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};
29 use util::small_vector::SmallVector;
30 use util::move_map::MoveMap;
34 pub trait Folder : Sized {
35 // Any additions to this trait should happen in form
36 // of a call to a public `noop_*` function that only calls
37 // out to the folder again, not other `noop_*` functions.
39 // This is a necessary API workaround to the problem of not
40 // being able to call out to the super default method
41 // in an overridden default method.
43 fn fold_crate(&mut self, c: Crate) -> Crate {
44 noop_fold_crate(c, self)
47 fn fold_meta_items(&mut self, meta_items: Vec<MetaItem>) -> Vec<MetaItem> {
48 noop_fold_meta_items(meta_items, self)
51 fn fold_meta_list_item(&mut self, list_item: NestedMetaItem) -> NestedMetaItem {
52 noop_fold_meta_list_item(list_item, self)
55 fn fold_meta_item(&mut self, meta_item: MetaItem) -> MetaItem {
56 noop_fold_meta_item(meta_item, self)
59 fn fold_view_path(&mut self, view_path: P<ViewPath>) -> P<ViewPath> {
60 noop_fold_view_path(view_path, self)
63 fn fold_foreign_item(&mut self, ni: ForeignItem) -> ForeignItem {
64 noop_fold_foreign_item(ni, self)
67 fn fold_item(&mut self, i: P<Item>) -> SmallVector<P<Item>> {
68 noop_fold_item(i, self)
71 fn fold_item_simple(&mut self, i: Item) -> Item {
72 noop_fold_item_simple(i, self)
75 fn fold_struct_field(&mut self, sf: StructField) -> StructField {
76 noop_fold_struct_field(sf, self)
79 fn fold_item_kind(&mut self, i: ItemKind) -> ItemKind {
80 noop_fold_item_kind(i, self)
83 fn fold_trait_item(&mut self, i: TraitItem) -> SmallVector<TraitItem> {
84 noop_fold_trait_item(i, self)
87 fn fold_impl_item(&mut self, i: ImplItem) -> SmallVector<ImplItem> {
88 noop_fold_impl_item(i, self)
91 fn fold_fn_decl(&mut self, d: P<FnDecl>) -> P<FnDecl> {
92 noop_fold_fn_decl(d, self)
95 fn fold_block(&mut self, b: P<Block>) -> P<Block> {
96 noop_fold_block(b, self)
99 fn fold_stmt(&mut self, s: Stmt) -> SmallVector<Stmt> {
100 noop_fold_stmt(s, self)
103 fn fold_arm(&mut self, a: Arm) -> Arm {
104 noop_fold_arm(a, self)
107 fn fold_pat(&mut self, p: P<Pat>) -> P<Pat> {
108 noop_fold_pat(p, self)
111 fn fold_expr(&mut self, e: P<Expr>) -> P<Expr> {
112 e.map(|e| noop_fold_expr(e, self))
115 fn fold_range_end(&mut self, re: RangeEnd) -> RangeEnd {
116 noop_fold_range_end(re, self)
119 fn fold_opt_expr(&mut self, e: P<Expr>) -> Option<P<Expr>> {
120 noop_fold_opt_expr(e, self)
123 fn fold_exprs(&mut self, es: Vec<P<Expr>>) -> Vec<P<Expr>> {
124 noop_fold_exprs(es, self)
127 fn fold_ty(&mut self, t: P<Ty>) -> P<Ty> {
128 noop_fold_ty(t, self)
131 fn fold_ty_binding(&mut self, t: TypeBinding) -> TypeBinding {
132 noop_fold_ty_binding(t, self)
135 fn fold_mod(&mut self, m: Mod) -> Mod {
136 noop_fold_mod(m, self)
139 fn fold_foreign_mod(&mut self, nm: ForeignMod) -> ForeignMod {
140 noop_fold_foreign_mod(nm, self)
143 fn fold_global_asm(&mut self, ga: P<GlobalAsm>) -> P<GlobalAsm> {
144 noop_fold_global_asm(ga, self)
147 fn fold_variant(&mut self, v: Variant) -> Variant {
148 noop_fold_variant(v, self)
