1 // Copyright 2012-2013 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.
19 // Context-passing AST walker. Each overridden visit method has full control
20 // over what happens with its node, it can do its own traversal of the node's
21 // children (potentially passing in different contexts to each), call
22 // visit::visit_* to apply the default traversal algorithm (again, it can
23 // override the context), or prevent deeper traversal by doing nothing.
25 // Note: it is an important invariant that the default visitor walks the body
26 // of a function in "execution order" (more concretely, reverse post-order
27 // with respect to the CFG implied by the AST), meaning that if AST node A may
28 // execute before AST node B, then A is visited first. The borrow checker in
29 // particular relies on this property.
32 // fn foo() or extern "Abi" fn foo()
33 FkItemFn(Ident, &'a Generics, Purity, AbiSet),
36 FkMethod(Ident, &'a Generics, &'a Method),
43 pub fn name_of_fn(fk: &FnKind) -> Ident {
45 FkItemFn(name, _, _, _) | FkMethod(name, _, _) => name,
46 FkFnBlock(..) => parse::token::special_idents::invalid
50 pub fn generics_of_fn(fk: &FnKind) -> Generics {
52 FkItemFn(_, generics, _, _) |
53 FkMethod(_, generics, _) => {
58 lifetimes: opt_vec::Empty,
59 ty_params: opt_vec::Empty,
65 pub trait Visitor<E: Clone> {
66 fn visit_ident(&mut self, _sp: Span, _ident: Ident, _e: E) {
67 /*! Visit the idents */
69 fn visit_mod(&mut self, m: &Mod, _s: Span, _n: NodeId, e: E) { walk_mod(self, m, e) }
70 fn visit_view_item(&mut self, i: &ViewItem, e: E) { walk_view_item(self, i, e) }
71 fn visit_foreign_item(&mut self, i: &ForeignItem, e: E) { walk_foreign_item(self, i, e) }
72 fn visit_item(&mut self, i: &Item, e: E) { walk_item(self, i, e) }
73 fn visit_local(&mut self, l: &Local, e: E) { walk_local(self, l, e) }
74 fn visit_block(&mut self, b: &Block, e: E) { walk_block(self, b, e) }
75 fn visit_stmt(&mut self, s: &Stmt, e: E) { walk_stmt(self, s, e) }
76 fn visit_arm(&mut self, a: &Arm, e: E) { walk_arm(self, a, e) }
77 fn visit_pat(&mut self, p: &Pat, e: E) { walk_pat(self, p, e) }
78 fn visit_decl(&mut self, d: &Decl, e: E) { walk_decl(self, d, e) }
79 fn visit_expr(&mut self, ex: &Expr, e: E) { walk_expr(self, ex, e) }
80 fn visit_expr_post(&mut self, _ex: &Expr, _e: E) { }
81 fn visit_ty(&mut self, t: &Ty, e: E) { walk_ty(self, t, e) }
82 fn visit_generics(&mut self, g: &Generics, e: E) { walk_generics(self, g, e) }
83 fn visit_fn(&mut self, fk: &FnKind, fd: &FnDecl, b: &Block, s: Span, n: NodeId, e: E) {
84 walk_fn(self, fk, fd, b, s, n , e)
86 fn visit_ty_method(&mut self, t: &TypeMethod, e: E) { walk_ty_method(self, t, e) }
87 fn visit_trait_method(&mut self, t: &TraitMethod, e: E) { walk_trait_method(self, t, e) }
88 fn visit_struct_def(&mut self, s: &StructDef, i: Ident, g: &Generics, n: NodeId, e: E) {
89 walk_struct_def(self, s, i, g, n, e)
91 fn visit_struct_field(&mut self, s: &StructField, e: E) { walk_struct_field(self, s, e) }
92 fn visit_variant(&mut self, v: &Variant, g: &Generics, e: E) { walk_variant(self, v, g, e) }
93 fn visit_opt_lifetime_ref(&mut self,
95 opt_lifetime: &Option<Lifetime>,
98 * Visits an optional reference to a lifetime. The `span` is
99 * the span of some surrounding reference should opt_lifetime
102 match *opt_lifetime {
103 Some(ref l) => self.visit_lifetime_ref(l, env),
107 fn visit_lifetime_ref(&mut self, _lifetime: &Lifetime, _e: E) {
108 /*! Visits a reference to a lifetime */
110 fn visit_lifetime_decl(&mut self, _lifetime: &Lifetime, _e: E) {
111 /*! Visits a declaration of a lifetime */
113 fn visit_explicit_self(&mut self, es: &ExplicitSelf, e: E) {
