snix_eval::vm

Struct ImportCache

Source 
struct ImportCache(FxHashMap<PathBuf, Value>);

Tuple Fields§

§0: FxHashMap<PathBuf, Value>

Implementations§

Source§

impl ImportCache

The ImportCache holds the Value resulting from importing a certain file, so that the same file doesn’t need to be re-evaluated multiple times. Currently the real path of the imported file (determined using std::fs::canonicalize(), not to be confused with our crate::value::canon_path()) is used to identify the file, just like C++ Nix does.

Errors while determining the real path are currently just ignored, since we pass around some fake paths like /__corepkgs__/fetchurl.nix.

In the future, we could use something more sophisticated, like file hashes. However, a consideration is that the eval cache is observable via impurities like pointer equality and builtins.trace.

Source

fn get(&self, path: PathBuf) -> Option<&Value>

Source

fn insert(&mut self, path: PathBuf, value: Value) -> Option<Value>

Trait Implementations§

Source§

impl Default for ImportCache

Source§

fn default() -> ImportCache

Returns the “default value” for a type. Read more

Auto Trait Implementations§

Blanket Implementations§

Source§

impl<T> Any for T
where T: 'static + ?Sized,

Source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
Source§

impl<T> Borrow<T> for T
where T: ?Sized,

Source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
Source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

Source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
Source§

impl<T> From<T> for T

Source§

fn from(t: T) -> T

Returns the argument unchanged.

Source§

impl<T, U> Into<U> for T
where U: From<T>,

Source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Source§

impl<T> IntoEither for T

Source§

fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
Source§

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
Source§

impl<T> Same for T

Source§

type Output = T

Should always be Self
Source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

Source§

type Error = Infallible

The type returned in the event of a conversion error.
Source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
Source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

Source§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
Source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
Source§

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

Source§

fn vzip(self) -> V