Groups > comp.lang.java.programmer > #9696

Re: Immutable Datastructures with good Sharing

From	Tom Anderson <twic@urchin.earth.li>
Newsgroups	comp.lang.java.programmer
Subject	Re: Immutable Datastructures with good Sharing
Date	2011-11-06 23:02 +0000
Organization	Stack Usenet News Service
Message-ID	<alpine.DEB.2.00.1111062256510.4201@urchin.earth.li> (permalink)
References	(7 earlier) <j95jkv$p42$1@news.albasani.net> <UCvtq.20364$Cr1.10065@newsfe03.iad> <j961n4$uts$1@news.albasani.net> <slrnjbd6fu.fvg.avl@gamma.logic.tuwien.ac.at> <CADC63E1.8F1D%bravegag@hotmail.com>

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On Sun, 6 Nov 2011, Giovanni Azua wrote:

> I haven't read/followed the whole OP Thread discussion but I thought it was
> worth mentioning/recommending the Google "Guava Project":
> http://code.google.com/p/guava-libraries/
>
> I think they really "went to town" on that one. You have strongly typed 
> Immutable Collection definitions for all Java Collection types e.g. 
> ImmutableMap.Builder, ImmutableList.Builder.

If you had read the whole thread, or indeed just the OP's initial post, 
you would understand that these classes are not helpful. They are 
certainly immutable, they don't have the sharing properties that Jan is 
after. They also don't expose any methods for doing the quasi-mutation he 
needs to do.

To recap, Jan wants to be able to say:

ImmutableStack<String> a = new ImmutableStack<String>(); // empty
ImmutableStack<String> b = a.push("foo");
assert a.isEmpty();
assert b.size() == 1;

That is, the quasi-mutation creates a new instance exhibiting the change, 
rather than changing an existing instance.

The Guava Immutable* classes do not have such methods.

> The design is awesome e.g. the Builder pattern as prescribed in 
> Effective Java (last edition)

I find the builder pattern immensely annoying, myself.

> and the performance gains are noticeable as well e.g. In a distributed 
> system I have been working on lately, switching the attribute instances 
> of the DTO Beans from ArrayList Java Collection to use instead the 
> implementation from Guava gave some noticeable 15-20% Serialization 
> performance gain e.g. Test case involving 1-Echo-Server and 1K-Clients.

That is a respectable gain!

> I really enjoy the improvement in code readability as well, it suits the
> appropriate template types e.g.
>
> // from
> List<RequestData> requests = new ArrayList<RequestData>();
>
> // to
> List<RequestData> requests = Lists.newArrayList();

I see absolutely no improvement in the code here, only unhelpful 
obfuscation.

