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> Fold<I> for FromEnv<I>

type Result = FromEnv<I>

The type of value that will be produced once folding is done. Typically this is Self, unless Self contains borrowed values, in which case owned values are produced (for example, one can fold over a &T value where T: Fold, in which case you get back a T, not a &T).

fn fold_with<'i>(
    self,
    folder: &mut dyn Folder<'i, I>,
    outer_binder: DebruijnIndex
) -> Fallible<Self::Result> where
    I: 'i, 

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.

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, 

Feeds a slice of this type into the given Hasher.

impl<I: PartialEq + Interner> PartialEq<FromEnv<I>> 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: &FromEnv<I>) -> bool

This method tests for !=.

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

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

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<'i, Z: Zipper<'i, I>>(
    zipper: &mut Z,
    variance: Variance,
    a: &Self,
    b: &Self
) -> Fallible<()> where
    I: 'i, 

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> StructuralEq for FromEnv<I>

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