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 //! A Folder represents an AST->AST fold; it accepts an AST piece,
12 //! and returns a piece of the same type. So, for instance, macro
13 //! expansion is a Folder that walks over an AST and produces another
16 //! Note: using a Folder (other than the MacroExpander Folder) on
17 //! an AST before macro expansion is probably a bad idea. For instance,
18 //! a folder renaming item names in a module will miss all of those
19 //! that are created by the expansion of a macro.
24 use codemap::{Spanned, respan};
25 use parse::token::{self, Token};
31 use util::move_map::MoveMap;
33 use rustc_data_structures::sync::Lrc;
35 pub trait Folder : Sized {
36 // Any additions to this trait should happen in form
37 // of a call to a public `noop_*` function that only calls
38 // out to the folder again, not other `noop_*` functions.
40 // This is a necessary API workaround to the problem of not
41 // being able to call out to the super default method
42 // in an overridden default method.
44 fn fold_crate(&mut self, c: Crate) -> Crate {
45 noop_fold_crate(c, self)
48 fn fold_meta_items(&mut self, meta_items: Vec<MetaItem>) -> Vec<MetaItem> {
49 noop_fold_meta_items(meta_items, self)
52 fn fold_meta_list_item(&mut self, list_item: NestedMetaItem) -> NestedMetaItem {
53 noop_fold_meta_list_item(list_item, self)
56 fn fold_meta_item(&mut self, meta_item: MetaItem) -> MetaItem {
57 noop_fold_meta_item(meta_item, self)
60 fn fold_use_tree(&mut self, use_tree: UseTree) -> UseTree {
61 noop_fold_use_tree(use_tree, self)
64 fn fold_foreign_item(&mut self, ni: ForeignItem) -> OneVector<ForeignItem> {
65 noop_fold_foreign_item(ni, self)
68 fn fold_foreign_item_simple(&mut self, ni: ForeignItem) -> ForeignItem {
69 noop_fold_foreign_item_simple(ni, self)
72 fn fold_item(&mut self, i: P<Item>) -> OneVector<P<Item>> {
73 noop_fold_item(i, self)
76 fn fold_item_simple(&mut self, i: Item) -> Item {
77 noop_fold_item_simple(i, self)
80 fn fold_fn_header(&mut self, header: FnHeader) -> FnHeader {
81 noop_fold_fn_header(header, self)
84 fn fold_struct_field(&mut self, sf: StructField) -> StructField {
85 noop_fold_struct_field(sf, self)
88 fn fold_item_kind(&mut self, i: ItemKind) -> ItemKind {
89 noop_fold_item_kind(i, self)
92 fn fold_trait_item(&mut self, i: TraitItem) -> OneVector<TraitItem> {
93 noop_fold_trait_item(i, self)
96 fn fold_impl_item(&mut self, i: ImplItem) -> OneVector<ImplItem> {
97 noop_fold_impl_item(i, self)
100 fn fold_fn_decl(&mut self, d: P<FnDecl>) -> P<FnDecl> {
101 noop_fold_fn_decl(d, self)
104 fn fold_asyncness(&mut self, a: IsAsync) -> IsAsync {
105 noop_fold_asyncness(a, self)
108 fn fold_block(&mut self, b: P<Block>) -> P<Block> {
109 noop_fold_block(b, self)
112 fn fold_stmt(&mut self, s: Stmt) -> OneVector<Stmt> {
113 noop_fold_stmt(s, self)
116 fn fold_arm(&mut self, a: Arm) -> Arm {
117 noop_fold_arm(a, self)
120 fn fold_pat(&mut self, p: P<Pat>) -> P<Pat> {
121 noop_fold_pat(p, self)
124 fn fold_anon_const(&mut self, c: AnonConst) -> AnonConst {
125 noop_fold_anon_const(c, self)
128 fn fold_expr(&mut self, e: P<Expr>) -> P<Expr> {
129 e.map(|e| noop_fold_expr(e, self))
132 fn fold_range_end(&mut self, re: RangeEnd) -> RangeEnd {
133 noop_fold_range_end(re, self)
136 fn fold_opt_expr(&mut self, e: P<Expr>) -> Option<P<Expr>> {
137 noop_fold_opt_expr(e, self)
140 fn fold_exprs(&mut self, es: Vec<P<Expr>>) -> Vec<P<Expr>> {
141 noop_fold_exprs(es, self)
144 fn fold_generic_arg(&mut self, arg: GenericArg) -> GenericArg {
146 GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.fold_lifetime(lt)),
147 GenericArg::Type(ty) => GenericArg::Type(self.fold_ty(ty)),
151 fn fold_ty(&mut self, t: P<Ty>) -> P<Ty> {
152 noop_fold_ty(t, self)
155 fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
156 noop_fold_lifetime(l, self)
159 fn fold_ty_binding(&mut self, t: TypeBinding) -> TypeBinding {
160 noop_fold_ty_binding(t, self)
163 fn fold_mod(&mut self, m: Mod) -> Mod {
164 noop_fold_mod(m, self)
167 fn fold_foreign_mod(&mut self, nm: ForeignMod) -> ForeignMod {
168 noop_fold_foreign_mod(nm, self)
171 fn fold_global_asm(&mut self, ga: P<GlobalAsm>) -> P<GlobalAsm> {
172 noop_fold_global_asm(ga, self)
175 fn fold_variant(&mut self, v: Variant) -> Variant {
176 noop_fold_variant(v, self)
179 fn fold_ident(&mut self, i: Ident) -> Ident {
180 noop_fold_ident(i, self)
183 fn fold_usize(&mut self, i: usize) -> usize {
184 noop_fold_usize(i, self)
187 fn fold_path(&mut self, p: Path) -> Path {
188 noop_fold_path(p, self)
191 fn fold_qpath(&mut self, qs: Option<QSelf>, p: Path) -> (Option<QSelf>, Path) {
192 noop_fold_qpath(qs, p, self)
195 fn fold_generic_args(&mut self, p: GenericArgs) -> GenericArgs {
196 noop_fold_generic_args(p, self)
199 fn fold_angle_bracketed_parameter_data(&mut self, p: AngleBracketedArgs)
200 -> AngleBracketedArgs
202 noop_fold_angle_bracketed_parameter_data(p, self)
205 fn fold_parenthesized_parameter_data(&mut self, p: ParenthesisedArgs)
208 noop_fold_parenthesized_parameter_data(p, self)
211 fn fold_local(&mut self, l: P<Local>) -> P<Local> {
212 noop_fold_local(l, self)
215 fn fold_mac(&mut self, _mac: Mac) -> Mac {
216 panic!("fold_mac disabled by default");
217 // NB: see note about macros above.
