generic arrays?

generic arrays?

[chris]

Hi,

Is it possible to do something like the following?

generic
   NI : Positive;
package P is

   type IV is array (1..NI) of float;

end P;

generic
   type X is ...
package T is


type TP is record
   A : X;
end TP;

end T;

with the ability to make the type of X = type of IV?  I want to 
instansiate T with IV after instantiating P, but don't know what to make 
X.  Is there any way to avoid using an access type to hold X in the 
record TP?  (in the case where type x is an unconstrained array of floats).


Cheers,
Chris

Re: generic arrays?

[Jeffrey Carter]

chris wrote:

> Is it possible to do something like the following?
> 
> generic
>   NI : Positive;
> package P is
>   type IV is array (1..NI) of float;
> end P;
> 
> generic
>   type X is ...
> package T is
>    type TP is record
>      A : X;
>    end TP;
> end T;
> 
> with the ability to make the type of X = type of IV?  I want to 
> instansiate T with IV after instantiating P, but don't know what to make 
> X.  Is there any way to avoid using an access type to hold X in the 
> record TP?  (in the case where type x is an unconstrained array of floats).

I must be misunderstanding something, because this seems easy and basic:

generic
    type X is [limited] private;
package T is
...

with P;
with T;
procedure W is
    package New_P is new P (Ni => 10);
    package New_T is new T (X => New_P.Iv);

    Q : New_T.Tp;
...

-- 
Jeff Carter
"C++ is like jamming a helicopter inside a Miata
and expecting some sort of improvement."
Drew Olbrich
51

Re: generic arrays?

[Jim Rogers]

chris <spamoff.danx@ntlworld.com> wrote in message news:<f4qZb.72$b_4.18@newsfe1-win>...
> Hi,

<snip>
 
> with the ability to make the type of X = type of IV?  I want to 
> instansiate T with IV after instantiating P, but don't know what to make 
> X.  Is there any way to avoid using an access type to hold X in the 
> record TP?  (in the case where type x is an unconstrained array of floats).

Try a discriminated record rather than a generic.

type Foo_Array is array(Positive range <>) of float;

type TP (Max : Positive) is record
   X : Foo_Array(1..Max);
end record;

Jim Rogers

Re: generic arrays?

[chris]

Jeffrey Carter wrote:
> I must be misunderstanding something, because this seems easy and basic:

You're right, it is!  Thanks!