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Re: Java blunders

From Martin Gregorie <martin@address-in-sig.invalid>
Newsgroups comp.lang.java.programmer
Subject Re: Java blunders
Date 2014-07-28 23:17 +0000
Organization A noiseless patient Spider
Message-ID <lr6lmn$lb2$1@dont-email.me> (permalink)
References (9 earlier) <lr121c$rlo$1@dont-email.me> <7lcat9t8j6tuo1v2tm1od8rhvhcgf5i7g9@4ax.com> <lr3gcr$aib$1@dont-email.me> <oqudncJQXNfN3EvOnZ2dnUVZ8sqdnZ2d@bt.com> <7yegqdunyocn$.1g7x8245ot44l$.dlg@40tude.net>

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On Mon, 28 Jul 2014 23:38:03 +0200, Joerg Meier wrote:

> While I often wished we had that kind of operator overloading, my
> biggest issue with it is that it looks like it is reassigning ca (and
> the explicit syntax, "ca = ca + p;", is even worse), when it in fact
> doesn't. And that opens all kind of worm cans:
>
You're reading too much into it. IIRC Algol 68 had the += operator and 
you might choose to overload either + or += to represent paying a cheque 
into an account. It seemed to me that in this case overloading += would 
read better than overloading + might. 
 
> - Can ca still be declared final ?
>
No - at least you couldn't in Algol 68. It wasn't really an OO language. 
Although it had a lot of features that became integral parts of the OO 
paradigm, it didn't any concept of a class or objects that might contain 
both data and methods. A mode was quite similar to a C struct, and code 
only existed as procedures and operators.
 
If you take away the "ca =" part, does "ca + p" still do anything? Yes, 
in exactly the same way that you can throw away the value returned by a 
Java method or a C function.  

Could you have "ca+p;", 

Yes. It would do whatever you'd written the new operator overloading + to 
do. If it was defined as 
op +(account,cheque):             it would return nothing, while 
op +(account,cheque)int:          might return the new balance and
op +=(account,cheque)ref account: would return a reference to the account.

As I said: this was Algol 68, which is not an OO language though I 
suspect that its operator overloading is very much in the spirit of the 
idea that messages are passed between objects and the A68 compiler had to 
do more or less the same when parsing an overloaded operator as the Java 
compiler does when parsing an overloaded method. 


