1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! AST walker. Each overridden visit method has full control over what
12 //! happens with its node, it can do its own traversal of the node's children,
13 //! call `visit::walk_*` to apply the default traversal algorithm, or prevent
14 //! deeper traversal by doing nothing.
16 //! Note: it is an important invariant that the default visitor walks the body
17 //! of a function in "execution order" (more concretely, reverse post-order
18 //! with respect to the CFG implied by the AST), meaning that if AST node A may
19 //! execute before AST node B, then A is visited first. The borrow checker in
20 //! particular relies on this property.
22 //! Note: walking an AST before macro expansion is probably a bad idea. For
23 //! instance, a walker looking for item names in a module will miss all of
24 //! those that are created by the expansion of a macro.
31 use owned_slice::OwnedSlice;
33 #[derive(Copy, Clone, PartialEq, Eq)]
35 /// fn foo() or extern "Abi" fn foo()
36 ItemFn(Ident, &'a Generics, Unsafety, Constness, Abi, Visibility),
39 Method(Ident, &'a MethodSig, Option<Visibility>),
45 /// Each method of the Visitor trait is a hook to be potentially
46 /// overridden. Each method's default implementation recursively visits
47 /// the substructure of the input via the corresponding `walk` method;
48 /// e.g. the `visit_mod` method by default calls `visit::walk_mod`.
50 /// If you want to ensure that your code handles every variant
51 /// explicitly, you need to override each method. (And you also need
52 /// to monitor future changes to `Visitor` in case a new method with a
53 /// new default implementation gets introduced.)
54 pub trait Visitor<'v> : Sized {
55 fn visit_name(&mut self, _span: Span, _name: Name) {
58 fn visit_ident(&mut self, span: Span, ident: Ident) {
59 self.visit_name(span, ident.name);
61 fn visit_mod(&mut self, m: &'v Mod, _s: Span, _n: NodeId) { walk_mod(self, m) }
62 fn visit_foreign_item(&mut self, i: &'v ForeignItem) { walk_foreign_item(self, i) }
63 fn visit_item(&mut self, i: &'v Item) { walk_item(self, i) }
64 fn visit_local(&mut self, l: &'v Local) { walk_local(self, l) }
65 fn visit_block(&mut self, b: &'v Block) { walk_block(self, b) }
66 fn visit_stmt(&mut self, s: &'v Stmt) { walk_stmt(self, s) }
67 fn visit_arm(&mut self, a: &'v Arm) { walk_arm(self, a) }
68 fn visit_pat(&mut self, p: &'v Pat) { walk_pat(self, p) }
69 fn visit_decl(&mut self, d: &'v Decl) { walk_decl(self, d) }
70 fn visit_expr(&mut self, ex: &'v Expr) { walk_expr(self, ex) }
71 fn visit_expr_post(&mut self, _ex: &'v Expr) { }
72 fn visit_ty(&mut self, t: &'v Ty) { walk_ty(self, t) }
73 fn visit_generics(&mut self, g: &'v Generics) { walk_generics(self, g) }
74 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: &'v Block, s: Span, _: NodeId) {
75 walk_fn(self, fk, fd, b, s)
77 fn visit_trait_item(&mut self, ti: &'v TraitItem) { walk_trait_item(self, ti) }
78 fn visit_impl_item(&mut self, ii: &'v ImplItem) { walk_impl_item(self, ii) }
79 fn visit_trait_ref(&mut self, t: &'v TraitRef) { walk_trait_ref(self, t) }
80 fn visit_ty_param_bound(&mut self, bounds: &'v TyParamBound) {
81 walk_ty_param_bound(self, bounds)
83 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef, m: &'v TraitBoundModifier) {
84 walk_poly_trait_ref(self, t, m)
86 fn visit_struct_def(&mut self, s: &'v StructDef, _: Ident, _: &'v Generics, _: NodeId) {
87 walk_struct_def(self, s)
89 fn visit_struct_field(&mut self, s: &'v StructField) { walk_struct_field(self, s) }
90 fn visit_enum_def(&mut self, enum_definition: &'v EnumDef,
91 generics: &'v Generics) {
92 walk_enum_def(self, enum_definition, generics)
95 fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics) { walk_variant(self, v, g) }
97 /// Visits an optional reference to a lifetime. The `span` is the span of some surrounding
98 /// reference should opt_lifetime be None.
