Groups > comp.lang.java.programmer > #4151

Re: Did the sort do anything?

From	Lew <noone@lewscanon.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Did the sort do anything?
Date	2011-05-16 03:44 -0400
Organization	albasani.net
Message-ID	<iqqkkv$4s6$1@news.albasani.net> (permalink)
References	(2 earlier) <iqgrhp$fh7$1@dont-email.me> <jsgqs61b31jq07e1tmr7d910rfacjeok5r@4ax.com> <iqq2b2$jhm$4@lust.ihug.co.nz> <N6-dnSCv9viQDE3QnZ2dnUVZ_v6dnZ2d@earthlink.com> <iqqec4$qi7$2@lust.ihug.co.nz>

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Lawrence D'Oliveiro wrote:
>  Patricia Shanahan wrote:
>> Lawrence D'Oliveiro wrote:

>>> If, on the other hand, you were sorting immutable objects of a Java
>>> “reference” type where the key was the entire object state, then
>>> stability would indeed be irrelevant, notwithstanding such types are not
>>> considered “primitive”.

>> Do you consider the result of System.identityHashCode(x) to be part of
>> the state of the object referenced by x?

> It is computed from the state, is it not?

No.  It most certainly is not.  The identity hash code is computed once for 
each object irrespective of and independently of anything else you might 
consider the object's state.

As a cursory reading of the Javadocs makes clear:
<http://download.oracle.com/javase/6/docs/api/java/lang/System.html#identityHashCode(java.lang.Object)>

Even without the rather intelligent step of checking the documentation, you 
can reason out that the answer must be no.  Either the identity hash code is 
part of the state, in which case it is not computed from the state but *is* 
part of the state, or it is not, in which case it is not computed from the 
state.  Which it is depends on your definition of "the state", i.e., whether 
you include the identity hash code as part of the state.  Yes, it's 
tautological, but that's the result of the way you framed the question.

