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Date: Sun, 17 Nov 2024 00:14:48 +0100
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Subject: [PHP-DEV] RFC: Records
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From: rob@bottled.codes ("Rob Landers")

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Hello internals,

I'm ready as I'm going to be to introduce to you: "Records" https://wiki=
.php.net/rfc/records!

Records allow for a lightweight syntax for defining value objects. These=
 are superior to read-only classes due to having value semantics and far=
 less boilerplate, for most things developers use read-only classes for.=
 They are almost as simple to use as arrays (and provide much of the sam=
e semantics), but typed.

As an example, if you wanted to define a simple User record:

record User(string $emailAddress, int $databaseId);

Then using it is as simple as calling it like a function, with the & sym=
bol:

$rob =3D &User("rob@bottled.codes", 1);

Since it has value semantics, we can get another instance, and it is str=
ongly equal to another of the same parameters:

$otherRob =3D &User("rob@bottled.codes", 1);
assert($otherRob =3D=3D=3D $rob); // true

Records may also have methods (even hooks), use traits, and implement in=
terfaces:

record Vector3(float $x, float $y, $z) implements Vector {
  use Vector;
  public float magnitude {
    get =3D> return sqrt($this->x ** 2 + $this->y ** 2 + $this->z ** 2)
  }
}

Further, an automatic (but overridable) "with" method is generated for e=
very record. This allows you to get a new record similar to a given one,=
 very easily:

record Planet(string $name);

$earth =3D &Planet("earth");
$mars =3D $earth->with(name: "mars");

The depth of records was an immense exploration of the PHP engine, langu=
age design, and is hopefully quite powerful for the needs of everyday PH=
P and niche libraries. I took care in every aspect and tried to cover ev=
ery possible case in the RFC, but I still probably missed some things. I=
 plan on having a full implementation done by the end of the year and op=
en to a vote by the end of January, but I'd like to open the discussion =
up here first. Love it or hate it, I'd like to hear your thoughts.

=E2=80=94 Rob
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<!DOCTYPE html><html><head><title></title><style type=3D"text/css">p.Mso=
Normal,p.MsoNoSpacing{margin:0}</style></head><body><div>Hello internals=
,<br></div><div><br></div><div>I'm ready as I'm going to be to introduce=
 to you: "Records"&nbsp;<a href=3D"https://wiki.php.net/rfc/records">htt=
ps://wiki.php.net/rfc/records</a>!<br></div><div><br></div><div>Records =
allow for a lightweight syntax for defining value objects. These are sup=
erior to read-only classes due to having value semantics and far less bo=
ilerplate, for most things developers use read-only classes for. They ar=
e almost as simple to use as arrays (and provide much of the same semant=
ics), but typed.<br></div><div><br></div><div>As an example, if you want=
ed to define a simple User record:<br></div><div><br></div><div>record U=
ser(string $emailAddress, int $databaseId);<br></div><div><br></div><div=
>Then using it is as simple as calling it like a function, with the &amp=
; symbol:<br></div><div><br></div><div>$rob =3D &amp;User("<a href=3D"ma=
ilto:rob@bottled.codes">rob@bottled.codes</a>", 1);<br></div><div><br></=
div><div>Since it has value semantics, we can get another instance, and =
it is strongly equal to another of the same parameters:<br></div><div><b=
r></div><div>$otherRob =3D &amp;User("<a href=3D"mailto:rob@bottled.code=
s">rob@bottled.codes</a>", 1);<br></div><div>assert($otherRob =3D=3D=3D =
$rob); // true<br></div><div><br></div><div>Records may also have method=
s (even hooks), use traits, and implement interfaces:<br></div><div><br>=
</div><div>record Vector3(float $x, float $y, $z) implements Vector {<br=
></div><div>&nbsp; use Vector;</div><div>&nbsp; public float magnitude {=
<br></div><div>&nbsp; &nbsp; get =3D&gt; return sqrt($this-&gt;x ** 2 + =
$this-&gt;y ** 2 + $this-&gt;z ** 2)<br></div><div>&nbsp; }<br></div><di=
v>}<br></div><div><br></div><div>Further, an automatic (but overridable)=
 "with" method is generated for every record. This allows you to get a n=
ew record similar to a given one, very easily:<br></div><div><br></div><=
div>record Planet(string $name);<br></div><div><br></div><div>$earth =3D=
 &amp;Planet("earth");<br></div><div>$mars =3D $earth-&gt;with(name: "ma=
rs");<br></div><div><br></div><div>The depth of records was an immense e=
xploration of the PHP engine, language design, and is hopefully quite po=
werful for the needs of everyday PHP and niche libraries. I took care in=
 every aspect and tried to cover every possible case in the RFC, but I s=
till probably missed some things. I plan on having a full implementation=
 done by the end of the year and open to a vote by the end of January, b=
ut I'd like to open the discussion up here first. Love it or hate it, I'=
d like to hear your thoughts.<br></div><div><br></div><div id=3D"sig1212=
29152">=E2=80=94 Rob</div></body></html>
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