RE: [sv-ec] class construction syntax - new feature proposal

Mirek,

Your proposal seems pretty clear to me - No need to reason about the cast. The one caveat is that we would have to agree that constructors are static methods, which seems eminently reasonable.

	Arturo

-----Original Message-----
From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of Mirek Forczek
Sent: Tuesday, October 07, 2008 12:43 AM
To: 'Steven Sharp'; sv-ec@eda-stds.org; daniel.mlynek@aldec.com
Subject: RE: [sv-ec] class construction syntax - new feature proposal

Hi Steven,

Why not just:

	b = C::new();

followig C++ syntax ? 

Regards,
Mirek

-----Original Message-----
From: owner-sv-ec@server.eda.org [mailto:owner-sv-ec@server.eda.org] On
Behalf Of Steven Sharp
Sent: 3 października 2008 18:51
To: sv-ec@server.eda-stds.org; daniel.mlynek@aldec.com
Subject: Re: [sv-ec] class construction syntax - new feature proposal

This comment is a month late, so I have included the original email at the
end for reference.

An alternative syntax would be to use a cast to the desired class type:

	b = C'(new());
	
A cast is equivalent to an assignment to an intermediate variable of the
cast type.  So this would be equivalent to an assignment to an intermediate
variable of type C.  This would indicate that new() should create an object
of type C, since it is assigning to a variable of type C.

It may seem odd to have an assignment that casts to a type other than that
of the LHS.  The cast is the opposite of the actual conversion that is being
done implicitly, from the derived class to the base class.  You could do
that explicitly if it seemed clearer:

	b = B'(C'(new()));



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>Subject: [sv-ec] class construction syntax - new feature proposal
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>
>There is one annoying thing in object contruction syntax in SV - there 
>is no neat and nice way to create an object of user choosen type and 
>assign it to handle of different (compatybile type) - consider:
> 
>class B;
>endclass
>class C extends B;
>endclass
> 
>C c;
>B b;
> 
>initial begin
>    c=new;
>    b=c; //I have to write 2 lines of code to create and assign object 
>of child type to handle of base type //my proposal is to accept syntax: 
>new <class_type_identifier> - which always creates an object of pointed 
>type and returns handle to it
>    b = new C;
>end
> 
>I haven't found mantis on it and I cannot see any obsticles to add it 
>to LRM.  I've think that this is very usefull - so please consider 
>adding such feature.
> 
> 
>DANiel
>
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Steven Sharp
sharp@cadence.com


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