218 // if you really want a folder that
219 // works on macros, use this
220 // definition in your trait impl:
221 // fold::noop_fold_mac(_mac, self)
224 fn fold_macro_def(&mut self, def: MacroDef) -> MacroDef {
225 noop_fold_macro_def(def, self)
228 fn fold_label(&mut self, label: Label) -> Label {
229 noop_fold_label(label, self)
232 fn fold_attribute(&mut self, at: Attribute) -> Option<Attribute> {
233 noop_fold_attribute(at, self)
236 fn fold_arg(&mut self, a: Arg) -> Arg {
237 noop_fold_arg(a, self)
240 fn fold_generics(&mut self, generics: Generics) -> Generics {
241 noop_fold_generics(generics, self)
244 fn fold_trait_ref(&mut self, p: TraitRef) -> TraitRef {
245 noop_fold_trait_ref(p, self)
248 fn fold_poly_trait_ref(&mut self, p: PolyTraitRef) -> PolyTraitRef {
249 noop_fold_poly_trait_ref(p, self)
252 fn fold_variant_data(&mut self, vdata: VariantData) -> VariantData {
253 noop_fold_variant_data(vdata, self)
256 fn fold_generic_param(&mut self, param: GenericParam) -> GenericParam {
257 noop_fold_generic_param(param, self)
260 fn fold_generic_params(&mut self, params: Vec<GenericParam>) -> Vec<GenericParam> {
261 noop_fold_generic_params(params, self)
264 fn fold_tt(&mut self, tt: TokenTree) -> TokenTree {
265 noop_fold_tt(tt, self)
268 fn fold_tts(&mut self, tts: TokenStream) -> TokenStream {
269 noop_fold_tts(tts, self)
272 fn fold_token(&mut self, t: token::Token) -> token::Token {
273 noop_fold_token(t, self)
276 fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal {
277 noop_fold_interpolated(nt, self)
280 fn fold_opt_bounds(&mut self, b: Option<GenericBounds>) -> Option<GenericBounds> {
281 noop_fold_opt_bounds(b, self)
284 fn fold_bounds(&mut self, b: GenericBounds) -> GenericBounds {
285 noop_fold_bounds(b, self)
288 fn fold_param_bound(&mut self, tpb: GenericBound) -> GenericBound {
289 noop_fold_param_bound(tpb, self)
292 fn fold_mt(&mut self, mt: MutTy) -> MutTy {
293 noop_fold_mt(mt, self)
296 fn fold_field(&mut self, field: Field) -> Field {
297 noop_fold_field(field, self)
300 fn fold_where_clause(&mut self, where_clause: WhereClause)
302 noop_fold_where_clause(where_clause, self)
305 fn fold_where_predicate(&mut self, where_predicate: WherePredicate)
307 noop_fold_where_predicate(where_predicate, self)
310 fn fold_vis(&mut self, vis: Visibility) -> Visibility {
311 noop_fold_vis(vis, self)
314 fn new_id(&mut self, i: NodeId) -> NodeId {
318 fn new_span(&mut self, sp: Span) -> Span {
323 pub fn noop_fold_meta_items<T: Folder>(meta_items: Vec<MetaItem>, fld: &mut T) -> Vec<MetaItem> {
324 meta_items.move_map(|x| fld.fold_meta_item(x))
327 pub fn noop_fold_use_tree<T: Folder>(use_tree: UseTree, fld: &mut T) -> UseTree {
329 span: fld.new_span(use_tree.span),
330 prefix: fld.fold_path(use_tree.prefix),
331 kind: match use_tree.kind {
332 UseTreeKind::Simple(rename, id1, id2) =>
333 UseTreeKind::Simple(rename.map(|ident| fld.fold_ident(ident)),
334 fld.new_id(id1), fld.new_id(id2)),
335 UseTreeKind::Glob => UseTreeKind::Glob,
336 UseTreeKind::Nested(items) => UseTreeKind::Nested(items.move_map(|(tree, id)| {
337 (fld.fold_use_tree(tree), fld.new_id(id))
343 pub fn fold_attrs<T: Folder>(attrs: Vec<Attribute>, fld: &mut T) -> Vec<Attribute> {
344 attrs.move_flat_map(|x| fld.fold_attribute(x))
347 pub fn fold_thin_attrs<T: Folder>(attrs: ThinVec<Attribute>, fld: &mut T) -> ThinVec<Attribute> {
348 fold_attrs(attrs.into(), fld).into()
351 pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body}: Arm,
352 fld: &mut T) -> Arm {
354 attrs: fold_attrs(attrs, fld),
355 pats: pats.move_map(|x| fld.fold_pat(x)),
356 guard: guard.map(|x| fld.fold_expr(x)),
357 body: fld.fold_expr(body),
361 pub fn noop_fold_ty_binding<T: Folder>(b: TypeBinding, fld: &mut T) -> TypeBinding {
363 id: fld.new_id(b.id),
364 ident: fld.fold_ident(b.ident),
365 ty: fld.fold_ty(b.ty),
366 span: fld.new_span(b.span),
370 pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> {
371 t.map(|Ty {id, node, span}| Ty {
374 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node,
375 TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)),
376 TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)),
377 TyKind::Rptr(region, mt) => {
378 TyKind::Rptr(region.map(|lt| noop_fold_lifetime(lt, fld)), fld.fold_mt(mt))
380 TyKind::BareFn(f) => {
381 TyKind::BareFn(f.map(|BareFnTy {generic_params, unsafety, abi, decl}| BareFnTy {
382 generic_params: fld.fold_generic_params(generic_params),
385 decl: fld.fold_fn_decl(decl)
388 TyKind::Never => node,
389 TyKind::Tup(tys) => TyKind::Tup(tys.move_map(|ty| fld.fold_ty(ty))),
390 TyKind::Paren(ty) => TyKind::Paren(fld.fold_ty(ty)),
391 TyKind::Path(qself, path) => {
392 let (qself, path) = fld.fold_qpath(qself, path);
393 TyKind::Path(qself, path)
395 TyKind::Array(ty, length) => {
396 TyKind::Array(fld.fold_ty(ty), fld.fold_anon_const(length))
398 TyKind::Typeof(expr) => {
399 TyKind::Typeof(fld.fold_anon_const(expr))
401 TyKind::TraitObject(bounds, syntax) => {
402 TyKind::TraitObject(bounds.move_map(|b| fld.fold_param_bound(b)), syntax)
404 TyKind::ImplTrait(id, bounds) => {
