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Date: Fri, 29 Jun 2012 16:25:23 +0200
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Subject: RFC proposal - Syntactic sugar for cloning
From: amaury@amaury.net (Amaury Bouchard)

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Hello everybody,

It's the first time I write on the internals mailing-list, so let me
introduce myself quickly. I'm a french and canadian CTO, working in Paris.
I lead some PHP projects (mainly the Temma framework and FineFS data
replication system).
I begin to learn PHP's internal engine, backed by Pierrick Charron.

I would like to do an RFC proposal (see below for the associated patch).
I was thinking about "what if PHP was a full-object language?". Like, for
example, how will we write the simplest code, assuming that objects are
handled using pointers since PHP 5.

Take a look at this code:
   $a = 3;
   $b = $a;
   $a++;

$b still contains the value 3.

Now, if we imagine that even the integer data type is managed in an object,
the same code will produce two pointers to the same object. Thus, $b will
have the value 4, as $a.
So, in this imaginary world, we would need to do a lot of object cloning. I
wondered how this could be less painful, and I thought about the Pascal
language's affectation operator (:=).

Then we would be able to write something like that:
   $a = 3;
   $b := $a;
   $c = $a;
   $a++;

$a equals 4, as $c. But $b equals 3.

Back in the real world, we are not cloning objects very often. But, like
many other syntactic sugars (as the short array syntax), I think it could
be handy in some circumstances.

There is a patch for this evolution, written by Pierrick.
Full source code: https://github.com/adoy/php-src/tree/amaury-clone
Code diff:
https://github.com/adoy/php-src/commit/5107c0355c50381c7e67230cdc9f563eb3936a15


I'm looking forward to your advices.

Cheers!

Amaury

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