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In-Reply-To: <CAHXoPRtjsPzgpYnhB05hjdZo6Q-MDr4TUGbn9LQ77-hKVTCZOA@mail.gmail.com>
Date: Sun, 29 Oct 2023 22:52:50 +0100
Message-ID: <CAPTD5yEYmhOqgCUMykhup5Ug0CRWee--3HvWO7jutwaUWOaD=g@mail.gmail.com>
To: Oladoyinbo Vincent <oladoyinbov@gmail.com>
Cc: internals@lists.php.net
Content-Type: multipart/alternative; boundary="0000000000000c2a940608e1f212"
Subject: Re: [PHP-DEV] Basic Type Alias
From: jorg.sowa@gmail.com (Jorg Sowa)

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I really like the idea and I would love to see it in PHP. I'm wondering
however, what would be the scope of the feature and how complex would be
designed type system. Examples I saw in this thread could be easily
replaced with union and intersection types (i.e. numeric as int|float). In
my opinion, there is a little benefit implementing in this shape making the
PHP core more complex.

The two use cases of user defined types in PHP which would benefit a lot
IMO, would be:
1. Typed arrays similar to Typescript.
2. Semantic types which would increase the security of systems. Example:
type UserId = int;

function setUserId_1(int $userId){}

function setUserId_2(UserId $userId){}

setUserId_1(5); // OK
setUserId_2(5); // TypeError

setUserId_1(UserId(5)); // OK
setUserId_2(UserId(5)); // OK

Kind regards,
Jorg

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