🚀 go-pugleaf

In article <4eu2a2$910@dub-news-svc-5.compuserve.com> Alfred 
Lorenz wrote:
>
>Hallo All,
>I tried to create a Method for a TCollection which works
>similar to ForEach or FirstThat. Unfortunately I allways 
>receive a Runtime-Error when calling the Method. I know 
>exactly where the Error occurs but i dont know why. Any
>idea how it could work?
>
>Type
>  PColFunc = ^TColFunc;
>  TColFunc = function(item: Pointer):boolean;
>
>Type
>  PObjSave = ^TObjSave;
>  TObjSave = Object(TCollection)
>    procedure DelEach(Test: pColFunc);
>  end;
>
>procedure TObjSave.DelEach(Test: pColFunc);
>Var AnyObj: Pointer; idx: word; TestFunc: tColFunc;
>begin
>  if Count = 0 then exit;
>  idx:= 0;
>  TestFunc:= Test^;
>  Repeat
>    AnyObj:= At(idx);
>    if TestFunc(AnyObj) then        =>   Runtime-Error!!!
>    Delete(AnyObj)
>    else inc(idx);
>  until idx = count;
>end;
The problem is that the "subfunction" Test pop'd a hidden 
parameter off the stack.  The call to Test has to model a 
call to a subfunction.  I can't think of how to do this with 
out using  assembler.  The simplest solution would be to add 
a "Result:Boolean" to you list of local variables and replace 
the if-statement with --
ASM
   les  AX, [ AnyObj ]
   push ES
   push AX
   push [ BP.Word.0 ]    { pass caller's stack frame ... }
   call DWORD PTR [ Test ]
   mov  [ Result ], AL
END
   If Result Then ...

This should do the trick.

...red