Anonymous array not allowed as components

Anonymous array not allowed as components

[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

Re: Anonymous array not allowed as components

[joakimds]

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

Re: Anonymous array not allowed as components

[L Dries]

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

Re: Anonymous array not allowed as components

[Jeffrey R. Carter]

On 11/1/19 10:34 AM, joakimds@kth.se wrote:
> 
> Unbounded_String is well-known for being "slow" ...

I worked on a fairly large, distributed, soft-real-time system that made 
extensive use of Unbounded_String, so it's certainly "fast" enough for that.

Nothing is "slow" or "fast" in isolation; such concepts are meaningful only in 
comparison to quantified timing requirements. Statements like this are only 
encouragement to commit premature optimization.

-- 
Jeff Carter
"It is the German who is so uncourteous to his verbs."
A Scandal in Bohemia
122

Re: Anonymous array not allowed as components

[AdaMagica]

Am Freitag, 1. November 2019 09:32:42 UTC+1 schrieb L Dries:
> I have an need for an array of Unbounded_Strings in which i define the 
> elements.
> 
> I declared it as:
>
type Container is record
      ...
>        Debug_Proc   : array (1 .. nr_Proc) of Unbounded_String :=
>          (Debug_Proc(Lan),
>           To_Unbounded_String("Only"),
>           To_Unbounded_String("Empty_Buffer"),
>           ...
>           etc.
end record;
> 
> Then I got the message:
> 
> 65:22 Anonymous array not allowed as components
> This results i a position just before "array"

Reading the compiler message, I get the impression that your Debug_Prog is a component of another record. Just define a matching type and use an object of this type as component.

Re: Anonymous array not allowed as components

[L Dries]

Op 1-11-2019 om 10:34 schreef AdaMagica:
>        ...
I found 1 failure in the code
Debug_Proc(Lan) must be Debug_NoProc(Lan)
but that does not solve the problem.
I just saw some information that i was not aware of:
It looks like the builder is creating the failure

-- 
L. Dries

Re: Anonymous array not allowed as components

[L Dries]

Op 1-11-2019 om 10:34 schreef AdaMagica:
> Am Freitag, 1. November 2019 09:32:42 UTC+1 schrieb L Dries:
>> I have an need for an array of Unbounded_Strings in which i define the
>> elements.
>>
>> I declared it as:
>>
> type Container is record
>        ...
>>         Debug_Proc   : array (1 .. nr_Proc) of Unbounded_String :=
>>           (Debug_Proc(Lan),
>>            To_Unbounded_String("Only"),
>>            To_Unbounded_String("Empty_Buffer"),
>>            ...
>>            etc.
> end record;
>>
>> Then I got the message:
>>
>> 65:22 Anonymous array not allowed as components
>> This results i a position just before "array"
> 
> Reading the compiler message, I get the impression that your Debug_Prog is a component of another record. Just define a matching type and use an object of this type as component.
> 
I just found the following solution

       type Combo_Entry is array (1 .. nr_Proc) of Unbounded_String;

       Debug_Proc   : Combo_Entry :=
         (Debug_NoProc(Lan),
          To_Unbounded_String("Only"),
          To_Unbounded_String("Empty_Buffer"),
          ...

This does not give the error anymore

-- 
L. Dries

Re: Anonymous array not allowed as components

[AdaMagica]

Am Freitag, 1. November 2019 11:33:57 UTC+1 schrieb L Dries:
> I just found the following solution
> 
>        type Combo_Entry is array (1 .. nr_Proc) of Unbounded_String;
> 
>        Debug_Proc   : Combo_Entry :=
>          (Debug_NoProc(Lan),
>           To_Unbounded_String("Only"),
>           To_Unbounded_String("Empty_Buffer"),
>           ...
> 
> This does not give the error anymore
> 
> -- 
> L. Dries

Yes, that's exactly what I meant.

Re: Anonymous array not allowed as components

[Jeffrey R. Carter]

On 11/1/19 9:32 AM, L Dries wrote:
> 
> Then I got the message:
> 
> 65:22 Anonymous array not allowed as components
> 
> What do I do wrong?

 From the error msg, I would guess that you're trying to use an anonymous array 
as a component. As the msg says, this is not allowed. You need to use a named 
array type.

-- 
Jeff Carter
"It is the German who is so uncourteous to his verbs."
A Scandal in Bohemia
122