Re: [RFC] [Discussion] Literal Scalar Types

On 15/06/2026 3:22 am, Seifeddine Gmati wrote:

Hello Internals, I'd like to start the discussion on a new RFC adding literal scalar types to PHP. - RFC: https://wiki.php.net/rfc/literal_scalar_types - Implementation: https://github.com/php/php-src/pull/22314 Thanks, Seifeddine.

I mainly see the benefit here as being able to be more strict about what a function actually accepts and returns, in cases where a dedicated enum would be overkill. Two things I'd like to understand better: Does the RFC allow referencing constants in type positions, or only raw literal values?

function foo(STATUS_ACTIVE|STATUS_INACTIVE $sort): void {}

What about enum values? For example:

function bar(Status::Active->value $status): void {}
// or simply as
function bar(Status::Active $status): void {}

Also, I'm not really a fan of mixing literal types with unions.

function foo(int|'bar' $param): void {}

To me, mixing these makes it harder to reason about what a function actually accepts. The whole point of literal types is to be (more) precise but the moment you throw a wide type like int into the union, that precision goes out the window. If a function takes int|'bar', what does that really tell me? It feels like it defeats the purpose. -- Regards, Jordi Kroon