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Date: Fri, 20 Dec 2013 09:27:32 +0000
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Subject: Re: [PHP-DEV] Re: power operator (again)
From: rowan.collins@gmail.com (Rowan Collins)

Kris Craig wrote (on 20/12/2013):
> But now, let's look at another scenario:
>
> <?php
>
> $x = -3;  // Or $x = -1 * 3, if you wish.
>
> $y = $x ** 2;
>
> ?>
>
> What would be the value of $y under this RFC?

That has nothing to do with operator associativity: $x has already been 
calculated as -3, just as if it were $y = (-3) ** 2

Consider the same thing with mixed addition and multiplication:

$y = 1 + 2 * 3;
// $y is 7, due to operator precedence

$y = (1 + 2) * 3;
// $y is 9, due to the brackets

$x = 1 + 2;
$y = $x * 3;
// $x is 3, so $y is 9; operator precedence is irrelevant

As I said before, I think people don't always think of "-3" as an 
operator applied to a literal, but by the same token, they are rather 
unlikely to write something like "-$x". That limits this whole debate on 
associativity to those cases where somebody hard-codes a negative value 
like -3, and doesn't think to add parentheses.

Regards,
-- 
Rowan Collins
[IMSoP]