151 fn fold_ident(&mut self, i: Ident) -> Ident {
152 noop_fold_ident(i, self)
155 fn fold_usize(&mut self, i: usize) -> usize {
156 noop_fold_usize(i, self)
159 fn fold_path(&mut self, p: Path) -> Path {
160 noop_fold_path(p, self)
163 fn fold_path_parameters(&mut self, p: PathParameters) -> PathParameters {
164 noop_fold_path_parameters(p, self)
167 fn fold_angle_bracketed_parameter_data(&mut self, p: AngleBracketedParameterData)
168 -> AngleBracketedParameterData
170 noop_fold_angle_bracketed_parameter_data(p, self)
173 fn fold_parenthesized_parameter_data(&mut self, p: ParenthesizedParameterData)
174 -> ParenthesizedParameterData
176 noop_fold_parenthesized_parameter_data(p, self)
179 fn fold_local(&mut self, l: P<Local>) -> P<Local> {
180 noop_fold_local(l, self)
183 fn fold_mac(&mut self, _mac: Mac) -> Mac {
184 panic!("fold_mac disabled by default");
185 // NB: see note about macros above.
186 // if you really want a folder that
187 // works on macros, use this
188 // definition in your trait impl:
189 // fold::noop_fold_mac(_mac, self)
192 fn fold_macro_def(&mut self, def: MacroDef) -> MacroDef {
193 noop_fold_macro_def(def, self)
196 fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
197 noop_fold_lifetime(l, self)
200 fn fold_lifetime_def(&mut self, l: LifetimeDef) -> LifetimeDef {
201 noop_fold_lifetime_def(l, self)
204 fn fold_attribute(&mut self, at: Attribute) -> Option<Attribute> {
205 noop_fold_attribute(at, self)
208 fn fold_arg(&mut self, a: Arg) -> Arg {
209 noop_fold_arg(a, self)
212 fn fold_generics(&mut self, generics: Generics) -> Generics {
213 noop_fold_generics(generics, self)
216 fn fold_trait_ref(&mut self, p: TraitRef) -> TraitRef {
217 noop_fold_trait_ref(p, self)
220 fn fold_poly_trait_ref(&mut self, p: PolyTraitRef) -> PolyTraitRef {
221 noop_fold_poly_trait_ref(p, self)
224 fn fold_variant_data(&mut self, vdata: VariantData) -> VariantData {
225 noop_fold_variant_data(vdata, self)
228 fn fold_lifetimes(&mut self, lts: Vec<Lifetime>) -> Vec<Lifetime> {
229 noop_fold_lifetimes(lts, self)
232 fn fold_lifetime_defs(&mut self, lts: Vec<LifetimeDef>) -> Vec<LifetimeDef> {
233 noop_fold_lifetime_defs(lts, self)
236 fn fold_ty_param(&mut self, tp: TyParam) -> TyParam {
237 noop_fold_ty_param(tp, self)
240 fn fold_ty_params(&mut self, tps: Vec<TyParam>) -> Vec<TyParam> {
241 noop_fold_ty_params(tps, self)
244 fn fold_tt(&mut self, tt: TokenTree) -> TokenTree {
245 noop_fold_tt(tt, self)
248 fn fold_tts(&mut self, tts: TokenStream) -> TokenStream {
249 noop_fold_tts(tts, self)
252 fn fold_token(&mut self, t: token::Token) -> token::Token {
253 noop_fold_token(t, self)
256 fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal {
257 noop_fold_interpolated(nt, self)
260 fn fold_opt_lifetime(&mut self, o_lt: Option<Lifetime>) -> Option<Lifetime> {
261 noop_fold_opt_lifetime(o_lt, self)
264 fn fold_opt_bounds(&mut self, b: Option<TyParamBounds>)
265 -> Option<TyParamBounds> {
266 noop_fold_opt_bounds(b, self)
269 fn fold_bounds(&mut self, b: TyParamBounds)
