Re: [BLACKBOX] Sorting Extended Records

From: [at]} <Wojtek>
Date: Mon, 28 Mar 2011 14:25:40 -0400

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Use type guard and type test:

> VAR base: BaseType; extended: ExtendedType;
> BEGIN
> base := extended; (* Always works. *)
> extended := base(ExtendedType); (* Works only if 'base' is
> actually a pointer to an 'ExtendedType' instance, traps
> otherwise. *)

IF base IS ExtendedType THEN
   extended := base(ExtendedType);
ELSE
   Log.String("base is not ExtendedType"); Log.Ln
END;

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Received on Mon Mar 28 2011 - 20:25:40 UTC