114 walk_explicit_self(self, es, e)
116 fn visit_mac(&mut self, macro: &Mac, e: E) {
117 walk_mac(self, macro, e)
119 fn visit_path(&mut self, path: &Path, _id: ast::NodeId, e: E) {
120 walk_path(self, path, e)
124 pub fn walk_inlined_item<E: Clone, V: Visitor<E>>(visitor: &mut V,
125 item: &ast::InlinedItem,
128 IIItem(i) => visitor.visit_item(i, env),
129 IIForeign(i) => visitor.visit_foreign_item(i, env),
130 IIMethod(_, _, m) => walk_method_helper(visitor, m, env),
135 pub fn walk_crate<E: Clone, V: Visitor<E>>(visitor: &mut V, krate: &Crate, env: E) {
136 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID, env)
139 pub fn walk_mod<E: Clone, V: Visitor<E>>(visitor: &mut V, module: &Mod, env: E) {
140 for view_item in module.view_items.iter() {
141 visitor.visit_view_item(view_item, env.clone())
144 for item in module.items.iter() {
145 visitor.visit_item(*item, env.clone())
149 pub fn walk_view_item<E: Clone, V: Visitor<E>>(visitor: &mut V, vi: &ViewItem, env: E) {
151 ViewItemExternMod(name, _, _) => {
152 visitor.visit_ident(vi.span, name, env)
154 ViewItemUse(ref paths) => {
155 for vp in paths.iter() {
157 ViewPathSimple(ident, ref path, id) => {
158 visitor.visit_ident(vp.span, ident, env.clone());
159 visitor.visit_path(path, id, env.clone());
161 ViewPathGlob(ref path, id) => {
162 visitor.visit_path(path, id, env.clone());
164 ViewPathList(ref path, ref list, _) => {
165 for id in list.iter() {
166 visitor.visit_ident(id.span, id.node.name, env.clone())
168 walk_path(visitor, path, env.clone());
176 pub fn walk_local<E: Clone, V: Visitor<E>>(visitor: &mut V, local: &Local, env: E) {
177 visitor.visit_pat(local.pat, env.clone());
178 visitor.visit_ty(local.ty, env.clone());
181 Some(initializer) => visitor.visit_expr(initializer, env),
185 fn walk_explicit_self<E: Clone, V: Visitor<E>>(visitor: &mut V,
186 explicit_self: &ExplicitSelf,
188 match explicit_self.node {
189 SelfStatic | SelfValue | SelfUniq => {}
190 SelfRegion(ref lifetime, _) => {
191 visitor.visit_opt_lifetime_ref(explicit_self.span, lifetime, env)
196 /// Like with walk_method_helper this doesn't correspond to a method
197 /// in Visitor, and so it gets a _helper suffix.
198 pub fn walk_trait_ref_helper<E: Clone, V: Visitor<E>>(visitor: &mut V,
199 trait_ref: &TraitRef,
201 visitor.visit_path(&trait_ref.path, trait_ref.ref_id, env)
204 pub fn walk_item<E: Clone, V: Visitor<E>>(visitor: &mut V, item: &Item, env: E) {
205 visitor.visit_ident(item.span, item.ident, env.clone());
207 ItemStatic(typ, _, expr) => {
208 visitor.visit_ty(typ, env.clone());
209 visitor.visit_expr(expr, env);
211 ItemFn(declaration, purity, abi, ref generics, body) => {
212 visitor.visit_fn(&FkItemFn(item.ident, generics, purity, abi),
219 ItemMod(ref module) => {
220 visitor.visit_mod(module, item.span, item.id, env)
222 ItemForeignMod(ref foreign_module) => {
223 for view_item in foreign_module.view_items.iter() {
224 visitor.visit_view_item(view_item, env.clone())
226 for foreign_item in foreign_module.items.iter() {
227 visitor.visit_foreign_item(*foreign_item, env.clone())
230 ItemTy(typ, ref type_parameters) => {
231 visitor.visit_ty(typ, env.clone());
232 visitor.visit_generics(type_parameters, env)
234 ItemEnum(ref enum_definition, ref type_parameters) => {
235 visitor.visit_generics(type_parameters, env.clone());
236 walk_enum_def(visitor, enum_definition, type_parameters, env)
238 ItemImpl(ref type_parameters,
242 visitor.visit_generics(type_parameters, env.clone());
243 match *trait_reference {
244 Some(ref trait_reference) => walk_trait_ref_helper(visitor,
