record default

[ginoo]

Code: Pascal  [Select][+][-]

1.  ciccio = record
2.     a : Integer;
3.     class operator Initialize(var value:ciccio);
4.   end;
5.  
6. var
7.   c : ciccio;
8.  
9. { ciccio }
10.  
11. class operator ciccio.Initialize(var value: ciccio);
12. begin
13.   value.a:=3;
14. end;
15.  
16. begin
17.   WriteLn(c.a);
18.   c.a := 10;
19.   WriteLn(c.a);
20.   c := Default(ciccio);
21.   WriteLn(c.a);
22.  
23. end.    
24.  

In my opinion, calling the record's default should call Initialize and set ciccio.a = 3.
What is the way, if any, to reinitialize a record after modifying it?

[Thaddy]

The behavior of Default() is as documented. To reset the record to 3, set the field to 3

[Khrys]

What is the way, if any, to reinitialize a record after modifying it?

Code: Pascal  [Select][+][-]

1. Initialize(c);

[ginoo]

What is the way, if any, to reinitialize a record after modifying it?

Code: Pascal  [Select][+][-]

1. Initialize(c);

It works.
Does it make sense to also call "finalize" at the end after calling "Initialize," or is it not important since it's a non-dynamic variable?

[Thaddy]

Only if your record contains managed types.

[ginoo]

Only if your record contains managed types.

Dear @Thaddy, I'm considering using inizialeze because it's cleaner to have a single initializer for record fetching with a lot of code. There are probably other ways, but I think this one is valid.

[Thaddy]

I was referring to finalize...

[Warfley]

In my opinion, calling the record's default should call Initialize and set ciccio.a = 3.
What is the way, if any, to reinitialize a record after modifying it?

Yes your opinion is right and in trunk this is fixed.

Until it is in stable instead of using default do the following:

Code: Pascal  [Select][+][-]

1. generic procedure SetDefault<T>(var AVar: T);
2. begin
3.   Finalize(AVar);
4.   Initialize(AVar);
5. end;

Or

Code: Pascal  [Select][+][-]

1. generic function ManagedDefault<T>:T;
2. begin {nothing needed} end;

[ginoo]

Just curious, I tried putting a managed type on the record and not using finalize. However, it says there's no memory leak. What's the problem with not calling "finalize"?

Code: Pascal  [Select][+][-]

1. type
2. ciccio = record
3.    a : String;
4.    class operator Initialize(var value:ciccio);
5.  end;
6.  
7. var
8.  c : ciccio;
9.  
10. { ciccio }
11.  
12. class operator ciccio.Initialize(var value: ciccio);
13. begin
14.  value.a:='pippo';
15. end;
16.  
17. begin
18.  WriteLn(c.a);
19.  c.a := 'caio';
20.  WriteLn(c.a);
21.  Initialize(c);
22.  c.a := 'caio2';
23.  WriteLn(c.a);
24.  Initialize(c);
25.  c.a := 'caio3';
26.  WriteLn(c.a);
27.  Initialize(c);
28.  WriteLn(c.a);
29. end.
30.  

     
0 memory blocks allocated : 0/0
0 memory blocks freed     : 0/0
0 unfreed memory blocks : 0
True heap size : 0
True free heap : 0

[Warfley]

Because StringConstants are not reference counted, because they are hardcoded in the program data.

Change your code to the following:

Code: Pascal  [Select][+][-]

1. c.a:='calo';
2. UniqueString(c.a);
3. ...

And try again. UniqueString makes sure that you have a unique copy of the string, which allocates a new memory object

[ginoo]

Yes, you're right. Thank you all.

[PascalDragon]

  ciccio = record
    a : Integer;
    class operator Initialize(var value:ciccio);
  end;

var
  c : ciccio;
[snip]

Please use [code][/code]-tags to make the code better visible and also to avoid the forum software potentially interpreting the code.

[ginoo]

Done

[PascalDragon]

Done

Thank you.