Re: RFC: Support for multi-line arrow functions

On 04.10.20 22:08, Rowan Tommins wrote:

If we added an opt-in syntax for "capture everything", we might instead write this: $f = function() use (*) {

     $x = $y = $z = null;

} Without re-initialising all local variables, we would no longer be able to know if they were actually local without looking at the surrounding scope for a value that might be captured. I am unconvinced by this trade-off of opt-out instead of opt-in. One use case I've seen proposed is closures which capture a large number of variables; I would be interested to see an example where this is the case and is not a "code smell" in the same way as requiring a large number of parameters.

Something like "use (*)" seems like a great enhancement to me. I often use a wrapper function for SQL transactions, something like:

public function update(int $numberId, int $addressId, bool $isMainNumber
= false): void
{
    $this->transaction->run(function () use ($numberId, $addressId,
$isMainNumber): void {
      // Do all SQL queries for the update
    });
}

In these cases there is a lot of redundancy because of having to import the variables, and if a variable is added, it has to be added in two places in a slightly different way. The following would be much nicer:

public function update(int $numberId, int $addressId, bool $isMainNumber
= false): void
{
    $this->transaction->run(function () use (*): void {
      // Do all SQL queries for the update
    });
}

This would also increase code readability.