<div dir="ltr">Java may have made an odd design design by putting "boolean equals(Object)" in the root Object class as a mechanism to test equality by value, but there's also:<div><br></div><div> <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Comparable.html">https://docs.oracle.com/javase/8/docs/api/java/lang/Comparable.html</a></div><div><br></div><div>This approach handles not just equals but also greater/less than comparisons for types that have ordered values. You could retrofit it to return an enum type instead of an int for better clarity.</div><div><br></div><div>Something to consider :)</div><div><br>S,</div><div>ALR</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Sep 22, 2016 at 10:19 AM, Konrad Kleine <span dir="ltr"><<a href="mailto:kkleine@redhat.com" target="_blank">kkleine@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Thomas,<div><br></div><div>thanks for not pointing in my direction :)</div><div><br></div><div>I can't wait to see a PR for this.</div><div><br></div><div>Regards,</div><div>Konrad</div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="h5">On Thu, Sep 22, 2016 at 3:32 PM, Thomas Mäder <span dir="ltr"><<a href="mailto:tmader@redhat.com" target="_blank">tmader@redhat.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5">
<div bgcolor="#FFFFFF" text="#000000">
<p>Hi folks, <br>
</p>
<p>some time back, we have introduced the "Equaler" interface. I
believe we're going down the wrong path with this: Java got this
wrong initially and we still suffer the consequences. Equaler
looks like this:</p>
<p>type Equaler interface {<br>
Equal(Equaler) bool<br>
}</p>
<p>There are a couple of drawbacks to this approach:</p>
<ol>
<li>There can only be a single implementation of Equals for all
time. But this too restrictive: for example, I might want to
include the version field in a struct in the comparison for some
cases, in other cases I simply don't care. Generally, there can
be many equivalence relationships for a given set of objects.
For all we know, we might consider two objects equal if they
have the same color.</li>
<li>You can't compose equality with this implementation<br>
In Java, this has given rise to classes like "EqualsBuilder"
that allowed to do exactly that.<br>
</li>
<li>We can't implement equality based on interfaces<br>
We'd have to reimplement equality for every struct (which is the
first parameter).</li>
<li>You always have to check for null before calling Equals()</li>
</ol>
<p>So I propose to rewrite the interface to :</p>
<p>Equality {</p>
<p> Equals(left interface{}, right interface{}) bool<br>
</p>
<p>}</p>
<p>I think it would make sense that I prepare a PR to illustrate my
approach porting the current implementations in the "models"
packe. A POC shouldn't take too long. <br>
</p>
<p>thoughts?</p><span><font color="#888888">
<p>/Thomas<br>
</p>
</font></span></div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Red Hat Developer Programs Architecture<div>@ALRubinger</div></div></div>
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