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Date: Mon, 21 Nov 2011 11:59:12 +0400
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To: Nikita Popov <nikita.ppv@googlemail.com>
Cc: PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] New dereferencing syntaxes in 5.4
From: irker@irker.net (=?UTF-8?B?0JDQu9C10LrRgdCw0L3QtNGAINCc0L7RgdC60LDQu9GR0LI=?=)

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Amateurish question to internals:
Why can not we do more general cases? For example (expr)[3];
(expr)->foo->bar;
(expr)()->baz[3]()->makeSomething()[4] = 16; etc.

Now we have (new some)->something; and doSomething()[12], but why only this
cases?

Big trouble in parser to do this? Can someone help me to find discussions
about it, if they exist.

With regards, Alexander Moskaliov
Irker@irker.net


2011/11/20 Nikita Popov <nikita.ppv@googlemail.com>

> Hi internals!
>
> I want to discuss some details of the new dereferencing syntaxes which
> were introduced in 5.4.
>
> 1. I already mentioned lack of support for dereferencing using the
> alternative array syntax earlier
> (http://markmail.org/thread/j6rs3bzgzhxmco7n) but there was no
> conclusion on that topic. Now the (new A)[0] dereferencing syntax
> landed without alternative syntax too. Does this mean that the general
> consensus is to deprecate and remove the {} syntax altogether in the
> future?
>
> 2. PHP always supported doing $arr[0]() and 5.4 added the reverse
> func()[0]. The addition seems slightly inconsistent though, as the
> combination of both does not work: func()[0]() will result in a syntax
> error. Same applies to method array dereferencing. Is this
> intentional?
>
> 3. The new expression method, property and array dereferencing
> syntaxes were added in expr_without_variable. I am not sure whether
> this was intentional or not. That way (new A)->b will not be a
> variable (in the parser sense), whereas $a->b will. What is the impact
> of this? One thing that will not work is doing (new A)->b = 'c'. I
> know, this looks fairly stupid, but if you consider that A might
> overload the __set operation it might actually make sense. (It won't
> make much sense, but hey, (new A)[0] doesn't make much sense to me
> either). Other areas that might be affected are return by reference,
> pass by reference and iterate by reference (but I didn't test this).
>
> So, I know, those are all edge cases, so leaving them as is won't hurt
> much. Still I think it's better to discuss them ;)
>
> Nikita
>
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