[][src]Struct chalk_ir::Binders

pub struct Binders<T: HasInterner> {
    pub binders: VariableKinds<T::Interner>,
    value: T,

Indicates that the value is universally quantified over N parameters of the given kinds, where N == self.binders.len(). A variable with depth i < N refers to the value at self.binders[i]. Variables with depth >= N are free.

(IOW, we use deBruijn indices, where binders are introduced in reverse order of self.binders.)


binders: VariableKinds<T::Interner>

The binders that quantify over the value.

value: T

The value being quantified over.


impl<I: Interner> Binders<WhereClause<I>>[src]

pub fn into_well_formed_goal(self, interner: &I) -> Binders<DomainGoal<I>>[src]

As with WhereClause::into_well_formed_goal, but for a quantified where clause. For example, forall<T> { Implemented(T: Trait)} would map to forall<T> { WellFormed(T: Trait) }.

pub fn into_from_env_goal(self, interner: &I) -> Binders<DomainGoal<I>>[src]

As with WhereClause::into_from_env_goal, but mapped over any binders. For example, forall<T> { Implemented(T: Trait)} would map to forall<T> { FromEnv(T: Trait) }.

pub fn trait_id(&self) -> Option<TraitId<I>>[src]

If the underlying where clause is a TraitRef, returns its trait id.

impl<T: HasInterner> Binders<T>[src]

pub fn new(binders: VariableKinds<T::Interner>, value: T) -> Self[src]

Create new binders.

pub fn empty(interner: &T::Interner, value: T) -> Self[src]

Wraps the given value in a binder without variables, i.e. for<> (value). Since our deBruijn indices count binders, not variables, this is sometimes useful.

pub fn skip_binders(&self) -> &T[src]

Skips the binder and returns the "bound" value. This is a risky thing to do because it's easy to get confused about De Bruijn indices and the like. skip_binder is only valid when you are either extracting data that has nothing to do with bound vars, or you are being very careful about your depth accounting.

Some examples where skip_binder is reasonable:

  • extracting the TraitId from a TraitRef;
  • checking if there are any fields in a StructDatum

pub fn as_ref(&self) -> Binders<&T>[src]

Converts &Binders<T> to Binders<&T>. Produces new Binders with cloned quantifiers containing a reference to the original value, leaving the original in place.

pub fn map<U, OP>(self, op: OP) -> Binders<U> where
    OP: FnOnce(T) -> U,
    U: HasInterner<Interner = T::Interner>, 

Maps the binders by applying a function.

pub fn filter_map<U, OP>(self, op: OP) -> Option<Binders<U>> where
    OP: FnOnce(T) -> Option<U>,
    U: HasInterner<Interner = T::Interner>, 

Transforms the inner value according to the given function; returns None if the function returns None.

pub fn map_ref<'a, U, OP>(&'a self, op: OP) -> Binders<U> where
    OP: FnOnce(&'a T) -> U,
    U: HasInterner<Interner = T::Interner>, 

Maps a function taking Binders<&T> over &Binders<T>.

pub fn identity_substitution(
    interner: &T::Interner
) -> Substitution<T::Interner>

Creates a Substitution containing bound vars such that applying this substitution will not change the value, i.e. ^0.0, ^0.1, ^0.2 and so on.

pub fn with_fresh_type_var(
    interner: &T::Interner,
    op: impl FnOnce(Ty<T::Interner>) -> T
) -> Binders<T>

Creates a fresh binders that contains a single type variable. The result of the closure will be embedded in this binder. Note that you should be careful with what you return from the closure to account for the binder that will be added.

XXX FIXME -- this is potentially a pretty footgun-y function.

pub fn len(&self, interner: &T::Interner) -> usize[src]

Returns the number of binders.

impl<T, I> Binders<Binders<T>> where
    T: Fold<I, I> + HasInterner<Interner = I>,
    T::Result: HasInterner<Interner = I>,
    I: Interner

pub fn fuse_binders(self, interner: &T::Interner) -> Binders<T::Result>[src]

This turns two levels of binders (for<A> for<B>) into one level (for<A, B>).

impl<T, I> Binders<T> where
    T: Fold<I, I> + HasInterner<Interner = I>,
    I: Interner

pub fn substitute(
    interner: &I,
    parameters: &impl AsParameters<I> + ?Sized
) -> T::Result

Substitute parameters for the variables introduced by these binders. So if the binders represent (e.g.) <X, Y> { T } and parameters is the slice [A, B], then returns [X => A, Y => B] T.