99 fn visit_opt_lifetime_ref(&mut self,
101 opt_lifetime: &'v Option<Lifetime>) {
102 match *opt_lifetime {
103 Some(ref l) => self.visit_lifetime_ref(l),
107 fn visit_lifetime_bound(&mut self, lifetime: &'v Lifetime) {
108 walk_lifetime_bound(self, lifetime)
110 fn visit_lifetime_ref(&mut self, lifetime: &'v Lifetime) {
111 walk_lifetime_ref(self, lifetime)
113 fn visit_lifetime_def(&mut self, lifetime: &'v LifetimeDef) {
114 walk_lifetime_def(self, lifetime)
116 fn visit_explicit_self(&mut self, es: &'v ExplicitSelf) {
117 walk_explicit_self(self, es)
119 fn visit_mac(&mut self, _mac: &'v Mac) {
120 panic!("visit_mac disabled by default");
121 // NB: see note about macros above.
122 // if you really want a visitor that
123 // works on macros, use this
124 // definition in your trait impl:
125 // visit::walk_mac(self, _mac)
127 fn visit_path(&mut self, path: &'v Path, _id: ast::NodeId) {
128 walk_path(self, path)
130 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) {
131 walk_path_segment(self, path_span, path_segment)
133 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'v PathParameters) {
134 walk_path_parameters(self, path_span, path_parameters)
136 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding) {
137 walk_assoc_type_binding(self, type_binding)
139 fn visit_attribute(&mut self, _attr: &'v Attribute) {}
142 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {
143 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
144 for attr in &krate.attrs {
145 visitor.visit_attribute(attr);
149 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod) {
150 for item in &module.items {
151 visitor.visit_item(&**item)
155 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
156 visitor.visit_pat(&*local.pat);
157 walk_ty_opt(visitor, &local.ty);
158 walk_expr_opt(visitor, &local.init);
161 pub fn walk_lifetime_def<'v, V: Visitor<'v>>(visitor: &mut V,
162 lifetime_def: &'v LifetimeDef) {
163 visitor.visit_name(lifetime_def.lifetime.span, lifetime_def.lifetime.name);
164 for bound in &lifetime_def.bounds {
165 visitor.visit_lifetime_bound(bound);
169 pub fn walk_lifetime_bound<'v, V: Visitor<'v>>(visitor: &mut V,
170 lifetime_ref: &'v Lifetime) {
171 visitor.visit_lifetime_ref(lifetime_ref)
174 pub fn walk_lifetime_ref<'v, V: Visitor<'v>>(visitor: &mut V,
175 lifetime_ref: &'v Lifetime) {
176 visitor.visit_name(lifetime_ref.span, lifetime_ref.name)
179 pub fn walk_explicit_self<'v, V: Visitor<'v>>(visitor: &mut V,
180 explicit_self: &'v ExplicitSelf) {
181 match explicit_self.node {
182 SelfStatic | SelfValue(_) => {},
183 SelfRegion(ref lifetime, _, _) => {
184 visitor.visit_opt_lifetime_ref(explicit_self.span, lifetime)
186 SelfExplicit(ref typ, _) => visitor.visit_ty(&**typ),
190 pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
191 trait_ref: &'v PolyTraitRef,
192 _modifier: &'v TraitBoundModifier)
195 walk_lifetime_decls_helper(visitor, &trait_ref.bound_lifetimes);
196 visitor.visit_trait_ref(&trait_ref.trait_ref);
199 pub fn walk_trait_ref<'v,V>(visitor: &mut V,
200 trait_ref: &'v TraitRef)
203 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
206 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
207 visitor.visit_ident(item.span, item.ident);
209 ItemExternCrate(..) => {}
212 ViewPathSimple(ident, ref path) => {
213 visitor.visit_ident(vp.span, ident);
214 visitor.visit_path(path, item.id);
216 ViewPathGlob(ref path) => {
217 visitor.visit_path(path, item.id);
219 ViewPathList(ref prefix, ref list) => {
222 PathListIdent { name, rename, .. } => {
223 visitor.visit_ident(id.span, name);
224 if let Some(ident) = rename {
225 visitor.visit_ident(id.span, ident);
228 PathListMod { rename, .. } => {
229 if let Some(ident) = rename {
230 visitor.visit_ident(id.span, ident);
236 // Note that the `prefix` here is not a complete
237 // path, so we don't use `visit_path`.
