rust/src/libsyntax/visit.rs
Jakub Bukaj 1faa09615e rollup merge of #19073: jakub-/issue-19069
Fixes #19069.

These were never intended not to be feature-gated but this PR is nonetheless a...

[breaking-change]
2014-11-19 22:39:12 +01:00

905 lines
33 KiB
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! AST walker. Each overridden visit method has full control over what
//! happens with its node, it can do its own traversal of the node's children,
//! call `visit::walk_*` to apply the default traversal algorithm, or prevent
//! deeper traversal by doing nothing.
//!
//! Note: it is an important invariant that the default visitor walks the body
//! of a function in "execution order" (more concretely, reverse post-order
//! with respect to the CFG implied by the AST), meaning that if AST node A may
//! execute before AST node B, then A is visited first. The borrow checker in
//! particular relies on this property.
//!
//! Note: walking an AST before macro expansion is probably a bad idea. For
//! instance, a walker looking for item names in a module will miss all of
//! those that are created by the expansion of a macro.
pub use self::FnKind::*;
use abi::Abi;
use ast::*;
use ast;
use codemap::Span;
use ptr::P;
use owned_slice::OwnedSlice;
pub enum FnKind<'a> {
/// fn foo() or extern "Abi" fn foo()
FkItemFn(Ident, &'a Generics, FnStyle, Abi),
/// fn foo(&self)
FkMethod(Ident, &'a Generics, &'a Method),
/// |x, y| ...
/// proc(x, y) ...
FkFnBlock,
}
/// 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 `visit::walk_mod`.
///
/// 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.)
pub trait Visitor<'v> {
fn visit_name(&mut self, _span: Span, _name: Name) {
// Nothing to do.
}
fn visit_ident(&mut self, span: Span, ident: Ident) {
self.visit_name(span, ident.name);
}
fn visit_mod(&mut self, m: &'v Mod, _s: Span, _n: NodeId) { walk_mod(self, m) }
fn visit_view_item(&mut self, i: &'v ViewItem) { walk_view_item(self, i) }
fn visit_foreign_item(&mut self, i: &'v ForeignItem) { walk_foreign_item(self, i) }
fn visit_item(&mut self, i: &'v Item) { walk_item(self, i) }
fn visit_local(&mut self, l: &'v Local) { walk_local(self, l) }
fn visit_block(&mut self, b: &'v Block) { walk_block(self, b) }
fn visit_stmt(&mut self, s: &'v Stmt) { walk_stmt(self, s) }
fn visit_arm(&mut self, a: &'v Arm) { walk_arm(self, a) }
fn visit_pat(&mut self, p: &'v Pat) { walk_pat(self, p) }
fn visit_decl(&mut self, d: &'v Decl) { walk_decl(self, d) }
fn visit_expr(&mut self, ex: &'v Expr) { walk_expr(self, ex) }
fn visit_expr_post(&mut self, _ex: &'v Expr) { }
fn visit_ty(&mut self, t: &'v Ty) { walk_ty(self, t) }
fn visit_generics(&mut self, g: &'v Generics) { walk_generics(self, g) }
fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: &'v Block, s: Span, _: NodeId) {
walk_fn(self, fk, fd, b, s)
}
fn visit_ty_method(&mut self, t: &'v TypeMethod) { walk_ty_method(self, t) }
fn visit_trait_item(&mut self, t: &'v TraitItem) { walk_trait_item(self, t) }
fn visit_trait_ref(&mut self, t: &'v TraitRef) { walk_trait_ref(self, t) }
fn visit_ty_param_bound(&mut self, bounds: &'v TyParamBound) {
walk_ty_param_bound(self, bounds)
}
fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef) {
walk_poly_trait_ref(self, t)
}
fn visit_struct_def(&mut self, s: &'v StructDef, _: Ident, _: &'v Generics, _: NodeId) {
walk_struct_def(self, s)
}
fn visit_struct_field(&mut self, s: &'v StructField) { walk_struct_field(self, s) }
fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics) { walk_variant(self, v, g) }
fn visit_opt_lifetime_ref(&mut self,
_span: Span,
opt_lifetime: &'v Option<Lifetime>) {
/*!