245 trait_reference, env.clone()),
248 visitor.visit_ty(typ, env.clone());
249 for method in methods.iter() {
250 walk_method_helper(visitor, *method, env.clone())
253 ItemStruct(struct_definition, ref generics) => {
254 visitor.visit_generics(generics, env.clone());
255 visitor.visit_struct_def(struct_definition,
261 ItemTrait(ref generics, ref trait_paths, ref methods) => {
262 visitor.visit_generics(generics, env.clone());
263 for trait_path in trait_paths.iter() {
264 visitor.visit_path(&trait_path.path,
268 for method in methods.iter() {
269 visitor.visit_trait_method(method, env.clone())
272 ItemMac(ref macro) => visitor.visit_mac(macro, env),
276 pub fn walk_enum_def<E: Clone, V:Visitor<E>>(visitor: &mut V,
277 enum_definition: &EnumDef,
280 for &variant in enum_definition.variants.iter() {
281 visitor.visit_variant(variant, generics, env.clone());
285 pub fn walk_variant<E: Clone, V: Visitor<E>>(visitor: &mut V,
289 visitor.visit_ident(variant.span, variant.node.name, env.clone());
291 match variant.node.kind {
292 TupleVariantKind(ref variant_arguments) => {
293 for variant_argument in variant_arguments.iter() {
294 visitor.visit_ty(variant_argument.ty, env.clone())
297 StructVariantKind(struct_definition) => {
298 visitor.visit_struct_def(struct_definition,
305 match variant.node.disr_expr {
306 Some(expr) => visitor.visit_expr(expr, env),
311 pub fn skip_ty<E, V: Visitor<E>>(_: &mut V, _: &Ty, _: E) {
315 pub fn walk_ty<E: Clone, V: Visitor<E>>(visitor: &mut V, typ: &Ty, env: E) {
317 TyUniq(ty) | TyVec(ty) | TyBox(ty) => {
318 visitor.visit_ty(ty, env)
320 TyPtr(ref mutable_type) => {
321 visitor.visit_ty(mutable_type.ty, env)
323 TyRptr(ref lifetime, ref mutable_type) => {
324 visitor.visit_opt_lifetime_ref(typ.span, lifetime, env.clone());
325 visitor.visit_ty(mutable_type.ty, env)
327 TyTup(ref tuple_element_types) => {
328 for &tuple_element_type in tuple_element_types.iter() {
329 visitor.visit_ty(tuple_element_type, env.clone())
332 TyClosure(ref function_declaration) => {
333 for argument in function_declaration.decl.inputs.iter() {
334 visitor.visit_ty(argument.ty, env.clone())
336 visitor.visit_ty(function_declaration.decl.output, env.clone());
337 for bounds in function_declaration.bounds.iter() {
338 walk_ty_param_bounds(visitor, bounds, env.clone())
340 visitor.visit_opt_lifetime_ref(
342 &function_declaration.region,
344 walk_lifetime_decls(visitor, &function_declaration.lifetimes,
347 TyBareFn(ref function_declaration) => {
348 for argument in function_declaration.decl.inputs.iter() {
349 visitor.visit_ty(argument.ty, env.clone())
351 visitor.visit_ty(function_declaration.decl.output, env.clone());
352 walk_lifetime_decls(visitor, &function_declaration.lifetimes,
355 TyPath(ref path, ref bounds, id) => {
356 visitor.visit_path(path, id, env.clone());
357 for bounds in bounds.iter() {
358 walk_ty_param_bounds(visitor, bounds, env.clone())
361 TyFixedLengthVec(ty, expression) => {
362 visitor.visit_ty(ty, env.clone());
363 visitor.visit_expr(expression, env)
365 TyTypeof(expression) => {
366 visitor.visit_expr(expression, env)
368 TyNil | TyBot | TyInfer => {}
372 fn walk_lifetime_decls<E: Clone, V: Visitor<E>>(visitor: &mut V,
373 lifetimes: &OptVec<Lifetime>,
375 for l in lifetimes.iter() {
376 visitor.visit_lifetime_decl(l, env.clone());
380 pub fn walk_path<E: Clone, V: Visitor<E>>(visitor: &mut V, path: &Path, env: E) {
381 for segment in path.segments.iter() {
382 visitor.visit_ident(path.span, segment.identifier, env.clone());
384 for &typ in segment.types.iter() {
385 visitor.visit_ty(typ, env.clone());
387 for lifetime in segment.lifetimes.iter() {