238 walk_path(visitor, prefix);
242 ItemStatic(ref typ, _, ref expr) |
243 ItemConst(ref typ, ref expr) => {
244 visitor.visit_ty(&**typ);
245 visitor.visit_expr(&**expr);
247 ItemFn(ref declaration, unsafety, constness, abi, ref generics, ref body) => {
248 visitor.visit_fn(FnKind::ItemFn(item.ident, generics, unsafety,
249 constness, abi, item.vis),
255 ItemMod(ref module) => {
256 visitor.visit_mod(module, item.span, item.id)
258 ItemForeignMod(ref foreign_module) => {
259 for foreign_item in &foreign_module.items {
260 visitor.visit_foreign_item(&**foreign_item)
263 ItemTy(ref typ, ref type_parameters) => {
264 visitor.visit_ty(&**typ);
265 visitor.visit_generics(type_parameters)
267 ItemEnum(ref enum_definition, ref type_parameters) => {
268 visitor.visit_generics(type_parameters);
269 visitor.visit_enum_def(enum_definition, type_parameters)
271 ItemDefaultImpl(_, ref trait_ref) => {
272 visitor.visit_trait_ref(trait_ref)
279 visitor.visit_generics(type_parameters);
280 match *trait_reference {
281 Some(ref trait_reference) => visitor.visit_trait_ref(trait_reference),
284 visitor.visit_ty(&**typ);
285 for impl_item in impl_items {
286 visitor.visit_impl_item(impl_item);
289 ItemStruct(ref struct_definition, ref generics) => {
290 visitor.visit_generics(generics);
291 visitor.visit_struct_def(&**struct_definition,
296 ItemTrait(_, ref generics, ref bounds, ref methods) => {
297 visitor.visit_generics(generics);
298 walk_ty_param_bounds_helper(visitor, bounds);
299 for method in methods {
300 visitor.visit_trait_item(method)
303 ItemMac(ref mac) => visitor.visit_mac(mac),
305 for attr in &item.attrs {
306 visitor.visit_attribute(attr);
310 pub fn walk_enum_def<'v, V: Visitor<'v>>(visitor: &mut V,
311 enum_definition: &'v EnumDef,
312 generics: &'v Generics) {
313 for variant in &enum_definition.variants {
314 visitor.visit_variant(&**variant, generics);
318 pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V,
319 variant: &'v Variant,
320 generics: &'v Generics) {
321 visitor.visit_ident(variant.span, variant.node.name);
323 match variant.node.kind {
324 TupleVariantKind(ref variant_arguments) => {
325 for variant_argument in variant_arguments {
326 visitor.visit_ty(&*variant_argument.ty)
329 StructVariantKind(ref struct_definition) => {
330 visitor.visit_struct_def(&**struct_definition,
336 match variant.node.disr_expr {
337 Some(ref expr) => visitor.visit_expr(&**expr),
340 for attr in &variant.node.attrs {
341 visitor.visit_attribute(attr);
345 pub fn skip_ty<'v, V: Visitor<'v>>(_: &mut V, _: &'v Ty) {
349 pub fn walk_ty_opt<'v, V: Visitor<'v>>(visitor: &mut V, optional_type: &'v Option<P<Ty>>) {
350 match *optional_type {
351 Some(ref ty) => visitor.visit_ty(&**ty),
356 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
358 TyVec(ref ty) | TyParen(ref ty) => {
359 visitor.visit_ty(&**ty)
361 TyPtr(ref mutable_type) => {
362 visitor.visit_ty(&*mutable_type.ty)
364 TyRptr(ref lifetime, ref mutable_type) => {
365 visitor.visit_opt_lifetime_ref(typ.span, lifetime);
366 visitor.visit_ty(&*mutable_type.ty)
368 TyTup(ref tuple_element_types) => {
369 for tuple_element_type in tuple_element_types {
370 visitor.visit_ty(&**tuple_element_type)
373 TyBareFn(ref function_declaration) => {
374 for argument in &function_declaration.decl.inputs {
375 visitor.visit_ty(&*argument.ty)
377 walk_fn_ret_ty(visitor, &function_declaration.decl.output);
