Enum JsOption

pub enum JsOption<T> {
    Some(T),
    Null,
    Undefined,
}

An Option-like type with two data-less variants in addition to Some: Null and Undefined.

Variants

Some(T)

Some value T

Null

Explicit absence of a value

Undefined

Implicit absence of a value

Implementations

impl<T> JsOption<T>

pub fn from_option(opt: Option<T>) -> Self

Construct a JsOption from a regular Option.

None will be converted to to Null.

pub fn from_implicit_option(opt: Option<T>) -> Self

Construct a JsOption from a regular Option.

None will be converted to Undefined.

pub fn into_option(self) -> Option<T>

Convert a JsOption to Option.

pub fn into_nested_option(self) -> Option<Option<T>>

Convert a JsOption<T> to Option<Option<T>>.

Null is represented as Some(None) while Undefined is represented as None.

pub const fn is_some(&self) -> bool

Returns true if the JsOption contains a value.

pub const fn is_null(&self) -> bool

Returns true if the JsOption is Null.

pub const fn is_undefined(&self) -> bool

Returns true if the JsOption is Undefined.

pub fn unwrap(self) -> T

Returns the contained Some value, consuming the self value.

Panics

Panics if the self value equals Null or Undefined.

pub fn unwrap_or(self, default: T) -> T

Returns the contained Some value or a provided default.

pub fn unwrap_or_else<F: FnOnce() -> T>(self, f: F) -> T

Returns the contained Some value computes is from a closure.

pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> JsOption<U>

Maps a JsOption<T> to JsOption<U> by applying a function to a contained value.

pub const fn as_ref(&self) -> JsOption<&T>

Converts from &Option<T> to Option<&T>.

pub fn as_mut(&mut self) -> JsOption<&mut T>

Converts from &mut Option<T> to Option<&mut T>.

impl<T: Default> JsOption<T>

pub fn unwrap_or_default(self) -> T

Returns the contained Some value or a default.

impl<T: Deref> JsOption<T>

pub fn as_deref(&self) -> JsOption<&<T as Deref>::Target>

Converts from &JsOption<T> to JsOption<&T::Target>.

impl<T: DerefMut> JsOption<T>

pub fn as_deref_mut(&mut self) -> JsOption<&mut <T as Deref>::Target>

Converts from &mut JsOption<T> to JsOption<&mut T::Target>.

Trait Implementations

impl<T: Clone> Clone for JsOption<T>

fn clone(&self) -> JsOption<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for JsOption<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Default for JsOption<T>

fn default() -> Self

Returns the default value, JsOption::Undefined.

impl<'de, T> Deserialize<'de> for JsOption<T>

where T: Deserialize<'de>,

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize a JsOption.

This implementation will never return Undefined. You need to use #[serde(default)] to get Undefined when the field is not present.

impl<T: Hash> Hash for JsOption<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: Ord> Ord for JsOption<T>

fn cmp(&self, other: &JsOption<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq for JsOption<T>

fn eq(&self, other: &JsOption<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialOrd> PartialOrd for JsOption<T>

fn partial_cmp(&self, other: &JsOption<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Serialize for JsOption<T>

where T: Serialize,

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize a JsOption.

Serialization will fail for JsOption::Undefined. You need to use #[skip_serializing_if = "JsOption::is_undefined"] to stop the field from being serialized altogether.

impl<T: Copy> Copy for JsOption<T>

impl<T: Eq> Eq for JsOption<T>

impl<T> StructuralPartialEq for JsOption<T>