* Visits an optional reference to a lifetime. The `span` is
* the span of some surrounding reference should opt_lifetime
* be None.
*/
match *opt_lifetime {
Some(ref l) => self.visit_lifetime_ref(l),
None => ()
}
}
fn visit_lifetime_ref(&mut self, lifetime: &'v Lifetime) {
self.visit_name(lifetime.span, lifetime.name)
}
fn visit_lifetime_def(&mut self, lifetime: &'v LifetimeDef) {
walk_lifetime_def(self, lifetime)
}
fn visit_explicit_self(&mut self, es: &'v ExplicitSelf) {
walk_explicit_self(self, es)
}
fn visit_mac(&mut self, _macro: &'v Mac) {
panic!("visit_mac disabled by default");
// NB: see note about macros above.
// if you really want a visitor that
// works on macros, use this
// definition in your trait impl:
// visit::walk_mac(self, _macro)
}
fn visit_path(&mut self, path: &'v Path, _id: ast::NodeId) {
walk_path(self, path)
}
fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) {
walk_path_segment(self, path_span, path_segment)
}
fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'v PathParameters) {
walk_path_parameters(self, path_span, path_parameters)
}
fn visit_attribute(&mut self, _attr: &'v Attribute) {}
}
pub fn walk_inlined_item<'v,V>(visitor: &mut V, item: &'v InlinedItem)
where V: Visitor<'v> {
match *item {
IIItem(ref i) => visitor.visit_item(&**i),
IIForeign(ref i) => visitor.visit_foreign_item(&**i),
IITraitItem(_, ref ti) => visitor.visit_trait_item(ti),
IIImplItem(_, MethodImplItem(ref m)) => {
walk_method_helper(visitor, &**m)
}
IIImplItem(_, TypeImplItem(ref typedef)) => {
visitor.visit_ident(typedef.span, typedef.ident);
visitor.visit_ty(&*typedef.typ);
}
}
}
pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {
visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
for attr in krate.attrs.iter() {
visitor.visit_attribute(attr);
}
}
pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod) {
for view_item in module.view_items.iter() {
visitor.visit_view_item(view_item)
}
for item in module.items.iter() {
visitor.visit_item(&**item)
}
}
pub fn walk_view_item<'v, V: Visitor<'v>>(visitor: &mut V, vi: &'v ViewItem) {
match vi.node {
ViewItemExternCrate(name, _, _) => {
visitor.visit_ident(vi.span, name)
}
ViewItemUse(ref vp) => {
match vp.node {
ViewPathSimple(ident, ref path, id) => {
visitor.visit_ident(vp.span, ident);
visitor.visit_path(path, id);
}
ViewPathGlob(ref path, id) => {
visitor.visit_path(path, id);
}
ViewPathList(ref prefix, ref list, _) => {
for id in list.iter() {
match id.node {
PathListIdent { name, .. } => {
visitor.visit_ident(id.span, name);
}
PathListMod { .. } => ()
}
}
// Note that the `prefix` here is not a complete
// path, so we don't use `visit_path`.
walk_path(visitor, prefix);
}
}
}
}
for attr in vi.attrs.iter() {
visitor.visit_attribute(attr);
}
}
pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
visitor.visit_pat(&*local.pat);
visitor.visit_ty(&*local.ty);
walk_expr_opt(visitor, &local.init);
}
pub fn walk_lifetime_def<'v, V: Visitor<'v>>(visitor: &mut V,
lifetime_def: &'v LifetimeDef) {
visitor.visit_lifetime_ref(&lifetime_def.lifetime);
for bound in lifetime_def.bounds.iter() {
visitor.visit_lifetime_ref(bound);
}
}
pub fn walk_explicit_self<'v, V: Visitor<'v>>(visitor: &mut V,
explicit_self: &'v ExplicitSelf) {
match explicit_self.node {
SelfStatic | SelfValue(_) => {},
SelfRegion(ref lifetime, _, _) => {
visitor.visit_opt_lifetime_ref(explicit_self.span, lifetime)
}
SelfExplicit(ref typ, _) => visitor.visit_ty(&**typ),
}
}
/// Like with walk_method_helper this doesn't correspond to a method
/// in Visitor, and so it gets a _helper suffix.
pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
trait_ref: &'v PolyTraitRef)
where V: Visitor<'v>
{
walk_lifetime_decls_helper(visitor, &trait_ref.bound_lifetimes);
visitor.visit_trait_ref(&trait_ref.trait_ref);
}
/// Like with walk_method_helper this doesn't correspond to a method
/// in Visitor, and so it gets a _helper suffix.
pub fn walk_trait_ref<'v,V>(visitor: &mut V,
trait_ref: &'v TraitRef)
where V: Visitor<'v>
{
visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
}
pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
visitor.visit_ident(item.span, item.ident);
match item.node {
ItemStatic(ref typ, _, ref expr) |
ItemConst(ref typ, ref expr) => {
visitor.visit_ty(&**typ);
visitor.visit_expr(&**expr);
}
ItemFn(ref declaration, fn_style, abi, ref generics, ref body) => {
visitor.visit_fn(FkItemFn(item.ident, generics, fn_style, abi),
&**declaration,
&**body,
item.span,
item.id)
}
ItemMod(ref module) => {
visitor.visit_mod(module, item.span, item.id)
}
ItemForeignMod(ref foreign_module) => {
for view_item in foreign_module.view_items.iter() {
visitor.visit_view_item(view_item)
}
for foreign_item in foreign_module.items.iter() {
visitor.visit_foreign_item(&**foreign_item)
}
}
ItemTy(ref typ, ref type_parameters) => {
visitor.visit_ty(&**typ);
visitor.visit_generics(type_parameters)
}
ItemEnum(ref enum_definition, ref type_parameters) => {
visitor.visit_generics(type_parameters);
walk_enum_def(visitor, enum_definition, type_parameters)
}
ItemImpl(ref type_parameters,
ref trait_reference,
ref typ,
ref impl_items) => {
visitor.visit_generics(type_parameters);
match *trait_reference {
Some(ref trait_reference) => visitor.visit_trait_ref(trait_reference),
None => ()
}
visitor.visit_ty(&**typ);
for impl_item in impl_items.iter() {
match *impl_item {
MethodImplItem(ref method) => {
walk_method_helper(visitor, &**method)
}
TypeImplItem(ref typedef) => {
visitor.visit_ident(typedef.span, typedef.ident);
visitor.visit_ty(&*typedef.typ);
}
}
}
}
ItemStruct(ref struct_definition, ref generics) => {
visitor.visit_generics(generics);
visitor.visit_struct_def(&**struct_definition,
item.ident,
generics,
item.id)
}
ItemTrait(ref generics, _, ref bounds, ref methods) => {
visitor.visit_generics(generics);
walk_ty_param_bounds_helper(visitor, bounds);
for method in methods.iter() {
visitor.visit_trait_item(method)
}
}
ItemMac(ref macro) => visitor.visit_mac(macro),
}
for attr in item.attrs.iter() {
visitor.visit_attribute(attr);
}
}
pub fn walk_enum_def<'v, V: Visitor<'v>>(visitor: &mut V,
enum_definition: &'v EnumDef,
generics: &'v Generics) {
for variant in enum_definition.variants.iter() {
visitor.visit_variant(&**variant, generics);
}
}
pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V,
variant: &'v Variant,
generics: &'v Generics) {
visitor.visit_ident(variant.span, variant.node.name);
match variant.node.kind {
TupleVariantKind(ref variant_arguments) => {
for variant_argument in variant_arguments.iter() {
visitor.visit_ty(&*variant_argument.ty)
}
}
StructVariantKind(ref struct_definition) => {
visitor.visit_struct_def(&**struct_definition,
variant.node.name,
generics,
variant.node.id)
}
}
match variant.node.disr_expr {
Some(ref expr) => visitor.visit_expr(&**expr),
None => ()
}
for attr in variant.node.attrs.iter() {
visitor.visit_attribute(attr);
}
}
pub fn skip_ty<'v, V: Visitor<'v>>(_: &mut V, _: &'v Ty) {
// Empty!
