Struct ProtectedVal

pub struct ProtectedVal<'a> { /* private fields */ }

Holds a value from the Vm that is guaranteed to not be garbage collected.

The underlying value is protected from garbage collection until ProtectedVal is dropped.

Implementations

impl<'a> ProtectedVal<'a>

pub fn new(vm: &'a mut Vm, v: Val<'a>) -> ProtectedVal<'a>

Create a new Val from an crate::val::UnsafeVal.

Safety

v must be a valid from originating (and not garbage collected) from vm.

pub fn split(&mut self) -> (&mut Vm, &Val<'_>)

Split the protected val into its Vm and Val.

Despite the split, the returned Val will still be safe from garbage collection.

pub fn with<T>(&mut self, f: impl Fn(&mut Vm, &Val<'_>) -> T) -> T

Run function f on the Vm and Val and return the result. This is a convenient way of gaining mutable reference to the underlying vm.

impl<'a> ProtectedVal<'a>

pub fn vm(&self) -> &Vm

Get a reference to the underlying Vm.

pub fn map<T>(&mut self, f: impl Fn(&mut Vm, &ProtectedVal<'a>) -> T) -> T

Maps an Option<T> to Option<U> by applying a function to a contained value (if Some) or returns None (if None).

pub fn try_str(&'a self) -> Result<&'a str, Val<'_>>

Try to get the string as a value or return its underlying value.

pub fn try_custom<T: CustomType>( &self, ) -> Result<CustomValRef<'_, T>, CustomValError>

Try to get the custom value of type T or return its underlying value if self is not of type T.

pub fn try_custom_mut<T: CustomType>( &self, ) -> Result<CustomValMut<'_, T>, CustomValError>

Returns the value as a custom type of T or Err if Self is not of the given custom value.

pub fn get_mutable_box_ref(&self) -> Result<Val<'_>, Val<'a>>

Get the Val that the mutable box is pointing to or Err<Val> if self is not a mutable box.

Methods from Deref<Target = Val<'a>>

pub fn is_custom(&self) -> bool

Returns true if a custom value is held.

pub fn try_custom<T: CustomType>( &self, vm: &'a Vm, ) -> Result<CustomValRef<'_, T>, CustomValError>

Returns the value as a custom type of T or None if Self is not of the given custom value.

pub fn try_custom_mut<T: CustomType>( &self, vm: &'a Vm, ) -> Result<CustomValMut<'_, T>, CustomValError>

Returns the value as a custom type of T or None if Self is not of the given custom value.

Trait Implementations

impl<'a> Debug for ProtectedVal<'a>

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

Formats the value using the given formatter.

impl<'a> Deref for ProtectedVal<'a>

type Target = Val<'a>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'a> Display for ProtectedVal<'a>

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

Formats the value using the given formatter.

impl<'a> Drop for ProtectedVal<'a>

fn drop(&mut self)

Executes the destructor for this type.