271 noop_fold_bounds(b, self)
274 fn fold_ty_param_bound(&mut self, tpb: TyParamBound) -> TyParamBound {
275 noop_fold_ty_param_bound(tpb, self)
278 fn fold_mt(&mut self, mt: MutTy) -> MutTy {
279 noop_fold_mt(mt, self)
282 fn fold_field(&mut self, field: Field) -> Field {
283 noop_fold_field(field, self)
286 fn fold_where_clause(&mut self, where_clause: WhereClause)
288 noop_fold_where_clause(where_clause, self)
291 fn fold_where_predicate(&mut self, where_predicate: WherePredicate)
293 noop_fold_where_predicate(where_predicate, self)
296 fn fold_vis(&mut self, vis: Visibility) -> Visibility {
297 noop_fold_vis(vis, self)
300 fn new_id(&mut self, i: NodeId) -> NodeId {
304 fn new_span(&mut self, sp: Span) -> Span {
309 pub fn noop_fold_meta_items<T: Folder>(meta_items: Vec<MetaItem>, fld: &mut T) -> Vec<MetaItem> {
310 meta_items.move_map(|x| fld.fold_meta_item(x))
313 pub fn noop_fold_view_path<T: Folder>(view_path: P<ViewPath>, fld: &mut T) -> P<ViewPath> {
314 view_path.map(|Spanned {node, span}| Spanned {
316 ViewPathSimple(ident, path) => {
317 ViewPathSimple(fld.fold_ident(ident), fld.fold_path(path))
319 ViewPathGlob(path) => {
320 ViewPathGlob(fld.fold_path(path))
322 ViewPathList(path, path_list_idents) => {
323 let path = fld.fold_path(path);
324 let path_list_idents = path_list_idents.move_map(|path_list_ident| Spanned {
325 node: PathListItem_ {
326 id: fld.new_id(path_list_ident.node.id),
327 rename: path_list_ident.node.rename.map(|ident| fld.fold_ident(ident)),
328 name: fld.fold_ident(path_list_ident.node.name),
330 span: fld.new_span(path_list_ident.span)
332 ViewPathList(path, path_list_idents)
335 span: fld.new_span(span)
339 pub fn fold_attrs<T: Folder>(attrs: Vec<Attribute>, fld: &mut T) -> Vec<Attribute> {
340 attrs.move_flat_map(|x| fld.fold_attribute(x))
343 pub fn fold_thin_attrs<T: Folder>(attrs: ThinVec<Attribute>, fld: &mut T) -> ThinVec<Attribute> {
344 fold_attrs(attrs.into(), fld).into()
347 pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body}: Arm, fld: &mut T) -> Arm {
349 attrs: fold_attrs(attrs, fld),
350 pats: pats.move_map(|x| fld.fold_pat(x)),
351 guard: guard.map(|x| fld.fold_expr(x)),
352 body: fld.fold_expr(body),
356 pub fn noop_fold_ty_binding<T: Folder>(b: TypeBinding, fld: &mut T) -> TypeBinding {
358 id: fld.new_id(b.id),
359 ident: fld.fold_ident(b.ident),
360 ty: fld.fold_ty(b.ty),
361 span: fld.new_span(b.span),
365 pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> {
366 t.map(|Ty {id, node, span}| Ty {
369 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node,
370 TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)),
371 TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)),
372 TyKind::Rptr(region, mt) => {
373 TyKind::Rptr(fld.fold_opt_lifetime(region), fld.fold_mt(mt))
375 TyKind::BareFn(f) => {
376 TyKind::BareFn(f.map(|BareFnTy {lifetimes, unsafety, abi, decl}| BareFnTy {
377 lifetimes: fld.fold_lifetime_defs(lifetimes),
380 decl: fld.fold_fn_decl(decl)
383 TyKind::Never => node,
384 TyKind::Tup(tys) => TyKind::Tup(tys.move_map(|ty| fld.fold_ty(ty))),
