Struct casbin::rhai::plugin::Dynamic

pub struct Dynamic(/* private fields */);

Dynamic type containing any value.

Implementations

impl Dynamic

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

👎Deprecated since 1.1.0: use into_string instead

Convert the Dynamic into a String and return it. If there are other references to the same string, a cloned copy is returned. Returns the name of the actual type if the cast fails.

Deprecated

This method is deprecated. Use into_string instead.

This method will be removed in the next major version.

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

👎Deprecated since 1.1.0: use into_immutable_string instead

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

Deprecated

This method is deprecated. Use into_immutable_string instead.

This method will be removed in the next major version.

impl Dynamic

pub const fn tag(&self) -> i16

Get the arbitrary data attached to this Dynamic.

pub fn set_tag(&mut self, value: i16) -> &mut Dynamic

Attach arbitrary data to this Dynamic.

pub const fn is_variant(&self) -> bool

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

pub fn is<T>(&self) -> bool

where T: Any + Clone,

Is the value held by this Dynamic a particular type?

Panics or Deadlocks When Value is Shared

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

pub fn type_id(&self) -> TypeId

Get the TypeId of the value held by this Dynamic.

Panics or Deadlocks When Value is Shared

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

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

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

Panics or Deadlocks When Value is Shared

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

impl Dynamic

pub const UNIT: Dynamic = _

A Dynamic containing a ().

pub const TRUE: Dynamic = _

A Dynamic containing a true.

pub const FALSE: Dynamic = _

A Dynamic containing a false.

pub const ZERO: Dynamic = _

A Dynamic containing the integer zero.

pub const ONE: Dynamic = _

A Dynamic containing the integer 1.

pub const TWO: Dynamic = _

A Dynamic containing the integer 2.

pub const THREE: Dynamic = _

A Dynamic containing the integer 3.

pub const TEN: Dynamic = _

A Dynamic containing the integer 10.

pub const HUNDRED: Dynamic = _

A Dynamic containing the integer 100.

pub const THOUSAND: Dynamic = _

A Dynamic containing the integer 1,000.

pub const MILLION: Dynamic = _

A Dynamic containing the integer 1,000,000.

pub const NEGATIVE_ONE: Dynamic = _

A Dynamic containing the integer -1.

pub const NEGATIVE_TWO: Dynamic = _

A Dynamic containing the integer -2.

pub const fn from_bool(value: bool) -> Dynamic

Create a new Dynamic from a bool.

pub const fn from_int(value: i32) -> Dynamic

Create a new Dynamic from an INT.

pub const fn from_char(value: char) -> Dynamic

Create a new Dynamic from a char.

pub fn from_array(array: Vec<Dynamic>) -> Dynamic

Create a Dynamic from an Array.

pub fn from_blob(blob: Vec<u8>) -> Dynamic

Create a Dynamic from a Blob.

pub fn from_map(map: BTreeMap<SmartString<LazyCompact>, Dynamic>) -> Dynamic

Create a Dynamic from a Map.

pub fn from_timestamp(value: Instant) -> Dynamic

Create a new Dynamic from an Instant.

Not available under no-std or no_time.

pub fn into_read_only(self) -> Dynamic

Make this Dynamic read-only (i.e. a constant).

pub fn is_read_only(&self) -> bool

Is this Dynamic read-only?

Constant Dynamic values are read-only.

Usage

If a &mut Dynamic to such a constant is passed to a Rust function, the function can use this information to return the error ErrorAssignmentToConstant if its value will be modified.

This safe-guards constant values from being modified within Rust functions.

Shared Values

If a Dynamic holds a shared value, then it is read-only only if the shared value itself is read-only.

pub fn from<T>(value: T) -> Dynamic

where T: Variant + Clone,

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

Arrays

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 custom type instead (stored as a trait object).

Use array.into() or array.into_iter() to convert a Vec<T> into a Dynamic as an Array value. See the examples for details.

Hash Maps

Similarly, passing in a HashMap<String, T> or BTreeMap<String, T> will not get a Map but a custom type.

Again, use map.into() to get a Dynamic with a Map value. See the examples for details.