378 walk_lifetime_decls_helper(visitor, &function_declaration.lifetimes);
380 TyPath(ref maybe_qself, ref path) => {
381 if let Some(ref qself) = *maybe_qself {
382 visitor.visit_ty(&qself.ty);
384 visitor.visit_path(path, typ.id);
386 TyObjectSum(ref ty, ref bounds) => {
387 visitor.visit_ty(&**ty);
388 walk_ty_param_bounds_helper(visitor, bounds);
390 TyFixedLengthVec(ref ty, ref expression) => {
391 visitor.visit_ty(&**ty);
392 visitor.visit_expr(&**expression)
394 TyPolyTraitRef(ref bounds) => {
395 walk_ty_param_bounds_helper(visitor, bounds)
397 TyTypeof(ref expression) => {
398 visitor.visit_expr(&**expression)
402 visitor.visit_mac(mac)
407 pub fn walk_lifetime_decls_helper<'v, V: Visitor<'v>>(visitor: &mut V,
408 lifetimes: &'v Vec<LifetimeDef>) {
410 visitor.visit_lifetime_def(l);
414 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
415 for segment in &path.segments {
416 visitor.visit_path_segment(path.span, segment);
420 pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,
422 segment: &'v PathSegment) {
423 visitor.visit_ident(path_span, segment.identifier);
424 visitor.visit_path_parameters(path_span, &segment.parameters);
427 pub fn walk_path_parameters<'v, V: Visitor<'v>>(visitor: &mut V,
429 path_parameters: &'v PathParameters) {
430 match *path_parameters {
431 ast::AngleBracketedParameters(ref data) => {
432 for typ in data.types.iter() {
433 visitor.visit_ty(&**typ);
435 for lifetime in &data.lifetimes {
436 visitor.visit_lifetime_ref(lifetime);
438 for binding in data.bindings.iter() {
439 visitor.visit_assoc_type_binding(&**binding);
442 ast::ParenthesizedParameters(ref data) => {
443 for typ in &data.inputs {
444 visitor.visit_ty(&**typ);
446 if let Some(ref typ) = data.output {
447 visitor.visit_ty(&**typ);
453 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V,
454 type_binding: &'v TypeBinding) {
455 visitor.visit_ident(type_binding.span, type_binding.ident);
456 visitor.visit_ty(&*type_binding.ty);
459 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
461 PatEnum(ref path, ref children) => {
462 visitor.visit_path(path, pattern.id);
463 if let Some(ref children) = *children {
464 for child in children {
465 visitor.visit_pat(&*child)
469 PatQPath(ref qself, ref path) => {
470 visitor.visit_ty(&qself.ty);
471 visitor.visit_path(path, pattern.id)
473 PatStruct(ref path, ref fields, _) => {
474 visitor.visit_path(path, pattern.id);
475 for field in fields {
476 visitor.visit_pat(&*field.node.pat)
479 PatTup(ref tuple_elements) => {
480 for tuple_element in tuple_elements {
481 visitor.visit_pat(&**tuple_element)
484 PatBox(ref subpattern) |
485 PatRegion(ref subpattern, _) => {
486 visitor.visit_pat(&**subpattern)
488 PatIdent(_, ref pth1, ref optional_subpattern) => {
489 visitor.visit_ident(pth1.span, pth1.node);
490 match *optional_subpattern {
492 Some(ref subpattern) => visitor.visit_pat(&**subpattern),
495 PatLit(ref expression) => visitor.visit_expr(&**expression),
496 PatRange(ref lower_bound, ref upper_bound) => {
497 visitor.visit_expr(&**lower_bound);
498 visitor.visit_expr(&**upper_bound)
501 PatVec(ref prepattern, ref slice_pattern, ref postpatterns) => {
502 for prepattern in prepattern {
503 visitor.visit_pat(&**prepattern)
505 if let Some(ref slice_pattern) = *slice_pattern {
506 visitor.visit_pat(&**slice_pattern)
508 for postpattern in postpatterns {
509 visitor.visit_pat(&**postpattern)