385 TyKind::Paren(ty) => TyKind::Paren(fld.fold_ty(ty)),
386 TyKind::Path(qself, path) => {
387 let qself = qself.map(|QSelf { ty, position }| {
393 TyKind::Path(qself, fld.fold_path(path))
395 TyKind::Array(ty, e) => {
396 TyKind::Array(fld.fold_ty(ty), fld.fold_expr(e))
398 TyKind::Typeof(expr) => {
399 TyKind::Typeof(fld.fold_expr(expr))
401 TyKind::TraitObject(bounds) => {
402 TyKind::TraitObject(bounds.move_map(|b| fld.fold_ty_param_bound(b)))
404 TyKind::ImplTrait(bounds) => {
405 TyKind::ImplTrait(bounds.move_map(|b| fld.fold_ty_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_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 name: fld.fold_ident(v.node.name),
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_expr(e)),
436 span: fld.new_span(v.span),
440 pub fn noop_fold_ident<T: Folder>(i: Ident, _: &mut T) -> Ident {
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 {identifier, span, parameters}| PathSegment {
451 identifier: fld.fold_ident(identifier),
452 span: fld.new_span(span),
453 parameters: parameters.map(|ps| ps.map(|ps| fld.fold_path_parameters(ps))),
455 span: fld.new_span(span)
459 pub fn noop_fold_path_parameters<T: Folder>(path_parameters: PathParameters, fld: &mut T)
462 match path_parameters {
463 PathParameters::AngleBracketed(data) =>
464 PathParameters::AngleBracketed(fld.fold_angle_bracketed_parameter_data(data)),
465 PathParameters::Parenthesized(data) =>
466 PathParameters::Parenthesized(fld.fold_parenthesized_parameter_data(data)),
470 pub fn noop_fold_angle_bracketed_parameter_data<T: Folder>(data: AngleBracketedParameterData,
472 -> AngleBracketedParameterData
474 let AngleBracketedParameterData { lifetimes, types, bindings } = data;
475 AngleBracketedParameterData { lifetimes: fld.fold_lifetimes(lifetimes),
476 types: types.move_map(|ty| fld.fold_ty(ty)),
477 bindings: bindings.move_map(|b| fld.fold_ty_binding(b)) }
480 pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesizedParameterData,
482 -> ParenthesizedParameterData
484 let ParenthesizedParameterData { inputs, output, span } = data;
485 ParenthesizedParameterData { inputs: inputs.move_map(|ty| fld.fold_ty(ty)),
486 output: output.map(|ty| fld.fold_ty(ty)),
487 span: fld.new_span(span) }
490 pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
491 l.map(|Local {id, pat, ty, init, span, attrs}| Local {
493 pat: fld.fold_pat(pat),
494 ty: ty.map(|t| fld.fold_ty(t)),
495 init: init.map(|e| fld.fold_expr(e)),
496 span: fld.new_span(span),
497 attrs: fold_attrs(attrs.into(), fld).into(),
501 pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<Attribute> {
505 path: fld.fold_path(attr.path),
506 tokens: fld.fold_tts(attr.tokens),
507 is_sugared_doc: attr.is_sugared_doc,
508 span: fld.new_span(attr.span),
512 pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
515 tts: fld.fold_tts(node.stream()).into(),
516 path: fld.fold_path(node.path),
518 span: fld.new_span(span)
522 pub fn noop_fold_macro_def<T: Folder>(def: MacroDef, fld: &mut T) -> MacroDef {
