Re: Immutable modifier

On 16 November 2015 at 09:33, Lorenzo Fontana <fontanalorenz@gmail.com> wrote: > I really like the concept of immutability, but I think that it should be > applicable at instance level rather than declaration. > > I would also prefer another keyword than immutable. > > Final does not make the properties immutable, it makes the class not > extensible. > On Nov 16, 2015 10:24, "Daniel Persson" <mailto.woden@gmail.com> wrote: > >> Any differance from the final keyword? >> >> http://php.net/manual/en/language.oop5.final.php >> >> On Mon, Nov 16, 2015 at 10:15 AM, Chris Riley <t.carnage@gmail.com> >> wrote: >> >> > Hi, >> > >> > There has been a lot of interest recently (eg psr-7) in immutable data. >> I'm >> > considering putting an RFC together to add language support for >> immutables: >> > >> > immutable class Foo { >> > public $bar; >> > public function __construct($bar) { >> > $this->bar = $bar; >> > } >> > } >> > >> > Immutable on a class declaration makes all (maybe only public?) >> properties >> > of the class immutable after construct; assigning to a property would >> > result in a Fatal error. >> > >> > class Foo { >> > public $bar; >> > immutable public $baz; >> > } >> > >> > Immutable on a property makes the property immutable once it takes on a >> > none null value. Attempts to modify the property after this results in a >> > fatal error. >> > >> > Any thoughts? >> > ~C >> > >> > What instance level syntax would you propose? $foo = new immutable bar(); ? or immutable $foo = new bar(); Gives less flexibility imo and less guarantees of correctness. Consider the current user land implementation of immutable classes: class Foo { private $bar; public function __construct($bar) { $this->bar = $bar; } public function getBar() { return $this->bar; } } Is already done at declaration declaration based immutability is probably more desirable. What keyword would you suggest other than immutable? ~C