GNAT GPL - Anonymous Access Type

GNAT GPL - Anonymous Access Type

[Anh Vo]

I got this error message "type declaration cannot refer to itself" when
compiling the record below.

type Node is
   record
      Value : Integer := 0;
      Next : access Node;
   end record;

I have the impression that this feature has not been implemented based
on this error. What do you guys think?

AV

Re: GNAT GPL - Anonymous Access Type

[Georg Bauhaus]

Anh Vo wrote:
> I got this error message "type declaration cannot refer to itself" when
> compiling the record below.
> 
> type Node is
>    record
>       Value : Integer := 0;
>       Next : access Node;
>    end record;
> 
> I have the impression that this feature has not been implemented based
> on this error. What do you guys think?

It is supported in GCC 4.1, -gnat05.

Re: GNAT GPL - Anonymous Access Type

[Alex R. Mosteo]

Anh Vo wrote:
> I got this error message "type declaration cannot refer to itself" when
> compiling the record below.
> 
> type Node is
>    record
>       Value : Integer := 0;
>       Next : access Node;
>    end record;
> 
> I have the impression that this feature has not been implemented based
> on this error. What do you guys think?

It's partially there (or was in latest GAP release, which is older than 
this GPL one). You can use it with types in other packages, for example, 
but either I understand something wrong with this feature and the 
"limited with" or the support is partial, since I couldn't do anything 
useful with these. I ran pretty quickly in some restrictions that 
prevented circular referencing.

Re: GNAT GPL - Anonymous Access Type

[Rob Norris]

On 27 Sep 2005 12:41:30 -0700, "Anh Vo" <anhvofrcaus@gmail.com> wrote:

>I got this error message "type declaration cannot refer to itself" when
>compiling the record below.
>
>type Node is
>   record
>      Value : Integer := 0;
>      Next : access Node;
>   end record;
>
>I have the impression that this feature has not been implemented based
>on this error. What do you guys think?
>
>AV

I think you need to declare Node first. Eg:

type Node; -- Declaration
type Node_Ptr is access Node;

-- Full definition
type Node is
   record
      Value : Integer := 0;
      Next  : Node_Ptr;
end record;	

Re: GNAT GPL - Anonymous Access Type

[Martin Dowie]

Rob Norris wrote:
> I think you need to declare Node first. Eg:

Yeah, that's Ada95 but the OP's version was trying to use the Ada2005 way of
doing this.

Cheers

-- Martin

Re: GNAT GPL - Anonymous Access Type

[Anh Vo]

Martin Dowie wrote:
> Rob Norris wrote:
> > I think you need to declare Node first. Eg:
>
> Yeah, that's Ada95 but the OP's version was trying to use the Ada2005 way of
> doing this.
>
> Cheers
>
> -- Martin

That is correct. In addition, Ada 2005 was the intention when I put
GNAT GPL in the subject.

AV

Re: GNAT GPL - Anonymous Access Type

[Anh Vo]

Thanks for your info. Currently, I could build gcc-4.1 for Red Hat
only. Just for info, the latest gcc-4.1 snapshot fails to build because
of Internal Compiler Error (ICE) / Bug Box.

AV

Re: GNAT GPL - Anonymous Access Type

[Jeffrey R. Carter]

Anh Vo wrote:

> I got this error message "type declaration cannot refer to itself" when
> compiling the record below.
> 
> type Node is
>    record
>       Value : Integer := 0;
>       Next : access Node;
>    end record;
> 
> I have the impression that this feature has not been implemented based
> on this error. What do you guys think?

Did you use -gnat05?

-- 
Jeff Carter
"You tiny-brained wipers of other people's bottoms!"
Monty Python & the Holy Grail
18

Re: GNAT GPL - Anonymous Access Type

[Anh Vo]

You bet I did. By the way, it worked in gcc-4.1 for Red Hat as
suggested by Georg Bauhaus.

AV

Re: GNAT GPL - Anonymous Access Type

[Britt Snodgrass]

It works with GNATMAKE Pro 5.04w (20050907-34)
but not with GNATMAKE Pro 5.03a (20050114-34), both tried with -gnat05,
so it looks like a recent addition to GNATPRO.

Britt

Re: GNAT GPL - Anonymous Access Type

[Simon Wright]

"Britt Snodgrass" <britt.snodgrass@gmail.com> writes:

> It works with GNATMAKE Pro 5.04w (20050907-34)
> but not with GNATMAKE Pro 5.03a (20050114-34), both tried with -gnat05,
> so it looks like a recent addition to GNATPRO.

With 4.0.0, I get

grendel:~/cf simon$ gnatgcc -c -gnatc ttt.ads
ttt.ads:5:15: generalized use of anonymous access types is an Ada 2005 extension
ttt.ads:5:15: unit must be compiled with -gnat05 switch

but disappointingly

grendel:~/cf simon$ gnatgcc -c -gnatc -gnat05 ttt.ads
ttt.ads:5:24: type declaration cannot refer to itself

OT: Re: GNAT GPL - Anonymous Access Type

[Martin Dowie]