524 tokens: fld.fold_tts(def.tokens.into()).into(),
529 pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
532 node: match li.node {
533 NestedMetaItemKind::MetaItem(mi) => {
534 NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
536 NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
538 span: fld.new_span(li.span)
542 pub fn noop_fold_meta_item<T: Folder>(mi: MetaItem, fld: &mut T) -> MetaItem {
545 node: match mi.node {
546 MetaItemKind::Word => MetaItemKind::Word,
547 MetaItemKind::List(mis) => {
548 MetaItemKind::List(mis.move_map(|e| fld.fold_meta_list_item(e)))
550 MetaItemKind::NameValue(s) => MetaItemKind::NameValue(s),
552 span: fld.new_span(mi.span)
556 pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg {
559 pat: fld.fold_pat(pat),
564 pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree {
566 TokenTree::Token(span, tok) =>
567 TokenTree::Token(fld.new_span(span), fld.fold_token(tok)),
568 TokenTree::Delimited(span, delimed) => TokenTree::Delimited(fld.new_span(span), Delimited {
569 tts: fld.fold_tts(delimed.stream()).into(),
570 delim: delimed.delim,
575 pub fn noop_fold_tts<T: Folder>(tts: TokenStream, fld: &mut T) -> TokenStream {
576 tts.map(|tt| fld.fold_tt(tt))
579 // apply ident folder if it's an ident, apply other folds to interpolated nodes
580 pub fn noop_fold_token<T: Folder>(t: token::Token, fld: &mut T) -> token::Token {
582 token::Ident(id) => token::Ident(fld.fold_ident(id)),
583 token::Lifetime(id) => token::Lifetime(fld.fold_ident(id)),
584 token::Interpolated(nt) => {
585 let nt = match Rc::try_unwrap(nt) {
587 Err(nt) => (*nt).clone(),
589 Token::interpolated(fld.fold_interpolated(nt.0))
595 /// apply folder to elements of interpolated nodes
597 // NB: this can occur only when applying a fold to partially expanded code, where
598 // parsed pieces have gotten implanted ito *other* macro invocations. This is relevant
599 // for macro hygiene, but possibly not elsewhere.
601 // One problem here occurs because the types for fold_item, fold_stmt, etc. allow the
602 // folder to return *multiple* items; this is a problem for the nodes here, because
603 // they insist on having exactly one piece. One solution would be to mangle the fold
604 // trait to include one-to-many and one-to-one versions of these entry points, but that
605 // would probably confuse a lot of people and help very few. Instead, I'm just going
606 // to put in dynamic checks. I think the performance impact of this will be pretty much
607 // nonexistent. The danger is that someone will apply a fold to a partially expanded
608 // node, and will be confused by the fact that their "fold_item" or "fold_stmt" isn't
609 // getting called on NtItem or NtStmt nodes. Hopefully they'll wind up reading this
610 // comment, and doing something appropriate.
612 // BTW, design choice: I considered just changing the type of, e.g., NtItem to contain
613 // multiple items, but decided against it when I looked at parse_item_or_view_item and
614 // tried to figure out what I would do with multiple items there....
