Am 09.09.2018 um 16:16 schrieb Michael Van Canneyt:
On Sun, 9 Sep 2018, Ryan Joseph wrote:
It seems syntacticly possible that default properties could be
recursive by having a default property reference a record/class with
another default property. Should that be allowed?
I don't think so. Let's start with 1 level.
For default arrays it's also only one level deep.
Ehm... news flash:
=== code begin ===
{$mode objfpc}
type
TTest1 = class
private
fField: LongInt;
function GetStuff(Index: Integer): Integer;
public
property Stuff[Index: Integer]: Integer read GetStuff; default;
end;
TTest2 = class
private
function GetTest(Index: Integer): TTest1;
public
property Test[Index: Integer]: TTest1 read GetTest; default;
end;
{ TTest2 }
function TTest2.GetTest(Index: Integer): TTest1;
begin
Result := TTest1.Create;
Result.fField := Index;
end;
{ TTest1 }
function TTest1.GetStuff(Index: Integer): Integer;
begin
Result := Index * fField;
end;
var
Test: TTest2;
begin
Test := TTest2.Create;
Writeln(Test[21][2]);
end.
=== code end ===
Compiles and prints
=== output begin ===
42
=== output end ===
Though one can argue that default array properties are used explicitely
using the "[…]"-syntax while a non-array default property is
automatically triggered with ".".
Regards,
Sven
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