[fpc-pascal] Re: Generics - how to rewrite TOjectDictionary

[dmitry boyarintsev]

please disregard my last note about "avoiding the sanity check"



On Mon, Apr 8, 2013 at 1:52 PM, dmitry boyarintsev <
skalogryz.lists at gmail.com> wrote:

> You can always use functions, to fight typecasting.
>
> function GetMyObject(dic: TStrings; const nm: string): TMyObject;
> var
>   i : integer;
> begin
>   if not Assigned(dic) then begin Result:=nil; Exit; end;
>   i:=dic.indexof(nm); // replace with IndexOfName if necessary
>   if (i<0) or (i>=dic.Count) or not (i.Objects[i] is TMyObject) then
> Result:=nil
>   else Result:=TMyObject(i.Objects[i]); // not using "as" , since "is" has
> already been used
> end;
>
> Of course, people would use ClassHelpers these days to have nice syntax
> and avoid the sanity check.
>
> thanks,
> Dmitry
>
>
> On Mon, Apr 8, 2013 at 1:42 AM, Marius2 <fpclazarus at home.nl> wrote:
>
>> Thanks Dimitri,
>>
>> Yes, I have used it lots of times and its really the last choice if theres
>> something available like the objectdictionary. In this case the dict is
>> also
>> the owner of the objects, it saves me the continious ugly typecasting,
>> takes
>> care of the extra administration with freeing objects and all the
>> additional
>> troubles you get over time with this solution (its not as bad as i'm
>> telling
>> now). In other words tstrings.objects are working fine, but i find it a
>> bad
>> strategy if you have to use it in flatout in the whole application.
>>
>> I'm curious how to rewrite/solve dictionaries, indexed list and even
>> sorted
>> strings.objects to a neat solution while (if possible) working with both
>> delphi and fpc/laz.
>>
>> Greetings,
>> Marius
>>
>>
>>
>>
>>
>> --
>> View this message in context:
>> http://free-pascal-general.1045716.n5.nabble.com/Generics-how-to-rewrite-TOjectDictionary-tp5714029p5714031.html
>> Sent from the Free Pascal - General mailing list archive at Nabble.com.
>> _______________________________________________
>> fpc-pascal maillist  -  fpc-pascal at lists.freepascal.org
>> http://lists.freepascal.org/mailman/listinfo/fpc-pascal
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freepascal.org/pipermail/fpc-pascal/attachments/20130408/d7727ad9/attachment.html>