}
pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
match typ.node {
TyVec(ref ty) | TyParen(ref ty) => {
visitor.visit_ty(&**ty)
}
TyPtr(ref mutable_type) => {
visitor.visit_ty(&*mutable_type.ty)
}
TyRptr(ref lifetime, ref mutable_type) => {
visitor.visit_opt_lifetime_ref(typ.span, lifetime);
visitor.visit_ty(&*mutable_type.ty)
}
TyTup(ref tuple_element_types) => {
for tuple_element_type in tuple_element_types.iter() {
visitor.visit_ty(&**tuple_element_type)
}
}
TyClosure(ref function_declaration) => {
for argument in function_declaration.decl.inputs.iter() {
visitor.visit_ty(&*argument.ty)
}
walk_fn_ret_ty(visitor, &function_declaration.decl.output);
walk_ty_param_bounds_helper(visitor, &function_declaration.bounds);
walk_lifetime_decls_helper(visitor, &function_declaration.lifetimes);
}
TyProc(ref function_declaration) => {
for argument in function_declaration.decl.inputs.iter() {
visitor.visit_ty(&*argument.ty)
}
walk_fn_ret_ty(visitor, &function_declaration.decl.output);
walk_ty_param_bounds_helper(visitor, &function_declaration.bounds);
walk_lifetime_decls_helper(visitor, &function_declaration.lifetimes);
}
TyBareFn(ref function_declaration) => {
for argument in function_declaration.decl.inputs.iter() {
visitor.visit_ty(&*argument.ty)
}
walk_fn_ret_ty(visitor, &function_declaration.decl.output);
walk_lifetime_decls_helper(visitor, &function_declaration.lifetimes);
}
TyPath(ref path, ref opt_bounds, id) => {
visitor.visit_path(path, id);
match *opt_bounds {
Some(ref bounds) => {
walk_ty_param_bounds_helper(visitor, bounds);
}
None => { }
}
}
TyQPath(ref qpath) => {
visitor.visit_ty(&*qpath.self_type);
visitor.visit_trait_ref(&*qpath.trait_ref);
visitor.visit_ident(typ.span, qpath.item_name);
}
TyFixedLengthVec(ref ty, ref expression) => {
visitor.visit_ty(&**ty);
visitor.visit_expr(&**expression)
}
TyPolyTraitRef(ref bounds) => {
walk_ty_param_bounds_helper(visitor, bounds)
}
TyTypeof(ref expression) => {
visitor.visit_expr(&**expression)
}
TyInfer => {}
}
}
pub fn walk_lifetime_decls_helper<'v, V: Visitor<'v>>(visitor: &mut V,
lifetimes: &'v Vec<LifetimeDef>) {
for l in lifetimes.iter() {
visitor.visit_lifetime_def(l);
}
}
pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
for segment in path.segments.iter() {
visitor.visit_path_segment(path.span, segment);
}
}
pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,
path_span: Span,
segment: &'v PathSegment) {
visitor.visit_ident(path_span, segment.identifier);
visitor.visit_path_parameters(path_span, &segment.parameters);
}
pub fn walk_path_parameters<'v, V: Visitor<'v>>(visitor: &mut V,
_path_span: Span,
path_parameters: &'v PathParameters) {
match *path_parameters {
ast::AngleBracketedParameters(ref data) => {
for typ in data.types.iter() {
visitor.visit_ty(&**typ);
}
for lifetime in data.lifetimes.iter() {
visitor.visit_lifetime_ref(lifetime);
}
}
ast::ParenthesizedParameters(ref data) => {
for typ in data.inputs.iter() {
visitor.visit_ty(&**typ);
}
for typ in data.output.iter() {
visitor.visit_ty(&**typ);
}
}
}
}
pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
match pattern.node {
PatEnum(ref path, ref children) => {
visitor.visit_path(path, pattern.id);
for children in children.iter() {
for child in children.iter() {
visitor.visit_pat(&**child)
}
}
}
PatStruct(ref path, ref fields, _) => {
visitor.visit_path(path, pattern.id);
for field in fields.iter() {
visitor.visit_pat(&*field.node.pat)
}
}
PatTup(ref tuple_elements) => {
for tuple_element in tuple_elements.iter() {
visitor.visit_pat(&**tuple_element)
}
}
PatBox(ref subpattern) |
PatRegion(ref subpattern) => {
visitor.visit_pat(&**subpattern)
}
