Trait Visitor

Source

pub trait Visitor<'ast>: Sized {
    type Result: VisitorResult = ();

Show 50 methods    // Provided methods
    fn visit_ident(&mut self, _ident: &'ast Ident) -> Self::Result { ... }
    fn visit_foreign_item(&mut self, i: &'ast ForeignItem) -> Self::Result { ... }
    fn visit_item(&mut self, i: &'ast Item) -> Self::Result { ... }
    fn visit_local(&mut self, l: &'ast Local) -> Self::Result { ... }
    fn visit_block(&mut self, b: &'ast Block) -> Self::Result { ... }
    fn visit_stmt(&mut self, s: &'ast Stmt) -> Self::Result { ... }
    fn visit_param(&mut self, param: &'ast Param) -> Self::Result { ... }
    fn visit_arm(&mut self, a: &'ast Arm) -> Self::Result { ... }
    fn visit_pat(&mut self, p: &'ast Pat) -> Self::Result { ... }
    fn visit_anon_const(&mut self, c: &'ast AnonConst) -> Self::Result { ... }
    fn visit_expr(&mut self, ex: &'ast Expr) -> Self::Result { ... }
    fn visit_method_receiver_expr(&mut self, ex: &'ast Expr) -> Self::Result { ... }
    fn visit_ty(&mut self, t: &'ast Ty) -> Self::Result { ... }
    fn visit_generic_param(&mut self, param: &'ast GenericParam) -> Self::Result { ... }
    fn visit_generics(&mut self, g: &'ast Generics) -> Self::Result { ... }
    fn visit_closure_binder(&mut self, b: &'ast ClosureBinder) -> Self::Result { ... }
    fn visit_where_predicate(&mut self, p: &'ast WherePredicate) -> Self::Result { ... }
    fn visit_fn(&mut self, fk: FnKind<'ast>, _: Span, _: NodeId) -> Self::Result { ... }
    fn visit_assoc_item(
        &mut self,
        i: &'ast AssocItem,
        ctxt: AssocCtxt,
    ) -> Self::Result { ... }
    fn visit_trait_ref(&mut self, t: &'ast TraitRef) -> Self::Result { ... }
    fn visit_param_bound(
        &mut self,
        bounds: &'ast GenericBound,
        _ctxt: BoundKind,
    ) -> Self::Result { ... }
    fn visit_precise_capturing_arg(
        &mut self,
        arg: &'ast PreciseCapturingArg,
    ) -> Self::Result { ... }
    fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) -> Self::Result { ... }
    fn visit_variant_data(&mut self, s: &'ast VariantData) -> Self::Result { ... }
    fn visit_field_def(&mut self, s: &'ast FieldDef) -> Self::Result { ... }
    fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef) -> Self::Result { ... }
    fn visit_variant(&mut self, v: &'ast Variant) -> Self::Result { ... }
    fn visit_variant_discr(&mut self, discr: &'ast AnonConst) -> Self::Result { ... }
    fn visit_label(&mut self, label: &'ast Label) -> Self::Result { ... }
    fn visit_lifetime(
        &mut self,
        lifetime: &'ast Lifetime,
        _: LifetimeCtxt,
    ) -> Self::Result { ... }
    fn visit_mac_call(&mut self, mac: &'ast MacCall) -> Self::Result { ... }
    fn visit_mac_def(
        &mut self,
        _mac: &'ast MacroDef,
        _id: NodeId,
    ) -> Self::Result { ... }
    fn visit_path(&mut self, path: &'ast Path, _id: NodeId) -> Self::Result { ... }
    fn visit_use_tree(
        &mut self,
        use_tree: &'ast UseTree,
        id: NodeId,
        _nested: bool,
    ) -> Self::Result { ... }
    fn visit_path_segment(
        &mut self,
        path_segment: &'ast PathSegment,
    ) -> Self::Result { ... }
    fn visit_generic_args(
        &mut self,
        generic_args: &'ast GenericArgs,
    ) -> Self::Result { ... }
    fn visit_generic_arg(
        &mut self,
        generic_arg: &'ast GenericArg,
    ) -> Self::Result { ... }
    fn visit_assoc_item_constraint(
        &mut self,
        constraint: &'ast AssocItemConstraint,
    ) -> Self::Result { ... }
    fn visit_attribute(&mut self, attr: &'ast Attribute) -> Self::Result { ... }
    fn visit_vis(&mut self, vis: &'ast Visibility) -> Self::Result { ... }
    fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FnRetTy) -> Self::Result { ... }
    fn visit_fn_header(&mut self, header: &'ast FnHeader) -> Self::Result { ... }
    fn visit_expr_field(&mut self, f: &'ast ExprField) -> Self::Result { ... }
    fn visit_pat_field(&mut self, fp: &'ast PatField) -> Self::Result { ... }
    fn visit_crate(&mut self, krate: &'ast Crate) -> Self::Result { ... }
    fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) -> Self::Result { ... }
    fn visit_format_args(&mut self, fmt: &'ast FormatArgs) -> Self::Result { ... }
    fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) -> Self::Result { ... }
    fn visit_capture_by(&mut self, _capture_by: &'ast CaptureBy) -> Self::Result { ... }
    fn visit_coroutine_kind(
        &mut self,
        _coroutine_kind: &'ast CoroutineKind,
    ) -> Self::Result { ... }
}

Expand description

Each method of the Visitor trait is a hook to be potentially overridden. Each method’s default implementation recursively visits the substructure of the input via the corresponding walk method; e.g., the visit_item method by default calls visit::walk_item.

If you want to ensure that your code handles every variant explicitly, you need to override each method. (And you also need to monitor future changes to Visitor in case a new method with a new default implementation gets introduced.)