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To: Quim Calpe <quim@kalpe.com>, PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] [RFC] Nullable Types
From: php@fleshgrinder.com (Fleshgrinder)

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To: Quim Calpe <quim@kalpe.com>, PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] [RFC] Nullable Types
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On 4/22/2016 11:42 AM, Quim Calpe wrote:
> IMHO, the point of Optional types is the intention, if you get an
> Option<Foo> from a method, you have to deal with a None branch. Of cour=
se
> you can just unwrap and go on, but it's a developer decision to do that=
,
> not an oversight as using a Foo|null (or ?Foo) as an object directly.
>=20

IMOH, the point of ?T is the intention, if you get a null from a method,
you have to deal with a null branch. Of course you can just ignore it
and go on, but it's a developer decision to do that, not an oversight as
using a Option<T> as an object directly.

Sorry, but this works in both directions. The problem is not null, the
problem is that there is no system that warns you (e.g. a compiler)
about the missing null check. I think that Ceylon solved this problem
extremely nicely without the introduction of something special.

function fn(): ?T {}

$x =3D fn();
if (is $x T) {}
else {}

Not doing as above is a compiler error in Ceylon. However, I already
wrote multiple times that there are already statical code analysis tools
available that can find exactly such things in your code. One just needs
to use them.

--=20
Richard "Fleshgrinder" Fussenegger


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