512 PatMac(ref mac) => visitor.visit_mac(mac),
516 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V,
517 foreign_item: &'v ForeignItem) {
518 visitor.visit_ident(foreign_item.span, foreign_item.ident);
520 match foreign_item.node {
521 ForeignItemFn(ref function_declaration, ref generics) => {
522 walk_fn_decl(visitor, &**function_declaration);
523 visitor.visit_generics(generics)
525 ForeignItemStatic(ref typ, _) => visitor.visit_ty(&**typ),
528 for attr in &foreign_item.attrs {
529 visitor.visit_attribute(attr);
533 pub fn walk_ty_param_bounds_helper<'v, V: Visitor<'v>>(visitor: &mut V,
534 bounds: &'v OwnedSlice<TyParamBound>) {
535 for bound in bounds.iter() {
536 visitor.visit_ty_param_bound(bound)
540 pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V,
541 bound: &'v TyParamBound) {
543 TraitTyParamBound(ref typ, ref modifier) => {
544 visitor.visit_poly_trait_ref(typ, modifier);
546 RegionTyParamBound(ref lifetime) => {
547 visitor.visit_lifetime_bound(lifetime);
552 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
553 for param in generics.ty_params.iter() {
554 visitor.visit_ident(param.span, param.ident);
555 walk_ty_param_bounds_helper(visitor, ¶m.bounds);
556 walk_ty_opt(visitor, ¶m.default);
558 walk_lifetime_decls_helper(visitor, &generics.lifetimes);
559 for predicate in &generics.where_clause.predicates {
561 &ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{ref bounded_ty,
564 visitor.visit_ty(&**bounded_ty);
565 walk_ty_param_bounds_helper(visitor, bounds);
567 &ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{ref lifetime,
570 visitor.visit_lifetime_ref(lifetime);
572 for bound in bounds {
573 visitor.visit_lifetime_ref(bound);
576 &ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
580 visitor.visit_path(path, id);
581 visitor.visit_ty(&**ty);
587 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy) {
588 if let Return(ref output_ty) = *ret_ty {
589 visitor.visit_ty(&**output_ty)
593 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) {
594 for argument in &function_declaration.inputs {
595 visitor.visit_pat(&*argument.pat);
596 visitor.visit_ty(&*argument.ty)
598 walk_fn_ret_ty(visitor, &function_declaration.output)
601 pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
602 function_kind: FnKind<'v>,
603 function_declaration: &'v FnDecl,
604 function_body: &'v Block,
606 walk_fn_decl(visitor, function_declaration);
608 match function_kind {
609 FnKind::ItemFn(_, generics, _, _, _, _) => {
610 visitor.visit_generics(generics);
612 FnKind::Method(_, sig, _) => {
613 visitor.visit_generics(&sig.generics);
614 visitor.visit_explicit_self(&sig.explicit_self);
616 FnKind::Closure(..) => {}
619 visitor.visit_block(function_body)
622 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) {
623 visitor.visit_ident(trait_item.span, trait_item.ident);
624 for attr in &trait_item.attrs {
625 visitor.visit_attribute(attr);
627 match trait_item.node {
628 ConstTraitItem(ref ty, ref default) => {
629 visitor.visit_ty(ty);
630 if let Some(ref expr) = *default {
631 visitor.visit_expr(expr);
634 MethodTraitItem(ref sig, None) => {
635 visitor.visit_explicit_self(&sig.explicit_self);
636 visitor.visit_generics(&sig.generics);
637 walk_fn_decl(visitor, &sig.decl);
639 MethodTraitItem(ref sig, Some(ref body)) => {
640 visitor.visit_fn(FnKind::Method(trait_item.ident, sig, None), &sig.decl,
641 body, trait_item.span, trait_item.id);
