Enum chalk_ir::FromEnv

pub enum FromEnv<I: Interner> {
    Trait(TraitRef<I>),
    Ty(Ty<I>),
}

Checks whether a type or trait ref can be derived from the contents of the environment.

Variants

Trait(TraitRef<I>)

A predicate which enables deriving everything which should be true if we know that some trait ref is well-formed. For example given the above trait definitions, we can use FromEnv(T: Copy) to derive that T: Clone, like in:

forall<T> {
    if (FromEnv(T: Copy)) {
        T: Clone
    }
}

Ty(Ty<I>)

A predicate which enables deriving everything which should be true if we know that some type is well-formed. For example given the above type definition, we can use FromEnv(Set<K>) to derive that K: Hash, like in:

forall<K> {
    if (FromEnv(Set<K>)) {
        K: Hash
    }
}

Trait Implementations

impl<I: Interner> CastTo<DomainGoal<I>> for FromEnv<I>

fn cast_to(self, _interner: I) -> DomainGoal<I>

Cast a value to type T.

impl<I: Clone + Interner> Clone for FromEnv<I>

fn clone(&self) -> FromEnv<I>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I: Interner> Debug for FromEnv<I>

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

Formats the value using the given formatter.

impl<I: Interner> HasInterner for FromEnv<I>

type Interner = I

The interner associated with the type.

impl<I: Hash + Interner> Hash for FromEnv<I>

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

Feeds this value into the given Hasher.

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<I: PartialEq + Interner> PartialEq for FromEnv<I>

fn eq(&self, other: &FromEnv<I>) -> 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<I: Interner> TypeFoldable<I> for FromEnv<I>

fn try_fold_with<E>( self, folder: &mut dyn FallibleTypeFolder<I, Error = E>, outer_binder: DebruijnIndex, ) -> Result<Self, E>

Apply the given folder folder to self; binders is the number of binders that are in scope when beginning the folder. Typically binders starts as 0, but is adjusted when we encounter Binders<T> in the IR or other similar constructs.

fn fold_with( self, folder: &mut dyn TypeFolder<I>, outer_binder: DebruijnIndex, ) -> Self

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

impl<I: Interner> TypeVisitable<I> for FromEnv<I>

fn visit_with<B>( &self, visitor: &mut dyn TypeVisitor<I, BreakTy = B>, outer_binder: DebruijnIndex, ) -> ControlFlow<B>

Apply the given visitor visitor to self; binders is the number of binders that are in scope when beginning the visitor. Typically binders starts as 0, but is adjusted when we encounter Binders<T> in the IR or other similar constructs.

impl<I: Interner> Zip<I> for FromEnv<I>

fn zip_with<Z: Zipper<I>>( zipper: &mut Z, variance: Variance, a: &Self, b: &Self, ) -> Fallible<()>

Uses the zipper to walk through two values, ensuring that they match.

impl<I: Interner> Copy for FromEnv<I>

where I::InternedType: Copy, I::InternedSubstitution: Copy,

impl<I: Eq + Interner> Eq for FromEnv<I>

impl<I: Interner> StructuralPartialEq for FromEnv<I>