-- 
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg

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Did the sort do anything? Roedy Green <see_website@mindprod.com.invalid> - 2011-05-10 08:06 -0700
  Re: Did the sort do anything? markspace <-@.> - 2011-05-10 08:48 -0700
    Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-14 15:33 +1200
      Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-14 08:56 -0400
        Re: Did the sort do anything? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-05-14 13:54 +0000
          Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-15 11:16 +1200
      Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-14 23:24 -0400
        Re: Did the sort do anything? Tom Anderson <twic@urchin.earth.li> - 2011-05-15 11:20 +0100
          Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-15 07:00 -0400
            Re: Did the sort do anything? Tom Anderson <twic@urchin.earth.li> - 2011-05-15 15:09 +0100
              Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-16 14:28 +1200
                Re: Did the sort do anything? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-05-15 22:38 -0400
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-16 19:11 +1200
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-16 03:47 -0400
                Re: Did the sort do anything? markspace <-@.> - 2011-05-16 14:14 -0700
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-15 22:40 -0400
                Re: Did the sort do anything? Tom Anderson <twic@urchin.earth.li> - 2011-05-16 21:31 +0100
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-17 09:12 +1200
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-16 17:24 -0400
                Re: Did the sort do anything? Tom Anderson <twic@urchin.earth.li> - 2011-05-17 13:26 +0100
          Re: Did the sort do anything? markspace <-@.> - 2011-05-15 04:56 -0700
            Re: Did the sort do anything? Tom Anderson <twic@urchin.earth.li> - 2011-05-15 15:12 +0100
              Re: Did the sort do anything? markspace <-@.> - 2011-05-15 07:52 -0700
          Re: Did the sort do anything? Michael Wojcik <mwojcik@newsguy.com> - 2011-05-18 11:14 -0400
            Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-18 13:02 -0400
            Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-20 18:49 +1200
              Re: Did the sort do anything? Robert Klemme <shortcutter@googlemail.com> - 2011-05-20 00:06 -0700
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-20 22:37 +1200
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-20 07:09 -0400
  Re: Did the sort do anything? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-05-10 16:11 +0000
  Re: Did the sort do anything? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-10 21:26 +0200
    Re: Did the sort do anything? Tom Anderson <twic@urchin.earth.li> - 2011-05-11 21:38 +0100
      Re: Did the sort do anything? Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-11 23:27 +0200
      Re: Did the sort do anything? Roedy Green <see_website@mindprod.com.invalid> - 2011-05-13 07:40 -0700
        Re: Did the sort do anything? Spock <spock@starfleet.ufp> - 2011-05-13 16:56 -0400
        Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-15 13:58 +1200
          Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-14 23:27 -0400
  Re: Did the sort do anything? Robert Klemme <shortcutter@googlemail.com> - 2011-05-11 20:40 +0200
    Re: Did the sort do anything? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-05-12 10:40 -0400
      Re: Did the sort do anything? Robert Klemme <shortcutter@googlemail.com> - 2011-05-13 03:50 -0700
      Re: Did the sort do anything? Roedy Green <see_website@mindprod.com.invalid> - 2011-05-13 07:46 -0700
        Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-16 14:32 +1200
          Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-15 19:50 -0700
            Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-16 17:57 +1200
              Re: Did the sort do anything? "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2011-05-16 03:35 -0400
              Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-16 03:44 -0400
              Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-16 03:53 -0700
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-17 00:02 +1200
                Re: Did the sort do anything? "javax.swing.JSnarker" <gharriman@boojum.mit.edu> - 2011-05-16 08:05 -0400
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-17 09:12 +1200
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-16 17:32 -0400
                Re: Did the sort do anything? thoolen <thoolen@tholenbot.thorium> - 2011-05-16 18:09 -0400
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-16 10:02 -0400
                Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-16 07:16 -0700
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-17 09:11 +1200
                Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-16 15:00 -0700
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-16 21:08 -0400
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-17 19:11 +1200
                Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-17 02:34 -0700
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-17 07:19 -0400
                [OT] Naming conventions. Was: Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-17 06:52 -0700
                Re: Naming conventions. Was: Re: Did the sort do anything? Robert Klemme <shortcutter@googlemail.com> - 2011-05-18 01:22 -0700
                Re: Naming conventions. Was: Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-18 03:42 -0700
                Re: Naming conventions. Was: Re: Did the sort do anything? RedGrittyBrick <RedGrittyBrick@spamweary.invalid> - 2011-05-18 11:53 +0100
                Re: Naming conventions. Was: Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-18 13:07 -0400
                Re: Naming conventions. Was: Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-18 10:37 -0700
                Re: Naming conventions. Was: Re: Did the sort do anything? Heike Svensson <hsvensson.1093x1_q@hotmail.nospam.com.please> - 2011-05-19 01:29 -0400
                Re: Naming conventions. Was: Re: Did the sort do anything? Robert Klemme <shortcutter@googlemail.com> - 2011-05-19 08:28 +0200
                Re: Naming conventions. Was: Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-19 08:50 -0400
                OT: National stereotypes. Was Re: Naming conventions. Was: Re: Did the sort do anything? RedGrittyBrick <RedGrittyBrick@spamweary.invalid> - 2011-05-23 10:25 +0100
                Re: OT: National stereotypes. Was Re: Naming conventions. Was: Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-23 09:05 -0400
                Re: OT: National stereotypes. Was Re: Naming conventions. Was: Re: Did the sort do anything? RedGrittyBrick <RedGrittyBrick@spamweary.invalid> - 2011-05-23 17:17 +0100
                Re: OT: National stereotypes. Was Re: Naming conventions. Was: Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-23 14:43 -0400
                Re: OT: National stereotypes. Was Re: Naming conventions. Was: Re: Did the sort do anything? Steve Sobol <sjsobol@JustThe.net> - 2011-05-23 08:27 -0700
                Re: OT: National stereotypes. Was Re: Naming conventions. Was: Re: Did the sort do anything? RedGrittyBrick <RedGrittyBrick@spamweary.invalid> - 2011-05-23 17:39 +0100
                Re: OT: National stereotypes. Was Re: Naming conventions. Was: Re:   Did the sort do anything? Robert Klemme <shortcutter@googlemail.com> - 2011-05-23 19:16 +0200
                Re: OT: National stereotypes. Was Re: Naming conventions. Was: Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-23 14:47 -0400
                Re: Did the sort do anything? Boojum <boojum42@gmai1.c0m> - 2011-05-18 07:19 -0400
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-20 18:46 +1200
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-20 07:10 -0400
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-17 07:16 -0400
                Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-17 06:56 -0700
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-20 18:46 +1200
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-20 07:11 -0400
                Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-20 05:00 -0700
                Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-20 05:20 -0700
                Re: Did the sort do anything? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-05-21 09:56 +1200
                Re: Did the sort do anything? Lew <noone@lewscanon.com> - 2011-05-20 18:12 -0400
                Re: Did the sort do anything? Patricia Shanahan <pats@acm.org> - 2011-05-20 21:26 -0700
                Re: Did the sort do anything? Gheerax IV <gheerax.4@gmail.invalid> - 2011-05-17 06:58 +0000
                Re: Did the sort do anything? Unitary Matrix <umatrix668@gmail.com> - 2011-05-17 00:13 -0700
                Re: Did the sort do anything? markspace <-@.> - 2011-05-17 07:41 -0700
    Re: Did the sort do anything? Roedy Green <see_website@mindprod.com.invalid> - 2011-05-13 07:42 -0700
      Re: Did the sort do anything? Robert Klemme <shortcutter@googlemail.com> - 2011-05-13 21:28 +0200
  Re: Did the sort do anything? Tom Anderson <twic@urchin.earth.li> - 2011-05-11 21:32 +0100

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