PatIdent(_, ref pth1, ref optional_subpattern) => {
visitor.visit_ident(pth1.span, pth1.node);
match *optional_subpattern {
None => {}
Some(ref subpattern) => visitor.visit_pat(&**subpattern),
}
}
PatLit(ref expression) => visitor.visit_expr(&**expression),
PatRange(ref lower_bound, ref upper_bound) => {
visitor.visit_expr(&**lower_bound);
visitor.visit_expr(&**upper_bound)
}
PatWild(_) => (),
PatVec(ref prepattern, ref slice_pattern, ref postpatterns) => {
for prepattern in prepattern.iter() {
visitor.visit_pat(&**prepattern)
}
for slice_pattern in slice_pattern.iter() {
visitor.visit_pat(&**slice_pattern)
}
for postpattern in postpatterns.iter() {
visitor.visit_pat(&**postpattern)
}
}
PatMac(ref macro) => visitor.visit_mac(macro),
}
}
pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V,
foreign_item: &'v ForeignItem) {
visitor.visit_ident(foreign_item.span, foreign_item.ident);
match foreign_item.node {
ForeignItemFn(ref function_declaration, ref generics) => {
walk_fn_decl(visitor, &**function_declaration);
visitor.visit_generics(generics)
}
ForeignItemStatic(ref typ, _) => visitor.visit_ty(&**typ),
}
for attr in foreign_item.attrs.iter() {
visitor.visit_attribute(attr);
}
}
pub fn walk_ty_param_bounds_helper<'v, V: Visitor<'v>>(visitor: &mut V,
bounds: &'v OwnedSlice<TyParamBound>) {
for bound in bounds.iter() {
visitor.visit_ty_param_bound(bound)
}
}
pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V,
bound: &'v TyParamBound) {
match *bound {
TraitTyParamBound(ref typ) => {
visitor.visit_poly_trait_ref(typ);
}
RegionTyParamBound(ref lifetime) => {
visitor.visit_lifetime_ref(lifetime);
}
}
}
pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
for type_parameter in generics.ty_params.iter() {
visitor.visit_ident(type_parameter.span, type_parameter.ident);
walk_ty_param_bounds_helper(visitor, &type_parameter.bounds);
match type_parameter.default {
Some(ref ty) => visitor.visit_ty(&**ty),
None => {}
}
}
walk_lifetime_decls_helper(visitor, &generics.lifetimes);
for predicate in generics.where_clause.predicates.iter() {
visitor.visit_ident(predicate.span, predicate.ident);
walk_ty_param_bounds_helper(visitor, &predicate.bounds);
}
}
pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy) {
if let Return(ref output_ty) = *ret_ty {
visitor.visit_ty(&**output_ty)
}
}
pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) {
for argument in function_declaration.inputs.iter() {
visitor.visit_pat(&*argument.pat);
visitor.visit_ty(&*argument.ty)
}
walk_fn_ret_ty(visitor, &function_declaration.output)
}
// Note: there is no visit_method() method in the visitor, instead override
// visit_fn() and check for FkMethod(). I named this visit_method_helper()
// because it is not a default impl of any method, though I doubt that really
// clarifies anything. - Niko
pub fn walk_method_helper<'v, V: Visitor<'v>>(visitor: &mut V, method: &'v Method) {
match method.node {
MethDecl(ident, ref generics, _, _, _, ref decl, ref body, _) => {
visitor.visit_ident(method.span, ident);
visitor.visit_fn(FkMethod(ident, generics, method),
&**decl,
&**body,
method.span,
method.id);
for attr in method.attrs.iter() {
visitor.visit_attribute(attr);
}
},
MethMac(ref mac) => visitor.visit_mac(mac)
}
}
pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
function_kind: FnKind<'v>,
function_declaration: &'v FnDecl,
function_body: &'v Block,
_span: Span) {
walk_fn_decl(visitor, function_declaration);
match function_kind {
FkItemFn(_, generics, _, _) => {
visitor.visit_generics(generics);
}
FkMethod(_, generics, method) => {
visitor.visit_generics(generics);
match method.node {
MethDecl(_, _, _, ref explicit_self, _, _, _, _) =>