Trait Implementations

impl<I: Interner> CastTo<Binders<WhereClause<I>>> for QuantifiedWhereClause<I>[src]

impl<I: Interner, T: HasInterner<Interner = I> + CastTo<Goal<I>>> CastTo<Goal<I>> for Binders<T>[src]

impl<I, T> CastTo<ProgramClause<I>> for Binders<T> where
    I: Interner,
    T: HasInterner<Interner = I> + CastTo<DomainGoal<I>>, 

impl<T: Clone + HasInterner> Clone for Binders<T> where
    T::Interner: Clone

impl<T: HasInterner + Copy> Copy for Binders<T> where
    <T::Interner as Interner>::InternedVariableKinds: Copy

impl<T: HasInterner + Debug> Debug for Binders<T>[src]

impl<T: Eq + HasInterner> Eq for Binders<T> where
    T::Interner: Eq

impl<T, I: Interner, TI: TargetInterner<I>> Fold<I, TI> for Binders<T> where
    T: HasInterner<Interner = I> + Fold<I, TI>,
    <T as Fold<I, TI>>::Result: HasInterner<Interner = TI>,
    I: Interner

type Result = Binders<T::Result>

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). Read more

impl<T: HasInterner> From<Binders<T>> for (VariableKinds<T::Interner>, T)[src]

impl<T: HasInterner> HasInterner for Binders<T>[src]

type Interner = T::Interner

The interner associated with the type.

impl<T: Hash + HasInterner> Hash for Binders<T> where
    T::Interner: Hash

impl<V, U> IntoIterator for Binders<V> where
    V: HasInterner + IntoIterator<Item = U>,
    U: HasInterner<Interner = V::Interner>, 

Allows iterating over a Binders<Vec>, for instance. Each element will include the same set of parameter bounds.

type Item = Binders<U>

The type of the elements being iterated over.

type IntoIter = BindersIntoIterator<V>

Which kind of iterator are we turning this into?

impl<T: PartialEq + HasInterner> PartialEq<Binders<T>> for Binders<T> where
    T::Interner: PartialEq

impl<T: HasInterner> StructuralEq for Binders<T>[src]

impl<T: HasInterner> StructuralPartialEq for Binders<T>[src]

impl<T, I: Interner> Visit<I> for Binders<T> where
    T: HasInterner + Visit<I>, 

impl<I: Interner, T: HasInterner<Interner = I> + Zip<I> + Fold<I, I, Result = T>> Zip<I> for Binders<T>[src]

Auto Trait Implementations

impl<T> RefUnwindSafe for Binders<T> where
    T: RefUnwindSafe,
    <<T as HasInterner>::Interner as Interner>::InternedVariableKinds: RefUnwindSafe

impl<T> Send for Binders<T> where
    T: Send,
    <<T as HasInterner>::Interner as Interner>::InternedVariableKinds: Send

impl<T> Sync for Binders<T> where
    T: Sync,
    <<T as HasInterner>::Interner as Interner>::InternedVariableKinds: Sync

impl<T> Unpin for Binders<T> where
    T: Unpin,
    <<T as HasInterner>::Interner as Interner>::InternedVariableKinds: Unpin

impl<T> UnwindSafe for Binders<T> where
    T: UnwindSafe,
    <<T as HasInterner>::Interner as Interner>::InternedVariableKinds: UnwindSafe

Blanket Implementations

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

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

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

impl<T> Cast for T[src]

impl<T, I> CastTo<Goal<I>> for T where
    I: Interner,
    T: CastTo<DomainGoal<I>>, 

impl<T, I> CastTo<ProgramClause<I>> for T where
    I: Interner,
    T: CastTo<DomainGoal<I>>, 

impl<T, I> CouldMatch<T> for T where
    I: Interner,
    T: Zip<I> + HasInterner<Interner = I> + ?Sized

impl<T> From<T> for T[src]

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

impl<I> IntoIterator for I where
    I: Iterator

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

type IntoIter = I

Which kind of iterator are we turning this into?

impl<T, I> Shift<I> for T where
    I: Interner,
    T: Fold<I, I>, 

impl<T> ToOwned for T where
    T: Clone

type Owned = T

The resulting type after obtaining ownership.

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

type Error = Infallible

The type returned in the event of a conversion error.

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

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

The type returned in the event of a conversion error.

impl<T, I> VisitExt<I> for T where
    I: Interner,
    T: Visit<I>,