615 pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
616 -> token::Nonterminal {
618 token::NtItem(item) =>
619 token::NtItem(fld.fold_item(item)
620 // this is probably okay, because the only folds likely
621 // to peek inside interpolated nodes will be renamings/markings,
622 // which map single items to single items
623 .expect_one("expected fold to produce exactly one item")),
624 token::NtBlock(block) => token::NtBlock(fld.fold_block(block)),
625 token::NtStmt(stmt) =>
626 token::NtStmt(fld.fold_stmt(stmt)
627 // this is probably okay, because the only folds likely
628 // to peek inside interpolated nodes will be renamings/markings,
629 // which map single items to single items
630 .expect_one("expected fold to produce exactly one statement")),
631 token::NtPat(pat) => token::NtPat(fld.fold_pat(pat)),
632 token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)),
633 token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)),
634 token::NtIdent(id) => token::NtIdent(Spanned::<Ident>{node: fld.fold_ident(id.node), ..id}),
635 token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)),
636 token::NtPath(path) => token::NtPath(fld.fold_path(path)),
637 token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)),
638 token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
639 token::NtImplItem(item) =>
640 token::NtImplItem(fld.fold_impl_item(item)
641 .expect_one("expected fold to produce exactly one item")),
642 token::NtTraitItem(item) =>
643 token::NtTraitItem(fld.fold_trait_item(item)
644 .expect_one("expected fold to produce exactly one item")),
645 token::NtGenerics(generics) => token::NtGenerics(fld.fold_generics(generics)),
646 token::NtWhereClause(where_clause) =>
647 token::NtWhereClause(fld.fold_where_clause(where_clause)),
648 token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)),
649 token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)),
653 pub fn noop_fold_fn_decl<T: Folder>(decl: P<FnDecl>, fld: &mut T) -> P<FnDecl> {
654 decl.map(|FnDecl {inputs, output, variadic}| FnDecl {
655 inputs: inputs.move_map(|x| fld.fold_arg(x)),
656 output: match output {
657 FunctionRetTy::Ty(ty) => FunctionRetTy::Ty(fld.fold_ty(ty)),
658 FunctionRetTy::Default(span) => FunctionRetTy::Default(fld.new_span(span)),
664 pub fn noop_fold_ty_param_bound<T>(tpb: TyParamBound, fld: &mut T)
668 TraitTyParamBound(ty, modifier) => TraitTyParamBound(fld.fold_poly_trait_ref(ty), modifier),
669 RegionTyParamBound(lifetime) => RegionTyParamBound(fld.fold_lifetime(lifetime)),
673 pub fn noop_fold_ty_param<T: Folder>(tp: TyParam, fld: &mut T) -> TyParam {
674 let TyParam {attrs, id, ident, bounds, default, span} = tp;
675 let attrs: Vec<_> = attrs.into();
677 attrs: attrs.into_iter()
678 .flat_map(|x| fld.fold_attribute(x).into_iter())
682 ident: fld.fold_ident(ident),
683 bounds: fld.fold_bounds(bounds),
684 default: default.map(|x| fld.fold_ty(x)),
685 span: fld.new_span(span),
689 pub fn noop_fold_ty_params<T: Folder>(tps: Vec<TyParam>, fld: &mut T) -> Vec<TyParam> {
690 tps.move_map(|tp| fld.fold_ty_param(tp))
693 pub fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
695 id: fld.new_id(l.id),
696 ident: fld.fold_ident(l.ident),
697 span: fld.new_span(l.span)
701 pub fn noop_fold_lifetime_def<T: Folder>(l: LifetimeDef, fld: &mut T)
703 let attrs: Vec<_> = l.attrs.into();
705 attrs: attrs.into_iter()
706 .flat_map(|x| fld.fold_attribute(x).into_iter())
709 lifetime: fld.fold_lifetime(l.lifetime),
710 bounds: fld.fold_lifetimes(l.bounds),
714 pub fn noop_fold_lifetimes<T: Folder>(lts: Vec<Lifetime>, fld: &mut T) -> Vec<Lifetime> {
715 lts.move_map(|l| fld.fold_lifetime(l))
