Re: [RFC] Readonly Properties

> On 24 Oct 2014, at 11:20, Nikita Popov <nikita.ppv@gmail.com> wrote: > > While I think the functionality behind this proposal is nice in principle, I have two > objections with the RFC: > > 1. It uses the "readonly" modifier, to refer to a property that is publicly readable, > but protectedly writable (or protectedly readable and privately writable). This isn't entirely > obvious from the term "readonly" and also does not match the behavior of other languages > employing a "readonly" modifier, like C#. An additional complication may be encountered in > the case where the readonly property stores an object, in which case I presume it will be possible > to modify the stored object ($obj->readonlyProp->prop = 42), which is likely not expected > "readonly" behavior. It’s not the best name, I agree, but there isn’t a better name I could come up with in discussions. I don’t think the object thing is an issue, it’s not like there’s much we can do about that. > > 2. If the aim of this RFC is to replace the getFoo() pattern with the use of "readonly > public $foo" properties, a primary difference will be that a getFoo() method can be declared in > an interface, whereas a "readonly public $foo" property cannot be. Thus code making use of > interfaces will not be able to employ this feature. And I don't think that allowing properties > in interfaces is reasonable at this point, because the implementations will be limited to > simple-storage properties - only with more comprehensive property accessor support would > implementations be allowed to use more complex backing code. Right, interfaces currently can’t declare properties and I’m not going to change that in this RFC. If I revisit getters and setters, that would be changed. Still, I think there is usefulness to this without interfaces… it’s just more limited, sadly. It would work quite well with getters and setters and interfaces, if later added. Within interfaces, readonly could be used to avoid compelling implementing classes to support writing: interface Point { public readonly $x, $y; } But without preventing implementing classes from supporting it. -- Andrea Faulds http://ajf.me/