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");
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");

// Arrays - this is a custom object!
let result = Dynamic::from(vec![1_i64, 2, 3]);
assert_eq!(result.type_name(), "alloc::vec::Vec<i64>");

// Use '.into()' to convert a Vec<T> into an Array
let result: Dynamic = vec![1_i64, 2, 3].into();
assert_eq!(result.type_name(), "array");

// Hash map
let mut map = HashMap::new();
map.insert("a".to_string(), 1_i64);

// This is a custom object!
let result = Dynamic::from(map.clone());
assert_eq!(result.type_name(), "std::collections::hash::map::HashMap<alloc::string::String, i64>");

// Use '.into()' to convert a HashMap<String, T> into an object map
let result: Dynamic = map.into();
assert_eq!(result.type_name(), "map");

pub fn take(&mut self) -> Dynamic

Return this Dynamic, replacing it with Dynamic::UNIT.

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

where T: Any,

Convert the Dynamic value into specific type.

Casting to a Dynamic just returns as is, but if it contains a shared value, it is cloned into a Dynamic with a normal value.

Returns None if types mismatched.

Panics or Deadlocks

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

These normally shouldn’t occur since most operations in Rhai is single-threaded.

Example

use rhai::Dynamic;

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

assert_eq!(x.try_cast::<u32>().expect("x should be u32"), 42);

pub fn cast<T>(self) -> T

where T: Any + Clone,

Convert the Dynamic value into a specific type.

Casting to a Dynamic just returns as is, but if it contains a shared value, it is cloned into a Dynamic with a normal value.

Panics or Deadlocks

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

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

These normally shouldn’t occur since most operations in Rhai is single-threaded.

Example

use rhai::Dynamic;

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

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

pub fn clone_cast<T>(&self) -> T

where T: Any + Clone,

Clone the Dynamic value and convert it into a specific type.

Casting to a Dynamic just returns as is, but if it contains a shared value, it is cloned into a Dynamic with a normal value.

Returns None if types mismatched.

Panics or Deadlocks

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

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

These normally shouldn’t occur since most operations in Rhai is single-threaded.

Example

use rhai::Dynamic;

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

assert_eq!(y.clone_cast::<u32>(), 42);

pub fn flatten_clone(&self) -> Dynamic

Flatten the Dynamic and clone it.

If the Dynamic is not a shared value, it returns a cloned copy.

If the Dynamic is a shared value, it returns a cloned copy of the shared value.

pub fn flatten(self) -> Dynamic

Flatten the Dynamic.

If the Dynamic is not a shared value, it returns itself.

If the Dynamic is a shared value, it returns the shared value if there are no outstanding references, or a cloned copy.

pub fn read_lock<T>(&self) -> Option<DynamicReadLock<'_, T>>

where T: Any + Clone,

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.

Panics or Deadlocks When Value is Shared

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

pub fn write_lock<T>(&mut self) -> Option<DynamicWriteLock<'_, T>>

where T: Any + Clone,

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.

Panics or Deadlocks When Value is Shared

Under the sync feature, this call may deadlock, or panic. Otherwise, this call panics if the data is currently borrowed for write.

pub fn is_unit(&self) -> bool

Return true if the Dynamic holds a ().

pub fn is_int(&self) -> bool

Return true if the Dynamic holds the system integer type INT.

pub fn is_bool(&self) -> bool

Return true if the Dynamic holds a bool.

pub fn is_char(&self) -> bool

Return true if the Dynamic holds a char.

pub fn is_string(&self) -> bool

Return true if the Dynamic holds an ImmutableString.

pub fn is_array(&self) -> bool

Return true if the Dynamic holds an Array.

Not available under no_index.

pub fn is_blob(&self) -> bool

Return true if the Dynamic holds a Blob.

Not available under no_index.

pub fn is_map(&self) -> bool

Return true if the Dynamic holds a Map.

Not available under no_object.

pub fn is_fnptr(&self) -> bool

Return true if the Dynamic holds a FnPtr.

pub fn is_timestamp(&self) -> bool

Return true if the Dynamic holds a timestamp.

Not available under no_time.

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

Cast the Dynamic as a unit (). Returns the name of the actual type if the cast fails.

pub fn as_int(&self) -> Result<i32, &'static str>

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

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

Convert the Dynamic into a String. If there are other references to the same string, a cloned copy is returned. Returns the name of the actual type if the cast fails.

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

Convert the Dynamic into an ImmutableString. Returns the name of the actual type if the cast fails.

pub fn into_array(self) -> Result<Vec<Dynamic>, &'static str>

Convert the Dynamic into an Array. Returns the name of the actual type if the cast fails.

Not available under no_index.

pub fn into_typed_array<T>(self) -> Result<Vec<T>, &'static str>

where T: Variant + Clone,

Convert the Dynamic into a Vec. Returns the name of the actual type if any cast fails.

