Hi, please look at
https://stackoverflow.com/questions/63675888/get-original-source-instance-in-clone
do you have anything against updating PHP to pass "instance before
cloned" to any __clone call from php?
no BC - user may accept this extra argument or declare function
__clone() without any param like now
With kind regards / Mit freundlichen Grüßen / S přátelským pozdravem,
Michael Voříšek
I understand... seems that $this is very confusing inside __clone():
when writing, it writes to the clone, when reading it reads from original.
Seems valid a new optional parameter definition with the original source.
Atenciosamente,
David Rodrigues
Em qua., 2 de set. de 2020 às 15:41, Michael Voříšek - ČVUT FEL <
vorismi3@fel.cvut.cz> escreveu:
Hi, please look at
https://stackoverflow.com/questions/63675888/get-original-source-instance-in-clone
do you have anything against updating PHP to pass "instance before
cloned" to any __clone call from php?no BC - user may accept this extra argument or declare function
__clone() without any param like nowWith kind regards / Mit freundlichen Grüßen / S přátelským pozdravem,
Michael Voříšek
On Wed, Sep 2, 2020 at 2:11 PM David Rodrigues david.proweb@gmail.com
wrote:
I understand... seems that
$thisis very confusing inside__clone():
when writing, it writes to the clone, when reading it reads from original.
That's not an accurate description of what happens today.
$newObj = clone $oldObj;
// 1. Engine creates a new instance of get_class($oldObj), without calling
the constructor
// 2. Engine copies all properties from the old object to the new object
// 3. Engine invokes $newObj->__clone()
public function __clone() {
// Userspace object handles any property specific re-initialization
required.
// $this always refers to the new object here.
}
The question Niki asked is appropriate; What would one want to do to
$oldObj here?
If the goal is to read from the old object, then you have that already.
The new object is a perfect copy, so read from that.
If the goal is to write to the old object, then justify why you need to do
so, because it's not a clone operation at that point.
-Sara
Now I rethinked about what I said. Really, maybe clone is not the best
option. So maybe we can just use a method that will clone and will have
access to both informations. But I don't know if it solves the original
message.
public function getUserCopy() {
$userCopy = clone $this;
$this->copies[] = $userCopy;
return $userCopy;
}
Considering it, we have access to both now, with "write to source" support
with no additional feature need.
Em qui, 3 de set de 2020 11:21, Sara Golemon pollita@php.net escreveu:
On Wed, Sep 2, 2020 at 2:11 PM David Rodrigues david.proweb@gmail.com
wrote:I understand... seems that
$thisis very confusing inside__clone():
when writing, it writes to the clone, when reading it reads from original.That's not an accurate description of what happens today.
$newObj = clone $oldObj;
// 1. Engine creates a new instance of get_class($oldObj), without calling
the constructor
// 2. Engine copies all properties from the old object to the new object
// 3. Engine invokes $newObj->__clone()
public function __clone() {
// Userspace object handles any property specific re-initialization
required.
// $this always refers to the new object here.
}The question Niki asked is appropriate; What would one want to do to
$oldObj here?
If the goal is to read from the old object, then you have that already.
The new object is a perfect copy, so read from that.
If the goal is to write to the old object, then justify why you need to do
so, because it's not a clone operation at that point.-Sara
On Thu, Sep 3, 2020 at 10:40 AM David Rodrigues david.proweb@gmail.com
wrote:
Now I rethinked about what I said. Really, maybe clone is not the best
option. So maybe we can just use a method that will clone and will have
access to both informations. But I don't know if it solves the original
message.public function getUserCopy() {
$userCopy = clone $this;
$this->copies[] = $userCopy;return $userCopy;}
If your goal is to track copies, then a static makes much more sense.
class AllKnowing {
private static $copies = [];
public function __construct(...) {
self::$copies[] = $this;
....
}
public function __clone() {
self::$copies[] = $this;
}
}
-Sara
It was just an example to avoid modify how clone works, using existing
features. :)
Em qui, 3 de set de 2020 13:00, Sara Golemon pollita@php.net escreveu:
On Thu, Sep 3, 2020 at 10:40 AM David Rodrigues david.proweb@gmail.com
wrote:Now I rethinked about what I said. Really, maybe clone is not the best
option. So maybe we can just use a method that will clone and will have
access to both informations. But I don't know if it solves the original
message.public function getUserCopy() {
$userCopy = clone $this;
$this->copies[] = $userCopy;return $userCopy;}
If your goal is to track copies, then a static makes much more sense.
class AllKnowing {
private static $copies = [];public function __construct(...) { self::$copies[] = $this; .... } public function __clone() { self::$copies[] = $this;}
}-Sara
On Thu, Sep 3, 2020 at 11:03 AM David Rodrigues david.proweb@gmail.com
wrote:
It was just an example to avoid modify how clone works, using existing
features. :)
Right, but the question remains "Why would we want the original object
during a clone operation?". No legitimate example of that has been
provided yet.
-Sara
The goal is to be able to access the original object and it's id/hash.
