RFC proposal : "new" keyword shorthand View as Markdown

Instead of ~ (which reminds me of the pendulum of symbols to written to symbols and back again every 10ish years; “or” vs “||”), why not make a shorthand way to write a function that calls a constructor (kinda sorta like C# extension methods)? Something kinda like:

class MyClass implements Invocable {
public function __construct($i) {}
}

MyClass($i);

Where the Invocable interface defines a function of the same class name in the namespace that is an alias for a new objects and forwards args to the constructor. This could be quite handy for value objects.

I’m not necessarily a fan of magic or symbols, but just tossing it out there to spark ideas.

— Rob
--

I'm not a fan of using ~ for this shorthand, due to the same issues
that have been brought up elsewhere (i.e. it already has meaning). But
the idea of a new interface auto-defining a function of the same name
is attractive. It's something I've done manually to mirror code in PHP
from other implementations existing in Scala leveraging case classes.

https://docs.scala-lang.org/tour/case-classes.html for anyone
unfamiliar with the construct:

case class Book(isbn: String)

val frankenstein = Book("978-0486282114")

Doing something like this in PHP is a bit more ... verbose today:

class Book
{
    public function __construct(public string $isbn) {}
}

function Book(string $isbn): Book
{
    return new Book($isbn);
}

$frankenstein = Book("978-0486282114")

That's a lot of boilerplate for the shorthand to not require a new
keyword. Which is to say, I both agree in principle with the RFC and
think this would add value (particularly if I could extend the default
behavior of this kind of interface to support immutability, comparison,
etc similar to Scala case classes). I'm just not a fan of the current ~
proposal.

~Eric

The issue with auto-generating a function constructor for a class is that we still don't have function autoloading. Which means this:

// Point.php

#[MakeFactoryFunction] (or whatever)
class Point {
public function __construct(public int $x, public int $y) {}
}

// index.php

$p = Point(4, 5);

will look for a function named "Point", not find one defined yet, and fatal.

If we had function autoloading, that would work, assuming a reasonable generic autoloader for that case could be written. Who was it that's been talking about that for a while? :-)

Or if we had some marker to indicate "this function call is a wrapper for a class so autoload it like a class", that could then trigger the class autoloader. But... that's basically what the original ~ proposal is, in the end. Though I agree that ~ is not a great symbol for it. PHP has, sadly, run out of unused symbols. (I've run into this a couple of times now.)

--Larry Garfield

Hello Benoit.
others already pointed out problems with the $obj = ~C(); syntax,
but also with the other option, $obj = C();.

Personally I would prefer a suffix operator that would look similar to
a static method call.
This would make it a lot easier to switch between calling a static
factory and "new."

Unfortunately, $obj = C::new(); is not an option, because "new" is a
legal method name, so there could already be existing methods with
that name.
Also, $obj = C::__construct(); would be just wrong.

But if we can find anything in that direction, I would much prefer it
over a prefix operator.
E.g. $obj = C::+(); is currently not valid syntax, so it would be a
candidate, even though I don't really like it.

-- Andreas

Le ven. 7 juin 2024, 21:31, Larry Garfield larry@garfieldtech.com a
écrit :

Instead of ~ (which reminds me of the pendulum of symbols to written to
symbols and back again every 10ish years; “or” vs “||”), why not make a
shorthand way to write a function that calls a constructor (kinda sorta
like C# extension methods)? Something kinda like:

class MyClass implements Invocable {
public function __construct($i) {}
}

MyClass($i);

Where the Invocable interface defines a function of the same class name
in the namespace that is an alias for a new objects and forwards args to
the constructor. This could be quite handy for value objects.

I’m not necessarily a fan of magic or symbols, but just tossing it out
there to spark ideas.

— Rob
--

I'm not a fan of using ~ for this shorthand, due to the same issues
that have been brought up elsewhere (i.e. it already has meaning). But
the idea of a new interface auto-defining a function of the same name
is attractive. It's something I've done manually to mirror code in PHP
from other implementations existing in Scala leveraging case classes.

https://docs.scala-lang.org/tour/case-classes.html for anyone
unfamiliar with the construct:

case class Book(isbn: String)

val frankenstein = Book("978-0486282114")

Doing something like this in PHP is a bit more ... verbose today:

class Book
{
    public function __construct(public string $isbn) {}
}

function Book(string $isbn): Book
{
    return new Book($isbn);
}

$frankenstein = Book("978-0486282114")

That's a lot of boilerplate for the shorthand to not require a new
keyword. Which is to say, I both agree in principle with the RFC and
think this would add value (particularly if I could extend the default
behavior of this kind of interface to support immutability, comparison,
etc similar to Scala case classes). I'm just not a fan of the current ~
proposal.

~Eric

The issue with auto-generating a function constructor for a class is that
we still don't have function autoloading. Which means this:

// Point.php

#[MakeFactoryFunction] (or whatever)
class Point {
public function __construct(public int $x, public int $y) {}
}

// index.php

$p = Point(4, 5);

will look for a function named "Point", not find one defined yet, and
fatal.

If we had function autoloading, that would work, assuming a reasonable
generic autoloader for that case could be written. Who was it that's been
talking about that for a while? :-)

Or if we had some marker to indicate "this function call is a wrapper for
a class so autoload it like a class", that could then trigger the class
autoloader. But... that's basically what the original ~ proposal is, in
the end. Though I agree that ~ is not a great symbol for it. PHP has,
sadly, run out of unused symbols. (I've run into this a couple of times
now.)

--Larry Garfield

Thank you all for these answer, I miss the not bitwise operator... Sorry
about that.

Totally agree, look like we run out of unused symbol. And that it's maybe
not the ideal solution to add a new one or combination of existing.

Benoit.

Hi all.

Em sex., 7 de jun. de 2024 às 17:53, Pierre pierre-php@processus.org
escreveu:
I do agree with you that when you use value objects, you need it a lot,
but I'd much prefer having a JS like value objects initializer syntax,
such as Point {x: 1, y: 2} syntax than creating another way to call
the constructor, which already has a mastered and comprehensive syntax
which is simply new.

I also think that new (4 chars, if we count the blank space) is short
enough.
But a JS-like syntax that's already known for representing objects could be
used.
I'm sympathetic to something like this (changing the OP examples):

class A {
public function b() {
echo "I'm B";
}
}

A::{}->b();

class Foo {
public function __construct(
public string $name
) {}
}

class Bar {
public function __construct(
public Foo $foo
) {}
}

$bar = Bar::{ Foo::{ "I'm foo in bar" } };
echo $bar->foo->name;

#[AttributeOverrides([
AttributeOverride::{
name: "id",
column: Column::{ name: "guest_id", type: "integer", length: 140 }
},
AttributeOverride::{
name: "name",
column: Column::{ name: "guest_name", nullable: false, unique:
true, length: 240 }
}]
)]

#[AttributeOverrides([
AttributeOverride::{
name: "id",
column: Column::{ name: "guest_id", type: "integer", length: 140 }
},
AttributeOverride::{
name: "name",
column: Column::{ name: "guest_name", nullable: false, unique:
true, length: 240 }
}]
)]

--
Erick