Re: A simple ADA puzzle (I haven't the answer)

[Martin Krischik <krischik@users.sourceforge.net>]

Abby wrote:

> Hi! I have this code:
> 
>   type LEN_TYPE is array (INTEGER range <>)
>     of CHARACTER;
> 
>   type STRING_TYPE (LEN : INTEGER := 0) is
>     record
>       STRING : LEN_TYPE (1 .. LEN);
>     end record;

STRING_TYPE'Size = (2**32 * 8 + 32);

>   type UNC2_ARRAY_TYPE is array (INTEGER range <>)
>     of STRING_TYPE;
> 
>   type RET2_TYPE (INIT : INTEGER := 0) is
>     record
>       IFOS : UNC2_ARRAY_TYPE (1 .. INIT);
>     end record;

RET2_TYPE'Size = ((2**32 * 8 +32) * (2**32 * 8)) +32;

 
>   type RET_TYPE
>        ( DEF : INTEGER := 0 )
>   is
>     record
>       ID  : INTEGER;
>       IFO : RET2_TYPE (INIT => DEF);
>     end record;

RET_TYPE'Size =  ((2**32 * 8 +32) * (2**32 * 8)) +32 + 2 * 32

>   type UNC_ARRAY_TYPE is
>     array (INTEGER range <>) of
>       RET_TYPE;
> 
> and i'd like to initialize and use a variable of type UNC_ARRAY_TYPE (for
> the unconstraint array and records choose any value you want, al least 1
> :) ). I can say that simply write  VAR : UNC_ARRAY_TYPE (1..3);  gives
> :some
> warning but compiles, but gives also a beautiful constraint_error when you
> use it, obviously. Any ideas? Thanx for your time!

Normalise to byte:

RET_TYPE'Storage_Elements =  ((2**32 +4 ) * (2**32)) +4 + 2 *4
RET_TYPE'Storage_Elements =  ((2**32 +4 ) * (2**32)) +12
RET_TYPE'Storage_Elements = 18.446.744.090.889.420.812

So unless you have 17.179.869.200 GB to spare the program is going to fail.

Try something like:

type Max_Len is range 0 .. 255;

type LEN_TYPE is array (Max_Len range <>)

But this will still be a static solution which will wast lots of memory

Maybe using Ada.Unbounded_Strings it the better option. And some component
library with some form of dynamic Array. There are lots of the around.


With Regards

Martin

With Regards

Martin
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