643 TypeTraitItem(ref bounds, ref default) => {
644 walk_ty_param_bounds_helper(visitor, bounds);
645 walk_ty_opt(visitor, default);
650 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
651 visitor.visit_ident(impl_item.span, impl_item.ident);
652 for attr in &impl_item.attrs {
653 visitor.visit_attribute(attr);
655 match impl_item.node {
656 ConstImplItem(ref ty, ref expr) => {
657 visitor.visit_ty(ty);
658 visitor.visit_expr(expr);
660 MethodImplItem(ref sig, ref body) => {
661 visitor.visit_fn(FnKind::Method(impl_item.ident, sig, Some(impl_item.vis)), &sig.decl,
662 body, impl_item.span, impl_item.id);
664 TypeImplItem(ref ty) => {
665 visitor.visit_ty(ty);
667 MacImplItem(ref mac) => {
668 visitor.visit_mac(mac);
673 pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V,
674 struct_definition: &'v StructDef) {
675 for field in &struct_definition.fields {
676 visitor.visit_struct_field(field)
680 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V,
681 struct_field: &'v StructField) {
682 if let NamedField(name, _) = struct_field.node.kind {
683 visitor.visit_ident(struct_field.span, name);
686 visitor.visit_ty(&*struct_field.node.ty);
688 for attr in &struct_field.node.attrs {
689 visitor.visit_attribute(attr);
693 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) {
694 for statement in &block.stmts {
695 visitor.visit_stmt(&**statement)
697 walk_expr_opt(visitor, &block.expr)
700 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) {
701 match statement.node {
702 StmtDecl(ref declaration, _) => visitor.visit_decl(&**declaration),
703 StmtExpr(ref expression, _) | StmtSemi(ref expression, _) => {
704 visitor.visit_expr(&**expression)
706 StmtMac(ref mac, _) => visitor.visit_mac(&**mac),
710 pub fn walk_decl<'v, V: Visitor<'v>>(visitor: &mut V, declaration: &'v Decl) {
711 match declaration.node {
712 DeclLocal(ref local) => visitor.visit_local(&**local),
713 DeclItem(ref item) => visitor.visit_item(&**item),
717 pub fn walk_expr_opt<'v, V: Visitor<'v>>(visitor: &mut V,
718 optional_expression: &'v Option<P<Expr>>) {
719 match *optional_expression {
721 Some(ref expression) => visitor.visit_expr(&**expression),
725 pub fn walk_exprs<'v, V: Visitor<'v>>(visitor: &mut V, expressions: &'v [P<Expr>]) {
726 for expression in expressions {
727 visitor.visit_expr(&**expression)
731 pub fn walk_mac<'v, V: Visitor<'v>>(_: &mut V, _: &'v Mac) {
735 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
736 match expression.node {
737 ExprBox(ref place, ref subexpression) => {
738 place.as_ref().map(|e|visitor.visit_expr(&**e));
739 visitor.visit_expr(&**subexpression)
741 ExprVec(ref subexpressions) => {
742 walk_exprs(visitor, subexpressions)
744 ExprRepeat(ref element, ref count) => {
745 visitor.visit_expr(&**element);
746 visitor.visit_expr(&**count)
748 ExprStruct(ref path, ref fields, ref optional_base) => {
749 visitor.visit_path(path, expression.id);
750 for field in fields {
751 visitor.visit_expr(&*field.expr)
753 walk_expr_opt(visitor, optional_base)
755 ExprTup(ref subexpressions) => {
756 for subexpression in subexpressions {
757 visitor.visit_expr(&**subexpression)
760 ExprCall(ref callee_expression, ref arguments) => {
761 for argument in arguments {
762 visitor.visit_expr(&**argument)
764 visitor.visit_expr(&**callee_expression)
766 ExprMethodCall(_, ref types, ref arguments) => {
767 walk_exprs(visitor, arguments);
