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:
```php
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:
```php
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.
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