On 1. 4. 2021 19:24:35, Bruce Weirdan <weir...@gmail.com> wrote: > Since `throw` is an expression (since PHP 8.0, > https://wiki.php.net/rfc/throw_expression), it must have a type for its > result, > as any expression has a type. And it's result is exactly `noreturn` (or > `never`, as this option seems to be preferred > judging by current vote results), because `throw` never returns. > > It's quite natural to extend that to function calls that never return as > well. And then it makes sense to declare that type > as a part of function signature like you can do with other types. > > -- > Best regards, > Bruce Weirdan mailto: > weir...@gmail.com >
Yes, this works very well in the typesystem. For example if we define the type of the match expression as a union of all its arms, then the arm that always throws or contains exit() has the noreturn/never type, which is thrown away in a union (int|string|never can be normalized to int|string).