Not available under no_index.

pub fn into_blob(self) -> Result<Vec<u8>, &'static str>

Convert the Dynamic into a Blob. Returns the name of the actual type if the cast fails.

Not available under no_index.

pub fn deep_scan(&mut self, filter: impl FnMut(&mut Dynamic))

Recursively scan for Dynamic values within this Dynamic (e.g. items in an array or map), calling a filter function on each.

Shared values are NOT scanned.

Trait Implementations

impl Clone for Dynamic

fn clone(&self) -> Dynamic

Clone the Dynamic value.

WARNING

The cloned copy is marked read-write even if the original is read-only.

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

Performs copy-assignment from source.

impl Debug for Dynamic

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

Formats the value using the given formatter.

impl Default for Dynamic

fn default() -> Dynamic

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Dynamic

fn deserialize<D>( deserializer: D ) -> Result<Dynamic, <D as Deserializer<'de>>::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Dynamic

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

Formats the value using the given formatter.

impl Extend<Dynamic> for FnPtr

fn extend<T>(&mut self, iter: T)

where T: IntoIterator<Item = Dynamic>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<T> From<&[T]> for Dynamic

where T: Variant + Clone,

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

Converts to this type from the input type.

impl From<()> for Dynamic

fn from(value: ()) -> Dynamic

Converts to this type from the input type.

impl<K, T> From<BTreeMap<K, T>> for Dynamic

where K: Into<SmartString<LazyCompact>>, T: Variant + Clone,

fn from(value: BTreeMap<K, T>) -> Dynamic

Converts to this type from the input type.

impl<K> From<BTreeSet<K>> for Dynamic

where K: Into<SmartString<LazyCompact>>,

fn from(value: BTreeSet<K>) -> Dynamic

Converts to this type from the input type.

impl From<FnPtr> for Dynamic

fn from(value: FnPtr) -> Dynamic

Converts to this type from the input type.

impl<K, T> From<HashMap<K, T>> for Dynamic

where K: Into<SmartString<LazyCompact>>, T: Variant + Clone,

fn from(value: HashMap<K, T>) -> Dynamic

Converts to this type from the input type.

impl<K> From<HashSet<K>> for Dynamic

where K: Into<SmartString<LazyCompact>>,

fn from(value: HashSet<K>) -> Dynamic

Converts to this type from the input type.

impl From<Instant> for Dynamic

fn from(value: Instant) -> Dynamic

Converts to this type from the input type.

impl From<Range<i32>> for Dynamic

fn from(value: Range<i32>) -> Dynamic

Converts to this type from the input type.

impl From<RangeInclusive<i32>> for Dynamic

fn from(value: RangeInclusive<i32>) -> Dynamic

Converts to this type from the input type.

impl<S> From<S> for Dynamic

where S: Into<ImmutableString>,

fn from(value: S) -> Dynamic

Converts to this type from the input type.

impl<T> From<Vec<T>> for Dynamic

where T: Variant + Clone,

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

Converts to this type from the input type.

impl From<bool> for Dynamic

fn from(value: bool) -> Dynamic

Converts to this type from the input type.

impl From<char> for Dynamic

fn from(value: char) -> Dynamic

Converts to this type from the input type.

impl From<i32> for Dynamic

fn from(value: i32) -> Dynamic

Converts to this type from the input type.

impl<T> FromIterator<T> for Dynamic

where T: Variant + Clone,

fn from_iter<X>(iter: X) -> Dynamic

where X: IntoIterator<Item = T>,

Creates a value from an iterator.

impl FromStr for Dynamic

type Err = ()

The associated error which can be returned from parsing.

fn from_str(value: &str) -> Result<Dynamic, <Dynamic as FromStr>::Err>

Parses a string s to return a value of this type.

impl Hash for Dynamic

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

where H: Hasher,

Hash the Dynamic value.

Panics

Panics if the Dynamic value contains an unrecognized trait object.

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<'de> IntoDeserializer<'de, Box<EvalAltResult>> for &'de Dynamic

type Deserializer = DynamicDeserializer<'de>

The type of the deserializer being converted into.

fn into_deserializer( self ) -> <&'de Dynamic as IntoDeserializer<'de, Box<EvalAltResult>>>::Deserializer

Convert this value into a deserializer.

impl Serialize for Dynamic

fn serialize<S>( &self, ser: S ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.