718 pub fn noop_fold_lifetime_defs<T: Folder>(lts: Vec<LifetimeDef>, fld: &mut T)
719 -> Vec<LifetimeDef> {
720 lts.move_map(|l| fld.fold_lifetime_def(l))
723 pub fn noop_fold_opt_lifetime<T: Folder>(o_lt: Option<Lifetime>, fld: &mut T)
724 -> Option<Lifetime> {
725 o_lt.map(|lt| fld.fold_lifetime(lt))
728 pub fn noop_fold_generics<T: Folder>(Generics {ty_params, lifetimes, where_clause, span}: Generics,
729 fld: &mut T) -> Generics {
731 ty_params: fld.fold_ty_params(ty_params),
732 lifetimes: fld.fold_lifetime_defs(lifetimes),
733 where_clause: fld.fold_where_clause(where_clause),
734 span: fld.new_span(span),
738 pub fn noop_fold_where_clause<T: Folder>(
739 WhereClause {id, predicates}: WhereClause,
744 predicates: predicates.move_map(|predicate| {
745 fld.fold_where_predicate(predicate)
750 pub fn noop_fold_where_predicate<T: Folder>(
751 pred: WherePredicate,
755 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{bound_lifetimes,
759 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
760 bound_lifetimes: fld.fold_lifetime_defs(bound_lifetimes),
761 bounded_ty: fld.fold_ty(bounded_ty),
762 bounds: bounds.move_map(|x| fld.fold_ty_param_bound(x)),
763 span: fld.new_span(span)
766 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime,
769 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
770 span: fld.new_span(span),
771 lifetime: fld.fold_lifetime(lifetime),
772 bounds: bounds.move_map(|bound| fld.fold_lifetime(bound))
775 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
779 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{
781 lhs_ty: fld.fold_ty(lhs_ty),
782 rhs_ty: fld.fold_ty(rhs_ty),
783 span: fld.new_span(span)
789 pub fn noop_fold_variant_data<T: Folder>(vdata: VariantData, fld: &mut T) -> VariantData {
791 ast::VariantData::Struct(fields, id) => {
792 ast::VariantData::Struct(fields.move_map(|f| fld.fold_struct_field(f)),
795 ast::VariantData::Tuple(fields, id) => {
796 ast::VariantData::Tuple(fields.move_map(|f| fld.fold_struct_field(f)),
799 ast::VariantData::Unit(id) => ast::VariantData::Unit(fld.new_id(id))
803 pub fn noop_fold_trait_ref<T: Folder>(p: TraitRef, fld: &mut T) -> TraitRef {
804 let id = fld.new_id(p.ref_id);
810 path: fld.fold_path(path),
815 pub fn noop_fold_poly_trait_ref<T: Folder>(p: PolyTraitRef, fld: &mut T) -> PolyTraitRef {
817 bound_lifetimes: fld.fold_lifetime_defs(p.bound_lifetimes),
818 trait_ref: fld.fold_trait_ref(p.trait_ref),
819 span: fld.new_span(p.span),
823 pub fn noop_fold_struct_field<T: Folder>(f: StructField, fld: &mut T) -> StructField {
825 span: fld.new_span(f.span),
826 id: fld.new_id(f.id),
827 ident: f.ident.map(|ident| fld.fold_ident(ident)),
828 vis: fld.fold_vis(f.vis),
829 ty: fld.fold_ty(f.ty),
830 attrs: fold_attrs(f.attrs, fld),
834 pub fn noop_fold_field<T: Folder>(f: Field, folder: &mut T) -> Field {
836 ident: respan(f.ident.span, folder.fold_ident(f.ident.node)),
837 expr: folder.fold_expr(f.expr),
838 span: folder.new_span(f.span),
839 is_shorthand: f.is_shorthand,
840 attrs: fold_thin_attrs(f.attrs, folder),
844 pub fn noop_fold_mt<T: Folder>(MutTy {ty, mutbl}: MutTy, folder: &mut T) -> MutTy {
846 ty: folder.fold_ty(ty),
851 pub fn noop_fold_opt_bounds<T: Folder>(b: Option<TyParamBounds>, folder: &mut T)
852 -> Option<TyParamBounds> {
853 b.map(|bounds| folder.fold_bounds(bounds))
856 fn noop_fold_bounds<T: Folder>(bounds: TyParamBounds, folder: &mut T)
858 bounds.move_map(|bound| folder.fold_ty_param_bound(bound))
861 pub fn noop_fold_block<T: Folder>(b: P<Block>, folder: &mut T) -> P<Block> {
862 b.map(|Block {id, stmts, rules, span}| Block {
