Trait rustc_hir::intravisit::Visitor

pub trait Visitor<'v>: Sized {
    type Map: Map<'v>;
    pub fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map>;

    pub fn visit_nested_item(&mut self, id: ItemId) { ... }
    pub fn visit_nested_trait_item(&mut self, id: TraitItemId) { ... }
    pub fn visit_nested_impl_item(&mut self, id: ImplItemId) { ... }
    pub fn visit_nested_body(&mut self, id: BodyId) { ... }
    pub fn visit_param(&mut self, param: &'v Param<'v>) { ... }
    pub fn visit_item(&mut self, i: &'v Item<'v>) { ... }
    pub fn visit_body(&mut self, b: &'v Body<'v>) { ... }
    pub fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self> { ... }
    pub fn visit_id(&mut self, _hir_id: HirId) { ... }
    pub fn visit_name(&mut self, _span: Span, _name: Symbol) { ... }
    pub fn visit_ident(&mut self, ident: Ident) { ... }
    pub fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) { ... }
    pub fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) { ... }
    pub fn visit_local(&mut self, l: &'v Local<'v>) { ... }
    pub fn visit_block(&mut self, b: &'v Block<'v>) { ... }
    pub fn visit_stmt(&mut self, s: &'v Stmt<'v>) { ... }
    pub fn visit_arm(&mut self, a: &'v Arm<'v>) { ... }
    pub fn visit_pat(&mut self, p: &'v Pat<'v>) { ... }
    pub fn visit_anon_const(&mut self, c: &'v AnonConst) { ... }
    pub fn visit_expr(&mut self, ex: &'v Expr<'v>) { ... }
    pub fn visit_ty(&mut self, t: &'v Ty<'v>) { ... }
    pub fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) { ... }
    pub fn visit_generics(&mut self, g: &'v Generics<'v>) { ... }
    pub fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) { ... }
    pub fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) { ... }
    pub fn visit_fn(
        &mut self, 
        fk: FnKind<'v>, 
        fd: &'v FnDecl<'v>, 
        b: BodyId, 
        s: Span, 
        id: HirId
    ) { ... }
    pub fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) { ... }
    pub fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) { ... }
    pub fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) { ... }
    pub fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) { ... }
    pub fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>) { ... }
    pub fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) { ... }
    pub fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) { ... }
    pub fn visit_poly_trait_ref(
        &mut self, 
        t: &'v PolyTraitRef<'v>, 
        m: TraitBoundModifier
    ) { ... }
    pub fn visit_variant_data(
        &mut self, 
        s: &'v VariantData<'v>, 
        _: Symbol, 
        _: &'v Generics<'v>, 
        _parent_id: HirId, 
        _: Span
    ) { ... }
    pub fn visit_struct_field(&mut self, s: &'v StructField<'v>) { ... }
    pub fn visit_enum_def(
        &mut self, 
        enum_definition: &'v EnumDef<'v>, 
        generics: &'v Generics<'v>, 
        item_id: HirId, 
        _: Span
    ) { ... }
    pub fn visit_variant(
        &mut self, 
        v: &'v Variant<'v>, 
        g: &'v Generics<'v>, 
        item_id: HirId
    ) { ... }
    pub fn visit_label(&mut self, label: &'v Label) { ... }
    pub fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) { ... }
    pub fn visit_lifetime(&mut self, lifetime: &'v Lifetime) { ... }
    pub fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) { ... }
    pub fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) { ... }
    pub fn visit_path_segment(
        &mut self, 
        path_span: Span, 
        path_segment: &'v PathSegment<'v>
    ) { ... }
    pub fn visit_generic_args(
        &mut self, 
        path_span: Span, 
        generic_args: &'v GenericArgs<'v>
    ) { ... }
    pub fn visit_assoc_type_binding(
        &mut self, 
        type_binding: &'v TypeBinding<'v>
    ) { ... }
    pub fn visit_attribute(&mut self, _attr: &'v Attribute) { ... }
    pub fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>) { ... }
    pub fn visit_vis(&mut self, vis: &'v Visibility<'v>) { ... }
    pub fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) { ... }
    pub fn visit_defaultness(&mut self, defaultness: &'v Defaultness) { ... }
}

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_mod method by default calls intravisit::walk_mod.

Note that this visitor does NOT visit nested items by default (this is why the module is called intravisit, to distinguish it from the AST's visit module, which acts differently). If you simply want to visit all items in the crate in some order, you should call Crate::visit_all_items. Otherwise, see the comment on visit_nested_item for details on how to visit nested items.

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.)

Associated Types

type Map: Map<'v>

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Required methods

pub fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map>

The default versions of the visit_nested_XXX routines invoke this method to get a map to use. By selecting an enum variant, you control which kinds of nested HIR are visited; see NestedVisitorMap for details. By "nested HIR", we are referring to bits of HIR that are not directly embedded within one another but rather indirectly, through a table in the crate. This is done to control dependencies during incremental compilation: the non-inline bits of HIR can be tracked and hashed separately.

