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On Sep 14, 2016 7:08 PM, Fleshgrinder <[email protected]> wrote:
>
> On 9/13/2016 11:38 PM, Mathieu Rochette wrote:
> > I agree that blocking clone seems unnecessary. I also don't see why it
> > is useful to have "clone" methods. Why not let "clone $this" produce a
> > copy that is open to modification within the scope it's cloned in ? or,
> > why would you limit yourself to one clone per method call ? maybe there
> > is something I'm missing but I don't get why introducing a new method
> > annotation is useful. it looks like an implementation details (using
> > clone instead of new) of the method is leaking
> >
> > class Natural {
> > private $n;
> > public function __construct(int $n) {assert($n >= 0); $this->n = $n;}
> > public function nextTen() {
> > for ($i = 0, $c = $this; $i < 10; $i++, $c = clone $c;) {
> > $c->n++;
> > yield $c;
> > }
> > }
> > }
>
> Why would you want to clone here?
>
> final immutable class NaturalNumber {
>
> private $n;
>
> public function __construct(int $n) {
> assert($n >= 0);
> $this->n = $n;
> }
>
> public function nextTen($n) {
> for ($i = $this->n; $i < 10; ++$i) {
> yield new static($i);
> }
> }
>
> }
>
> That being said, the whole example is kind of weird. What kind of
> functionality is that? Why is a value object creating multiple instances
> for itself? Single responsibility seems to be broken because some kind
> of collection should take care of that anyways.
yeah the example is not that great, I'll usually want to clone to avoid calling
a constructor with to many parameters (or a constructor doing too many things
not needed here)
>
> final immutable class NaturalNumber {
>
> private $n;
>
> public function __construct(int $n) {/*...*/}
>
> public clone function add(int $n) {
> $this->n += $n;
>
> return $this;
> }
>
> }
>
> final class NaturalNumberCollection {
>
> public function nextTen(NaturalNumber $start) {
> // This cast does not work (yet) ...
> for ($i = (int) $start; $i < 10; ++$i) {
> yield $start->add($i);
> }
> }
>
> }
>
> Same result but we just separated things nicely. I think the clone
> modifier would help to create better code and keep it easy to understand.
>
> On 9/13/2016 11:38 PM, Mathieu Rochette wrote:
> > again, why mark method as clone method in an interface, if the interface
> > is already marked as immutable isn't it enough to specify the return
> > type "static" ?
>
> Because it is unclear if you want to mutate in this context or return a
> new instance altogether.
what's the difference between the two for an immutable class?
>
> --
> Richard "Fleshgrinder" Fussenegger
>