405 TyKind::ImplTrait(fld.new_id(id), bounds.move_map(|b| fld.fold_param_bound(b)))
407 TyKind::Mac(mac) => {
408 TyKind::Mac(fld.fold_mac(mac))
411 span: fld.new_span(span)
415 pub fn noop_fold_foreign_mod<T: Folder>(ForeignMod {abi, items}: ForeignMod,
416 fld: &mut T) -> ForeignMod {
419 items: items.move_flat_map(|x| fld.fold_foreign_item(x)),
423 pub fn noop_fold_global_asm<T: Folder>(ga: P<GlobalAsm>,
424 _: &mut T) -> P<GlobalAsm> {
428 pub fn noop_fold_variant<T: Folder>(v: Variant, fld: &mut T) -> Variant {
431 ident: fld.fold_ident(v.node.ident),
432 attrs: fold_attrs(v.node.attrs, fld),
433 data: fld.fold_variant_data(v.node.data),
434 disr_expr: v.node.disr_expr.map(|e| fld.fold_anon_const(e)),
436 span: fld.new_span(v.span),
440 pub fn noop_fold_ident<T: Folder>(ident: Ident, fld: &mut T) -> Ident {
441 Ident::new(ident.name, fld.new_span(ident.span))
444 pub fn noop_fold_usize<T: Folder>(i: usize, _: &mut T) -> usize {
448 pub fn noop_fold_path<T: Folder>(Path { segments, span }: Path, fld: &mut T) -> Path {
450 segments: segments.move_map(|PathSegment { ident, args }| PathSegment {
451 ident: fld.fold_ident(ident),
452 args: args.map(|args| args.map(|args| fld.fold_generic_args(args))),
454 span: fld.new_span(span)
458 pub fn noop_fold_qpath<T: Folder>(qself: Option<QSelf>,
460 fld: &mut T) -> (Option<QSelf>, Path) {
461 let qself = qself.map(|QSelf { ty, path_span, position }| {
464 path_span: fld.new_span(path_span),
468 (qself, fld.fold_path(path))
471 pub fn noop_fold_generic_args<T: Folder>(generic_args: GenericArgs, fld: &mut T) -> GenericArgs
474 GenericArgs::AngleBracketed(data) => {
475 GenericArgs::AngleBracketed(fld.fold_angle_bracketed_parameter_data(data))
477 GenericArgs::Parenthesized(data) => {
478 GenericArgs::Parenthesized(fld.fold_parenthesized_parameter_data(data))
483 pub fn noop_fold_angle_bracketed_parameter_data<T: Folder>(data: AngleBracketedArgs,
485 -> AngleBracketedArgs
487 let AngleBracketedArgs { args, bindings, span } = data;
489 args: args.move_map(|arg| fld.fold_generic_arg(arg)),
490 bindings: bindings.move_map(|b| fld.fold_ty_binding(b)),
491 span: fld.new_span(span)
495 pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesisedArgs,
499 let ParenthesisedArgs { inputs, output, span } = data;
501 inputs: inputs.move_map(|ty| fld.fold_ty(ty)),
502 output: output.map(|ty| fld.fold_ty(ty)),
503 span: fld.new_span(span)
507 pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
508 l.map(|Local {id, pat, ty, init, span, attrs}| Local {
510 pat: fld.fold_pat(pat),
511 ty: ty.map(|t| fld.fold_ty(t)),
512 init: init.map(|e| fld.fold_expr(e)),
513 span: fld.new_span(span),
514 attrs: fold_attrs(attrs.into(), fld).into(),
518 pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<Attribute> {
522 path: fld.fold_path(attr.path),
523 tokens: fld.fold_tts(attr.tokens),
524 is_sugared_doc: attr.is_sugared_doc,
525 span: fld.new_span(attr.span),
529 pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
532 tts: fld.fold_tts(node.stream()).into(),
533 path: fld.fold_path(node.path),
536 span: fld.new_span(span)
540 pub fn noop_fold_macro_def<T: Folder>(def: MacroDef, fld: &mut T) -> MacroDef {
542 tokens: fld.fold_tts(def.tokens.into()).into(),
547 pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
550 node: match li.node {
551 NestedMetaItemKind::MetaItem(mi) => {
552 NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
554 NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
556 span: fld.new_span(li.span)
560 pub fn noop_fold_meta_item<T: Folder>(mi: MetaItem, fld: &mut T) -> MetaItem {
563 node: match mi.node {
564 MetaItemKind::Word => MetaItemKind::Word,
565 MetaItemKind::List(mis) => {
566 MetaItemKind::List(mis.move_map(|e| fld.fold_meta_list_item(e)))
568 MetaItemKind::NameValue(s) => MetaItemKind::NameValue(s),
570 span: fld.new_span(mi.span)
574 pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg {
577 pat: fld.fold_pat(pat),
582 pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree {
584 TokenTree::Token(span, tok) =>
585 TokenTree::Token(fld.new_span(span), fld.fold_token(tok)),
586 TokenTree::Delimited(span, delimed) => TokenTree::Delimited(fld.new_span(span), Delimited {
587 tts: fld.fold_tts(delimed.stream()).into(),
588 delim: delimed.delim,
593 pub fn noop_fold_tts<T: Folder>(tts: TokenStream, fld: &mut T) -> TokenStream {
594 tts.map(|tt| fld.fold_tt(tt))
597 // apply ident folder if it's an ident, apply other folds to interpolated nodes
598 pub fn noop_fold_token<T: Folder>(t: token::Token, fld: &mut T) -> token::Token {
600 token::Ident(id, is_raw) => token::Ident(fld.fold_ident(id), is_raw),
601 token::Lifetime(id) => token::Lifetime(fld.fold_ident(id)),
602 token::Interpolated(nt) => {
603 let nt = match Lrc::try_unwrap(nt) {
605 Err(nt) => (*nt).clone(),
607 Token::interpolated(fld.fold_interpolated(nt.0))
613 /// apply folder to elements of interpolated nodes
615 // NB: this can occur only when applying a fold to partially expanded code, where
616 // parsed pieces have gotten implanted ito *other* macro invocations. This is relevant
617 // for macro hygiene, but possibly not elsewhere.
