Groups > comp.lang.java.programmer > #33841

Re: stream concat distinct indeterministic

From	Andreas Leitgeb <avl@logic.at>
Newsgroups	comp.lang.java.programmer
Subject	Re: stream concat distinct indeterministic
Date	2016-02-16 18:40 +0000
Organization	A noiseless patient Spider
Message-ID	<slrnnc6rdk.456.avl@login.logic.tuwien.ac.at> (permalink)
References	<6e75cf37-61c1-4ab8-af9b-851fc280244d@googlegroups.com> <n9suo2$qjc$1@dont-email.me> <e28ed25c-f151-4ec2-9258-6727405398d7@googlegroups.com>

Show all headers | View raw

Philipp Kraus <philipp.kraus.flashpixx@gmail.com> wrote:
> The stream uses a class which overloads equal (for my data structure), ...

If you overload equals, then did you also overload hashCode such that it
is consistent with your equals?

I ask, because without knowing much about Java 8 streams yet, "distinct"
sounds like some hashmap or hashset might be used internally, and these
structures will produce odd behaviour, if equals and hashCode are not 
consistent.

Note: a custom equals and default hashCode are almost never consistent.

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

stream concat distinct indeterministic Philipp Kraus <philipp.kraus.flashpixx@gmail.com> - 2016-02-15 08:08 -0800
  Re: stream concat distinct indeterministic Arne Vajhøj <arne@vajhoej.dk> - 2016-02-15 11:30 -0500
    Re: stream concat distinct indeterministic Philipp Kraus <philipp.kraus.flashpixx@gmail.com> - 2016-02-15 12:54 -0800
      Re: stream concat distinct indeterministic Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-15 16:13 -0500
        Re: stream concat distinct indeterministic Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-15 21:58 +0000
          Re: stream concat distinct indeterministic Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-15 17:45 -0500
            Re: stream concat distinct indeterministic Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-15 23:29 +0000
              Re: stream concat distinct indeterministic Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-16 07:47 -0500
        Re: stream concat distinct indeterministic Arne Vajhøj <arne@vajhoej.dk> - 2016-02-15 21:45 -0500
  Re: stream concat distinct indeterministic Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-15 11:38 -0500
    Re: stream concat distinct indeterministic Philipp Kraus <philipp.kraus.flashpixx@gmail.com> - 2016-02-15 09:05 -0800
      Re: stream concat distinct indeterministic Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-15 14:08 -0500
      Re: stream concat distinct indeterministic Andreas Leitgeb <avl@logic.at> - 2016-02-16 18:40 +0000

csiph-web