Re: Anonymous array not allowed as components

[L Dries <bertus.dries@planet.nl>]

Op 1-11-2019 om 10:34 schreef joakimds@kth.se:
> Den fredag 1 november 2019 kl. 09:32:42 UTC+1 skrev L Dries:
>> I have an need for an array of Unbounded_Strings in which i define the
>> elements.
>>
>> I declared it as:
>>
>>         Debug_Proc   : array (1 .. nr_Proc) of Unbounded_String :=
>>           (Debug_Proc(Lan),
>>            To_Unbounded_String("Only"),
>>            To_Unbounded_String("Empty_Buffer"),
>>            ...
>>            etc.
>>
>> Then I got the message:
>>
>> 65:22 Anonymous array not allowed as components
>> This results i a position just before "array"
>>
>> The value nr_Proc is defined in another package.
>> Debug_Proc(Lan) is an Unbounded String
>> I tried to replace nr_Proc by a value. The same result.
>> I tried to replave the value of the first Unbounded String by "--",
>> again no result
>> I tried set it as an constant array, also no result.
>>
>> What do I do wrong?
>> -- 
>> L. Dries
> 
> Hello L. Dries,
> 
> Unbounded_String is well-known for being "slow" because it does unnecessary heap-allocations. To avoid performance penalty the XString type has been defined in the GNATColl library. The point is that one should have very good reasons to use Unbound_String in one's application and not use it needlessly.
> 
> In your case what you want is to map each integer in an interval to a specific String. If that's the case I recommend taking advantage of expression functions and case statements introduced in Ada 2012:
> 
> type Index is new Integer range 1 .. nr_Proc;
> 
> function Debug_Proc (I : Index) return String is
> (case I is
>    when 1 => "Only",
>    when 2 => "Empty_Buffer", ...);
> 
> or maybe it is:
> 
> function Debug_Proc (I : Index) return String is
> ((case I is
>    when 1 => "Only",
>    when 2 => "Empty_Buffer", ...));
> 
> The compiler will tell you.
> 
> Best regards,
> Joakim
> 

I will look nto that possibility, but for this project it is too late 
because changing would mean almost completely rewriting the program.

-- 
L. Dries