October 2012 at 17:35:48 UTC, Jonathan M Davis
wrote:
On Wednesday, October 10, 2012 19:02:31 Zhenya wrote:
Hi!
I thought that this should compile:
class Foo{}
const(Foo) foo = new Foo;// the same that const Foo foo?
foo = new Foo;
but compiler say that foo is const reference and it can't
modify
it.
It is normally?If yes,how can I declare non-const reference to
const instance of class?
const Foo and const(Foo) are the same thing. They both create a
const
reference to const data. This is in contrast to a pointer where
const Bar* and
const(Bar)* are different. With a reference, there is no way to
indicate that
the object is const but not the reference. The type system just
doesn't
support the idea of a class object existing separately from a
reference, so
there's no way to make that distinction.
If you want to have a mutable reference to a const object, then
you need a
wrapper around the reference where the wrapper is mutable but
the reference
isn't. std.typecons.Rebindable does this. It's what you should
use.
- Jonathan M Davis
Thank you)
this() in struct
Hi! I'm sorry,maybe this topic already was discussed,but could anybody explain me why default constructor was disallowed in structs?
Re: this() in struct
On Tuesday, 9 October 2012 at 17:21:47 UTC, Zhenya wrote: Hi! I'm sorry,maybe this topic already was discussed,but could anybody explain me why default constructor was disallowed in structs? And if I have to do some initialization of data members,what is the way to do it?
Re: this() in struct
On Tuesday, 9 October 2012 at 18:29:18 UTC, Jonathan M Davis
wrote:
On Tuesday, October 09, 2012 19:08:35 Zhenya wrote:
On Tuesday, 9 October 2012 at 17:21:47 UTC, Zhenya wrote:
Hi!
I'm sorry,maybe this topic already was discussed,but could
anybody explain me
why default constructor was disallowed in structs?
And if I have to do some initialization of data members,what is
the way to do it?
It's because of the init property. All types in D are
default-initialized to
their init property, and that property must be known at compile
time (meaning
that it doesn't work very well for it to involve a
constructor). For structs,
the init property is decided by what all of the member
variables are directly
initialized to. So,
struct S
{
int i = 5;
string s = hello;
}
assert(S.init == S(5, hello));
S s;
assert(s == S.init);
This has the unfortunate result that we don't get a default
constructor. The
workaround is to declare a static opCall function.
struct S
{
int i = 5;
string s = hello;
static S opCall()
{
return S(22, catch);
}
}
S s;
assert(s == S.init);
S s2 = S();
auto s3 = S();
assert(s2 == S(22, catch));
assert(s2 == s3);
It doesn't make it so that the struct is default-initialized to
the result of
static opCall, and it doesn't guarantee that the result of
static opCall is
used when no constructor is called, but if you use S()
explicitly, then it
will be used.
A solid design decision in the language (e.g. requiring that
everything be
default-initialized) can have the unfortunate side effect of
restricting other
choices, and in this case, mucks up default constructors for
structs.
- Jonathan M Davis
Ok.Then can I do my own .init property that can be executed in
compile-time?
Re: this() in struct
On Tuesday, 9 October 2012 at 18:29:18 UTC, Jonathan M Davis
wrote:
On Tuesday, October 09, 2012 19:08:35 Zhenya wrote:
On Tuesday, 9 October 2012 at 17:21:47 UTC, Zhenya wrote:
Hi!
I'm sorry,maybe this topic already was discussed,but could
anybody explain me
why default constructor was disallowed in structs?
And if I have to do some initialization of data members,what is
the way to do it?