769 visitor.visit_ty(&**typ)
772 ExprBinary(_, ref left_expression, ref right_expression) => {
773 visitor.visit_expr(&**left_expression);
774 visitor.visit_expr(&**right_expression)
776 ExprAddrOf(_, ref subexpression) | ExprUnary(_, ref subexpression) => {
777 visitor.visit_expr(&**subexpression)
780 ExprCast(ref subexpression, ref typ) => {
781 visitor.visit_expr(&**subexpression);
782 visitor.visit_ty(&**typ)
784 ExprIf(ref head_expression, ref if_block, ref optional_else) => {
785 visitor.visit_expr(&**head_expression);
786 visitor.visit_block(&**if_block);
787 walk_expr_opt(visitor, optional_else)
789 ExprWhile(ref subexpression, ref block, _) => {
790 visitor.visit_expr(&**subexpression);
791 visitor.visit_block(&**block)
793 ExprIfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
794 visitor.visit_pat(&**pattern);
795 visitor.visit_expr(&**subexpression);
796 visitor.visit_block(&**if_block);
797 walk_expr_opt(visitor, optional_else);
799 ExprWhileLet(ref pattern, ref subexpression, ref block, _) => {
800 visitor.visit_pat(&**pattern);
801 visitor.visit_expr(&**subexpression);
802 visitor.visit_block(&**block);
804 ExprForLoop(ref pattern, ref subexpression, ref block, _) => {
805 visitor.visit_pat(&**pattern);
806 visitor.visit_expr(&**subexpression);
807 visitor.visit_block(&**block)
809 ExprLoop(ref block, _) => visitor.visit_block(&**block),
810 ExprMatch(ref subexpression, ref arms, _) => {
811 visitor.visit_expr(&**subexpression);
813 visitor.visit_arm(arm)
816 ExprClosure(_, ref function_declaration, ref body) => {
817 visitor.visit_fn(FnKind::Closure,
818 &**function_declaration,
823 ExprBlock(ref block) => visitor.visit_block(&**block),
824 ExprAssign(ref left_hand_expression, ref right_hand_expression) => {
825 visitor.visit_expr(&**right_hand_expression);
826 visitor.visit_expr(&**left_hand_expression)
828 ExprAssignOp(_, ref left_expression, ref right_expression) => {
829 visitor.visit_expr(&**right_expression);
830 visitor.visit_expr(&**left_expression)
832 ExprField(ref subexpression, _) => {
833 visitor.visit_expr(&**subexpression);
835 ExprTupField(ref subexpression, _) => {
836 visitor.visit_expr(&**subexpression);
838 ExprIndex(ref main_expression, ref index_expression) => {
839 visitor.visit_expr(&**main_expression);
840 visitor.visit_expr(&**index_expression)
842 ExprRange(ref start, ref end) => {
843 walk_expr_opt(visitor, start);
844 walk_expr_opt(visitor, end)
846 ExprPath(ref maybe_qself, ref path) => {
847 if let Some(ref qself) = *maybe_qself {
848 visitor.visit_ty(&qself.ty);
850 visitor.visit_path(path, expression.id)
852 ExprBreak(_) | ExprAgain(_) => {}
853 ExprRet(ref optional_expression) => {
854 walk_expr_opt(visitor, optional_expression)
856 ExprMac(ref mac) => visitor.visit_mac(mac),
857 ExprParen(ref subexpression) => {
858 visitor.visit_expr(&**subexpression)
860 ExprInlineAsm(ref ia) => {
861 for input in &ia.inputs {
862 let (_, ref input) = *input;
863 visitor.visit_expr(&**input)
865 for output in &ia.outputs {
866 let (_, ref output, _) = *output;
867 visitor.visit_expr(&**output)
872 visitor.visit_expr_post(expression)
875 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
876 for pattern in &arm.pats {
877 visitor.visit_pat(&**pattern)
879 walk_expr_opt(visitor, &arm.guard);
880 visitor.visit_expr(&*arm.body);
881 for attr in &arm.attrs {
882 visitor.visit_attribute(attr);