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Date: Mon, 1 Dec 2014 20:30:46 +0000
Cc: Robert Stoll <php@tutteli.ch>,
 internals <internals@lists.php.net>,
 guilhermeblanco@gmail.com
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References: <003c01d00d6e$f4fd77c0$def86740$@tutteli.ch> <868FD3D8-4E80-46F4-872A-125D3FD8F40D@ajf.me> <547CA967.20607@gmail.com>
To: Stanislav Malyshev <smalyshev@gmail.com>
Subject: Re: [PHP-DEV] [RFC] Static classes (Was Abstract final classes)
From: ajf@ajf.me (Andrea Faulds)


> On 1 Dec 2014, at 17:46, Stanislav Malyshev <smalyshev@gmail.com> =
wrote:
>=20
> Hi!
>=20
>> (2) Add lexically-scoped variables, and allow normal global functions
>> to be closures. By this I mean we add something like JavaScript=E2=80=99=
s
>> `let` keyword that would make a variable that is unset when it falls
>> out of scope (end of a {} block, end of a file etc.). Then, we allow
>> normal functions to use the `use ($var)` syntax and close over
>> variables. That=E2=80=99d look something like this:
>>=20
>>        <?php
>>        let $x =3D 0;
>>        function getCounter() use(&$x) {
>>            return $x;
>>        }
>>        function incrementCounter() use(&$x) {
>>            return $x++;
>>        }
>>        // since this is the end of the file, $x falls out of scope
>>=20


> Moreover, since your example is clearly not a singleton - it is hard =
to
> imagine any program that would have use for just one counter but never
> any more - it is a classic example of something that should be an
> object.

That was just a frivolous example to show how the syntax works, it=E2=80=99=
s not a sensible example of why you=E2=80=99d want this functionality.

> This looks like you're trying to create a class without calling it a
> class. Now, I agree that not everything should be a class. But what
> you're doing - set of functions linked by common behavior and sharing =
a
> common state - is a perfect fit for something classes and objects are
> used in PHP. So why not just use them instead of inventing creative =
ways
> of doing the same but in more complicated way?

> It might be a wrong example, but I have hard time seeing any
> example of something that has a group of functions, bound by common
> functionality, has a shared state and still should not and can not be
> expressed as a class/object. That's literally what they are made for.

> Now, utility classes do suck, but they suck not because they do what =
you
> described - on the contrary, they suck exactly because they are =
usually
> a bag of random, unrelated functions bound by nothing but the common
> trait of "we don't have other places to put them in". But for that,
> plain old functions work just fine in PHP.

Yeah, I see your point. For encapsulated state with associated functions =
to work with that state, a class is the way to go. For miscellaneous =
functions with no shared state, they should just be functions, not in a =
class.

However, I still don=E2=80=99t think `static` is a good idea. Adding =
function autoloading eliminates one use case - a bag of random, =
unrelated functions. But it leaves the other: a set of functions to =
operate on global state. The problem is that, well, global state is =
rarely a good thing, I don=E2=80=99t think we should be encouraging it. =
If people really want to make a singleton or a final class with a =
private constructor, be my guest, but I don=E2=80=99t think we should =
make it any easier for them.

--
Andrea Faulds
http://ajf.me/