On Mon, February 27, 2012 11:05 pm, Anthony Ferrara wrote:
> <?php
> class Foo {
> public $value = 1;
> }
> class Bar {
> public $value = 1;
> public function __castTo($type) {
> return $this->value;
> }
> public function __assign($value) {
> $this->value = $value;
> return $value != 10;
> }
> }
>
> $a = new Foo;
> $b = new Bar;
> $a++;
So, here's the thing...
This obviously trivial example makes perfect sense, until you realize
that some moron (and PHP has lots of them) will sooner or later make
++ do something completely weird, and I'm going to have to edit their
code-base and will have to dig through umpteen class files to figure
out what the heck ++ means...
I can see a lot of legitimate serious coders using this wisely.
Unfortunately, I can see a million scripters using it very un-wisely.
I can even see people overloading the plus operator for an object
wrapped around an array in multiple different ways, then pulling in
different libraries that seem quite useful, and the only way I can
figure out what "+" means is to dig through even more files and figure
out which bastard child this object comes from, that was passed into
some random function that uses + on it.
And then god knows what happens when you do:
$foo = new Foo(); //from library A
$bar = new Bar(); //from library B
$foobar = $foo + $bar;
//Will this last statement even make sense, even though both Foo and
Bar override the + operator, just in entirely different ways...
How can you even guarantee that $foo, presumably taking precedence,
won't attempt to access a non-existent property of Bar, generating an
ignored E_NOTICE on most hosts, and introduce a subtle bug that nobody
notices for months, even years, in a seldom-used function?
Consider the trivial example where Foo uses array_sum() and Bar uses
count() comes up with a number. It's a totally meaningless number in
any real-world scenario. How would one detect this bug, really, in
some mish-mash of libraries from PEAR/PECL/homebrew-MVC/Framework.
I'm sure you can define the "rules" in a page or so for precedence in
type-casting and what happens when.
But I really am not interested in figuring out the "rules" for + when
I've been using it the same way since 2nd grade, with modest changes
over the years that follow the spirit of "+"
Your proposal lets one re-define + to mean whatever one wants, and
while you might not abuse that, somebody else will...
You might as well install runkit on everybody's server and let them
have at it. :-)
PHP was founded on the KISS principle, so that newbies can, in fact,
write sub-optimal but working code quickly to get a website up, and to
keep newbie fingers out of mashing gears.
This is way over-the-top from that principle.
--
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