Problem with anonymous arrays

Problem with anonymous arrays

[Delf]

Hi.
I've got a little problem:

/CODE/
...
   N: constant Integer := 4;

   protected Choice is
      entry EnterOnRP (I: Integer);
      procedure ExitTheRP;
   private
      WhoCanPass: Integer := -1;
      MAXCARS: Integer := 5;
      NbCarsOnRP: Integer := 0;
      WantToGo: array(0..(N - 1)) of Boolean := (0..(N - 1) => FALSE);
   end Choice;
...
\CODE\

When I compile, I obtain the following message:
Giratoire.adb:17:17: anonymous arrays not allowed as components

What I have to modify ?
Thanks a lot.

--
Delf

Re: Problem with anonymous arrays

[Lutz Donnerhacke]

* Delf wrote:
>    N: constant Integer := 4;
>
>    protected Choice is
>       entry EnterOnRP (I: Integer);
>       procedure ExitTheRP;
>    private
>       WhoCanPass: Integer := -1;
>       MAXCARS: Integer := 5;
>       NbCarsOnRP: Integer := 0;
>       WantToGo: array(0..(N - 1)) of Boolean := (0..(N - 1) => FALSE);
>    end Choice;
>
> When I compile, I obtain the following message:
> Giratoire.adb:17:17: anonymous arrays not allowed as components
>
> What I have to modify ?

type Bool_Array is array (0 .. (N-1) of Boolean;
protected type Choice is
  ...
  WantToGo : Bool_Array := (others => False);
end Choice;

Re: Problem with anonymous arrays

[Delf]

Le Sat, 24 Apr 2004 23:26:53 +0000, Lutz Donnerhacke a ecrit:

> type Bool_Array is array (0 .. (N-1) of Boolean;
> protected type Choice is
>   ...
>   WantToGo : Bool_Array := (others => False);
> end Choice;

Thanks for your help.

--
Delf

Re: Problem with anonymous arrays

[Delf]

Le Sun, 25 Apr 2004 00:46:34 +0200, Delf a ecrit:

> /CODE/
> ...
>    N: constant Integer := 4;
> 
>    protected Choice is
>       entry EnterOnRP (I: Integer);
>       procedure ExitTheRP;
>    private
>       WhoCanPass: Integer := -1;
>       MAXCARS: Integer := 5;
>       NbCarsOnRP: Integer := 0;
>       WantToGo: array(0..(N - 1)) of Boolean := (0..(N - 1) => FALSE);
>    end Choice;
> ...
> \CODE\

+ line 

entry EnterGiratoire (I: Integer) when NbCarsOnRP = 0 or (NbCarsOnRP > 0 and NbCarsOnRP < MAXCARS and I = WhoCanPass) is

But gnatmake says: Giratoire.adb:35:109: "I" is undefined

So I can't use I... How to do to counter this error ?
Thanks.

--
Delf

Re: Problem with anonymous arrays

[Lutz Donnerhacke]

* Delf wrote:
> entry EnterGiratoire (I: Integer) when NbCarsOnRP = 0 or (NbCarsOnRP > 0
> and NbCarsOnRP < MAXCARS and I = WhoCanPass) is
>
> But gnatmake says: Giratoire.adb:35:109: "I" is undefined

I is defined AFTER the guard is passed.
If you like to access parameters TO the guard you have to use entry families:

type Family is range 1 .. 16;
protected type XXX is
  entry EnterGiratoire(Family)(other: Parameter);
end XXX;

protected body XXX is
  entry EnterGiratoire(for I in Family)(other : Parameter)
   when ... I = WhoCanPass is
  begin
     ...
  end EnterGiratoire;
end XXX;

Please note, that entry families can be instantiated as separate procedures
for each possible value of the family parameter. So the usable range of
values is limited. GNAT allows the whole Integer range, but fails miserably
in instantiating with Storage_Error.

Re: Problem with anonymous arrays

[Lutz Donnerhacke]

* Delf wrote:
> entry EnterGiratoire (I: Integer) when NbCarsOnRP = 0 or (NbCarsOnRP > 0
> and NbCarsOnRP < MAXCARS and I = WhoCanPass) is
>
> But gnatmake says: Giratoire.adb:35:109: "I" is undefined

I is defined AFTER the guard is passed.
If you like to provide parameters TO the guard you have to use entry families:

type Family is range 1 .. 16;
protected type XXX is
  entry EnterGiratoire(Family)(other: Parameter);
end XXX;

protected body XXX is
  entry EnterGiratoire(for I in Family)(other : Parameter)
   when ... I = WhoCanPass is
  begin
     ...
  end EnterGiratoire;
end XXX;

Please note, that entry families can be instantiated as separate procedures
for each possible value of the family parameter. So the usable range of
values is limited. GNAT allows the whole Integer range, but fails miserably
in instantiating with Storage_Error.