On Sun, Jul 13, 2025 at 2:00 PM Marc Bennewitz <marc@mabe.berlin> wrote:
>
>
> On 13.07.25 18:17, Nick wrote:
>
>
> On 13. Jul 2025, at 20:38, Marc Bennewitz <marc@mabe.berlin> wrote:
>
> Hi Nick, Claude,
>
> Hey Marc,
>
> I think it's important to explicitly mark it as "this value will be stored in 
> memory", I mean just silently caching the get hook could quickly lead to 
> unexpected behavior. Like one would expect the value to be changed
>
> The most here made the argument that "a changing value from a readonly get 
> hook" would be the unexpected behaviour.
> That’s why we ended up with the current “alternative implementation 2”. 
> Please see my last answer to Rob for a fair example [1] .
>
> The current preferred alternative implementation covers both situations...
>
> If a property is `readonly`:
> - you can set once
> - on read you always get the same (once computed) value back
>
> This is exactly the behavior I mean which is somehow unexpected if not marked 
> explicitly as the result could be cached and the property value will never 
> change.
>
> Not being able to write to something doesn't generally mean reading the value 
> will never change. `get => random_int(0, 100);`
>
> I don't want to say that the path we want to go with readonly being able to 
> assume the value will never change is wrong but I think it's not clear for 
> the user and can be missed quickly - even with a test as you have to read the 
> property multiple time to notice the difference.
>
>
> If a property is NOT `readonly`:
> - you can set often
> - on read you always get the fresh (often computed) value back
>
> I argue that this is a very easy mental model.
> I hope that voters agree on “cached may be implied by readonly”, as Claude 
> called it.
>
> All what I'm saying is that this behavior should be explicit and not applied 
> implicitly on a readonly get hook.

I agree with Marc here, not surprisingly.

> To have an `init` hook doesn’t solve the get hook issue.
>
> As far as I understood the init hook it would still disallow readonly+get but 
> allow readonly+init and init would be called once the first time the property 
> gets read and the result would end up in the backing store.
>
> As a result you get the same behavior as `cached get` with the only 
> difference that you write `init => random_int();` instead of `cached get => 
> random_int();`

Agreed. Nick, I am not sure how the init hook doesn't "solve the get
hook issue". As I understand it, the get hook issue is that get hooks
are not allowed on readonly properties. The init hook would be
identical to a "cached get" hook on a readonly property, so why
doesn't it solve the issue?

> Or did I misunderstand it?

I share the same understanding as you, Marc.

> The cached modifier I would expect to be an attribute applicable to any 
> function which uses another cache store similar to how it's possible in 
> python to memorize function calls which would be a very different feature.
>
> As earlier answered to Claude [2], I seek to write less code. To introduce a 
> `cached` modifier voids this for no strong reason (please see “mental model” 
> above).
>
> See above - and `init` is just once more character.

I was going to respond to this point earlier, but Marc beat me to it.
An "init" hook is one more character than a get hook, is explicit over
a get hook that works differently only for readonly properties, *and*
is far fewer characters than the explicit "cached" modifier get hook
option.

On top of that, as Claude mentioned an init hook provides the ability
to differentiate between a null property and an uninitialized property
- an init hook would only be called for uninitialized properties, so
no need for $this->foo ??= "bar".

Reply via email to