Simon Wright wrote:
> "Britt Snodgrass" <britt.snodgrass@gmail.com> writes:
>
>> It works with GNATMAKE Pro 5.04w (20050907-34)
>> but not with GNATMAKE Pro 5.03a (20050114-34), both tried with
>> -gnat05, so it looks like a recent addition to GNATPRO.
>
> With 4.0.0, I get
>
> grendel:~/cf simon$ gnatgcc -c -gnatc ttt.ads
> ttt.ads:5:15: generalized use of anonymous access types is an Ada
> 2005 extension ttt.ads:5:15: unit must be compiled with -gnat05 switch
>
> but disappointingly
>
> grendel:~/cf simon$ gnatgcc -c -gnatc -gnat05 ttt.ads
> ttt.ads:5:24: type declaration cannot refer to itself

"grendel" - marillion fan Simon? or is it the anglo-saxon poetry? :-)

Re: GNAT GPL - Anonymous Access Type

[Rob Norris]

On Wed, 28 Sep 2005 11:57:47 +0100, "Martin Dowie"
<martin.dowie@baesystems.com> wrote:

>Rob Norris wrote:
>> I think you need to declare Node first. Eg:
>
>Yeah, that's Ada95 but the OP's version was trying to use the Ada2005 way of
>doing this.
>
>Cheers
>
>-- Martin
>

I see:
http://en.wikibooks.org/wiki/Ada_Programming/Types/access#Anonymous_access

Perhaps GNAT GPL doesn't do the full 2005.

Re: GNAT GPL - Anonymous Access Type

[Anh Vo]

I agree since the new package Ada.Real_Time.Execution_Time does not
exist yet.

AV

Re: GNAT GPL - Anonymous Access Type

[Martin Dowie]

Anh Vo wrote:
> I agree since the new package Ada.Real_Time.Execution_Time does not
> exist yet.

I have a version of this that works for ObjectAda on Windows if anyone 
would like it...

Cheers

-- Martin

Re: OT: Re: GNAT GPL - Anonymous Access Type

[Simon Wright]

"Martin Dowie" <martin.dowie@baesystems.com> writes:

> Simon Wright wrote:

>> grendel:~/cf simon$ gnatgcc -c -gnatc -gnat05 ttt.ads
>> ttt.ads:5:24: type declaration cannot refer to itself
>
> "grendel" - marillion fan Simon? or is it the anglo-saxon poetry? :-)

I was running out of dragons' names -- smaug, fafnir, tiamat, orm, ...
(I just checked out fafnir, would you believe www.godchecker.com!!)

Re: GNAT GPL - Anonymous Access Type

[Anh Vo]

Martin Dowie wrote:
> Anh Vo wrote:
> > I agree since the new package Ada.Real_Time.Execution_Time does not
> > exist yet.
>
> I have a version of this that works for ObjectAda on Windows if anyone
> would like it...
>
> Cheers
>
> -- Martin

Did you mean that ObjectAda on Windows has implemented Ada 2005 syntax.
If it is true, yes I would like get my hand on it. Thanks.

AV

Re: GNAT GPL - Anonymous Access Type

[Martin Dowie]

Anh Vo wrote:
> Martin Dowie wrote:
> 
>>Anh Vo wrote:
>>
>>>I agree since the new package Ada.Real_Time.Execution_Time does not
>>>exist yet.
>>
>>I have a version of this that works for ObjectAda on Windows if anyone
>>would like it...
>>
>>Cheers
>>
>>-- Martin
> 
> 
> Did you mean that ObjectAda on Windows has implemented Ada 2005 syntax.
> If it is true, yes I would like get my hand on it. Thanks.

No, I mean that I have an implementation for 
Ada.Real_Time.Execution_Time for ObjectAda for Windows.

Cheers

-- Martin

Re: OT: Re: GNAT GPL - Anonymous Access Type

[Martin Dowie]

Simon Wright wrote:
> "Martin Dowie" <martin.dowie@baesystems.com> writes:
>
>> Simon Wright wrote:
>
>>> grendel:~/cf simon$ gnatgcc -c -gnatc -gnat05 ttt.ads
>>> ttt.ads:5:24: type declaration cannot refer to itself
>>
>> "grendel" - marillion fan Simon? or is it the anglo-saxon poetry? :-)
>
> I was running out of dragons' names -- smaug, fafnir, tiamat, orm, ...
> (I just checked out fafnir, would you believe www.godchecker.com!!)

I'd believe anything on the net these days... ;-)

Re: OT: Re: GNAT GPL - Anonymous Access Type

[Martin Dowie]

Martin Dowie wrote:
> Simon Wright wrote:
>> "Martin Dowie" <martin.dowie@baesystems.com> writes:
>>
>>> Simon Wright wrote:
>>
>>>> grendel:~/cf simon$ gnatgcc -c -gnatc -gnat05 ttt.ads
>>>> ttt.ads:5:24: type declaration cannot refer to itself
>>>
>>> "grendel" - marillion fan Simon? or is it the anglo-saxon poetry?
>>> :-)
>>
>> I was running out of dragons' names -- smaug, fafnir, tiamat, orm,
>> ... (I just checked out fafnir, would you believe
>> www.godchecker.com!!)
>
> I'd believe anything on the net these days... ;-)

Like this: http://www.simonkelk.co.uk/sizeofwales.html :-)

Re: GNAT GPL - Anonymous Access Type

[Martin Dowie]

Martin Dowie wrote:
> No, I mean that I have an implementation for
> Ada.Real_Time.Execution_Time for ObjectAda for Windows.

Except it's actually called "Ada.Execution_Time". ;-)