Trait chalk_ir::visit::Visitor[−][src]

pub trait Visitor<'i, I: Interner> where
    I: 'i, {
    type BreakTy;

Show 15 methods    fn as_dyn(&mut self) -> &mut dyn Visitor<'i, I, BreakTy = Self::BreakTy>;

    fn interner(&self) -> &'i I;

    fn visit_ty(
        &mut self, 
        ty: &Ty<I>, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn visit_lifetime(
        &mut self, 
        lifetime: &Lifetime<I>, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn visit_const(
        &mut self, 
        constant: &Const<I>, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn visit_program_clause(
        &mut self, 
        clause: &ProgramClause<I>, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn visit_goal(
        &mut self, 
        goal: &Goal<I>, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn visit_domain_goal(
        &mut self, 
        domain_goal: &DomainGoal<I>, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn forbid_free_vars(&self) -> bool { ... }

    fn visit_free_var(
        &mut self, 
        bound_var: BoundVar, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn forbid_free_placeholders(&self) -> bool { ... }

    fn visit_free_placeholder(
        &mut self, 
        universe: PlaceholderIndex, 
        _outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn visit_where_clause(
        &mut self, 
        where_clause: &WhereClause<I>, 
        outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

    fn forbid_inference_vars(&self) -> bool { ... }

    fn visit_inference_var(
        &mut self, 
        var: InferenceVar, 
        _outer_binder: DebruijnIndex
    ) -> ControlFlow<Self::BreakTy> { ... }

}
Expand description

A “visitor” recursively folds some term – that is, some bit of IR, such as a Goal, and computes a value as a result.

To apply a visitor, use the Visit::visit_with method, like so

ⓘ
let result = x.visit_with(&mut visitor, 0);

Associated Types

The “break type” of the visitor, often (). It represents the result the visitor yields when it stops visiting.

Required methods

Creates a dyn value from this visitor. Unfortunately, this must be added manually to each impl of visitor; it permits the default implements below to create a &mut dyn Visitor from Self without knowing what Self is (by invoking this method). Effectively, this limits impls of visitor to types for which we are able to create a dyn value (i.e., not [T] types).

Gets the visitor’s interner.

Provided methods

Top-level callback: invoked for each Ty<I> that is encountered when visiting. By default, invokes super_visit_with, which will in turn invoke the more specialized visiting methods below, like visit_free_var.

Top-level callback: invoked for each Lifetime<I> that is encountered when visiting. By default, invokes super_visit_with, which will in turn invoke the more specialized visiting methods below, like visit_free_var.

Top-level callback: invoked for each Const<I> that is encountered when visiting. By default, invokes super_visit_with, which will in turn invoke the more specialized visiting methods below, like visit_free_var.

Invoked for every program clause. By default, recursively visits the goals contents.

Invoked for every goal. By default, recursively visits the goals contents.

Invoked for each domain goal.

If overridden to return true, then visiting will panic if a free variable is encountered. This should be done if free type/lifetime/const variables are not expected.

Invoked for BoundVar instances that are not bound within the type being visited over:

If overridden to return true, we will panic when a free placeholder type/lifetime is encountered.

Invoked for each occurrence of a placeholder type; these are used when we instantiate binders universally.

Invoked for each where clause.

If overridden to return true, inference variables will trigger panics when visited. Used when inference variables are unexpected.

Invoked for each occurrence of a inference type; these are used when we instantiate binders universally.

Implementors