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Date: Mon, 1 Apr 2024 15:09:05 +0100
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Subject: Re: [PHP-DEV] [RFC] Invoke __callStatic when non-static public
 methods are called statically
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From: imsop.php@rwec.co.uk ("Rowan Tommins [IMSoP]")

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On 29/03/2024 18:14, Robert Landers wrote:
> When generating proxies for existing types, you often need to share
> some state between the proxies. To do that, you put static
> methods/properties on the proxy class and hope to the PHP Gods that
> nobody will ever accidentally name something in their concrete class
> with the name you chose for things. To help with that, you create some
> kind of insane prefix.


Separating static and non-static methods wouldn't solve this - the 
concrete class could equally add a static method with the same name but 
a different signature, and your generated proxy would fail to compile.

In fact, exactly the same thing happens with instance methods in testing 
libraries: test doubles have a mixture of methods for configuring mock / 
spy behaviour, and methods mimicking or forwarding calls to the real 
interface / class. Those names could collide, and require awkward 
workarounds.

In a statically typed language, a concrete class can have two methods 
with the same name, but different static types, e.g. when explicitly 
implementing interfaces. In a "duck typing" system like PHP's, that's 
much trickier, because a call to $foo->bar() doesn't have a natural way 
to choose which "bar" is meant.


> I'd much rather see static and non-static methods being able to
> have the same name

Allowing this would lead to ambiguous calls, because as others have 
pointed out, :: doesn't always denote a static call. Consider this code:

class Test {
   public function test() { echo 'instance test'; }
   public static function test() { echo 'static test'; }
}

class Test2 extends Test {
   public function runTest() { parent::test(); }
}

(new Test2)->runTest();

Currently, this can call either of the test() methods if you comment the 
other out: https://3v4l.org/5HlPE https://3v4l.org/LBALm

If both are defined, which should it call? And if you wanted the other, 
how would you specify that? We would need some new syntax to remove the 
ambiguity.


Regards,

-- 
Rowan Tommins
[IMSoP]

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    <div class="moz-cite-prefix">On 29/03/2024 18:14, Robert Landers
      wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAPzBOBM5LMNBJt+qAsKOX+W17jRjnYHKyqRyBs69=u8Bdx-KAw@mail.gmail.com">
      <pre>When generating proxies for existing types, you often need to share
some state between the proxies. To do that, you put static
methods/properties on the proxy class and hope to the PHP Gods that
nobody will ever accidentally name something in their concrete class
with the name you chose for things. To help with that, you create some
kind of insane prefix.</pre>
    </blockquote>
    <p><br>
    </p>
    <p>Separating static and non-static methods wouldn't solve this -
      the concrete class could equally add a static method with the same
      name but a different signature, and your generated proxy would
      fail to compile.</p>
    <p>In fact, exactly the same thing happens with instance methods in
      testing libraries: test doubles have a mixture of methods for
      configuring mock / spy behaviour, and methods mimicking or
      forwarding calls to the real interface / class. Those names could
      collide, and require awkward workarounds.<br>
    </p>
    <p>In a statically typed language, a concrete class can have two
      methods with the same name, but different static types, e.g. when
      explicitly implementing interfaces. In a "duck typing" system like
      PHP's, that's much trickier, because a call to $foo-&gt;bar()
      doesn't have a natural way to choose which "bar" is meant.</p>
    <p><br>
    </p>
    <p>
      <blockquote type="cite">
        <pre class="moz-quote-pre" wrap="">I'd much rather see static and non-static methods being able to
have the same name</pre>
      </blockquote>
    </p>
    <p>Allowing this would lead to ambiguous calls, because as others
      have pointed out, :: doesn't always denote a static call. Consider
      this code:</p>
    <p>class Test {<br>
        public function test() { echo 'instance test'; }<br>
        public static function test() { echo 'static test'; }<br>
      }</p>
    <p>class Test2 extends Test {<br>
        public function runTest() { parent::test(); }<br>
      }</p>
    <p>(new Test2)-&gt;runTest();</p>
    <p>Currently, this can call either of the test() methods if you
      comment the other out: <a class="moz-txt-link-freetext" href="https://3v4l.org/5HlPE">https://3v4l.org/5HlPE</a>
      <a class="moz-txt-link-freetext" href="https://3v4l.org/LBALm">https://3v4l.org/LBALm</a><br>
    </p>
    <p>If both are defined, which should it call? And if you wanted the
      other, how would you specify that? We would need some new syntax
      to remove the ambiguity.<br>
    </p>
    <p><br>
    </p>
    <p>Regards,<br>
    </p>
    <pre class="moz-signature" cols="72">-- 
Rowan Tommins
[IMSoP]</pre>
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