It's because of the init property. All types in D are
default-initialized to
their init property, and that property must be known at compile
time (meaning
that it doesn't work very well for it to involve a
constructor). For structs,
the init property is decided by what all of the member
variables are directly
initialized to. So,
struct S
{
int i = 5;
string s = hello;
}
assert(S.init == S(5, hello));
S s;
assert(s == S.init);
This has the unfortunate result that we don't get a default
constructor. The
workaround is to declare a static opCall function.
struct S
{
int i = 5;
string s = hello;
static S opCall()
{
return S(22, catch);
}
}
S s;
assert(s == S.init);
S s2 = S();
auto s3 = S();
assert(s2 == S(22, catch));
assert(s2 == s3);
It doesn't make it so that the struct is default-initialized to
the result of
static opCall, and it doesn't guarantee that the result of
static opCall is
used when no constructor is called, but if you use S()
explicitly, then it
will be used.
A solid design decision in the language (e.g. requiring that
everything be
default-initialized) can have the unfortunate side effect of
restricting other
choices, and in this case, mucks up default constructors for
structs.
- Jonathan M Davis
Ok.Then,can I do my own .init property,that can be executed in
compile time?
Re: this() in struct
On Tuesday, 9 October 2012 at 19:04:40 UTC, Jonathan M Davis
wrote:
On Tuesday, October 09, 2012 20:09:56 Zhenya wrote:
Ok.Then can I do my own .init property that can be executed in
compile-time?
No. You directly initialize the member variables to what you
want them to be,
and that's the values that they have in the init property. You
can't have
anything like a function or constructor to initialize them all
together.
However, you _can_ use the results of functions to initialize
the member
variables if the functions will work at compile time. e.g.
struct S
{
int i = foo();
string s = bar(joe);
}
int foo()
{
return 7;
}
string bar(string str)
{
return str ~ schmoe;
}
assert(S.init == S(7, joe schmoe));
- Jonathan M Davis
Understood.Thank you very much guys =)
CFTE+DevIL=?
Hi! I need to load some textures for my game,but I woud like to do it in compile time. I know that CTFE imposes restrictions on functions.So can I execute some DevIL(Derelict3) functions?
Re: compiler assertion
On Saturday, 29 September 2012 at 13:03:31 UTC, Philippe Sigaud
wrote:
On Fri, Sep 28, 2012 at 10:32 PM, Zhenya zh...@list.ru wrote:
Thank you,understood.
This should work, hopefully:
import std.stdio;
import std.typetuple;
template sum(U...)
{
static if(U.length == 0)
enum sum = 0;
else
enum sum = U[0]+sum!(U[1..$]);
}
void main()
{
enum s = sum!(1,2,3,4);
writeln(s);
}
You can also do it with a standard function, and forcing its
execution
at compile-time by using 'enum':
U[0] sum(U...)(U u) if (U.length 0)
{
U[0] result =0;
foreach(value;u)
result += value;
return result;
}
void main()
{
enum s = sum(1,2,3,4);
writeln(s);
}
Note that doing that without any check on the U's is a bit
dangerous.
I just wanted to do something like template,that takes value
parametres and deduce it's types,so I guess that I can use code
that you wrote for it with some type checking.
compiler assertion
Hi!
Is it normally,that this simple code does'nt compile with this
assertion:
dmd: template.c:5542: Identifier*
TemplateInstance::genIdent(Objects*): Assertion `global.errors'
failed.
import std.stdio;
import std.typetuple;
template sum(T:TypeTuple!U,U...)
{
static if(U.length == 0)
enum sum = 0;
else
enum sum = U[0]+sum!(U[1..$]);
}
void main()
{
enum s = sum!(1,2,3,4);
writeln(s);
}
?
Re: compiler assertion
On Friday, 28 September 2012 at 20:27:07 UTC, Jonathan M Davis wrote: On Friday, September 28, 2012 22:19:56 Zhenya wrote: Hi! Is it normally,that this simple code does'nt compile with this assertion: dmd: template.c:5542: Identifier* TemplateInstance::genIdent(Objects*): Assertion `global.errors' failed. It's always a bug in the compiler if you see a compiler assertion. What you're seeing is probably this bug: http://d.puremagic.com/issues/show_bug.cgi?id=8421 - Jonathan M Davis Thank you,understood.