visitor.visit_explicit_self(explicit_self),
MethMac(ref mac) =>
visitor.visit_mac(mac)
}
}
FkFnBlock(..) => {}
}
visitor.visit_block(function_body)
}
pub fn walk_ty_method<'v, V: Visitor<'v>>(visitor: &mut V, method_type: &'v TypeMethod) {
visitor.visit_ident(method_type.span, method_type.ident);
visitor.visit_explicit_self(&method_type.explicit_self);
for argument_type in method_type.decl.inputs.iter() {
visitor.visit_ty(&*argument_type.ty)
}
visitor.visit_generics(&method_type.generics);
walk_fn_ret_ty(visitor, &method_type.decl.output);
for attr in method_type.attrs.iter() {
visitor.visit_attribute(attr);
}
}
pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_method: &'v TraitItem) {
match *trait_method {
RequiredMethod(ref method_type) => visitor.visit_ty_method(method_type),
ProvidedMethod(ref method) => walk_method_helper(visitor, &**method),
TypeTraitItem(ref associated_type) => {
visitor.visit_ident(associated_type.ty_param.span,
associated_type.ty_param.ident)
}
}
}
pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V,
struct_definition: &'v StructDef) {
for field in struct_definition.fields.iter() {
visitor.visit_struct_field(field)
}
}
pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V,
struct_field: &'v StructField) {
match struct_field.node.kind {
NamedField(name, _) => {
visitor.visit_ident(struct_field.span, name)
}
_ => {}
}
visitor.visit_ty(&*struct_field.node.ty);
for attr in struct_field.node.attrs.iter() {
visitor.visit_attribute(attr);
}
}
pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) {
for view_item in block.view_items.iter() {
visitor.visit_view_item(view_item)
}
for statement in block.stmts.iter() {
visitor.visit_stmt(&**statement)
}
walk_expr_opt(visitor, &block.expr)
}
pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) {
match statement.node {
StmtDecl(ref declaration, _) => visitor.visit_decl(&**declaration),
StmtExpr(ref expression, _) | StmtSemi(ref expression, _) => {
visitor.visit_expr(&**expression)
}
StmtMac(ref macro, _) => visitor.visit_mac(macro),
}
}
pub fn walk_decl<'v, V: Visitor<'v>>(visitor: &mut V, declaration: &'v Decl) {
match declaration.node {
DeclLocal(ref local) => visitor.visit_local(&**local),
DeclItem(ref item) => visitor.visit_item(&**item),
}
}
pub fn walk_expr_opt<'v, V: Visitor<'v>>(visitor: &mut V,
optional_expression: &'v Option<P<Expr>>) {
match *optional_expression {
None => {}
Some(ref expression) => visitor.visit_expr(&**expression),
}
}
pub fn walk_exprs<'v, V: Visitor<'v>>(visitor: &mut V, expressions: &'v [P<Expr>]) {
for expression in expressions.iter() {
visitor.visit_expr(&**expression)
}
}
pub fn walk_mac<'v, V: Visitor<'v>>(_: &mut V, _: &'v Mac) {
// Empty!
}
pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
match expression.node {
ExprBox(ref place, ref subexpression) => {
visitor.visit_expr(&**place);
visitor.visit_expr(&**subexpression)
}
ExprVec(ref subexpressions) => {
walk_exprs(visitor, subexpressions.as_slice())
}
ExprRepeat(ref element, ref count) => {
visitor.visit_expr(&**element);
visitor.visit_expr(&**count)
}
ExprStruct(ref path, ref fields, ref optional_base) => {
visitor.visit_path(path, expression.id);
for field in fields.iter() {
visitor.visit_expr(&*field.expr)
}
walk_expr_opt(visitor, optional_base)
}
ExprTup(ref subexpressions) => {
for subexpression in subexpressions.iter() {
visitor.visit_expr(&**subexpression)
}
}
ExprCall(ref callee_expression, ref arguments) => {
for argument in arguments.iter() {
visitor.visit_expr(&**argument)
}
visitor.visit_expr(&**callee_expression)
}
ExprMethodCall(_, ref types, ref arguments) => {
walk_exprs(visitor, arguments.as_slice());
for typ in types.iter() {