388 visitor.visit_lifetime_ref(lifetime, env.clone());
393 pub fn walk_pat<E: Clone, V: Visitor<E>>(visitor: &mut V, pattern: &Pat, env: E) {
395 PatEnum(ref path, ref children) => {
396 visitor.visit_path(path, pattern.id, env.clone());
397 for children in children.iter() {
398 for child in children.iter() {
399 visitor.visit_pat(*child, env.clone())
403 PatStruct(ref path, ref fields, _) => {
404 visitor.visit_path(path, pattern.id, env.clone());
405 for field in fields.iter() {
406 visitor.visit_pat(field.pat, env.clone())
409 PatTup(ref tuple_elements) => {
410 for tuple_element in tuple_elements.iter() {
411 visitor.visit_pat(*tuple_element, env.clone())
414 PatUniq(subpattern) |
415 PatRegion(subpattern) => {
416 visitor.visit_pat(subpattern, env)
418 PatIdent(_, ref path, ref optional_subpattern) => {
419 visitor.visit_path(path, pattern.id, env.clone());
420 match *optional_subpattern {
422 Some(subpattern) => visitor.visit_pat(subpattern, env),
425 PatLit(expression) => visitor.visit_expr(expression, env),
426 PatRange(lower_bound, upper_bound) => {
427 visitor.visit_expr(lower_bound, env.clone());
428 visitor.visit_expr(upper_bound, env)
430 PatWild | PatWildMulti => (),
431 PatVec(ref prepattern, ref slice_pattern, ref postpatterns) => {
432 for prepattern in prepattern.iter() {
433 visitor.visit_pat(*prepattern, env.clone())
435 for slice_pattern in slice_pattern.iter() {
436 visitor.visit_pat(*slice_pattern, env.clone())
438 for postpattern in postpatterns.iter() {
439 visitor.visit_pat(*postpattern, env.clone())
445 pub fn walk_foreign_item<E: Clone, V: Visitor<E>>(visitor: &mut V,
446 foreign_item: &ForeignItem,
448 visitor.visit_ident(foreign_item.span, foreign_item.ident, env.clone());
450 match foreign_item.node {
451 ForeignItemFn(function_declaration, ref generics) => {
452 walk_fn_decl(visitor, function_declaration, env.clone());
453 visitor.visit_generics(generics, env)
455 ForeignItemStatic(typ, _) => visitor.visit_ty(typ, env),
459 pub fn walk_ty_param_bounds<E: Clone, V: Visitor<E>>(visitor: &mut V,
460 bounds: &OptVec<TyParamBound>,
462 for bound in bounds.iter() {
464 TraitTyParamBound(ref typ) => {
465 walk_trait_ref_helper(visitor, typ, env.clone())
467 RegionTyParamBound => {}
472 pub fn walk_generics<E: Clone, V: Visitor<E>>(visitor: &mut V,
475 for type_parameter in generics.ty_params.iter() {
476 walk_ty_param_bounds(visitor, &type_parameter.bounds, env.clone());
477 match type_parameter.default {
478 Some(ty) => visitor.visit_ty(ty, env.clone()),
482 walk_lifetime_decls(visitor, &generics.lifetimes, env);
485 pub fn walk_fn_decl<E: Clone, V: Visitor<E>>(visitor: &mut V,
486 function_declaration: &FnDecl,
488 for argument in function_declaration.inputs.iter() {
489 visitor.visit_pat(argument.pat, env.clone());
490 visitor.visit_ty(argument.ty, env.clone())
492 visitor.visit_ty(function_declaration.output, env)
495 // Note: there is no visit_method() method in the visitor, instead override
496 // visit_fn() and check for FkMethod(). I named this visit_method_helper()
497 // because it is not a default impl of any method, though I doubt that really
498 // clarifies anything. - Niko
499 pub fn walk_method_helper<E: Clone, V: Visitor<E>>(visitor: &mut V,
502 visitor.visit_ident(method.span, method.ident, env.clone());
503 visitor.visit_fn(&FkMethod(method.ident, &method.generics, method),
511 pub fn walk_fn<E: Clone, V: Visitor<E>>(visitor: &mut V,
512 function_kind: &FnKind,
513 function_declaration: &FnDecl,
514 function_body: &Block,
518 walk_fn_decl(visitor, function_declaration, env.clone());
520 match *function_kind {
