... and I can always CHANGE-CLASS, can't I?

On Sun, Feb 7, 2021 at 9:46 AM Hans Hübner <hans.huebner@gmail.com> wrote:
Am So., 7. Feb. 2021 um 09:35 Uhr schrieb Manfred Bergmann <manfred.bergmann@me.com>:
> Am 07.02.2021 um 09:23 schrieb Hans Hübner <hans.huebner@gmail.com>:
>
> Am So., 7. Feb. 2021 um 09:20 Uhr schrieb Manfred Bergmann <manfred.bergmann@me.com>:
> But fundamentally, you also can’t create an instance of a class in Common Lisp from just the symbol. The class definition must be known.
>
> This simply is untrue.  You can use FIND-CLASS to find a class named by a symbol and then instantiate it.

Well, OK. Sure. But when I do that I have again a dependency on the concrete class, or? And it would be similar as knowing the class right from the start.

You don't.  You have a dependency on the name of a class.  The name could refer to two entirely different classes between invocations of FIND-CLASS.  The name could also come from an external source.  Thus, this is purely a run-time dependency and it would be quite possible that FIND-CLASS returns NIL if given a symbol that does not designate a currently-defined class. 


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