[fpc-pascal] Caller agnostic procedure variables

[Sven Barth]

Michael Van Canneyt via fpc-pascal <fpc-pascal at lists.freepascal.org>
schrieb am Di., 15. Feb. 2022, 15:29:

>
>
> On Tue, 15 Feb 2022, Ryan Joseph via fpc-pascal wrote:
>
> >
> >
> >> On Feb 15, 2022, at 8:26 PM, Sven Barth via fpc-pascal <
> fpc-pascal at lists.freepascal.org> wrote:
> >>
> >> It's relatively "easy" to implement assigning a nested function to
> function references. However assigning a nested function variable to a
> function reference is much harder.
> >> Assigning a function reference to a nested function variable is hard as
> well.
> >>
> >
> > I'm getting lost with the terms now I think.
> > If your function takes a function reference parameter and you assign it
> a nested function  pointer,
> > this is difficult? I believe this was Michaels request in that code
> snippet.
>
> Sven will need to confirm, but as I understand it:
>
> Procedure DoDemo(aTest : TProc);
>
> Procedure MyTest;
>
>    Procedure DoSub;
>    begin
>    end;
>
> begin
>    DoDemo(DoSub)
> end;
>
> is easy.
>
> but
>
> Procedure DoDemo(aTest : TProc);
>
> Procedure MyTest;
>
> Var
>    ASub : procedure is nested;
>
> begin
>    aSub:=SomeFunctionThatReturnsANestedProc;
>    DoDemo(aSub);
> end;
>
> is difficult.
>

Correct (yes, I saw your addendum).

Regards,
Sven

>
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