[RFC] Accessors : read-only / write-only keywords

Hey Rasmus, please try and keep these replies in the appropriate thread...

I am in favor of eliminating the read-only/write-only keywords and implementing no "special code" to make what was read-only/write-only language enforced. I think the alternatives with final are just fine and good enough and will let userland programming enforce it if they so desire.

Example of user-land enforced 'read-only' code:

class A {
public $b {
get() { ... }
private final set($x) { throw new Exception("cannot set $b"); }
}
}

This solution introduces no magic on the engine side and lets those who need a read-only / write-only type scenario to "work."

Does this sound like an effective solution for everyone?

-----Original Message-----
From: Rasmus Schultz [mailto:rasmus@mindplay.dk]
Sent: Saturday, October 20, 2012 9:45 AM
To: internals@lists.php.net
Subject: [PHP-DEV] Re: internals Digest 20 Oct 2012 09:49:39 -0000 Issue 2820

I second getting rid of write-onle - the only real case I can think of, is something like a password property on a user/account model-
type, which gets encrypted and thus can't be read, and as Amaury pointed out, that should be a setPassword() method instead,
perhaps even a separate UserPasswordService component. Certainly not an accessor.

As for read-only, I strongly advice against overloading the const keyword with an entirely new meaning, if that's what you're
suggesting?

Just drop the idea of read-only altogether, please - it's so marginally useful in the first place, unconventional compared to other
languages, and will just get in the way. For most properties that only have a read-accessor, it won't even make any sense for someone
to try to extend that with a write-accessor. And as said, if you want to keep the internal value safe from write, just declare the actual
property as private.

---------- Forwarded message ----------
From: Amaury Bouchard amaury@amaury.net
To: Clint Priest cpriest@zerocue.com
Cc: "internals@lists.php.net" internals@lists.php.net
Date: Sat, 20 Oct 2012 10:09:35 +0200
Subject: Re: [PHP-DEV] [RFC] Accessors v1.1 -> v1.2 Summary read-only / write-only keywords

"no equivalent replacement has been suggested" => ouch

read-only => const

write-only => shouldn't exists. A write-only accessor is just a method disguised in property.

It's not a good idea to allow:
$obj->prop = 3;
when the meaning is:
$obj->meth(3);