---- En vie, 08 may 2020 23:40:22 +0200 Bob Weinand <bobw...@hotmail.com>
escribió ----
> > Am 04.05.2020 um 10:53 schrieb Manuel Canga <p...@manuelcanga.dev>:
> >
> > Hi internals,
> >
> >
> >
> > I would like to present a possible new RFC( "keep type of reference
> > params" ) for your
> >
> > consideration.
> >
> >
> >
> > Firstly, an example:
> >
> >
> >
> > ```
> >
> > <?php
> >
> >
> >
> > function my_array_shift( array & $array ) {
> >
> > $array = "string";
> >
> > }
> >
> >
> >
> > $array = [ 0, 1, 2, 3, 4 ];
> >
> >
> >
> > my_array_shift($array);
> >
> >
> >
> > count( $array );
> >
> > ```
> >
> >
> >
> > The result of this code is a warning( in count line ) because of $array is
> > a string.
> >
> > However, I think it should be an error or exception when a string is
> > assigned to $array var.
> >
> > In my opinion, $array var would have to keep its type when function ends.
> >
> >
> >
> > What is your opinion ? Do you see it useful ?
> >
> > Thanks and I'm sorry for my English( I'm a Spanish ).
> >
> > Regards
> >
> > --
> >
> > Manuel Canga
>
> Hey Manuel,
>
> the primary issue (apart from the BC break) here is leaking the reference
> across the function boundary.
>
> function a(array &$a) {
> $GLOBALS["globalA"] = &$a;
> }
>
> funcition b() {
> $GLOBALS["globalA"] = 10;
> }
>
> $a = 1;
> a($a);
> b();
> // $a is magically changed to 10
>
> Yes, you can here verify, that $a is an array at the function boundaries,
> but you cannot afterwards.
>
> If we had proper inout parameters (which do not leak a reference, but assign
> the value of the variable (in callee scope) back to the passed variable from
> caller), then we could easily enforce it.
>
> But as it stands now, this is not an option. (Especially due to the false
> promise this seems to make.)
>
> Bob
Thanks Bob, that was a great example
I explain...I am very forgetful, so it's very easy for me to write somethink
like this:
```
function filter_something( &string $to_filter) {
$to_filter = strtolower($to_lower);
$to_filter = sanitize_this($to_filter);
.....
}
filter_something($my_string);
```
Sometimes, one of these functions can returns a false|null|numeric|... instead
of expected type.
Also, If any function in 'filter_somethid' would throw an exception, value in
$to_filter would finish inconsistent
However, with:
```
function filter_something( inout string $to_filter) {
$to_filter = strtolower($to_lower);
$to_filter = sanitize_this($to_filter);
.....
}
filter_something(inout $my_string);
```
PHP could in the end produce exception when any function in `filter_something`
modify type of $my_string or
PHP could keep value of `$to_filter` as well if any function throwed an
exception.
Regards
--
Manuel Canga
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