619 // One problem here occurs because the types for fold_item, fold_stmt, etc. allow the
620 // folder to return *multiple* items; this is a problem for the nodes here, because
621 // they insist on having exactly one piece. One solution would be to mangle the fold
622 // trait to include one-to-many and one-to-one versions of these entry points, but that
623 // would probably confuse a lot of people and help very few. Instead, I'm just going
624 // to put in dynamic checks. I think the performance impact of this will be pretty much
625 // nonexistent. The danger is that someone will apply a fold to a partially expanded
626 // node, and will be confused by the fact that their "fold_item" or "fold_stmt" isn't
627 // getting called on NtItem or NtStmt nodes. Hopefully they'll wind up reading this
628 // comment, and doing something appropriate.
630 // BTW, design choice: I considered just changing the type of, e.g., NtItem to contain
631 // multiple items, but decided against it when I looked at parse_item_or_view_item and
632 // tried to figure out what I would do with multiple items there....
633 pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
634 -> token::Nonterminal {
636 token::NtItem(item) =>
637 token::NtItem(fld.fold_item(item)
638 // this is probably okay, because the only folds likely
639 // to peek inside interpolated nodes will be renamings/markings,
640 // which map single items to single items
641 .expect_one("expected fold to produce exactly one item")),
642 token::NtBlock(block) => token::NtBlock(fld.fold_block(block)),
643 token::NtStmt(stmt) =>
644 token::NtStmt(fld.fold_stmt(stmt)
645 // this is probably okay, because the only folds likely
646 // to peek inside interpolated nodes will be renamings/markings,
647 // which map single items to single items
648 .expect_one("expected fold to produce exactly one statement")),
649 token::NtPat(pat) => token::NtPat(fld.fold_pat(pat)),
650 token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)),
651 token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)),
652 token::NtIdent(ident, is_raw) => token::NtIdent(fld.fold_ident(ident), is_raw),
653 token::NtLifetime(ident) => token::NtLifetime(fld.fold_ident(ident)),
654 token::NtLiteral(expr) => token::NtLiteral(fld.fold_expr(expr)),
655 token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)),
656 token::NtPath(path) => token::NtPath(fld.fold_path(path)),
657 token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)),
658 token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
659 token::NtImplItem(item) =>
660 token::NtImplItem(fld.fold_impl_item(item)
661 .expect_one("expected fold to produce exactly one item")),
662 token::NtTraitItem(item) =>
663 token::NtTraitItem(fld.fold_trait_item(item)
664 .expect_one("expected fold to produce exactly one item")),
665 token::NtGenerics(generics) => token::NtGenerics(fld.fold_generics(generics)),
666 token::NtWhereClause(where_clause) =>
667 token::NtWhereClause(fld.fold_where_clause(where_clause)),
668 token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)),
669 token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)),
670 token::NtForeignItem(ni) =>
671 token::NtForeignItem(fld.fold_foreign_item(ni)
672 // see reasoning above
673 .expect_one("expected fold to produce exactly one item")),
677 pub fn noop_fold_asyncness<T: Folder>(asyncness: IsAsync, fld: &mut T) -> IsAsync {
679 IsAsync::Async { closure_id, return_impl_trait_id } => IsAsync::Async {
680 closure_id: fld.new_id(closure_id),
681 return_impl_trait_id: fld.new_id(return_impl_trait_id),
683 IsAsync::NotAsync => IsAsync::NotAsync,
687 pub fn noop_fold_fn_decl<T: Folder>(decl: P<FnDecl>, fld: &mut T) -> P<FnDecl> {
688 decl.map(|FnDecl {inputs, output, variadic}| FnDecl {
689 inputs: inputs.move_map(|x| fld.fold_arg(x)),
690 output: match output {
691 FunctionRetTy::Ty(ty) => FunctionRetTy::Ty(fld.fold_ty(ty)),
692 FunctionRetTy::Default(span) => FunctionRetTy::Default(fld.new_span(span)),
698 pub fn noop_fold_param_bound<T>(pb: GenericBound, fld: &mut T) -> GenericBound where T: Folder {
700 GenericBound::Trait(ty, modifier) => {
701 GenericBound::Trait(fld.fold_poly_trait_ref(ty), modifier)
703 GenericBound::Outlives(lifetime) => {
704 GenericBound::Outlives(noop_fold_lifetime(lifetime, fld))
709 pub fn noop_fold_generic_param<T: Folder>(param: GenericParam, fld: &mut T) -> GenericParam {
710 let attrs: Vec<_> = param.attrs.into();
712 ident: fld.fold_ident(param.ident),
713 id: fld.new_id(param.id),
714 attrs: attrs.into_iter()
715 .flat_map(|x| fld.fold_attribute(x).into_iter())
718 bounds: param.bounds.move_map(|l| noop_fold_param_bound(l, fld)),
719 kind: match param.kind {
720 GenericParamKind::Lifetime => GenericParamKind::Lifetime,
721 GenericParamKind::Type { default } => GenericParamKind::Type {
722 default: default.map(|ty| fld.fold_ty(ty))
728 pub fn noop_fold_generic_params<T: Folder>(
729 params: Vec<GenericParam>,
731 ) -> Vec<GenericParam> {
732 params.move_map(|p| fld.fold_generic_param(p))
735 pub fn noop_fold_label<T: Folder>(label: Label, fld: &mut T) -> Label {
737 ident: fld.fold_ident(label.ident),
741 fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
743 id: fld.new_id(l.id),
744 ident: fld.fold_ident(l.ident),
