Re: instance version of match ?

Hi, Am 29.03.22 um 14:34 schrieb Rowan Tommins:

On 29/03/2022 11:59, Robert Landers wrote:

         $object instanceof AnotherInterface => 'bar',

We can see that SomeInterface will resolve the interface and not the constant.

Yeah, the instanceof operator is magic in that regard - it has a special parsing rule to consume the next token and avoid it being evaluated as a constant.

I think what they are proposing is that when the match is an object, and the branches are class/interface/etc names, it should just do an instanceof operation instead of a value-equals operation.

That wouldn't work, because the type of value passed to match() can vary at run-time, but you'd need to compile the expression one way or the other. If it did work, it would be extremely confusing: function example(string|object $input) {

     return match($input)  {
           SomeClass => 'found class',
          SOME_CONSTANT => 'found constant',
     };

} var_dump( example(new SomeClass) ); var_dump( example(SOME_CONSTANT) ); Do both of those matches succeed? What if I set `const SomeClass = 'hello';`? So unfortunately we need some extra syntax to say that something should be an instanceof check, and therefore a class name.

While I liked the intention of Karoly, I did not like the proposed magic. Would it be an idea (and possible) to extend the syntax somehow like: $result = match ($value) {

    instanceof MyObject => ...,

= 42 => ...,

    !== 5 => ...

}; to be equivalent to: $result = match (true) {

    $value instanceof MyObject => ...,
    $value >= 42 => ...,
    $value !== 5 => ...

}; Regards Thomas