Union types | true pseudo-type

I'd like to bring back the topic of supporting "true" as a type in PHP 8
union types.
Now that the RFC https://wiki.php.net/rfc/union_types_v2 has been
successfully voted, I'd like to revive the discussion about adding the
"true" pseudo-type in addition to "false".

[..]

Thoughts?

— Benjamin

Hey,

Looking at my current project's code, I found one place where we use a
"string|true" as return type for an authentication method which returns
true or an error code if it fails.

Of course all the use cases we can argue about whether they are valid
and so on, but my main problem is the weird state of having false as a
type and not true. It just feels like an inconsistency in the language
that'll surely bite people when they'll try to use true as a type.

It might not be often, but it's kind of a shame if we can foresee it and
prevent it from happening.

TL;DR: true

Best,
Jordi

--
Jordi Boggiano
@seldaek - https://seld.be

On Mon, Jan 20, 2020 at 6:30 PM Benjamin Morel benjamin.morel@gmail.com
wrote:

Hi internals,

I'd like to bring back the topic of supporting "true" as a type in PHP 8
union types.
Now that the RFC https://wiki.php.net/rfc/union_types_v2 has been
successfully voted, I'd like to revive the discussion about adding the
"true" pseudo-type in addition to "false".

In addition to my Packagist survey
https://externals.io/message/106844#107304, I'd like to point out that I
just came across a native method in the SSH2 extension, that does use true
as a type:

https://www.php.net/manual/en/function.ssh2-auth-none.php

Returns TRUE if the server does accept "none" as an authentication method,

or an array of accepted authentication methods on failure.

Of course, you could type-hint it array|bool, but the same could be said
for |false.

Thoughts?

Generally I'm fine with also allowing the "true" type. We certainly have
quite a few extension methods that return isolated true values for legacy
reasons. However, before "true" is allowed, it is important to answer the
two questions at the end of
https://wiki.php.net/rfc/union_types_v2#literal_types.

Namely, how do true/false interact with weak typing coercions (currently
"false" only accepts "false", but not 0 or "") and whether true|false
should be equivalent to bool (also related to the previous question).

Regards,
Nikita