I found something clever! short way to define a RECORD with a couple of values.

[jamie]

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4. {$modeSwitch AdvancedRecords}
5.  
6. interface
7.  
8. uses
9.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls;
10.  
11. type
12.  
13.   { TForm1 }
14.  TMyRecord = Record
15.   x,Y:Integer;
16.   Function fReadXY(xx,yy:Integer):TMyRecord; inline;
17.   Public
18.   property XY[xx,yy:integer]:TMyRecord read freadXY; default;
19.  end;
20.  
21.   TForm1 = class(TForm)
22.     Button1: TButton;
23.     procedure Button1Click(Sender: TObject);
24.   private
25.  
26.   public
27.  
28.   end;
29.  
30. var
31.   Form1: TForm1;
32.  
33. implementation
34. {$R *.lfm}
35. Function TMyRecord.fReadXY(xx,yy:Integer):TMyRecord;
36. Begin
37.  x := xx;
38.  y := yy;
39.  result := Self;
40. End;
41. { TForm1 }
42. Procedure Displayit(AR:TMyRecord); overload;
43. begin
44.   Form1.Caption := Ar.x.Tostring+','+AR.y.Tostring;
45. end;
46. procedure TForm1.Button1Click(Sender: TObject);
47. Var
48.   Y,Z:TMyrecord;
49. begin
50.   Y[10,40]; // this works;
51.   DisplayiT(Z[1000,45]);// This works as value
52. end;
53.  
54. end.
55.  
56.  

Now I can Add the constructor in there so that we can create parametrize instances, but I found this interesting because I can assign and test it inline with an if statement I believe, Haven't don't that yet

[jamie]

An update to this use.
The records I have do have Constructors already and I found that I did not need to add a function, I can call the constructor and it works the same it seems. so no need to add a function.

Code: Pascal  [Select][+][-]

1. // within the Reocord
2. Property C[x,y:Integer]:TMyPoint Read Create; default;
3.  

With that you can shorthand the call to the Constructor.

so in code

Code: Pascal  [Select][+][-]

1. Var
2.  A,B:TMyPoint;
3. Begin
4.   A[x,y];
5.   B:= A[x,y]
6.  //on so on.
7.  

This saves me tons of typing !

Also, I noticed it only works with a READ accessor, Write accessor does not seem to be accepted.

[JdeHaan]

Nice idea!

Code: Pascal  [Select][+][-]

1. program records;
2. {$mode delphi}
3.  
4.   TLocal = record
5.     Name: ShortString;
6.     Level: Integer;
7.     Captured: Boolean;
8.     constructor Create(aName: String; aLevel: Integer; aCaptured: Boolean);
9.     property Value[aName: String; aLevel: Integer; aCaptured: Boolean]:TLocal read Create; default;
10.   end;
11.  
12. constructor TLocal.Create(aName: String; aLevel: Integer; aCaptured: Boolean);
13. begin
14.   Name := aName;
15.   Level := aLevel;
16.   Captured := aCaptured;
17. end;
18.  
19. var
20.   Local: TLocal;
21.  
22. begin
23.   Local['Name', 42, True];
24.   Writeln(Local.Name, ', ', Local.Level, ', ', Local.Captured);
25. end.
26.  

It works with ShortString fields, but not with fields of type String.

[jamie]

Managed types, I never tried that. I normally use primitive types.


you could try to prefix the NAME with Self.NAME := aName;

[jamie]

You may want to try using the DEFAULT(Self) while in the constructor before setting the strings.

[jamie]

It seems a Constructor does not work well with managed types.

back to using a function instead which works for managed types.

[JdeHaan]

Confirmed: with a function you can use a managed type.

Code: Pascal  [Select][+][-]

1.   TLocal = record
2.     Name: String;
3.     Level: Integer;
4.     Captured: Boolean;
5.     function Init(aName: String; aLevel: Integer; aCaptured: Boolean): TLocal;
6.     property Value[aName: String; aLevel: Integer; aCaptured: Boolean]:TLocal read Init; default;
7.   end;
8.  
9. function TLocal.Init(aName: String; aLevel: Integer; aCaptured: Boolean): TLocal;
10. begin
11.   Name := aName;
12.   Level := aLevel;
13.   Captured := aCaptured;
14.   Result := Self;
15. end;
16.  
17. begin
18.   Local['Name', 42, True];
19.   Writeln(Local.Name, ', ', Local.Level, ', ', Local.Captured);
20.   // prints 'name', 42, true
21. end.
22.