tom

-- 
Taking care of business

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Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 04:03 +0100
  Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 12:42 +0100
    Re: Immutable Datastructures with good Sharing markspace <-@.> - 2011-11-05 09:35 -0700
      Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 19:33 +0100
        Re: Immutable Datastructures with good Sharing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-05 14:42 -0400
          Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 19:52 +0100
            Re: Immutable Datastructures with good Sharing Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-05 19:32 +0000
            Re: Immutable Datastructures with good Sharing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-05 15:31 -0400
              Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 20:50 +0100
                Re: Immutable Datastructures with good Sharing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-05 16:26 -0400
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 21:35 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 21:38 +0100
                Re: Immutable Datastructures with good Sharing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-05 16:59 -0400
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 22:06 +0100
                Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-05 16:41 -0400
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 21:42 +0100
                Re: Immutable Datastructures with good Sharing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-05 17:11 -0400
            Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-05 16:20 -0400
              Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 21:33 +0100
                Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-05 16:38 -0400
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 21:41 +0100
                Re: Immutable Datastructures with good Sharing markspace <-@.> - 2011-11-05 17:20 -0700
                Re: Immutable Datastructures with good Sharing Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-11-05 22:13 -0300
                Re: Immutable Datastructures with good Sharing markspace <-@.> - 2011-11-05 20:05 -0700
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 10:27 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 10:14 +0100
    Re: Immutable Datastructures with good Sharing Lew <lewbloch@gmail.com> - 2011-11-05 10:06 -0700
      Re: Immutable Datastructures with good Sharing Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-11-05 10:55 -0700
        Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 19:30 +0100
          Re: Immutable Datastructures with good Sharing Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-11-05 18:16 -0400
            Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 23:20 +0100
            Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 23:38 +0100
        Re: Immutable Datastructures with good Sharing Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-11-05 17:47 -0300
        Re: Immutable Datastructures with good Sharing Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-11-05 14:26 -0700
      Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-05 16:14 -0400
  Re: Immutable Datastructures with good Sharing Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-11-05 14:35 -0700
    Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 22:42 +0100
      Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 22:50 +0100
      Re: Immutable Datastructures with good Sharing Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-11-05 14:51 -0700
        Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 22:58 +0100
          Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 23:03 +0100
            Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-05 23:07 +0100
            Re: Immutable Datastructures with good Sharing Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2011-11-06 09:44 +0200
              Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 10:22 +0100
                Re: Immutable Datastructures with good Sharing Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-11-06 09:05 -0400
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 14:16 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 14:22 +0100
                Re: Immutable Datastructures with good Sharing Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-06 14:30 +0000
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 16:02 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 16:08 +0100
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-06 16:18 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 16:54 +0100
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-06 17:31 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 22:33 +0100
                Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-06 16:47 -0500
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-06 16:58 +0100
                Re: Immutable Datastructures with good Sharing Tom Anderson <twic@urchin.earth.li> - 2011-11-07 01:01 +0000
                Re: Immutable Datastructures with good Sharing Lew <lewbloch@gmail.com> - 2011-11-06 17:26 -0800
                Re: Immutable Datastructures with good Sharing Tom Anderson <twic@urchin.earth.li> - 2011-11-07 23:45 +0000
                Re: Immutable Datastructures with good Sharing Lew <lewbloch@gmail.com> - 2011-11-06 14:44 -0800
                Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-06 17:51 -0500
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-07 01:28 +0100
                Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-06 19:50 -0500
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-07 02:13 +0100
                Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-06 20:20 -0500
                Re: Immutable Datastructures with good Sharing Lew <lewbloch@gmail.com> - 2011-11-06 17:29 -0800
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-07 11:22 +0100
                Re: Immutable Datastructures with good Sharing Tom Anderson <twic@urchin.earth.li> - 2011-11-06 23:02 +0000
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-07 00:32 +0100
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-07 01:10 +0100
                Re: Immutable Datastructures with good Sharing Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-07 10:24 +0000
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-07 11:52 +0100
                Re: Immutable Datastructures with good Sharing Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-11-07 11:12 +0000
                Re: Immutable Datastructures with good Sharing Arne Vajhøj <arne@vajhoej.dk> - 2011-11-07 17:24 -0500
                Re: Immutable Datastructures with good Sharing Giovanni Azua <bravegag@hotmail.com> - 2011-11-07 02:08 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-07 05:03 +0100
                Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-07 05:13 +0100
                Re: Immutable Datastructures with good Sharing Tom Anderson <twic@urchin.earth.li> - 2011-11-07 23:38 +0000
                Re: Immutable Datastructures with good Sharing Tom Anderson <twic@urchin.earth.li> - 2011-11-09 22:06 +0000
                Re: Immutable Datastructures with good Sharing Gene Wirchenko <genew@ocis.net> - 2011-11-09 18:02 -0800
  Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-07 00:28 +0100
    Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-07 00:39 +0100
      Re: Immutable Datastructures with good Sharing Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-11-06 20:57 -0400
        Re: Immutable Datastructures with good Sharing Jan Burse <janburse@fastmail.fm> - 2011-11-07 04:58 +0100
          Re: Immutable Datastructures with good Sharing Silvio Bierman <silvio@moc.com> - 2011-11-07 15:13 +0100
            Re: Immutable Datastructures with good Sharing Cthun <cthun_202@qmail.net.au> - 2011-11-07 12:54 -0500
              Re: Immutable Datastructures with good Sharing "B1ll Gat3s" <wm.g4t3s@m1cr0s0f7.c0m> - 2011-11-07 18:07 -0500
                Re: Immutable Datastructures with good Sharing B1ll Gat3s <wm.g4t3s@m1cr0s0f7.c0m> - 2011-11-07 22:07 -0500
                Re: Immutable Datastructures with good Sharing "B1ll Gat3s" <wm.g4t3s@m1cr0s0f7.c0m> - 2011-11-08 00:17 -0500
                Re: Immutable Datastructures with good Sharing thoolen <th00len@th0lenbot.thorium> - 2011-11-08 16:03 -0500
                Re: Immutable Datastructures with good Sharing Cthun <cthun_202@qmail.net.au> - 2011-11-08 15:49 -0500
                Re: Immutable Datastructures with good Sharing "B1ll Gat3s" <wm.g4t3s@m1cr0s0f7.c0m> - 2011-11-08 18:01 -0500
                Re: Immutable Datastructures with good Sharing thoolen <th00len@th0lenbot.thorium> - 2011-11-08 20:46 -0500
                Re: Immutable Datastructures with good Sharing "Cthun" <cthun_202@qmail.net.au> - 2011-11-08 22:43 -0500
                Re: Immutable Datastructures with good Sharing thoolen <th00len@th0lenbot.thorium> - 2011-11-09 08:28 -0500
                Re: Immutable Datastructures with good Sharing thoolen <th00len@th0lenbot.thorium> - 2011-11-08 16:00 -0500
  Re: Immutable Datastructures with good Sharing Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-11-07 08:46 -0800

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