Re: [RFC] Deprecate implicitly nullable parameter type

On 22 January 2024 10:21:12 GMT, tag Knife <fenniclog@gmail.com> wrote: >As you are mistaking iint $var = null params as >"nullable". Which they >are not, they are "optional default" parameters. The feature which is being discussed is that, for the specific case of "= null", the parameter is made both optional *and* nullable. To make it clearer, the following all declare default values within the allowed type: int $foo = 1 int|string $foo = 'hello' ?int $foo = 1 ?int $foo = null The following all lead to a type error, because the default value isn't allowed for the declared type: int $foo = 'hello' int|string $foo = new DateTime; ?int $foo = 'hello' However, there is a special case: for purely historical reasons, a default of null is allowed *even when it doesn't match the declared type*: int $foo = null int|string $foo = null These are processed as though they were declared as nullable types; and the fix for the proposed deprecation would be to do so: ?int $foo = null int|string|null $foo = null The fact that the feature is tricky to explain is a good reason to deprecate it, and I think I support the proposal unless I see a good argument against. Regards, -- Rowan Tommins [IMSoP]