Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Martin Gregorie <martin@address-in-sig.invalid>
Newsgroups: comp.lang.java.programmer
Subject: Re: How to assign an object to another in it method?
Date: Thu, 13 Jul 2017 11:35:30 -0000 (UTC)
Organization: A noiseless patient Spider
Lines: 25
Message-ID: <ok7lu2$ngc$2@dont-email.me>
References: <oi5q4t$1okn$1@gioia.aioe.org> <factory-20170619011810@ram.dialup.fu-berlin.de> <oi8mfs$ies$1@dont-email.me> <b0821ba8-d4ab-49e9-980f-3d2c772bfd9f@googlegroups.com> <bdd41c94-f8b7-4c7d-869f-5375e68da69e@googlegroups.com> <slrnol7802.o2q.avl@logic.at> <46334961-cc18-491f-828c-32e7401c7832@googlegroups.com> <ojc6ac$i54$1@gioia.aioe.org> <ojd820$gl5$1@dont-email.me> <ojddsm$8df$1@gioia.aioe.org> <slrnolkjtk.o2q.avl@logic.at> <ojet3n$ek2$1@gioia.aioe.org> <ojf0vn$7d0$1@jstuckle.eternal-september.org> <ojhgd6$bjn$1@gioia.aioe.org> <ojhi20$39m$1@jstuckle.eternal-september.org> <ojs006$1ls2$1@gioia.aioe.org> <ojs35k$hf4$1@jstuckle.eternal-september.org> <slrnoma4gp.o2q.avl@logic.at> <ok39b0$eic$1@jstuckle.eternal-september.org> <ok3qco$jk0$2@gioia.aioe.org> <ok3ujr$d31$1@jstuckle.eternal-september.org> <ok3v81$o5g$1@gioia.aioe.org> <ok63ib$krk$1@jstuckle.eternal-september.org> <slrnomehsu.o2q.avl@logic.at>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 13 Jul 2017 11:35:30 -0000 (UTC)
Injection-Info: mx02.eternal-september.org; posting-host="a030be9b927e55fdbc797641d56ce0cb"; logging-data="24076"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX19XnxCgtQfPuJHnXyxaGepKQ0UfYjPdQuI="
User-Agent: Pan/0.141 (Tarzan's Death; 168b179 git.gnome.org/pan2)
Cancel-Lock: sha1:3EpO+3PWl+CNdSNCRWXm/Fe5Dok=
Xref: csiph.com comp.lang.java.programmer:36881

On Thu, 13 Jul 2017 10:08:52 +0000, Andreas Leitgeb wrote:

> Ideally, a subclass should be allowed to "remove" methods in a way that
> the compiler could preempt some mistakes: "If you already know you're
> dealing with a Square, then rather use Square's setDimension(int length)
> instead of the inherited setDimension(int,int)".  Obviously the compiler
> couldn't catch cases like ((Rectangle)square).setDimensions(1,2), so not
> all runtime errors can be prevented at compile time, but at least some.
>
In this case why wouldn't you override Rectangle.setDimensions() with a 
variant that throws an exception if the two dimensions differ as well as 
adding the trivial method:

  public void setDimensions(int size)
  {
    super.setDimensions(size, size);
  }

for convenience?


-- 
martin@   | Martin Gregorie
gregorie. | Essex, UK
org       |