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

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Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-22 11:41 -0700
  Re: Java blunders Daniele Futtorovic <da.futt.news@laposte.net> - 2014-07-22 21:12 +0200
    Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-22 19:46 -0400
      Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 04:14 -0700
  Re: Java blunders Joerg Meier <joergmmeier@arcor.de> - 2014-07-22 23:47 +0200
    Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 04:23 -0700
      Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-23 12:32 +0000
        Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-23 08:55 -0400
          Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 06:21 -0700
        Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-23 19:53 -0400
          Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 18:49 -0700
      Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-23 19:52 -0400
  Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-22 19:44 -0400
    Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 04:27 -0700
      Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-23 19:55 -0400
        Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 18:53 -0700
          Re: Java blunders Joerg Meier <joergmmeier@arcor.de> - 2014-07-24 11:24 +0200
            Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-25 06:34 -0700
          Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-24 19:31 -0400
            Re: Java blunders Gene Wirchenko <genew@telus.net> - 2014-07-25 13:22 -0700
              Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-25 17:17 -0400
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-25 23:12 +0000
                Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 09:06 -0700
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-26 20:11 +0000
                Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-26 17:27 -0400
                Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-27 10:49 -0700
                Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-27 10:10 -0700
                Re: Java blunders Gene Wirchenko <genew@telus.net> - 2014-07-28 13:53 -0700
                Re: Java blunders Stuart <DerTopper@web.de> - 2014-07-30 08:05 +0200
                Re: Java blunders Sebastian <news@seyweiler.dyndns.org> - 2014-07-30 11:12 +0200
                Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-27 10:13 -0700
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-27 18:28 +0000
                Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-27 14:46 -0400
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-27 21:18 +0000
                Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-27 18:10 -0400
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-28 01:25 +0000
                Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-28 08:02 -0400
                Re: Java blunders Mike Amling <mamling@chaff.us> - 2014-07-31 13:26 -0500
                Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-31 14:48 -0400
                Re: Java blunders "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-07-28 13:22 +0100
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-28 12:52 +0000
                Re: Java blunders Joerg Meier <joergmmeier@arcor.de> - 2014-07-28 23:38 +0200
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-28 23:17 +0000
                Re: Java blunders Silvio <silvio@internet.com> - 2014-07-29 13:34 +0200
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-29 12:45 +0000
                Re: Java blunders Silvio <silvio@internet.com> - 2014-07-29 17:10 +0200
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-29 16:29 +0000
                Re: Java blunders lipska the kat <lipskathekat@example.com> - 2014-07-29 20:15 +0100
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-29 22:02 +0000
                Re: Java blunders Silvio <silvio@internet.com> - 2014-07-29 22:43 +0200
                Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-29 22:10 +0000
                Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-27 19:18 -0500
                Re: Java blunders Gene Wirchenko <genew@telus.net> - 2014-07-28 13:54 -0700
                Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-31 23:07 -0400
                Re: Java blunders James Hostick <james.hostick@gmail.com> - 2014-08-01 22:10 -0700
            Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 08:31 -0700
              Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-26 21:04 +0000
                Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-27 10:51 -0700
                Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-28 08:50 -0700
                Re: Java blunders Joerg Meier <joergmmeier@arcor.de> - 2014-07-28 23:42 +0200
              Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-31 23:04 -0400
          Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-28 22:23 +0200
            Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-28 16:39 -0400
              Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-29 00:11 +0200
              Re: Java blunders Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2014-07-30 12:07 +0300
                Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-30 08:05 -0400
    Re: Java blunders Wanja Gayk <brixomatic@yahoo.com> - 2014-07-25 01:34 +0200
      Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-24 19:43 -0400
  Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-22 21:02 -0500
    Re: Java blunders Leif Roar Moldskred <leifm@huldreskog.lan> - 2014-07-23 02:01 -0500
      Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 18:58 -0700
      Re: Java blunders thinbluernime <thinbluernime3@gmail.com> - 2014-07-25 03:55 +0000
        Re: Java blunders Leif Roar Moldskred <leifm@huldreskog.lan> - 2014-07-25 00:32 -0500
          Re: Java blunders thinbluernime <thinbluernime3@gmail.com> - 2014-07-26 07:28 +0000
            Re: Java blunders "Gavino" <invalid@invalid.invalid> - 2014-07-26 19:43 +0200
        Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-25 06:36 -0700
          Re: Java blunders "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-07-25 15:47 +0100
            Re: Java blunders David Postill <david.postill@gmail.com> - 2014-07-25 18:29 +0200
            Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 09:27 -0700
        Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-25 06:37 -0700
    Re: Java blunders Joerg Meier <joergmmeier@arcor.de> - 2014-07-23 13:17 +0200
      Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 06:27 -0700
    Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 04:44 -0700
      Re: Java blunders Silvio <silvio@internet.com> - 2014-07-23 16:23 +0200
        Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-23 12:02 -0400
          Re: Java blunders Silvio <silvio@internet.com> - 2014-07-24 11:37 +0200
            Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-28 22:37 +0200
        Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 09:33 -0700
          Re: Java blunders thinbluernime <thinbluernime3@gmail.com> - 2014-07-25 03:57 +0000
        Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-23 21:38 -0400
          Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 18:59 -0700
            Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-24 07:33 +0000
          Re: Java blunders Silvio <silvio@internet.com> - 2014-07-24 11:47 +0200
            Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-24 19:34 -0400
              Re: Java blunders Silvio <silvio@internet.com> - 2014-07-25 08:48 +0200
                Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-25 08:07 -0400
                Re: Java blunders "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-07-25 13:54 +0100
                Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-31 22:53 -0400
            Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-25 07:04 -0700
        Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-28 22:01 +0200
      Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-28 21:56 +0200
    Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 06:28 -0700
      Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-23 08:33 -0500
    Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-23 21:34 -0400
      Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-23 19:06 -0700
      Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-23 22:11 -0500
        Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-24 07:36 +0000
          Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-24 19:39 -0400
            Re: Java blunders "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-07-25 13:40 +0100
        Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-24 19:38 -0400
          Re: Java blunders Gene Wirchenko <genew@telus.net> - 2014-07-25 13:30 -0700
  Re: Java blunders taqmcg@gmail.com - 2014-07-23 11:26 -0700
    Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-23 15:14 -0400
      Re: Java blunders thinbluernime <thinbluernime3@gmail.com> - 2014-07-25 04:07 +0000
        Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-07-25 08:35 -0400
          Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 09:41 -0700
        Re: Java blunders Wanja Gayk <brixomatic@yahoo.com> - 2014-08-03 16:41 +0200
          Re: Java blunders Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-03 11:31 -0400
    Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-23 22:41 -0500
      Re: Java blunders taqmcg@gmail.com - 2014-07-24 10:09 -0700
        Re: Java blunders "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-07-25 13:22 +0100
        Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-25 20:34 -0500
          Re: Java blunders "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-07-28 13:33 +0100
            Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-28 08:35 -0500
        Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 09:44 -0700
          Re: Java blunders Martin Gregorie <martin@address-in-sig.invalid> - 2014-07-26 23:36 +0000
  Re: Java blunders Gene Wirchenko <genew@telus.net> - 2014-07-23 20:48 -0700
    Re: Java blunders Silvio <silvio@internet.com> - 2014-07-24 11:56 +0200
      Re: Java blunders Silvio <silvio@internet.com> - 2014-07-24 16:07 +0200
        Re: Java blunders Gene Wirchenko <genew@telus.net> - 2014-07-25 13:38 -0700
          Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 10:02 -0700
    Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-24 19:29 -0400
      Re: Java blunders Gene Wirchenko <genew@telus.net> - 2014-07-25 13:45 -0700
    Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 10:53 -0700
  Re: Java blunders Wanja Gayk <brixomatic@yahoo.com> - 2014-07-25 01:28 +0200
  Re: Java blunders "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-07-25 14:16 +0100
  Re: Java blunders Joerg Meier <joergmmeier@arcor.de> - 2014-07-25 17:39 +0200
  Re: Java blunders Roedy Green <see_website@mindprod.com.invalid> - 2014-07-26 16:21 -0700
  Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-28 23:59 +0200
    Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-29 00:41 +0200
      Re: Java blunders Josip Almasi <joe@vrspace.org> - 2014-07-29 01:54 +0200
    Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-31 22:38 -0400
    Re: Java blunders Arne Vajhøj <arne@vajhoej.dk> - 2014-07-31 22:39 -0400
  Re: Java blunders w.tom.adams@gmail.com - 2014-07-30 07:57 -0700
    Re: Java blunders Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2014-07-30 10:22 -0500

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