Usecases:
- something is associated with the object using the object id/hash and
it needs to be cloned as well
we need the original object to obtain it's id/hash for spl_object_id and
spl_object_hash methods
- bounded Closures ar associated with the original object and they needs
to be rebound to the cloned object
example:
public function __clone(self $origThis)
{
if ((new \ReflectionFunction($this->fx))->getClosureThis() ===
$origThis) {
$this->fx = \Closure::bind($this->fx, $this);
}
}
Modification of php is simple:
https://github.com/php/php-src/pull/6063/files#diff-beea8c5a8ceb318220b34b73e4ecfc98R252
we simply pass the old object as 1 parameter. I belive, passing old
object have positives and no performance nor compatibility impact. All
other current solutions require an extra property and a lot of code, as
assigning in constructor is not enough (due serialization etc.), or it
is even impossible, if object was created using reflection without
constructor.
With kind regards / Mit freundlichen Grüßen / S přátelským pozdravem,
Michael Voříšek
On Thu, Sep 3, 2020 at 10:40 AM David Rodrigues david.proweb@gmail.com
wrote:Now I rethinked about what I said. Really, maybe clone is not the best
option. So maybe we can just use a method that will clone and will have
access to both informations. But I don't know if it solves the original
message.public function getUserCopy() {
$userCopy = clone $this;
$this->copies[] = $userCopy;return $userCopy;
}
If your goal is to track copies, then a static makes much more sense.class AllKnowing {
private static $copies = [];public function __construct(...) {
self::$copies[] = $this;
....
}public function __clone() {
self::$copies[] = $this;
}
}-Sara
Just to I know, it can't be done by an intermediary method like my previous
example? Why are the limitations to that?
About PR, could you provide some additional tests?
Thanks!
Em qui, 3 de set de 2020 13:37, Michael Voříšek - ČVUT FEL <
vorismi3@fel.cvut.cz> escreveu:
The goal is to be able to access the original object and it's id/hash.
Usecases:
- something is associated with the object using the object id/hash and
it needs to be cloned as wellwe need the original object to obtain it's id/hash for spl_object_id and
spl_object_hash methods
- bounded Closures ar associated with the original object and they needs
to be rebound to the cloned objectexample:
public function __clone(self $origThis)
{
if ((new \ReflectionFunction($this->fx))->getClosureThis() ===
$origThis) {
$this->fx = \Closure::bind($this->fx, $this);
}
}Modification of php is simple:
https://github.com/php/php-src/pull/6063/files#diff-beea8c5a8ceb318220b34b73e4ecfc98R252
we simply pass the old object as 1 parameter. I belive, passing old
object have positives and no performance nor compatibility impact. All
other current solutions require an extra property and a lot of code, as
assigning in constructor is not enough (due serialization etc.), or it
is even impossible, if object was created using reflection without
constructor.With kind regards / Mit freundlichen Grüßen / S přátelským pozdravem,
Michael Voříšek
On Thu, Sep 3, 2020 at 10:40 AM David Rodrigues david.proweb@gmail.com
wrote:Now I rethinked about what I said. Really, maybe clone is not the best
option. So maybe we can just use a method that will clone and will have
access to both informations. But I don't know if it solves the original
message.public function getUserCopy() {
$userCopy = clone $this;
$this->copies[] = $userCopy;return $userCopy;
}
If your goal is to track copies, then a static makes much more sense.class AllKnowing {
private static $copies = [];public function __construct(...) {
self::$copies[] = $this;
....
}public function __clone() {
self::$copies[] = $this;
}
}-Sara
On Wed, Sep 2, 2020 at 8:42 PM Michael Voříšek - ČVUT FEL <
vorismi3@fel.cvut.cz> wrote:
Hi, please look at
https://stackoverflow.com/questions/63675888/get-original-source-instance-in-clone
do you have anything against updating PHP to pass "instance before
cloned" to any __clone call from php?no BC - user may accept this extra argument or declare function
__clone() without any param like now
Could you please provide some more information on what the intended
use-case is?
I'm not opposed to this change, but I also don't understand why it is
needed.
Regards,
Nikita
On Wed, Sep 2, 2020 at 7:41 PM Michael Voříšek - ČVUT FEL <
vorismi3@fel.cvut.cz> wrote:
do you have anything against updating PHP to pass "instance before
cloned" to any __clone call from php?
Yes, I think that allowing the original object to be modified by a cloning
operation could be the cause for a lot of confusion. If we had a proper way
to make it read-only I wouldn't mind, but as is, it doesn't sound like a
good idea.
I don't see problem to allow modify the original object, once that you are
doing it by using a new argument, and not the $this itself.
Em qui, 3 de set de 2020 08:49, Pedro Magalhães mail@pmmaga.net escreveu:
On Wed, Sep 2, 2020 at 7:41 PM Michael Voříšek - ČVUT FEL <
vorismi3@fel.cvut.cz> wrote:do you have anything against updating PHP to pass "instance before
cloned" to any __clone call from php?Yes, I think that allowing the original object to be modified by a cloning
operation could be the cause for a lot of confusion. If we had a proper way
to make it read-only I wouldn't mind, but as is, it doesn't sound like a
good idea.