śr., 18 mar 2020, 03:36 użytkownik Jakob Givoni <ja...@givoni.dk> napisał:
> Thank you, Michał, for chiming in :-)
>
> On Tue, Mar 17, 2020 at 10:52 AM Michał Brzuchalski
> <michal.brzuchal...@gmail.com> wrote:
> > For object initializer, I was hoping to introduce a feature which with
> the benefits of typed properties
> > could reduce the boilerplate on initializing object and setting their
> properties in one expression.
> Exactly my motivation with COPA as well;
> - Typed properties - check,
> - Reduce boilerplate - check,
> - Initializing and setting properties in one expression - check.
>
> > With object initializer, this could be reduced to:
> >
> > $this->dispatch(new SomeCommand { foo = 'bar', baz = false });
> And with COPA it would be;
> $this->dispatch((new SomeCommand)->[ foo = 'bar', baz = false ]);
> Subtle differences, when compared to the currently available alternative.
>
The difference is in object state initialization :
Using Object Initializer enforce that if a class is instantiated with the
Object Initializer, at the end of the instantiation and properties
initialization, all visible properties *(depends on initialization scope)* are
initialized, otherwise, a RuntimeException is thrown. This helps to avoid
bugs where a property is added to the class but forgot to be assigned it a
value in all cases where the class is instantiated and initialized.
https://wiki.php.net/rfc/object-initializer#restrictions
You can't do that with COPA cause it has nothing to do with object
instantiation.
> > But as mentioned IMO this is a different feature than what you propose
> and personally I see no point
> > in reducing only assignment statements without combining it with object
> construction for these kinds
> > of small objects, DTO's, commands, queries and events.
> Maybe you missed that COPA can be combined with object construction?
>
> > but personally I don't need a constructor at all in those cases since we
> > have typed properties and it looks like they could be also marked as
> read-only in next major PHP version.
> Exactly, and as I couldn't help notice that you voted for the Write
> Once Properties RFC, which clearly states that
> object construction is a fuzzy term (meaning don't take it too
> seriously) and lazy initialization is a feature...
>
> I hope you will either reconsider your support for COPA or let me know
> what I'm missing so I can
> consider other directions.
>
