[Discussion] Revisiting typed closures

Hello internals, I would like to revisit the idea of giving closures a typed call signature. e.g. Closure(int, string): array -- enforced at the point a value crosses a type boundary (an argument, a return, a property), the same places any other type is checked. Today a closure can only be typed as Closure or callable, neither of which says anything about its parameters or return, even though that information is right there. I know this is not new ground: Callable Prototypes was declined in 2016, and Garfield and Grekas shared two further RFCs in 2023 -- Structural Typing for Closures, and Allow Closures to Declare Interfaces they Implement -- both still in draft. Before taking it further, I would like to know whether closure typing is still considered worth pursuing -- or whether the topic is now regarded as settled. References: - https://wiki.php.net/rfc/callable-types - https://wiki.php.net/rfc/structural-typing-for-closures - https://wiki.php.net/rfc/allow-closures-to-declare-interfaces-they-implement Thanks.