visitor.visit_ty(&**typ)
}
}
ExprBinary(_, ref left_expression, ref right_expression) => {
visitor.visit_expr(&**left_expression);
visitor.visit_expr(&**right_expression)
}
ExprAddrOf(_, ref subexpression) | ExprUnary(_, ref subexpression) => {
visitor.visit_expr(&**subexpression)
}
ExprLit(_) => {}
ExprCast(ref subexpression, ref typ) => {
visitor.visit_expr(&**subexpression);
visitor.visit_ty(&**typ)
}
ExprIf(ref head_expression, ref if_block, ref optional_else) => {
visitor.visit_expr(&**head_expression);
visitor.visit_block(&**if_block);
walk_expr_opt(visitor, optional_else)
}
ExprWhile(ref subexpression, ref block, _) => {
visitor.visit_expr(&**subexpression);
visitor.visit_block(&**block)
}
ExprIfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
visitor.visit_pat(&**pattern);
visitor.visit_expr(&**subexpression);
visitor.visit_block(&**if_block);
walk_expr_opt(visitor, optional_else);
}
ExprWhileLet(ref pattern, ref subexpression, ref block, _) => {
visitor.visit_pat(&**pattern);
visitor.visit_expr(&**subexpression);
visitor.visit_block(&**block);
}
ExprForLoop(ref pattern, ref subexpression, ref block, _) => {
visitor.visit_pat(&**pattern);
visitor.visit_expr(&**subexpression);
visitor.visit_block(&**block)
}
ExprLoop(ref block, _) => visitor.visit_block(&**block),
ExprMatch(ref subexpression, ref arms, _) => {
visitor.visit_expr(&**subexpression);
for arm in arms.iter() {
visitor.visit_arm(arm)
}
}
ExprFnBlock(_, ref function_declaration, ref body) => {
visitor.visit_fn(FkFnBlock,
&**function_declaration,
&**body,
expression.span,
expression.id)
}
ExprUnboxedFn(_, _, ref function_declaration, ref body) => {
visitor.visit_fn(FkFnBlock,
&**function_declaration,
&**body,
expression.span,
expression.id)
}
ExprProc(ref function_declaration, ref body) => {
visitor.visit_fn(FkFnBlock,
&**function_declaration,
&**body,
expression.span,
expression.id)
}
ExprBlock(ref block) => visitor.visit_block(&**block),
ExprAssign(ref left_hand_expression, ref right_hand_expression) => {
visitor.visit_expr(&**right_hand_expression);
visitor.visit_expr(&**left_hand_expression)
}
ExprAssignOp(_, ref left_expression, ref right_expression) => {
visitor.visit_expr(&**right_expression);
visitor.visit_expr(&**left_expression)
}
ExprField(ref subexpression, _, ref types) => {
visitor.visit_expr(&**subexpression);
for typ in types.iter() {
visitor.visit_ty(&**typ)
}
}
ExprTupField(ref subexpression, _, ref types) => {
visitor.visit_expr(&**subexpression);
for typ in types.iter() {
visitor.visit_ty(&**typ)
}
}
ExprIndex(ref main_expression, ref index_expression) => {
visitor.visit_expr(&**main_expression);
visitor.visit_expr(&**index_expression)
}
ExprSlice(ref main_expression, ref start, ref end, _) => {
visitor.visit_expr(&**main_expression);
walk_expr_opt(visitor, start);
walk_expr_opt(visitor, end)
}
ExprPath(ref path) => {
visitor.visit_path(path, expression.id)
}
ExprBreak(_) | ExprAgain(_) => {}
ExprRet(ref optional_expression) => {
walk_expr_opt(visitor, optional_expression)
}
ExprMac(ref macro) => visitor.visit_mac(macro),
ExprParen(ref subexpression) => {
visitor.visit_expr(&**subexpression)
}
ExprInlineAsm(ref ia) => {
for input in ia.inputs.iter() {
let (_, ref input) = *input;
visitor.visit_expr(&**input)
}
for output in ia.outputs.iter() {
let (_, ref output, _) = *output;
visitor.visit_expr(&**output)
}
}
}
visitor.visit_expr_post(expression)
}
pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
for pattern in arm.pats.iter() {
visitor.visit_pat(&**pattern)
}
walk_expr_opt(visitor, &arm.guard);
visitor.visit_expr(&*arm.body);
for attr in arm.attrs.iter() {
visitor.visit_attribute(attr);
}
}