[fpc-pascal] flexible record design

spir ☣ denis.spir at gmail.com
Fri May 28 18:40:38 CEST 2010

On Fri, 28 May 2010 16:03:28 +0200 (CEST)
Michael Van Canneyt <michael at freepascal.org> wrote:

> TStrings provides an abstract interface. It allows you to associate an
> object with each string in the list.
> This means you can do a
>    L.Strings[i]:=Key;
>    L.Objects[i]:=MyObject;
> Or, in 1 statement:
>    L.AddObject(Key,MyObject);
> And you can retrieve it with
>    I:=L.IndexOf(MyKey);
>    If (I=-1) then
>     // no mykey in list
>    else
>     MyObject:=L.Objects[i];
Thank you very much, that's what I needed to understand.
If I get it right, using the Objects property is analog to what I intended to do with a TStringList for names // to a TFPList for values.
> However, it does not actually implement this; it just provides a common
> API for a string list with associated objects.
> TStringList actually implements - in a simplistic way - the functionality
> to store the strings, and the associated objects.

All right, now I get it. Just a point about doc: Some methods implemented in TStringList, but virtual in TString, are listed in the interface of TStringList at http://www.freepascal.org/docs-html/rtl/classes/tstringlist.html. But the ones dealings with associated objects aren't listed there (including the Objects property). This feature is also not mentionned in the description. So, I thought TStringList simply does not implement this functionality.
Another point: in the description of TList and TFPList is written that the notification system (not implemented on TFPList) is slows down some mechanisms. Is there a version of TStringList without this feature.
I need the simplest and most efficient version, because the type I'm now designing will be the elementary building block of a rather big system.


vit esse estrany ☣


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