Re: [RFC] Nullable Casting

> On 8 Apr 2019, at 16:35, Benjamin Morel <benjamin.morel@gmail.com> wrote: > >> register_cast_function('?int', 'castToIntOrNull'); > > I would quite oppose such a generic implementation, as it might have > unexpected consequences in other parts of the codebase : it's a global > configuration set at runtime. > > I quite like the idea of nullable casting though, as I've come across a few > cases myself where this would have been useful and would have made the code > more concise/readable. > > Ben > > On Mon, 8 Apr 2019 at 04:55, Dan Ackroyd <Danack@basereality.com> wrote: > >> On Sat, 6 Apr 2019 at 08:53, Guilliam Xavier <guilliam.xavier@gmail.com> >> wrote: >>> >>> Hello internals, >>> >>> David and I would like to open the discussion on our joint RFC: >>> >>> https://wiki.php.net/rfc/nullable-casting >>> >>> Mainly, it would enable to use e.g. (?int)$x besides >>> (int)$x. >>> >> >> I'm guessing you don't actually have ths function getIntOrNull() in >> your code-base? To help me understand where this would be useful, >> could you provide some 'real-world' code where this would be useful? >> >> By the way, this RFC is a special case of something that could be far >> more generic. If it was possible to register callbacks to be used when >> casting, people could do something like this: >> >> function castToIntOrNull($value) >> { >> if ($value === null) { >> return null; >> } >> >> return (int)$int; >> } >> >> register_cast_function('?int', 'castToIntOrNull'); >> >> $x = (?int)getIntOrNull(); >> >> >>> Additionally, it was requested on the mailing list to consider adding >>> support of nullable types to the settype() function, >>> e.g. settype($variable, "?int") >> >> Someone probably needs to make an argument for it to be in core, >> rather than just saying that it's something that could be done. >> >> cheers >> Dan >> Ack >> >> -- >> PHP Internals - PHP Runtime Development Mailing List >> To unsubscribe, visit: http://www.php.net/unsub.php >> >> I’ve come across this pattern (string variable contains a number or nothing) myself, but it also then makes me think - if your target ’type’ is ?int and you pass an empty string, wouldn’t you expect to get null rather than 0 ?