I found an article about component programming that I completely agree with. Here it is:

http://www.artima.com/intv/simplexity.html

First class support for properties, delegates, signals and slots will open a brave new world for D...it will make it competitive with C# which quickly becomes the most preferred programming language around the globe.

I see all this talk of signals and slots, cant these things be implemented really easily ?  Im not sure I see any merit it making it part of the language.

Charles
"Achilleas Margaritis" <axilmar@b-online.gr> wrote in message
news:bjb5df$2o5p$1@digitaldaemon.com...
> I found an article about component programming that I completely agree
with.
> Here it is:
>
> http://www.artima.com/intv/simplexity.html
>
> First class support for properties, delegates, signals and slots will open
a
> brave new world for D...it will make it competitive with C# which quickly becomes the most preferred programming language around the globe.
>
>
>
>

Charles Sanders wrote:
> I see all this talk of signals and slots, cant these things be implemented
> really easily ?  Im not sure I see any merit it making it part of the
> language.

If something is "implemented really easily", the fact that you can do so should not need to be phrased as a question.

I think the article makes some excellent points.  Simplicity for me is not when its easy for me to do, but when its easy for someone else to understand and use straight away.

"Achilleas Margaritis" <axilmar@b-online.gr> escreveu na mensagem news:bjb5df$2o5p$1@digitaldaemon.com...
> I found an article about component programming that I completely agree
with.
> Here it is:
>
> http://www.artima.com/intv/simplexity.html
>
> First class support for properties, delegates, signals and slots will open
a
> brave new world for D...it will make it competitive with C# which quickly becomes the most preferred programming language around the globe.

Using your example (from other thread) I don't see why signals and slots should be part of the language, but I see why implicit template instantiation is desirable. Your example was:


> class Window {
>     public signal onMouseMove(Event &event);
> }
>
> class Button {
>     public slot mouseMoved(Event &event);
> }
>
> Button btn;
> btn.onMouseMove += mouseMoved;


With implicit template instantiation you could write:


class Window {
    public Signal onMouseMove = ...;
}

class Button {
    public Slot mouseMoved = ...;
}

Button btn;
btn.onMouseMove ~= mouseMoved;


and everything should work ok (I use ~= instead of += because it's D way of appending to a data structure). Today with explicit template instantiation we need some more keywords:


class Window {
    private alias instance TSignal(Event).Signal Signal;
    public Signal onMouseMove;
}

class Button {
    private alias instance TSlot(Event).Slot Slot;
    public Slot mouseMoved;
}

Button btn;
btn.onMouseMove ~= mouseMoved;


With implicit instatiation the compiler should be able to figure out the template parameter "Event" on the body of the "onMouseMove" and "mouseMoved" declarations (essentially delegates).

    Best regards,
    Daniel Yokomiso.

"Daddy, why doesn't this magnet pick up this floppy disk?"


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> ...it will make it competitive with C# which quickly
> becomes the most preferred programming language around the globe.

I tend to disagree here. What is the basis for this statement?

Jotham wrote:

> Charles Sanders wrote:
> 
>> I see all this talk of signals and slots, cant these things be implemented
>> really easily ?  Im not sure I see any merit it making it part of the
>> language.
> 
> 
> If something is "implemented really easily", the fact that you can do so should not need to be phrased as a question.
> 
> I think the article makes some excellent points.  Simplicity for me is not when its easy for me to do, but when its easy for someone else to understand and use straight away.

Sounds like all we need is for a slot template to be added to Phobos.

 -- andy

"Achilleas Margaritis" <axilmar@b-online.gr> wrote in message news:bjb5df$2o5p$1@digitaldaemon.com...
> I found an article about component programming that I completely agree
with.
> Here it is:
>
> http://www.artima.com/intv/simplexity.html
>

BTW, the fact that delegation does not break overloading to me makes it look more like syntactic sugar that is really an interface. I wonder how they can claim to resolve such overloads at compile time. For example, given some method

m ( X someObject )
{
    delegate d = someObject.func;
}

and a class Y : X {
    void func()  { ... }     // overloads X.func
}

how can they know in advance that d will be pointing toY.func() when m(y) is called? Y could be compiled separately. Perhaps the virtual table needs only be walked once (at the point where d is assigned) and then calling the delegate becomes a simple call instruction. But to me it needs to be resolved at run time. And moreover, you lose the information that the object being called was 'y' (or not? do they store the reference too?)

"Jeroen van Bemmel" <someone@somewhere.com> wrote in message news:bjclpp$1vvr$1@digitaldaemon.com...
> > ...it will make it competitive with C# which quickly
> > becomes the most preferred programming language around the globe.
>
> I tend to disagree here. What is the basis for this statement?
>
>

The amount of articles and internet "noise" around the subject. From reading newsgroups, message boards and articles I highly get the impression that that C# is quickly becoming very popular. Of course, I don't have statistics in my hand, nor I imply that it is the most used development environment.

Achilleas Margaritis wrote:
> The amount of articles and internet "noise" around the subject. From reading
> newsgroups, message boards and articles I highly get the impression that
> that C# is quickly becoming very popular. Of course, I don't have statistics
> in my hand, nor I imply that it is the most used development environment.

Just look at MONO and DOTNET - this projets got a boost hardly comparable with any other compiler development effort out there!

Besides, i see people leaving from D to C#, but not yet the other way around...

The fact is, we cannot close our eyes. C# is a real rival to D, probably to a further extent than C++ and certainly more than Java.

-eye

> The fact is, we cannot close our eyes. C# is a real rival to D, probably to a further extent than C++ and certainly more than Java.

I agree with this. No-one really kids themselves that Java's efficient on Win32. And few C++ people (myself included) think that D is a rival. I see D as being primarily a better .NET, though not 100%. Probably its "market" is 20% C, 20% C++, 50% .NET, 10% Java. (But that's only my opinion, of course. ;) )