> On May 27, 2021, at 12:05 PM, Rowan Tommins <rowan.coll...@gmail.com> wrote:
>
> On 27/05/2021 16:33, Mike Schinkel wrote:
>> Since the argument against is_initialized() seems to almost universally be
>> that we should not write code that lets type properties be uninitialized
>> past the constructor then it would follow that PHP is in the wrong to even
>> allow uninitialized state past the constructor?
>
>
> Yes, that is my view. The problem is that there is currently no easy way to
> enforce this, because constructors are just methods that run after the object
> is created, and there are a handful of ways to create objects without calling
> them at all which would need to be accounted for as well.
>
>
>> If a property is defined as `?int` or `null|int` why should PHP allow an
>> uninitialized state to begin with? Why shouldn't PHP initialize any of
>> those properties to null to begin with?
>>
>> And for non-nullable, why shouldn't PHP default `int` to 0, `string` to
>> `""`, `array` to `[]`, etc.?
>
>
> Implicitly assigning a default from some magic list would be messy, but
> requiring that the user specified one would be trivial (or would have been,
> when typed properties were added): ?Foo $foo=null; int $bar=0; etc
>
> The problem is that for non-scalar, non-nullable properties, there is no way
> to specify a default. One solution would have been to simply ban such
> declarations (i.e. require ?Foo $foo=null rather than Foo $foo) but that was
> considered too restrictive, so marking the properties "uninitialized" is the
> compromise.
>
> We're probably stuck with that compromise for now, but continuing to treat it
> primarily as an error state hopefully leaves us room to do something cleaner
> in future if we can work out how.
So we are full circle.
Since we cannot guarantee that properties are not in said "error" state it begs
the question as to why developers shouldn't be able to introspect this error
state in a performant manner.
-Mike
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