Sebb,

Pair _is_ a Map.Entry.

Gary

On Thu, Sep 26, 2024, 9:46 AM sebb <[email protected]> wrote:

> On Thu, 26 Sept 2024 at 14:33, Gary D. Gregory <[email protected]>
> wrote:
> >
> > Andrea,
> >
> > The relevant contract is
> https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/Map.Entry.html#equals(java.lang.Object)
>
> Which says "Returns true if the given object is also a map entry and ..."
>
> Also any class that overrides Object equals must be symmetric (and
> transitive etc).
>
> Note that Map.Entry#equals returns false when compared against Pair;
> it is compliant, even though it omits to repeat the Object contract in
> its Javadoc.
>
> It is Pair#equals that gets it wrong.
>
> > Gary
> >
> > On 2024/09/26 12:45:07 Andrea Spinelli wrote:
> > > IMHO, a Pair should not be equal to anything which is not a Pair.
> > >
> > > Reading the contract for equals
> > >
> > >
> https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/Object.html#equals(java.lang.Object)
> > >
> > >
> > > it must be symmetric, so Pair.equals should return false if the
> argument is a MapEntry
> > >
> > >
> > >
> > >
> > >
> > >
> > > ________________________________
> > > Da: Dávid Szigecsán <[email protected]>
> > > Inviato: giovedì 26 settembre 2024 13:36
> > > A: Commons Users List <[email protected]>
> > > Oggetto: Re: Bug in org.apache.commons.lang3.tuple.Pair
> > >
> > > Hi,
> > > As I see the "problem".
> > > Pair.equal() returns true if the other entity is not an instance of
> Pair.
> > > In this case it is a Map.Entry.
> > > Map.Entry.equals() howewer checks if the other is an instance of the
> same
> > > class. So if we want them to be equals, we should change the Map.Entry,
> > > that is out of our limit of power. To make it symmetric we could check
> for
> > > the instances of the same class also (and return false in this case),
> but I
> > > think we don't want this.
> > >
> > > Dávid
> > >
> > > Alex Tsvetkov <[email protected]> ezt írta (időpont: 2024.
> szept. 26.,
> > > Cs 13:11):
> > >
> > > > Hi.
> > > >
> > > > I found a bug in the implementation of the method `equals` of class
> `Pair`.
> > > >
> > > > Implementation must be symmetric. Current implementation is not.
> > > >
> > > > Her test showing the problem:
> > > >
> > > > ```
> > > >
> > > > @Test
> > > > void run() {
> > > >     var pair = Pair.of("a", "b");
> > > >     var entry = new Map.Entry<String, String>() {
> > > >         public String getKey() { return "a"; }
> > > >         public String getValue() { return "b"; }
> > > >         public String setValue(String value) { return null; }
> > > >     };
> > > >     assertTrue(pair.equals(entry)); // true
> > > >     assertTrue(entry.equals(pair)); // false
> > > > }
> > > > ```
> > > >
> > >
> > > --
> > > Il messaggio è stato analizzato da Libraesva ESG.
> > > Seguire il link qui sotto per segnalarlo eventualmente come spam:
> > > http://antispam01.imteam.it/action/4XDs5M0fYhzKmXJ/report-as-bad
> > > Seguire il link qui sotto per mettere in blocklist il mittente:
> > > http://antispam01.imteam.it/action/4XDs5M0fYhzKmXJ/blocklist
> > >
> > >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: [email protected]
> > For additional commands, e-mail: [email protected]
> >
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [email protected]
> For additional commands, e-mail: [email protected]
>
>

Reply via email to