Re: [RFC] Nullable Types
| From: | Levi Morrison | Date: | Wed, 20 Apr 2016 18:28:17 +0000 |
| Subject: | Re: [RFC] Nullable Types | ||
| References: | 1 2 | Groups: | php.internals |
| Request: | Send a blank email to internals+get-92563@lists.php.net to get a copy of this message | ||
On Wed, Apr 20, 2016 at 11:55 AM, Jesse Schalken <me@jesseschalken.com> wrote:
> I read the RFC and it all sounds good to me. I appreciate the care taken to
> ensure method compatibility rules are correct, a smooth interop with =null,
> and to consider impact on union types if added later (? just becomes sugar).
>
> I'm not sure if it's been mentioned or not, but the position of the ? has
> impact on the ability to add a foo[] shorthand for generic arrays. Namely,
> if the ? is at the start, then the syntax becomes ambiguous.
>
> string[]? (nullable array of strings)
>
> string?[] (array of nullable strings)
>
> ?string[] (ambiguous, need to consult precedence rules and/or use brackets)
>
>
> I'm not sure how HHVM/Hack deals with that, or if it even has the foo[]
> shorthand.
You would write
array<?string>; Hack doesn't have a short-hand syntax.