Ada code snippet help (array of arrays)

Ada code snippet help (array of arrays)

[Vamp4L]

Trying to figure out why my code doesn't work
This line in particular doesn't compile "if Theater(Seat)(reserved) =
F then" :

with Ada.Text_Io; use Ada.Text_Io;
procedure Ch4Ex22 is
   package Int_Io is new Integer_Io(Integer);
   use Int_Io;
   package Boolean_Io is new Enumeration_Io(Boolean);
   use Boolean_Io;

   T: constant Boolean := True;
   F: constant Boolean := False;
   type Seatattributes is (Reserved, Balcony);
   type SeatType is array(SeatAttributes) of Boolean;
   type Theater is array (1..50) of SeatType;
   A: Theater := (1=>(T,F),2..7=>(F,F),8=>(T,F),9..15=>(F,F),16=>
(T,F),
      17..23=>(F,F),24=>(T,F),25..29=>(F,F),30..31=>(F,T),32=>(T,T),
33..49=>(F,T),50=>(T,T));

   begin

      for Seat in Theater'range loop
         if Theater(Seat)(reserved) = F then
            Put(Seat, 1); New_Line;
         end if;
      end loop;

end Ch4Ex22;

Re: Ada code snippet help (array of arrays)

[Georg Bauhaus]

Vamp4L schrieb:
> Trying to figure out why my code doesn't work
> This line in particular doesn't compile "if Theater(Seat)(reserved) =
> F then" :
> 
> with Ada.Text_Io; use Ada.Text_Io;
> procedure Ch4Ex22 is
>    package Int_Io is new Integer_Io(Integer);
>    use Int_Io;
>    package Boolean_Io is new Enumeration_Io(Boolean);
>    use Boolean_Io;
> 
>    T: constant Boolean := True;
>    F: constant Boolean := False;
>    type Seatattributes is (Reserved, Balcony);
>    type SeatType is array(SeatAttributes) of Boolean;
>    type Theater is array (1..50) of SeatType;
>    A: Theater := (1=>(T,F),2..7=>(F,F),8=>(T,F),9..15=>(F,F),16=>
> (T,F),
>       17..23=>(F,F),24=>(T,F),25..29=>(F,F),30..31=>(F,T),32=>(T,T),
> 33..49=>(F,T),50=>(T,T));
> 
>    begin
> 
>       for Seat in Theater'range loop
>          if Theater(Seat)(reserved) = F then

"Theater" is the name of a type. I guess you meant
the array object A?

>             Put(Seat, 1); New_Line;
>          end if;
>       end loop;
> 
> end Ch4Ex22;


-- 
--
Georg Bauhaus
Y A Time Drain  http://www.9toX.de

Re: Ada code snippet help (array of arrays)

[Vamp4L]

Thanks, I figured it was something stupid :)

Re: Ada code snippet help (array of arrays)

[Jacob Sparre Andersen]

Vamp4L <vampiro4l@gmail.com> writes:

>    F: constant Boolean := False;

>          if Theater(Seat)(reserved) = F then

The common way to write this is:

           if not Theater (Seat) (Reserved) then

Greetings,

Jacob
-- 
�What fun is it being "cool" if you can't wear a sombrero?�

Re: Ada code snippet help (array of arrays)

[Egil Høvik]

On May 13, 4:11 pm, Vamp4L <vampir...@gmail.com> wrote:
> Trying to figure out why my code doesn't work
> This line in particular doesn't compile "if Theater(Seat)(reserved) =
> F then" :
>
> with Ada.Text_Io; use Ada.Text_Io;
> procedure Ch4Ex22 is
>    package Int_Io is new Integer_Io(Integer);
>    use Int_Io;
>    package Boolean_Io is new Enumeration_Io(Boolean);
>    use Boolean_Io;
>
>    T: constant Boolean := True;
>    F: constant Boolean := False;

No need to define your own constants... True and False are
already enumerated values (constants) of type Boolean.

>    type Seatattributes is (Reserved, Balcony);
>    type SeatType is array(SeatAttributes) of Boolean;

Attributes of a type are usually represented as a record:

type Seating is
record
   Reserved : Boolean;
   Balcony : Boolean;
end record;


>    type Theater is array (1..50) of SeatType;
>    A: Theater := (1=>(T,F),2..7=>(F,F),8=>(T,F),9..15=>(F,F),16=>
> (T,F),
>       17..23=>(F,F),24=>(T,F),25..29=>(F,F),30..31=>(F,T),32=>(T,T),
> 33..49=>(F,T),50=>(T,T));
>

How about:

A : Theater := (
   1 | 8 | 16 | 24 => (Reserved => True, Balcony => False),
   2..7 | 9..15 | 17..23 | 25..29 => (Reserved => False, Balcony =>
False),
   30..31 | 33..49 => (Reserved => False, Balcony => True),
   32 | 50 => (Reserved => True, Balcony => True ));

>    begin
>
>       for Seat in Theater'range loop
>          if Theater(Seat)(reserved) = F then
>             Put(Seat, 1); New_Line;
>          end if;
>       end loop;
>
> end Ch4Ex22;

Re: Ada code snippet help (array of arrays)

[Adam Beneschan]

On May 14, 1:05 am, Egil Høvik <egilho...@hotmail.com> wrote:

> >    T: constant Boolean := True;
> >    F: constant Boolean := False;
>
> No need to define your own constants... True and False are
> already enumerated values (constants) of type Boolean.

I think he defined those just for readability.  If you have a large
constant array, it might look better, look more like a chart, take up
less space on the screen, be easier to line up, etc., if you can do it
with shorter names such as single letters.  I've seen this sort of
thing done before.

                              -- Adam

Re: Ada code snippet help (array of arrays)

[Dmitry A. Kazakov]

On Thu, 14 May 2009 08:16:22 -0700 (PDT), Adam Beneschan wrote:

> On May 14, 1:05 am, Egil H�vik <egilho...@hotmail.com> wrote:
> 
>>>    T: constant Boolean := True;
>>>    F: constant Boolean := False;
>>
>> No need to define your own constants... True and False are
>> already enumerated values (constants) of type Boolean.
> 
> I think he defined those just for readability.  If you have a large
> constant array, it might look better, look more like a chart, take up
> less space on the screen, be easier to line up, etc., if you can do it
> with shorter names such as single letters.  I've seen this sort of
> thing done before.

Well, in this case I have a better proposal:

   X : constant Boolean_Array (1..100) :=
          (  1..10 | 13..15 | 45 | 77 => True, others => False);

In fact, need to specify enumeration literals no more than just once!

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de