Re: [RFC] Readonly property hooks

Hi Larry et al. Le mar. 8 juil. 2025 à 17:12, Larry Garfield <larry@garfieldtech.com> a écrit : > On Tue, Jul 1, 2025, at 9:27 AM, Tim Düsterhus wrote: > > Hi > > > > Am 2025-06-09 17:11, schrieb Larry Garfield: > >> I also fleshed out the __get mention with an example that shows what > >> you can already do today, and in fact could since 8.1 when readonly was > >> introduced. The hard guarantee of idempotency has never actually been > >> there. (This also speaks to Claude's concern.) > > > > I don't think this really resolves Claude's concern. While it is > > certainly true that the guarantees do not currently hold, I don't > > believe this is strong enough of a reason not to provide for stronger > > guarantees in a *newly introduced feature*. The point of property hooks > > is for me that “dynamic properties” are easier to reason about compared > > to __get(). As a user when accessing a proper > > readonly property, I > > do not want to check if there is a property hook that might result in > > non-readonly behavior. As an engine developer I want to be able to > > optimize based on the readonly-ness of a property. Without > > such > > guarantees, the “readonly” keyword does not provide value to me. > > The only way to make the readonliness fully guaranteed would be to force a > readonly property to be cached; (IE, the hook is only called at all if the > property is uninitialized.) But there's no obvious way to make that clear > in the code that it's what's happening. > > > I also believe the LazyProduct example to be broken, since lazy-loading > > individual properties might result in an object that is internally > > consistent if the database changes in-between. > > That's true with any lazy-loading scenario. The use of hooks doesn't > change that at all. > This RFC makes sense to me. I read Claude's concern, and I agree with Larry's response: the engine already allows readonly to be bypassed using __get. The added hook doesn't make anything more lenient. I also read Tim's argument that new features could be stricter. If one wants to be stricter and forbid extra behaviors that could be added by either the proposed hooks or __get, then the answer is : make the class final. This is the only real way to enforce readonly-ness in PHP. If a class is final and uses readonly with either hooks or __get, then that's the original author's choice. There's no need for extra engine-assisted strictness in this case. You cannot write such code in a non-readonly way by mistake, so it has to be by intent. Nicolas PS: as I keep repeating, readonly doesn't immutable at all. I know this is written as such in the original RFC, but the concrete definition and implementation of readonly isn't: you can set mutable objects to readonly properties, and that means even readonly classes/properties are mutable, in the generic case.