748 pub fn noop_fold_generics<T: Folder>(Generics { params, where_clause, span }: Generics,
749 fld: &mut T) -> Generics {
751 params: fld.fold_generic_params(params),
752 where_clause: fld.fold_where_clause(where_clause),
753 span: fld.new_span(span),
757 pub fn noop_fold_where_clause<T: Folder>(
758 WhereClause {id, predicates, span}: WhereClause,
763 predicates: predicates.move_map(|predicate| {
764 fld.fold_where_predicate(predicate)
770 pub fn noop_fold_where_predicate<T: Folder>(
771 pred: WherePredicate,
775 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{bound_generic_params,
779 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
780 bound_generic_params: fld.fold_generic_params(bound_generic_params),
781 bounded_ty: fld.fold_ty(bounded_ty),
782 bounds: bounds.move_map(|x| fld.fold_param_bound(x)),
783 span: fld.new_span(span)
786 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime,
789 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
790 span: fld.new_span(span),
791 lifetime: noop_fold_lifetime(lifetime, fld),
792 bounds: bounds.move_map(|bound| noop_fold_param_bound(bound, fld))
795 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
799 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{
801 lhs_ty: fld.fold_ty(lhs_ty),
802 rhs_ty: fld.fold_ty(rhs_ty),
803 span: fld.new_span(span)
809 pub fn noop_fold_variant_data<T: Folder>(vdata: VariantData, fld: &mut T) -> VariantData {
811 ast::VariantData::Struct(fields, id) => {
812 ast::VariantData::Struct(fields.move_map(|f| fld.fold_struct_field(f)),
815 ast::VariantData::Tuple(fields, id) => {
816 ast::VariantData::Tuple(fields.move_map(|f| fld.fold_struct_field(f)),
819 ast::VariantData::Unit(id) => ast::VariantData::Unit(fld.new_id(id))
823 pub fn noop_fold_trait_ref<T: Folder>(p: TraitRef, fld: &mut T) -> TraitRef {
824 let id = fld.new_id(p.ref_id);
830 path: fld.fold_path(path),
835 pub fn noop_fold_poly_trait_ref<T: Folder>(p: PolyTraitRef, fld: &mut T) -> PolyTraitRef {
837 bound_generic_params: fld.fold_generic_params(p.bound_generic_params),
838 trait_ref: fld.fold_trait_ref(p.trait_ref),
839 span: fld.new_span(p.span),
843 pub fn noop_fold_struct_field<T: Folder>(f: StructField, fld: &mut T) -> StructField {
845 span: fld.new_span(f.span),
846 id: fld.new_id(f.id),
847 ident: f.ident.map(|ident| fld.fold_ident(ident)),
848 vis: fld.fold_vis(f.vis),
849 ty: fld.fold_ty(f.ty),
850 attrs: fold_attrs(f.attrs, fld),
854 pub fn noop_fold_field<T: Folder>(f: Field, folder: &mut T) -> Field {
856 ident: folder.fold_ident(f.ident),
857 expr: folder.fold_expr(f.expr),
858 span: folder.new_span(f.span),
859 is_shorthand: f.is_shorthand,
860 attrs: fold_thin_attrs(f.attrs, folder),
864 pub fn noop_fold_mt<T: Folder>(MutTy {ty, mutbl}: MutTy, folder: &mut T) -> MutTy {
866 ty: folder.fold_ty(ty),
871 pub fn noop_fold_opt_bounds<T: Folder>(b: Option<GenericBounds>, folder: &mut T)
872 -> Option<GenericBounds> {
873 b.map(|bounds| folder.fold_bounds(bounds))
876 fn noop_fold_bounds<T: Folder>(bounds: GenericBounds, folder: &mut T)
878 bounds.move_map(|bound| folder.fold_param_bound(bound))
881 pub fn noop_fold_block<T: Folder>(b: P<Block>, folder: &mut T) -> P<Block> {
882 b.map(|Block {id, stmts, rules, span, recovered}| Block {
883 id: folder.new_id(id),
884 stmts: stmts.move_flat_map(|s| folder.fold_stmt(s).into_iter()),
886 span: folder.new_span(span),
891 pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
893 ItemKind::ExternCrate(orig_name) => ItemKind::ExternCrate(orig_name),
894 ItemKind::Use(use_tree) => {
895 ItemKind::Use(use_tree.map(|tree| folder.fold_use_tree(tree)))
897 ItemKind::Static(t, m, e) => {
898 ItemKind::Static(folder.fold_ty(t), m, folder.fold_expr(e))
900 ItemKind::Const(t, e) => {
901 ItemKind::Const(folder.fold_ty(t), folder.fold_expr(e))
903 ItemKind::Fn(decl, header, generics, body) => {
904 let generics = folder.fold_generics(generics);
905 let header = folder.fold_fn_header(header);
906 let decl = folder.fold_fn_decl(decl);
907 let body = folder.fold_block(body);
908 ItemKind::Fn(decl, header, generics, body)
910 ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)),
911 ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)),
912 ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)),
913 ItemKind::Ty(t, generics) => {
914 ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics))
916 ItemKind::Existential(bounds, generics) => ItemKind::Existential(
917 folder.fold_bounds(bounds),
918 folder.fold_generics(generics),
920 ItemKind::Enum(enum_definition, generics) => {
921 let generics = folder.fold_generics(generics);
922 let variants = enum_definition.variants.move_map(|x| folder.fold_variant(x));
923 ItemKind::Enum(ast::EnumDef { variants: variants }, generics)
925 ItemKind::Struct(struct_def, generics) => {
926 let generics = folder.fold_generics(generics);
927 ItemKind::Struct(folder.fold_variant_data(struct_def), generics)
929 ItemKind::Union(struct_def, generics) => {
930 let generics = folder.fold_generics(generics);
931 ItemKind::Union(folder.fold_variant_data(struct_def), generics)
933 ItemKind::Impl(unsafety,
939 impl_items) => ItemKind::Impl(
943 folder.fold_generics(generics),
944 ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref.clone())),