If for some reason you want the nested behavior, but don't have a Map at your disposal: then you should override the visit_nested_XXX methods, and override this method to panic!(). This way, if a new visit_nested_XXX variant is added in the future, we will see the panic in your code and fix it appropriately.

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Provided methods

pub fn visit_nested_item(&mut self, id: ItemId)

Invoked when a nested item is encountered. By default does nothing unless you override nested_visit_map to return other than None, in which case it will walk the item. You probably don't want to override this method -- instead, override nested_visit_map or use the "shallow" or "deep" visit patterns described on itemlikevisit::ItemLikeVisitor. The only reason to override this method is if you want a nested pattern but cannot supply a Map; see nested_visit_map for advice.

pub fn visit_nested_trait_item(&mut self, id: TraitItemId)

Like visit_nested_item(), but for trait items. See visit_nested_item() for advice on when to override this method.

pub fn visit_nested_impl_item(&mut self, id: ImplItemId)

Like visit_nested_item(), but for impl items. See visit_nested_item() for advice on when to override this method.

pub fn visit_nested_body(&mut self, id: BodyId)

Invoked to visit the body of a function, method or closure. Like visit_nested_item, does nothing by default unless you override nested_visit_map to return other than None, in which case it will walk the body.

pub fn visit_param(&mut self, param: &'v Param<'v>)

pub fn visit_item(&mut self, i: &'v Item<'v>)

Visits the top-level item and (optionally) nested items / impl items. See visit_nested_item for details.

pub fn visit_body(&mut self, b: &'v Body<'v>)

pub fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self>

When invoking visit_all_item_likes(), you need to supply an item-like visitor. This method converts a "intra-visit" visitor into an item-like visitor that walks the entire tree. If you use this, you probably don't want to process the contents of nested item-like things, since the outer loop will visit them as well.

pub fn visit_id(&mut self, _hir_id: HirId)

pub fn visit_name(&mut self, _span: Span, _name: Symbol)

pub fn visit_ident(&mut self, ident: Ident)

pub fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId)

pub fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>)

pub fn visit_local(&mut self, l: &'v Local<'v>)

pub fn visit_block(&mut self, b: &'v Block<'v>)

pub fn visit_stmt(&mut self, s: &'v Stmt<'v>)

pub fn visit_arm(&mut self, a: &'v Arm<'v>)

pub fn visit_pat(&mut self, p: &'v Pat<'v>)

pub fn visit_anon_const(&mut self, c: &'v AnonConst)

pub fn visit_expr(&mut self, ex: &'v Expr<'v>)

pub fn visit_ty(&mut self, t: &'v Ty<'v>)

pub fn visit_generic_param(&mut self, p: &'v GenericParam<'v>)

pub fn visit_generics(&mut self, g: &'v Generics<'v>)

pub fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>)

pub fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>)

pub fn visit_fn(
    &mut self,
    fk: FnKind<'v>,
    fd: &'v FnDecl<'v>,
    b: BodyId,
    s: Span,
    id: HirId
)

pub fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId)

pub fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>)

pub fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef)

pub fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>)

pub fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>)

pub fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>)

pub fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>)

pub fn visit_poly_trait_ref(
    &mut self,
    t: &'v PolyTraitRef<'v>,
    m: TraitBoundModifier
)

pub fn visit_variant_data(
    &mut self,
    s: &'v VariantData<'v>,
    _: Symbol,
    _: &'v Generics<'v>,
    _parent_id: HirId,
    _: Span
)

pub fn visit_struct_field(&mut self, s: &'v StructField<'v>)

pub fn visit_enum_def(
    &mut self,
    enum_definition: &'v EnumDef<'v>,
    generics: &'v Generics<'v>,
    item_id: HirId,
    _: Span
)

pub fn visit_variant(
    &mut self,
    v: &'v Variant<'v>,
    g: &'v Generics<'v>,
    item_id: HirId
)

pub fn visit_label(&mut self, label: &'v Label)

pub fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>)

pub fn visit_lifetime(&mut self, lifetime: &'v Lifetime)

pub fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span)

pub fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId)

pub fn visit_path_segment(
    &mut self,
    path_span: Span,
    path_segment: &'v PathSegment<'v>
)

pub fn visit_generic_args(
    &mut self,
    path_span: Span,
    generic_args: &'v GenericArgs<'v>
)

pub fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>)

pub fn visit_attribute(&mut self, _attr: &'v Attribute)

pub fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>)

pub fn visit_vis(&mut self, vis: &'v Visibility<'v>)

pub fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind)

pub fn visit_defaultness(&mut self, defaultness: &'v Defaultness)

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Implementors

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