On Thu, May 15, 2025, at 10:11, Rowan Tommins [IMSoP] wrote: > > > On 14 May 2025 22:27:32 BST, Rob Landers <rob@bottled.codes> wrote: > > > >As written, that simply isn't possible in PHP because there is only one > >class allowed with a given name. Names of classes are global. I don't think > >this has to be the case, though. Different languages take different > >approaches to this. For example, JavaScript allows each module to "close > >over" its dependencies so each module can import its own version of > >dependencies. > > I would say that JavaScript doesn't just *allow* this, as an added feature, > it *requires* it, as a fundamental design decision: > > - In JavaScript, Python, etc, when you declare a function or class, you are > creating an anonymous object, and assigning it to a local variable. Code > reuse requires you to pass that object around. > - In PHP, Java, C#, etc, when you declare a function or class, you are adding > a permanent named item to a global list. Code reuse is about knowing the > global names of things. > > It's worth noting that JavaScript didn't need to add *any* features to make > NPM, Bower, etc work; everything they do is based on the fact that > declarations are objects which can be passed around at will. > > That's why I don't think "JavaScript can do it" is relevant, because the > *way* JavaScript does it is impossible in PHP. We're much better off looking > at how *PHP* works, and what problems we're actually trying to solve. > > And that in turn is why I was reaching for Linux containers as an alternative > analogy, to think about the problem without jumping to the wrong solution. > > Rowan Tommins > [IMSoP] >
Hey Rowan, When working on nested classes, I did spend quite a bit of time tinkering with alternative implementations. One of those implementations was having the ability for classes to have their own class tables (both literally and emulated via name mangling) which would have allowed for classes to have private classes that could share names with external classes. This turned out to be an utter disaster of an idea for many reasons. Namely, PHP doesn't really have any native support for shadowing names. Sure, there is aliasing via use statements, but that only works for classes outside the current namespace. As long as we can guarantee that a module acts as a special namespace (under the hood), the only potential for collisions will be in the module itself. All that is to say that I don't think comparing PHP to JavaScript is appropriate when considering modules. JavaScript doesn't have types, so I can pass you an EpicStringV2 when you're expecting an EpicStringV1, and as long as my EpicStringV2 has the right prototypical behavior and data, it will work just fine. PHP is typed, and fairly strongly typed. There is effectively no way to have multiple versions of the same type running around a codebase and pass type checks. Changing this would be effectively impossible and probably unsound from a type-theory perspective. — Rob