946 impl_items.move_flat_map(|item| folder.fold_impl_item(item)),
948 ItemKind::Trait(is_auto, unsafety, generics, bounds, items) => ItemKind::Trait(
951 folder.fold_generics(generics),
952 folder.fold_bounds(bounds),
953 items.move_flat_map(|item| folder.fold_trait_item(item)),
955 ItemKind::TraitAlias(generics, bounds) => ItemKind::TraitAlias(
956 folder.fold_generics(generics),
957 folder.fold_bounds(bounds)),
958 ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)),
959 ItemKind::MacroDef(def) => ItemKind::MacroDef(folder.fold_macro_def(def)),
963 pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T)
964 -> OneVector<TraitItem> {
965 OneVector::one(TraitItem {
966 id: folder.new_id(i.id),
967 ident: folder.fold_ident(i.ident),
968 attrs: fold_attrs(i.attrs, folder),
969 generics: folder.fold_generics(i.generics),
971 TraitItemKind::Const(ty, default) => {
972 TraitItemKind::Const(folder.fold_ty(ty),
973 default.map(|x| folder.fold_expr(x)))
975 TraitItemKind::Method(sig, body) => {
976 TraitItemKind::Method(noop_fold_method_sig(sig, folder),
977 body.map(|x| folder.fold_block(x)))
979 TraitItemKind::Type(bounds, default) => {
980 TraitItemKind::Type(folder.fold_bounds(bounds),
981 default.map(|x| folder.fold_ty(x)))
983 ast::TraitItemKind::Macro(mac) => {
984 TraitItemKind::Macro(folder.fold_mac(mac))
987 span: folder.new_span(i.span),
992 pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T)
993 -> OneVector<ImplItem> {
994 OneVector::one(ImplItem {
995 id: folder.new_id(i.id),
996 vis: folder.fold_vis(i.vis),
997 ident: folder.fold_ident(i.ident),
998 attrs: fold_attrs(i.attrs, folder),
999 generics: folder.fold_generics(i.generics),
1000 defaultness: i.defaultness,
1001 node: match i.node {
1002 ast::ImplItemKind::Const(ty, expr) => {
1003 ast::ImplItemKind::Const(folder.fold_ty(ty), folder.fold_expr(expr))
1005 ast::ImplItemKind::Method(sig, body) => {
1006 ast::ImplItemKind::Method(noop_fold_method_sig(sig, folder),
1007 folder.fold_block(body))
1009 ast::ImplItemKind::Type(ty) => ast::ImplItemKind::Type(folder.fold_ty(ty)),
1010 ast::ImplItemKind::Existential(bounds) => {
1011 ast::ImplItemKind::Existential(folder.fold_bounds(bounds))
1013 ast::ImplItemKind::Macro(mac) => ast::ImplItemKind::Macro(folder.fold_mac(mac))
1015 span: folder.new_span(i.span),
1020 pub fn noop_fold_fn_header<T: Folder>(mut header: FnHeader, folder: &mut T) -> FnHeader {
1021 header.asyncness = folder.fold_asyncness(header.asyncness);
1025 pub fn noop_fold_mod<T: Folder>(Mod {inner, items}: Mod, folder: &mut T) -> Mod {
1027 inner: folder.new_span(inner),
1028 items: items.move_flat_map(|x| folder.fold_item(x)),
1032 pub fn noop_fold_crate<T: Folder>(Crate {module, attrs, span}: Crate,
1033 folder: &mut T) -> Crate {
1034 let mut items = folder.fold_item(P(ast::Item {
1035 ident: keywords::Invalid.ident(),
1037 id: ast::DUMMY_NODE_ID,
1038 vis: respan(span.shrink_to_lo(), ast::VisibilityKind::Public),
1040 node: ast::ItemKind::Mod(module),
1044 let (module, attrs, span) = match items.next() {
1046 assert!(items.next().is_none(),
1047 "a crate cannot expand to more than one item");
1048 item.and_then(|ast::Item { attrs, span, node, .. }| {
1050 ast::ItemKind::Mod(m) => (m, attrs, span),
1051 _ => panic!("fold converted a module to not a module"),
1068 // fold one item into possibly many items
1069 pub fn noop_fold_item<T: Folder>(i: P<Item>, folder: &mut T) -> OneVector<P<Item>> {
1070 OneVector::one(i.map(|i| folder.fold_item_simple(i)))
1073 // fold one item into exactly one item
1074 pub fn noop_fold_item_simple<T: Folder>(Item {id, ident, attrs, node, vis, span, tokens}: Item,
1075 folder: &mut T) -> Item {
1077 id: folder.new_id(id),
1078 vis: folder.fold_vis(vis),
1079 ident: folder.fold_ident(ident),
1080 attrs: fold_attrs(attrs, folder),
1081 node: folder.fold_item_kind(node),
1082 span: folder.new_span(span),
1084 // FIXME: if this is replaced with a call to `folder.fold_tts` it causes
1085 // an ICE during resolve... odd!
1090 pub fn noop_fold_foreign_item<T: Folder>(ni: ForeignItem, folder: &mut T)
1091 -> OneVector<ForeignItem> {
1092 OneVector::one(folder.fold_foreign_item_simple(ni))
1095 pub fn noop_fold_foreign_item_simple<T: Folder>(ni: ForeignItem, folder: &mut T) -> ForeignItem {
1097 id: folder.new_id(ni.id),
1098 vis: folder.fold_vis(ni.vis),
1099 ident: folder.fold_ident(ni.ident),
1100 attrs: fold_attrs(ni.attrs, folder),
1101 node: match ni.node {
1102 ForeignItemKind::Fn(fdec, generics) => {
1103 ForeignItemKind::Fn(folder.fold_fn_decl(fdec), folder.fold_generics(generics))
1105 ForeignItemKind::Static(t, m) => {
1106 ForeignItemKind::Static(folder.fold_ty(t), m)
1108 ForeignItemKind::Ty => ForeignItemKind::Ty,
1109 ForeignItemKind::Macro(mac) => ForeignItemKind::Macro(folder.fold_mac(mac)),
1111 span: folder.new_span(ni.span)
1115 pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig {
1117 header: folder.fold_fn_header(sig.header),
1118 decl: folder.fold_fn_decl(sig.decl)
1122 pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
1123 p.map(|Pat {id, node, span}| Pat {
1124 id: folder.new_id(id),
1126 PatKind::Wild => PatKind::Wild,
1127 PatKind::Ident(binding_mode, ident, sub) => {
1128 PatKind::Ident(binding_mode,
