Re:Go 1.18
by dialogbox on Tuesday March 15, 2022 @06:37PM
(#30692861)
IMO using Optional type means the inner value must be not null. And if it's Some(null), it should mean exactly same as None.
[ Parent
| on HN ]
distinguishing `Some(null)` and `None` is often considered a feature of Optional ;)
to use a tired example: when getting a value out of a map via some `myMap.get(key)`, you may want to distinguish "not present" = `None` and "present, with value null" = `Some(null)`
the right solution is to just not have nulls in the first place, then there's no problem ;)
(Assuming we are discussing the Option type from rust)
Some(null) is not a valid result.
The whole point of the Option type is to let you know:
a) we got a result: Some(value)
b) there is no result: None
It's trivial to store a null pointer in an Option::Some().
struct Foo;
fn main() {
let option_with_null: Option<*const Foo> = Some(std::ptr::null());
dbg!(option_with_null);
dbg!(option_with_null.is_none());
}
[src/main.rs:6] option_with_null = Some(
0x0000000000000000,
)
[src/main.rs:7] option_with_null.is_none() = false
As the creator of the function, you should try to adhere to the conventions and not try to break them.