Hey Seifeddine, I'm not sure why my last message did not receive a response, but I will try again.
> similar to what we see in TypeScript This is exactly my concern. Literal types are useful in TypeScript, but they are also often directly overused. I do not think PHP should encourage the same pattern. I would prefer type aliases, such as Robert’s proposal from last year, as a foundation before considering this direction: https://wiki.php.net/rfc/typed-aliases My concern is that the RFC encourages public APIs like function f(1|2|3 $x) or function sort('asc'|'desc' $direction), where magic scalar values become part of the runtime API instead of being represented by a properly domain modeled entity. Modern AI-assisted engineering makes semantic naming even more important. Inline literal types such as 1|2|3 or 'asc'|'desc' provide less semantic signal than named concepts such as enums or type aliases. This can make code harder not only for humans, but also for AI tools that rely heavily on names and surrounding context. However, I'm aware that this secondary argument is not very plausible in this group. Language features should be evaluated from the long-term user and API-design perspective, not only from the static-analysis perspective. From that perspective, I think this RFC approaches the problem from the wrong side. Kind regards, Jorg