1129 folder.fold_ident(ident),
1130 sub.map(|x| folder.fold_pat(x)))
1132 PatKind::Lit(e) => PatKind::Lit(folder.fold_expr(e)),
1133 PatKind::TupleStruct(pth, pats, ddpos) => {
1134 PatKind::TupleStruct(folder.fold_path(pth),
1135 pats.move_map(|x| folder.fold_pat(x)), ddpos)
1137 PatKind::Path(qself, pth) => {
1138 let (qself, pth) = folder.fold_qpath(qself, pth);
1139 PatKind::Path(qself, pth)
1141 PatKind::Struct(pth, fields, etc) => {
1142 let pth = folder.fold_path(pth);
1143 let fs = fields.move_map(|f| {
1144 Spanned { span: folder.new_span(f.span),
1145 node: ast::FieldPat {
1146 ident: folder.fold_ident(f.node.ident),
1147 pat: folder.fold_pat(f.node.pat),
1148 is_shorthand: f.node.is_shorthand,
1149 attrs: fold_attrs(f.node.attrs.into(), folder).into()
1152 PatKind::Struct(pth, fs, etc)
1154 PatKind::Tuple(elts, ddpos) => {
1155 PatKind::Tuple(elts.move_map(|x| folder.fold_pat(x)), ddpos)
1157 PatKind::Box(inner) => PatKind::Box(folder.fold_pat(inner)),
1158 PatKind::Ref(inner, mutbl) => PatKind::Ref(folder.fold_pat(inner), mutbl),
1159 PatKind::Range(e1, e2, Spanned { span, node: end }) => {
1160 PatKind::Range(folder.fold_expr(e1),
1161 folder.fold_expr(e2),
1162 Spanned { span, node: folder.fold_range_end(end) })
1164 PatKind::Slice(before, slice, after) => {
1165 PatKind::Slice(before.move_map(|x| folder.fold_pat(x)),
1166 slice.map(|x| folder.fold_pat(x)),
1167 after.move_map(|x| folder.fold_pat(x)))
1169 PatKind::Paren(inner) => PatKind::Paren(folder.fold_pat(inner)),
1170 PatKind::Mac(mac) => PatKind::Mac(folder.fold_mac(mac))
1172 span: folder.new_span(span)
1176 pub fn noop_fold_range_end<T: Folder>(end: RangeEnd, _folder: &mut T) -> RangeEnd {
1180 pub fn noop_fold_anon_const<T: Folder>(constant: AnonConst, folder: &mut T) -> AnonConst {
1181 let AnonConst {id, value} = constant;
1183 id: folder.new_id(id),
1184 value: folder.fold_expr(value),
1188 pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mut T) -> Expr {
1191 ExprKind::Box(e) => {
1192 ExprKind::Box(folder.fold_expr(e))
1194 ExprKind::ObsoleteInPlace(a, b) => {
1195 ExprKind::ObsoleteInPlace(folder.fold_expr(a), folder.fold_expr(b))
1197 ExprKind::Array(exprs) => {
1198 ExprKind::Array(folder.fold_exprs(exprs))
1200 ExprKind::Repeat(expr, count) => {
1201 ExprKind::Repeat(folder.fold_expr(expr), folder.fold_anon_const(count))
1203 ExprKind::Tup(exprs) => ExprKind::Tup(folder.fold_exprs(exprs)),
1204 ExprKind::Call(f, args) => {
1205 ExprKind::Call(folder.fold_expr(f),
1206 folder.fold_exprs(args))
1208 ExprKind::MethodCall(seg, args) => {
1209 ExprKind::MethodCall(
1211 ident: folder.fold_ident(seg.ident),
1212 args: seg.args.map(|args| {
1213 args.map(|args| folder.fold_generic_args(args))
1216 folder.fold_exprs(args))
1218 ExprKind::Binary(binop, lhs, rhs) => {
1219 ExprKind::Binary(binop,
1220 folder.fold_expr(lhs),
1221 folder.fold_expr(rhs))
1223 ExprKind::Unary(binop, ohs) => {
1224 ExprKind::Unary(binop, folder.fold_expr(ohs))
1226 ExprKind::Lit(l) => ExprKind::Lit(l),
1227 ExprKind::Cast(expr, ty) => {
1228 ExprKind::Cast(folder.fold_expr(expr), folder.fold_ty(ty))
1230 ExprKind::Type(expr, ty) => {
1231 ExprKind::Type(folder.fold_expr(expr), folder.fold_ty(ty))
1233 ExprKind::AddrOf(m, ohs) => ExprKind::AddrOf(m, folder.fold_expr(ohs)),
1234 ExprKind::If(cond, tr, fl) => {
1235 ExprKind::If(folder.fold_expr(cond),
1236 folder.fold_block(tr),
1237 fl.map(|x| folder.fold_expr(x)))
1239 ExprKind::IfLet(pats, expr, tr, fl) => {
1240 ExprKind::IfLet(pats.move_map(|pat| folder.fold_pat(pat)),
1241 folder.fold_expr(expr),
1242 folder.fold_block(tr),
1243 fl.map(|x| folder.fold_expr(x)))
1245 ExprKind::While(cond, body, opt_label) => {
1246 ExprKind::While(folder.fold_expr(cond),
1247 folder.fold_block(body),
1248 opt_label.map(|label| folder.fold_label(label)))
1250 ExprKind::WhileLet(pats, expr, body, opt_label) => {
1251 ExprKind::WhileLet(pats.move_map(|pat| folder.fold_pat(pat)),
1252 folder.fold_expr(expr),
1253 folder.fold_block(body),
1254 opt_label.map(|label| folder.fold_label(label)))
1256 ExprKind::ForLoop(pat, iter, body, opt_label) => {
1257 ExprKind::ForLoop(folder.fold_pat(pat),
1258 folder.fold_expr(iter),
1259 folder.fold_block(body),
1260 opt_label.map(|label| folder.fold_label(label)))
1262 ExprKind::Loop(body, opt_label) => {
1263 ExprKind::Loop(folder.fold_block(body),
1264 opt_label.map(|label| folder.fold_label(label)))
1266 ExprKind::Match(expr, arms) => {
1267 ExprKind::Match(folder.fold_expr(expr),
1268 arms.move_map(|x| folder.fold_arm(x)))
1270 ExprKind::Closure(capture_clause, asyncness, movability, decl, body, span) => {
1271 ExprKind::Closure(capture_clause,
1272 folder.fold_asyncness(asyncness),
1274 folder.fold_fn_decl(decl),
1275 folder.fold_expr(body),
1276 folder.new_span(span))
1278 ExprKind::Block(blk, opt_label) => {
1279 ExprKind::Block(folder.fold_block(blk),
1280 opt_label.map(|label| folder.fold_label(label)))
1282 ExprKind::Async(capture_clause, node_id, body) => {
1285 folder.new_id(node_id),
1286 folder.fold_block(body),
1289 ExprKind::Assign(el, er) => {
1290 ExprKind::Assign(folder.fold_expr(el), folder.fold_expr(er))
1292 ExprKind::AssignOp(op, el, er) => {
1293 ExprKind::AssignOp(op,
1294 folder.fold_expr(el),
1295 folder.fold_expr(er))
