Enum Value

pub enum Value<T> {
    I32(i32),
    I64(i64),
    F32(f32),
    F64(f64),
    ExternRef(ExternRef),
    FuncRef(Option<T>),
    V128(u128),
}

Possible runtime values that a WebAssembly module can either consume or produce.

Variants

I32(i32)

A 32-bit integer.

In Wasm integers are sign-agnostic, i.e. this can either be signed or unsigned.

I64(i64)

A 64-bit integer.

In Wasm integers are sign-agnostic, i.e. this can either be signed or unsigned.

F32(f32)

A 32-bit float.

F64(f64)

A 64-bit float.

ExternRef(ExternRef)

An externref value which can hold opaque data to the wasm instance itself.

Note that this is a nullable value as well.

FuncRef(Option<T>)

A first-class reference to a WebAssembly function.

V128(u128)

A 128-bit number

Implementations

impl<T> Value<T>

where T: WasmValueType,

pub fn null() -> Self

Returns a null externref value.

pub fn ty(&self) -> Type

Returns the corresponding Type for this Value.

pub unsafe fn write_value_to(&self, p: *mut i128)

Writes it’s value to a given pointer

Safety

p must be:

• Sufficiently aligned for the Rust equivalent of the type in self
• Non-null and pointing to valid, mutable memory

pub unsafe fn read_value_from(store: &dyn Any, p: *const i128, ty: Type) -> Self

Gets a Value given a pointer and a Type

Safety

p must be:

• Properly aligned to the specified ty’s Rust equivalent
• Non-null and pointing to valid memory

pub fn i32(&self) -> Option<i32>

Attempt to access the underlying value of this Value, returning None if it is not the correct type.

pub fn unwrap_i32(&self) -> i32

Returns the underlying value of this Value, panicking if it’s the wrong type.

Panics

Panics if self is not of the right type.

pub fn i64(&self) -> Option<i64>

Attempt to access the underlying value of this Value, returning None if it is not the correct type.

pub fn unwrap_i64(&self) -> i64

Returns the underlying value of this Value, panicking if it’s the wrong type.

Panics

Panics if self is not of the right type.

pub fn f32(&self) -> Option<f32>

Attempt to access the underlying value of this Value, returning None if it is not the correct type.

pub fn unwrap_f32(&self) -> f32

Returns the underlying value of this Value, panicking if it’s the wrong type.

Panics

Panics if self is not of the right type.

pub fn f64(&self) -> Option<f64>

Attempt to access the underlying value of this Value, returning None if it is not the correct type.

pub fn unwrap_f64(&self) -> f64

Returns the underlying value of this Value, panicking if it’s the wrong type.

Panics

Panics if self is not of the right type.

pub fn externref(&self) -> Option<ExternRef>

Attempt to access the underlying value of this Value, returning None if it is not the correct type.

pub fn unwrap_externref(&self) -> ExternRef

Returns the underlying value of this Value, panicking if it’s the wrong type.

Panics

Panics if self is not of the right type.

pub fn funcref(&self) -> Option<&Option<T>>

Attempt to access the underlying value of this Value, returning None if it is not the correct type.

pub fn unwrap_funcref(&self) -> &Option<T>

Returns the underlying value of this Value, panicking if it’s the wrong type.

Panics

Panics if self is not of the right type.

pub fn v128(&self) -> Option<u128>

Attempt to access the underlying value of this Value, returning None if it is not the correct type.

pub fn unwrap_v128(&self) -> u128

Returns the underlying value of this Value, panicking if it’s the wrong type.

Panics

Panics if self is not of the right type.

Trait Implementations

impl<T: Clone> Clone for Value<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for Value<T>

where T: WasmValueType,

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

Formats the value using the given formatter.

impl<T> From<ExternRef> for Value<T>

where T: WasmValueType,

fn from(val: ExternRef) -> Self

Converts to this type from the input type.

impl<T> From<f32> for Value<T>

where T: WasmValueType,

fn from(val: f32) -> Self

Converts to this type from the input type.

impl<T> From<f64> for Value<T>

where T: WasmValueType,

fn from(val: f64) -> Self

Converts to this type from the input type.

impl<T> From<i32> for Value<T>

where T: WasmValueType,

fn from(val: i32) -> Self

Converts to this type from the input type.

impl<T> From<i64> for Value<T>

where T: WasmValueType,

fn from(val: i64) -> Self

Converts to this type from the input type.

impl<T> From<u32> for Value<T>

where T: WasmValueType,

fn from(val: u32) -> Self

Converts to this type from the input type.

impl<T> From<u64> for Value<T>

where T: WasmValueType,

fn from(val: u64) -> Self

Converts to this type from the input type.

impl<T: PartialEq> PartialEq for Value<T>

fn eq(&self, other: &Value<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> ToString for Value<T>

where T: WasmValueType,

fn to_string(&self) -> String

Converts the given value to a String.

impl<T> TryFrom<Value<T>> for f32

where T: WasmValueType,

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: Value<T>) -> Result<Self, Self::Error>

Performs the conversion.

impl<T> TryFrom<Value<T>> for f64

where T: WasmValueType,

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: Value<T>) -> Result<Self, Self::Error>

Performs the conversion.

impl<T> TryFrom<Value<T>> for i32

where T: WasmValueType,

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: Value<T>) -> Result<Self, Self::Error>

Performs the conversion.

impl<T> TryFrom<Value<T>> for i64

where T: WasmValueType,

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: Value<T>) -> Result<Self, Self::Error>

Performs the conversion.

impl<T> TryFrom<Value<T>> for u32

where T: WasmValueType,

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: Value<T>) -> Result<Self, Self::Error>

Performs the conversion.

impl<T> TryFrom<Value<T>> for u64

where T: WasmValueType,

type Error = &'static str

The type returned in the event of a conversion error.

fn try_from(value: Value<T>) -> Result<Self, Self::Error>

Performs the conversion.

impl<T> StructuralPartialEq for Value<T>