PHP Type Alias

Sounds great. But I supsect PHP had to make big tradeoffs for its checked-at-runtime types that would make this hard.<p>In contrast to TypeScript or Flow, which can only check the program flow at compile time, PHP will crash and burn if you pass an int into a string function parameter at runtime.<p>Would you expect the presumed type aliases to be checked at runtime too?<p>There are already union types in PHP 8, but no aliases.<p>I think in PHP it is always the best approach to work with classes, whose type you can check at runtime (in contrast to duck-typed languages such as JS, where there is instanceof but that is generally a last resort).<p>Structural types checked at compile time are a different approach to the one PHP chose I think. Alhough the lines between compilation and execution are blurry in a JIT language of course.

That is something I was looking for to be honest with you, but didn&#x27;t know how to &quot;look&quot; for it lol.<p>I had in mind the modern C++ `using` mechanism for creating my own types, but didn&#x27;t know how to write such logic.<p>I guess a union would be handy dealing with different alias types, depending on the use case, if you understand what I mean.<p>On the other hand, `match` is far better to be used if we really get type aliases as you suggest.

How about overloading `as` operator instead and use `alias` in place of `type`?<p>Something like `alias Numeric as int|float;`