1297 ExprKind::Field(el, ident) => {
1298 ExprKind::Field(folder.fold_expr(el), folder.fold_ident(ident))
1300 ExprKind::Index(el, er) => {
1301 ExprKind::Index(folder.fold_expr(el), folder.fold_expr(er))
1303 ExprKind::Range(e1, e2, lim) => {
1304 ExprKind::Range(e1.map(|x| folder.fold_expr(x)),
1305 e2.map(|x| folder.fold_expr(x)),
1308 ExprKind::Path(qself, path) => {
1309 let (qself, path) = folder.fold_qpath(qself, path);
1310 ExprKind::Path(qself, path)
1312 ExprKind::Break(opt_label, opt_expr) => {
1313 ExprKind::Break(opt_label.map(|label| folder.fold_label(label)),
1314 opt_expr.map(|e| folder.fold_expr(e)))
1316 ExprKind::Continue(opt_label) => {
1317 ExprKind::Continue(opt_label.map(|label| folder.fold_label(label)))
1319 ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
1320 ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
1322 inputs: asm.inputs.move_map(|(c, input)| {
1323 (c, folder.fold_expr(input))
1325 outputs: asm.outputs.move_map(|out| {
1327 constraint: out.constraint,
1328 expr: folder.fold_expr(out.expr),
1330 is_indirect: out.is_indirect,
1336 ExprKind::Mac(mac) => ExprKind::Mac(folder.fold_mac(mac)),
1337 ExprKind::Struct(path, fields, maybe_expr) => {
1338 ExprKind::Struct(folder.fold_path(path),
1339 fields.move_map(|x| folder.fold_field(x)),
1340 maybe_expr.map(|x| folder.fold_expr(x)))
1342 ExprKind::Paren(ex) => {
1343 let sub_expr = folder.fold_expr(ex);
1345 // Nodes that are equal modulo `Paren` sugar no-ops should have the same ids.
1347 node: ExprKind::Paren(sub_expr),
1348 span: folder.new_span(span),
1349 attrs: fold_attrs(attrs.into(), folder).into(),
1352 ExprKind::Yield(ex) => ExprKind::Yield(ex.map(|x| folder.fold_expr(x))),
1353 ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)),
1354 ExprKind::Catch(body) => ExprKind::Catch(folder.fold_block(body)),
1356 id: folder.new_id(id),
1357 span: folder.new_span(span),
1358 attrs: fold_attrs(attrs.into(), folder).into(),
1362 pub fn noop_fold_opt_expr<T: Folder>(e: P<Expr>, folder: &mut T) -> Option<P<Expr>> {
1363 Some(folder.fold_expr(e))
1366 pub fn noop_fold_exprs<T: Folder>(es: Vec<P<Expr>>, folder: &mut T) -> Vec<P<Expr>> {
1367 es.move_flat_map(|e| folder.fold_opt_expr(e))
1370 pub fn noop_fold_stmt<T: Folder>(Stmt {node, span, id}: Stmt, folder: &mut T) -> OneVector<Stmt> {
1371 let id = folder.new_id(id);
1372 let span = folder.new_span(span);
1373 noop_fold_stmt_kind(node, folder).into_iter().map(|node| {
1374 Stmt { id: id, node: node, span: span }
1378 pub fn noop_fold_stmt_kind<T: Folder>(node: StmtKind, folder: &mut T) -> OneVector<StmtKind> {
1380 StmtKind::Local(local) => OneVector::one(StmtKind::Local(folder.fold_local(local))),
1381 StmtKind::Item(item) => folder.fold_item(item).into_iter().map(StmtKind::Item).collect(),
1382 StmtKind::Expr(expr) => {
1383 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Expr).collect()
1385 StmtKind::Semi(expr) => {
1386 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Semi).collect()
1388 StmtKind::Mac(mac) => OneVector::one(StmtKind::Mac(mac.map(|(mac, semi, attrs)| {
1389 (folder.fold_mac(mac), semi, fold_attrs(attrs.into(), folder).into())
1394 pub fn noop_fold_vis<T: Folder>(vis: Visibility, folder: &mut T) -> Visibility {
1396 VisibilityKind::Restricted { path, id } => {
1397 respan(vis.span, VisibilityKind::Restricted {
1398 path: path.map(|path| folder.fold_path(path)),
1399 id: folder.new_id(id),
1409 use ast::{self, Ident};
1410 use util::parser_testing::{string_to_crate, matches_codepattern};
1416 // this version doesn't care about getting comments or docstrings in.
1417 fn fake_print_crate(s: &mut pprust::State,
1418 krate: &ast::Crate) -> io::Result<()> {
1419 s.print_mod(&krate.module, &krate.attrs)
1422 // change every identifier to "zz"
1423 struct ToZzIdentFolder;
1425 impl Folder for ToZzIdentFolder {
1426 fn fold_ident(&mut self, _: ast::Ident) -> ast::Ident {
1427 Ident::from_str("zz")
1429 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1430 fold::noop_fold_mac(mac, self)
1434 // maybe add to expand.rs...
1435 macro_rules! assert_pred {
1436 ($pred:expr, $predname:expr, $a:expr , $b:expr) => (
1438 let pred_val = $pred;
1441 if !(pred_val(&a_val, &b_val)) {
1442 panic!("expected args satisfying {}, got {} and {}",
1443 $predname, a_val, b_val);
1449 // make sure idents get transformed everywhere
1450 #[test] fn ident_transformation () {
1452 let mut zz_fold = ToZzIdentFolder;
1453 let ast = string_to_crate(
1454 "#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string());
1455 let folded_crate = zz_fold.fold_crate(ast);
1457 matches_codepattern,
1458 "matches_codepattern",
1459 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1460 "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
1464 // even inside macro defs....
1465 #[test] fn ident_transformation_in_defs () {
1467 let mut zz_fold = ToZzIdentFolder;
1468 let ast = string_to_crate(
1469 "macro_rules! a {(b $c:expr $(d $e:token)f+ => \
1470 (g $(d $d $e)+))} ".to_string());
1471 let folded_crate = zz_fold.fold_crate(ast);
1473 matches_codepattern,
1474 "matches_codepattern",
1475 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1476 "macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string());