521 FkItemFn(_, generics, _, _) => {
522 visitor.visit_generics(generics, env.clone());
524 FkMethod(_, generics, method) => {
525 visitor.visit_generics(generics, env.clone());
527 visitor.visit_explicit_self(&method.explicit_self, env.clone());
532 visitor.visit_block(function_body, env)
535 pub fn walk_ty_method<E: Clone, V: Visitor<E>>(visitor: &mut V,
536 method_type: &TypeMethod,
538 visitor.visit_ident(method_type.span, method_type.ident, env.clone());
539 visitor.visit_explicit_self(&method_type.explicit_self, env.clone());
540 for argument_type in method_type.decl.inputs.iter() {
541 visitor.visit_ty(argument_type.ty, env.clone())
543 visitor.visit_generics(&method_type.generics, env.clone());
544 visitor.visit_ty(method_type.decl.output, env);
547 pub fn walk_trait_method<E: Clone, V: Visitor<E>>(visitor: &mut V,
548 trait_method: &TraitMethod,
550 match *trait_method {
551 Required(ref method_type) => {
552 visitor.visit_ty_method(method_type, env)
554 Provided(method) => walk_method_helper(visitor, method, env),
558 pub fn walk_struct_def<E: Clone, V: Visitor<E>>(visitor: &mut V,
559 struct_definition: &StructDef,
564 for field in struct_definition.fields.iter() {
565 visitor.visit_struct_field(field, env.clone())
569 pub fn walk_struct_field<E: Clone, V: Visitor<E>>(visitor: &mut V,
570 struct_field: &StructField,
572 match struct_field.node.kind {
573 NamedField(name, _) => {
574 visitor.visit_ident(struct_field.span, name, env.clone())
579 visitor.visit_ty(struct_field.node.ty, env)
582 pub fn walk_block<E: Clone, V: Visitor<E>>(visitor: &mut V, block: &Block, env: E) {
583 for view_item in block.view_items.iter() {
584 visitor.visit_view_item(view_item, env.clone())
586 for statement in block.stmts.iter() {
587 visitor.visit_stmt(*statement, env.clone())
589 walk_expr_opt(visitor, block.expr, env)
592 pub fn walk_stmt<E: Clone, V: Visitor<E>>(visitor: &mut V, statement: &Stmt, env: E) {
593 match statement.node {
594 StmtDecl(declaration, _) => visitor.visit_decl(declaration, env),
595 StmtExpr(expression, _) | StmtSemi(expression, _) => {
596 visitor.visit_expr(expression, env)
598 StmtMac(ref macro, _) => visitor.visit_mac(macro, env),
602 pub fn walk_decl<E: Clone, V: Visitor<E>>(visitor: &mut V, declaration: &Decl, env: E) {
603 match declaration.node {
604 DeclLocal(ref local) => visitor.visit_local(*local, env),
605 DeclItem(item) => visitor.visit_item(item, env),
609 pub fn walk_expr_opt<E: Clone, V: Visitor<E>>(visitor: &mut V,
610 optional_expression: Option<@Expr>,
612 match optional_expression {
614 Some(expression) => visitor.visit_expr(expression, env),
618 pub fn walk_exprs<E: Clone, V: Visitor<E>>(visitor: &mut V,
619 expressions: &[@Expr],
621 for expression in expressions.iter() {
622 visitor.visit_expr(*expression, env.clone())
626 pub fn walk_mac<E, V: Visitor<E>>(_: &mut V, _: &Mac, _: E) {
630 pub fn walk_expr<E: Clone, V: Visitor<E>>(visitor: &mut V, expression: &Expr, env: E) {
631 match expression.node {
632 ExprVstore(subexpression, _) => {
633 visitor.visit_expr(subexpression, env.clone())
635 ExprBox(place, subexpression) => {
636 visitor.visit_expr(place, env.clone());
637 visitor.visit_expr(subexpression, env.clone())
639 ExprVec(ref subexpressions, _) => {
640 walk_exprs(visitor, subexpressions.as_slice(), env.clone())
642 ExprRepeat(element, count, _) => {
643 visitor.visit_expr(element, env.clone());
644 visitor.visit_expr(count, env.clone())
646 ExprStruct(ref path, ref fields, optional_base) => {
647 visitor.visit_path(path, expression.id, env.clone());
648 for field in fields.iter() {
649 visitor.visit_expr(field.expr, env.clone())
