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Subject: Re: [PHP-DEV] The future of objects and operators
From: rowan.collins@gmail.com (Rowan Tommins)

On 6 May 2022 23:16:37 BST, Jordan LeDoux <jordan=2Eledoux@gmail=2Ecom> wro=
te:
>I'm not sure at this point how voters think objects and operators should
>work together into the future=2E I'd like to see if anyone is willing to =
have
>high-level discussion about the ideas, instead of picking at the
>implementation or details of a particular RFC=2E


Hi Jordan,

I like Larry's "4 levels", but I've been thinking that there's some existi=
ng functionality in PHP which takes a different direction: rather than over=
loading *operators*, the language lets you overload *behaviour*=2E We have =
magic methods like __get and __call, and interfaces like Iterator, Countabl=
e, and ArrayAccess=2E Some hook into a particular function, or even operato=
r, but they're generally described in terms of what they do, not what they =
look like, if you see what I mean=2E

From=20that point of view, overloading comparison and equality *behaviour* m=
akes sense - it could affect not just the =3D=3D and <=3D> operators, but t=
hings like in_array() and sort()=2E I think this distinction is more pronou=
nced in PHP than some languages, because the standard library isn't "self-h=
osted": a sort() call doesn't literally compile to a call to $a <=3D> $b

It's less obvious how that applies to mathematical operators - should impl=
ementing "addition" allow an object to be used with array_sum() perhaps? An=
d what about deriving one operation from another, e=2Eg=2E $foo*3 running $=
foo+$foo+$foo, or $foo**3 running $foo*$foo*$foo?

I don't really have a conclusion here, I just wanted to throw it out there=
 as a different mental model to consider=2E

Regards,

--=20
Rowan Tommins
[IMSoP]