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Re: A question on designated initializers

From "Pascal J. Bourguignon" <pjb@informatimago.com>
Newsgroups comp.lang.objective-c
Subject Re: A question on designated initializers
Date 2015-11-25 18:41 +0100
Organization Informatimago
Message-ID <874mgaugc9.fsf@kuiper.lan.informatimago.com> (permalink)
References (4 earlier) <n32tc0$hik$1@news.albasani.net> <87oaeivr7a.fsf@kuiper.lan.informatimago.com> <n337jb$6mt$2@dont-email.me> <87d1uyvj8a.fsf@kuiper.lan.informatimago.com> <n34ppq$km8$1@dont-email.me>

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Don Bruder <dakidd@sonic.net> writes:

> You'll pardon my skepticism, I hope - I'm an empiricist at heart...

I assumed so much, and therefore I assumed you already ran the code, and
saw the infinite loop for yourself!


> Gonna do some playing and see what I can come up with, but at this 
> stage, what you're saying is so *TOTALLY* counterintuitive I can't even 
> start to accept it. Everything I've ever grasped about 
> inheritance/subclassing tells me that I'm not supposed to "need" to know 
> the internals of the class I'm deriving from - it's a black box. So long 
> as you do thus and so, your subclass will work. "Thus and so" in this 
> case meaning "Make damn sure you chain back to the root object by 
> calling your superclass' init method or all hell's gonna break loose". 

Well, either your class is "documented", with a class invariant
and a set of pre- and post- conditions for each method, or you have to
know the internals.

Since you never find those invariants and sets of pre- and
post-conditions documented, you never know, and always have to know the
internals, which indeed, is a very bad situation.


-- 
__Pascal Bourguignon__                 http://www.informatimago.com/
“The factory of the future will have only two employees, a man and a
dog. The man will be there to feed the dog. The dog will be there to
keep the man from touching the equipment.” -- Carl Bass CEO Autodesk

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Thread

A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-22 13:39 -0800
  Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-22 14:48 -0800
    Re: A question on designated initializers Louis Wu <louiswu@ringworld.net> - 2015-11-22 16:26 -0800
      Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-22 17:24 -0800
        Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-23 02:39 +0100
  Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-23 01:18 +0100
    Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-22 16:49 -0800
      Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-23 02:02 +0100
        Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-27 17:19 -0800
          Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-28 13:22 +0100
            Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-28 17:37 -0800
              Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-29 03:45 +0100
  Re: A question on designated initializers Don Bruder <dakidd@sonic.net> - 2015-11-22 19:15 -0800
    Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-23 18:44 -0800
      Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-24 04:58 +0100
        Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-24 16:42 -0800
          Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-25 02:00 +0100
        Re: A question on designated initializers Greg Parker <gparker@apple.com> - 2015-11-25 01:25 -0800
      Re: A question on designated initializers Don Bruder <dakidd@sonic.net> - 2015-11-24 07:38 -0800
        Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-24 15:54 -0800
          Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-25 01:49 +0100
            Re: A question on designated initializers Don Bruder <dakidd@sonic.net> - 2015-11-24 18:51 -0800
              Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-25 04:41 +0100
                Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-25 00:25 -0800
                Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-25 14:16 +0100
                Re: A question on designated initializers Jon Rossen <jonr17@comcast.net> - 2015-11-25 17:30 -0800
                Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-26 03:03 +0100
                Re: A question on designated initializers Don Bruder <dakidd@sonic.net> - 2015-11-25 09:08 -0800
                Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-11-25 18:41 +0100
                Re: A question on designated initializers Don Bruder <dakidd@sonic.net> - 2015-12-02 14:37 -0800
                Re: A question on designated initializers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2015-12-03 00:58 +0100
          Re: A question on designated initializers Don Bruder <dakidd@sonic.net> - 2015-11-24 18:29 -0800

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