Struct chalk_solve::infer::unify::Unifier

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struct Unifier<'t, I: Interner> {
    table: &'t mut InferenceTable<I>,
    environment: &'t Environment<I>,
    goals: Vec<InEnvironment<Goal<I>>>,
    interner: I,
    db: &'t dyn UnificationDatabase<I>,
}

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§table: &'t mut InferenceTable<I>§environment: &'t Environment<I>§goals: Vec<InEnvironment<Goal<I>>>§interner: I§db: &'t dyn UnificationDatabase<I>

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impl<'t, I: Interner> Unifier<'t, I>

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fn new( interner: I, db: &'t dyn UnificationDatabase<I>, table: &'t mut InferenceTable<I>, environment: &'t Environment<I>, ) -> Self

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fn relate<T>( self, variance: Variance, a: &T, b: &T, ) -> Fallible<RelationResult<I>>
where T: ?Sized + Zip<I>,

The main entry point for the Unifier type and really the only type meant to be called externally. Performs a relation of a and b and returns the Unification Result.

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fn relate_ty_ty( &mut self, variance: Variance, a: &Ty<I>, b: &Ty<I>, ) -> Fallible<()>

Relate a, b with the variance such that if variance = Covariant, a is a subtype of b.

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fn unify_var_var(&mut self, a: InferenceVar, b: InferenceVar) -> Fallible<()>

Unify two inference variables

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fn unify_general_var_specific_ty( &mut self, general_var: InferenceVar, specific_ty: Ty<I>, ) -> Fallible<()>

Unify a general inference variable with a specific inference variable (type kind is not General). For example, unify a TyVariableKind::General inference variable with a TyVariableKind::Integer variable, resulting in the general inference variable narrowing to an integer variable.

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fn relate_binders<'a, T>( &mut self, variance: Variance, a: &Binders<T>, b: &Binders<T>, ) -> Fallible<()>
where T: Clone + TypeFoldable<I> + HasInterner<Interner = I> + Zip<I>, 't: 'a,

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fn relate_alias_ty( &mut self, variance: Variance, alias: &AliasTy<I>, ty: &Ty<I>, ) -> Fallible<()>

Relate an alias like <T as Trait>::Item or impl Trait with some other type ty. If the variance is Invariant, creates a goal like

AliasEq(<T as Trait>::Item = U) // associated type projection
AliasEq(impl Trait = U) // impl trait

Otherwise, this creates a new variable ?X, creates a goal like

AliasEq(Alias = ?X)

and relates ?X and ty.

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fn generalize_ty( &mut self, ty: &Ty<I>, universe_index: UniverseIndex, variance: Variance, ) -> Ty<I>

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fn generalize_lifetime( &mut self, lifetime: &Lifetime<I>, universe_index: UniverseIndex, variance: Variance, ) -> Lifetime<I>

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fn generalize_const( &mut self, const_: &Const<I>, universe_index: UniverseIndex, ) -> Const<I>

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fn generalize_generic_var( &mut self, sub_var: &GenericArg<I>, universe_index: UniverseIndex, variance: Variance, ) -> GenericArg<I>

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fn generalize_substitution_skip_self<F: Fn(usize) -> Option<Variance>>( &mut self, substitution: &Substitution<I>, universe_index: UniverseIndex, get_variance: F, ) -> Substitution<I>

Generalizes all but the first

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fn generalize_substitution<F: Fn(usize) -> Variance>( &mut self, substitution: &Substitution<I>, universe_index: UniverseIndex, get_variance: F, ) -> Substitution<I>

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fn relate_var_ty( &mut self, variance: Variance, var: InferenceVar, var_kind: TyVariableKind, ty: &Ty<I>, ) -> Fallible<()>

Unify an inference variable var with some non-inference variable ty, just bind var to ty. But we must enforce two conditions:

  • var does not appear inside of ty (the standard OccursCheck)
  • ty does not reference anything in a lifetime that could not be named in var (the extended OccursCheck created to handle universes)
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fn relate_lifetime_lifetime( &mut self, variance: Variance, a: &Lifetime<I>, b: &Lifetime<I>, ) -> Fallible<()>

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fn unify_lifetime_var( &mut self, variance: Variance, var: InferenceVar, value: &Lifetime<I>, value_ui: UniverseIndex, ) -> Fallible<()>

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fn relate_const_const<'a>( &mut self, variance: Variance, a: &'a Const<I>, b: &'a Const<I>, ) -> Fallible<()>

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fn unify_var_const(&mut self, var: InferenceVar, c: &Const<I>) -> Fallible<()>

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fn push_lifetime_outlives_goals( &mut self, variance: Variance, a: Lifetime<I>, b: Lifetime<I>, )

Relate a, b such that if variance = Covariant, a is a subtype of b and thus a must outlive b.

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fn push_subtype_goal(&mut self, a: Ty<I>, b: Ty<I>)

Pushes a goal of a being a subtype of b.

Trait Implementations§

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impl<'i, I: Interner> Zipper<I> for Unifier<'i, I>

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fn zip_tys(&mut self, variance: Variance, a: &Ty<I>, b: &Ty<I>) -> Fallible<()>

Indicates that the two types a and b were found in matching spots.
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fn zip_lifetimes( &mut self, variance: Variance, a: &Lifetime<I>, b: &Lifetime<I>, ) -> Fallible<()>

Indicates that the two lifetimes a and b were found in matching spots.
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fn zip_consts( &mut self, variance: Variance, a: &Const<I>, b: &Const<I>, ) -> Fallible<()>

Indicates that the two consts a and b were found in matching spots.
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fn zip_binders<T>( &mut self, variance: Variance, a: &Binders<T>, b: &Binders<T>, ) -> Fallible<()>
where T: Clone + HasInterner<Interner = I> + Zip<I> + TypeFoldable<I>,

Zips two values appearing beneath binders.
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fn interner(&self) -> I

Retrieves the interner from the underlying zipper object
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fn unification_database(&self) -> &dyn UnificationDatabase<I>

Retrieves the UnificationDatabase from the underlying zipper object
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fn zip_substs( &mut self, ambient: Variance, variances: Option<Variances<I>>, a: &[GenericArg<I>], b: &[GenericArg<I>], ) -> Result<(), NoSolution>
where Self: Sized,

Zips two substs

Auto Trait Implementations§

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impl<'t, I> Freeze for Unifier<'t, I>
where I: Freeze,

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impl<'t, I> !RefUnwindSafe for Unifier<'t, I>

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impl<'t, I> !Send for Unifier<'t, I>

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impl<'t, I> !Sync for Unifier<'t, I>

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impl<'t, I> Unpin for Unifier<'t, I>

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impl<'t, I> !UnwindSafe for Unifier<'t, I>

Blanket Implementations§

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

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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

Mutably borrows from an owned value. Read more
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impl<T> Cast for T

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fn cast<U>(self, interner: <U as HasInterner>::Interner) -> U
where Self: CastTo<U>, U: HasInterner,

Cast a value to type U using CastTo.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

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

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

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type Error = Infallible

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

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a [WithDispatch] wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more