651 walk_expr_opt(visitor, optional_base, env.clone())
653 ExprTup(ref subexpressions) => {
654 for subexpression in subexpressions.iter() {
655 visitor.visit_expr(*subexpression, env.clone())
658 ExprCall(callee_expression, ref arguments) => {
659 for argument in arguments.iter() {
660 visitor.visit_expr(*argument, env.clone())
662 visitor.visit_expr(callee_expression, env.clone())
664 ExprMethodCall(_, ref types, ref arguments) => {
665 walk_exprs(visitor, arguments.as_slice(), env.clone());
666 for &typ in types.iter() {
667 visitor.visit_ty(typ, env.clone())
670 ExprBinary(_, left_expression, right_expression) => {
671 visitor.visit_expr(left_expression, env.clone());
672 visitor.visit_expr(right_expression, env.clone())
674 ExprAddrOf(_, subexpression) | ExprUnary(_, subexpression) => {
675 visitor.visit_expr(subexpression, env.clone())
678 ExprCast(subexpression, typ) => {
679 visitor.visit_expr(subexpression, env.clone());
680 visitor.visit_ty(typ, env.clone())
682 ExprIf(head_expression, if_block, optional_else) => {
683 visitor.visit_expr(head_expression, env.clone());
684 visitor.visit_block(if_block, env.clone());
685 walk_expr_opt(visitor, optional_else, env.clone())
687 ExprWhile(subexpression, block) => {
688 visitor.visit_expr(subexpression, env.clone());
689 visitor.visit_block(block, env.clone())
691 ExprForLoop(pattern, subexpression, block, _) => {
692 visitor.visit_pat(pattern, env.clone());
693 visitor.visit_expr(subexpression, env.clone());
694 visitor.visit_block(block, env.clone())
696 ExprLoop(block, _) => visitor.visit_block(block, env.clone()),
697 ExprMatch(subexpression, ref arms) => {
698 visitor.visit_expr(subexpression, env.clone());
699 for arm in arms.iter() {
700 visitor.visit_arm(arm, env.clone())
703 ExprFnBlock(function_declaration, body) => {
704 visitor.visit_fn(&FkFnBlock,
705 function_declaration,
711 ExprProc(function_declaration, body) => {
712 visitor.visit_fn(&FkFnBlock,
713 function_declaration,
719 ExprBlock(block) => visitor.visit_block(block, env.clone()),
720 ExprAssign(left_hand_expression, right_hand_expression) => {
721 visitor.visit_expr(right_hand_expression, env.clone());
722 visitor.visit_expr(left_hand_expression, env.clone())
724 ExprAssignOp(_, left_expression, right_expression) => {
725 visitor.visit_expr(right_expression, env.clone());
726 visitor.visit_expr(left_expression, env.clone())
728 ExprField(subexpression, _, ref types) => {
729 visitor.visit_expr(subexpression, env.clone());
730 for &typ in types.iter() {
731 visitor.visit_ty(typ, env.clone())
734 ExprIndex(main_expression, index_expression) => {
735 visitor.visit_expr(main_expression, env.clone());
736 visitor.visit_expr(index_expression, env.clone())
738 ExprPath(ref path) => {
739 visitor.visit_path(path, expression.id, env.clone())
741 ExprBreak(_) | ExprAgain(_) => {}
742 ExprRet(optional_expression) => {
743 walk_expr_opt(visitor, optional_expression, env.clone())
746 ExprMac(ref macro) => visitor.visit_mac(macro, env.clone()),
747 ExprParen(subexpression) => {
748 visitor.visit_expr(subexpression, env.clone())
750 ExprInlineAsm(ref assembler) => {
751 for &(_, input) in assembler.inputs.iter() {
752 visitor.visit_expr(input, env.clone())
754 for &(_, output) in assembler.outputs.iter() {
755 visitor.visit_expr(output, env.clone())
760 visitor.visit_expr_post(expression, env.clone())
763 pub fn walk_arm<E: Clone, V: Visitor<E>>(visitor: &mut V, arm: &Arm, env: E) {
764 for pattern in arm.pats.iter() {
765 visitor.visit_pat(*pattern, env.clone())
767 walk_expr_opt(visitor, arm.guard, env.clone());
768 visitor.visit_block(arm.body, env)