Struct rhai::Dynamic

pub struct Dynamic(_);

Dynamic type containing any value.

Implementations

impl Dynamic

pub fn is_variant(&self) -> bool

Does this Dynamic hold a variant data type instead of one of the support system primitive types?

pub fn is<T: Variant + Clone>(&self) -> bool

Is the value held by this Dynamic a particular type?

pub fn type_id(&self) -> TypeId

Get the TypeId of the value held by this Dynamic.

pub fn type_name(&self) -> &'static str

Get the name of the type of the value held by this Dynamic.

impl Dynamic

pub fn from<T: Variant + Clone>(value: T) -> Self

Create a Dynamic from any type. A Dynamic value is simply returned as is.

Safety

This type uses some unsafe code, mainly for type casting.

Notes

Beware that you need to pass in an Array type for it to be recognized as an Array. A Vec<T> does not get automatically converted to an Array, but will be a generic restricted trait object instead, because Vec<T> is not a supported standard type.

Similarly, passing in a HashMap<String, T> will not get a Map but a trait object.

Examples

use rhai::Dynamic;

let result = Dynamic::from(42_i64);
assert_eq!(result.type_name(), "i64");
assert_eq!(result.to_string(), "42");

let result = Dynamic::from("hello".to_string());
assert_eq!(result.type_name(), "string");
assert_eq!(result.to_string(), "hello");

let new_result = Dynamic::from(result);
assert_eq!(new_result.type_name(), "string");
assert_eq!(new_result.to_string(), "hello");

pub fn try_cast<T: Variant>(self) -> Option<T>

Get a copy of the Dynamic value as a specific type. Casting to a Dynamic just returns as is.

Returns an error with the name of the value's actual type when the cast fails.

Example

use rhai::Dynamic;

let x = Dynamic::from(42_u32);

assert_eq!(x.try_cast::<u32>().unwrap(), 42);

pub fn cast<T: Variant + Clone>(self) -> T

Get a copy of the Dynamic value as a specific type. Casting to a Dynamic just returns as is.

Panics

Panics if the cast fails (e.g. the type of the actual value is not the same as the specified type).

Example

use rhai::Dynamic;

let x = Dynamic::from(42_u32);

assert_eq!(x.cast::<u32>(), 42);

pub fn downcast_ref<T: Variant + Clone>(&self) -> Option<&T>

Get a reference of a specific type to the Dynamic. Casting to Dynamic just returns a reference to it. Returns None if the cast fails.

pub fn downcast_mut<T: Variant + Clone>(&mut self) -> Option<&mut T>

Get a mutable reference of a specific type to the Dynamic. Casting to Dynamic just returns a mutable reference to it. Returns None if the cast fails.

pub fn as_int(&self) -> Result<INT, &'static str>

Cast the Dynamic as the system integer type INT and return it. Returns the name of the actual type if the cast fails.

pub fn as_float(&self) -> Result<FLOAT, &'static str>

Cast the Dynamic as the system floating-point type FLOAT and return it. Returns the name of the actual type if the cast fails.

pub fn as_bool(&self) -> Result<bool, &'static str>

Cast the Dynamic as a bool and return it. Returns the name of the actual type if the cast fails.

pub fn as_char(&self) -> Result<char, &'static str>

Cast the Dynamic as a char and return it. Returns the name of the actual type if the cast fails.

pub fn as_str(&self) -> Result<&str, &'static str>

Cast the Dynamic as a string and return the string slice. Returns the name of the actual type if the cast fails.

pub fn take_string(self) -> Result<String, &'static str>

Convert the Dynamic into String and return it. Returns the name of the actual type if the cast fails.

Trait Implementations

impl Clone for Dynamic

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Dynamic

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

Formats the value using the given formatter.

impl Default for Dynamic

fn default() -> Self

Returns the "default value" for a type.

impl Display for Dynamic

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

Formats the value using the given formatter.

impl<'_, T: Variant + Clone> From<&'_ [T]> for Dynamic

fn from(value: &[T]) -> Self

Performs the conversion.

impl From<()> for Dynamic

fn from(value: ()) -> Self

Performs the conversion.

impl<T: Variant + Clone> From<HashMap<String, T, RandomState>> for Dynamic

fn from(value: HashMap<String, T>) -> Self

Performs the conversion.

impl From<ImmutableString> for Dynamic

fn from(value: ImmutableString) -> Self

Performs the conversion.

impl From<String> for Dynamic

fn from(value: String) -> Self

Performs the conversion.

impl<T: Variant + Clone> From<Vec<T>> for Dynamic

fn from(value: Vec<T>) -> Self

Performs the conversion.

impl From<bool> for Dynamic

fn from(value: bool) -> Self

Performs the conversion.

impl From<char> for Dynamic

fn from(value: char) -> Self

Performs the conversion.

impl From<f64> for Dynamic

fn from(value: FLOAT) -> Self

Performs the conversion.

impl From<i64> for Dynamic

fn from(value: INT) -> Self

Performs the conversion.