Struct starlark::values::FrozenValue

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

A Value that can never be changed. Can be converted back to a Value with to_value.

A FrozenValue exists on a FrozenHeap, which in turn can be kept alive by a FrozenHeapRef. If the frozen heap gets dropped while a FrozenValue from it still exists, the program will probably segfault, so be careful when working directly with FrozenValues. See the type OwnedFrozenValue for a little bit more safety.

Implementations

impl FrozenValue

pub fn new_none() -> Self

Create a new value representing None in Starlark.

pub fn new_bool(x: bool) -> Self

Create a new boolean in Starlark.

pub fn is_none(self) -> bool

Is a value a Starlark None.

pub fn unpack_bool(self) -> Option<bool>

Return the bool if the value is a boolean, otherwise None.

pub fn unpack_i32(self) -> Option<i32>

Obtain the underlying integer if it fits in an i32. Note floats are not considered integers, i. e. unpack_i32 for 1.0 will return None.

pub fn to_value<'v>(self) -> Value<'v>

Convert a FrozenValue back to a Value.

pub fn downcast_frozen_ref<T: StarlarkValue<'static>>( self ) -> Option<FrozenRef<'static, T>>

Downcast to given type.

pub fn downcast_frozen_str(self) -> Option<FrozenRef<'static, str>>

Downcast to string.

pub fn downcast_frozen_starlark_str( self ) -> Option<FrozenRef<'static, StarlarkStr>>

Note: see docs about [‘Value::unpack_box_str’] about instability

Trait Implementations

impl AllocFrozenValue for FrozenValue

fn alloc_frozen_value(self, _heap: &FrozenHeap) -> FrozenValue

Allocate a value in the frozen heap and return a reference to the allocated value.

impl<'v> AllocValue<'v> for FrozenValue

fn alloc_value(self, _heap: &'v Heap) -> Value<'v>

Allocate the value on a heap and return a reference to the allocated value.

impl Allocative for FrozenValue

fn visit<'allocative_a, 'allocative_b: 'allocative_a>( &self, visitor: &'allocative_a mut Visitor<'allocative_b> )

impl Clone for FrozenValue

fn clone(&self) -> FrozenValue

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for FrozenValue

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

Formats the value using the given formatter.

impl Default for FrozenValue

fn default() -> Self

Returns the “default value” for a type.

impl Display for FrozenValue

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

Formats the value using the given formatter.

impl Dupe for FrozenValue

fn dupe(&self) -> Self

impl Equivalent<FrozenValue> for Value<'_>

fn equivalent(&self, key: &FrozenValue) -> bool

Compare self to key and return true if they are equal.

impl Equivalent<Value<'_>> for FrozenValue

fn equivalent(&self, key: &Value<'_>) -> bool

Compare self to key and return true if they are equal.

impl Freeze for FrozenValue

type Frozen = FrozenValue

When type is frozen, it is frozen into this type.

fn freeze(self, _freezer: &Freezer) -> Result<FrozenValue>

Freeze a value. The frozen value must be equal to the original, and produce the same hash.

impl PartialEq for FrozenValue

fn eq(&self, other: &FrozenValue) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

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

impl<'pst> ProvidesStaticType<'pst> for FrozenValue

type StaticType = FrozenValue

Same type as Self but with lifetimes dropped to 'static.

impl Serialize for FrozenValue

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

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StarlarkTypeRepr for FrozenValue

fn starlark_type_repr() -> Ty

The representation of a type that a user would use verbatim in starlark type annotations

impl<'v> Trace<'v> for FrozenValue

fn trace(&mut self, _tracer: &Tracer<'v>)

Recursively “trace” the value.

impl<'v> ValueLike<'v> for FrozenValue

type String = FrozenValueTyped<'static, StarlarkStr>

StringValue or FrozenStringValue.

fn to_value(self) -> Value<'v>

Produce a Value regardless of the type you are starting with.

fn from_frozen_value(v: FrozenValue) -> Self

Convert from FrozenValue.

fn downcast_ref<T: StarlarkValue<'v>>(self) -> Option<&'v T>

Get a reference to underlying data or None if contained object has different type than requested.

fn collect_repr(self, collector: &mut String)

repr(x).

fn write_hash(self, hasher: &mut StarlarkHasher) -> Result<()>

Hash the value.

fn equals(self, other: Value<'v>) -> Result<bool>

x == other.

fn compare(self, other: Value<'v>) -> Result<Ordering>

x <=> other.

fn invoke( self, args: &Arguments<'v, '_>, eval: &mut Evaluator<'v, '_> ) -> Result<Value<'v>>

Call this value as a function with given arguments.

fn get_hashed(self) -> Result<Hashed<Self>>

Get hash value.

fn collect_str(self, collector: &mut String)

str(x).

fn downcast_ref_err<T: StarlarkValue<'v>>(self) -> Result<&'v T>

Get a reference to underlying data or Err if contained object has different type than requested.

impl<'v> Coerce<Value<'v>> for FrozenValue

impl<'v> CoerceKey<Value<'v>> for FrozenValue

impl Copy for FrozenValue

impl Eq for FrozenValue

impl Send for FrozenValue

impl Sync for FrozenValue