863 id: folder.new_id(id),
864 stmts: stmts.move_flat_map(|s| folder.fold_stmt(s).into_iter()),
866 span: folder.new_span(span),
870 pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
872 ItemKind::ExternCrate(string) => ItemKind::ExternCrate(string),
873 ItemKind::Use(view_path) => {
874 ItemKind::Use(folder.fold_view_path(view_path))
876 ItemKind::Static(t, m, e) => {
877 ItemKind::Static(folder.fold_ty(t), m, folder.fold_expr(e))
879 ItemKind::Const(t, e) => {
880 ItemKind::Const(folder.fold_ty(t), folder.fold_expr(e))
882 ItemKind::Fn(decl, unsafety, constness, abi, generics, body) => {
883 let generics = folder.fold_generics(generics);
884 let decl = folder.fold_fn_decl(decl);
885 let body = folder.fold_block(body);
886 ItemKind::Fn(decl, unsafety, constness, abi, generics, body)
888 ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)),
889 ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)),
890 ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)),
891 ItemKind::Ty(t, generics) => {
892 ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics))
894 ItemKind::Enum(enum_definition, generics) => {
895 let generics = folder.fold_generics(generics);
896 let variants = enum_definition.variants.move_map(|x| folder.fold_variant(x));
897 ItemKind::Enum(ast::EnumDef { variants: variants }, generics)
899 ItemKind::Struct(struct_def, generics) => {
900 let generics = folder.fold_generics(generics);
901 ItemKind::Struct(folder.fold_variant_data(struct_def), generics)
903 ItemKind::Union(struct_def, generics) => {
904 let generics = folder.fold_generics(generics);
905 ItemKind::Union(folder.fold_variant_data(struct_def), generics)
907 ItemKind::DefaultImpl(unsafety, ref trait_ref) => {
908 ItemKind::DefaultImpl(unsafety, folder.fold_trait_ref((*trait_ref).clone()))
910 ItemKind::Impl(unsafety,
916 impl_items) => ItemKind::Impl(
920 folder.fold_generics(generics),
921 ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref.clone())),
923 impl_items.move_flat_map(|item| folder.fold_impl_item(item)),
925 ItemKind::Trait(unsafety, generics, bounds, items) => ItemKind::Trait(
927 folder.fold_generics(generics),
928 folder.fold_bounds(bounds),
929 items.move_flat_map(|item| folder.fold_trait_item(item)),
931 ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)),
932 ItemKind::MacroDef(def) => ItemKind::MacroDef(folder.fold_macro_def(def)),
936 pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T)
937 -> SmallVector<TraitItem> {
938 SmallVector::one(TraitItem {
939 id: folder.new_id(i.id),
940 ident: folder.fold_ident(i.ident),
941 attrs: fold_attrs(i.attrs, folder),
943 TraitItemKind::Const(ty, default) => {
944 TraitItemKind::Const(folder.fold_ty(ty),
945 default.map(|x| folder.fold_expr(x)))
947 TraitItemKind::Method(sig, body) => {
948 TraitItemKind::Method(noop_fold_method_sig(sig, folder),
949 body.map(|x| folder.fold_block(x)))
951 TraitItemKind::Type(bounds, default) => {
952 TraitItemKind::Type(folder.fold_bounds(bounds),
953 default.map(|x| folder.fold_ty(x)))
955 ast::TraitItemKind::Macro(mac) => {
956 TraitItemKind::Macro(folder.fold_mac(mac))
959 span: folder.new_span(i.span)
963 pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T)
964 -> SmallVector<ImplItem> {
965 SmallVector::one(ImplItem {
966 id: folder.new_id(i.id),
967 vis: folder.fold_vis(i.vis),
968 ident: folder.fold_ident(i.ident),
969 attrs: fold_attrs(i.attrs, folder),
970 defaultness: i.defaultness,
972 ast::ImplItemKind::Const(ty, expr) => {
973 ast::ImplItemKind::Const(folder.fold_ty(ty), folder.fold_expr(expr))
975 ast::ImplItemKind::Method(sig, body) => {
976 ast::ImplItemKind::Method(noop_fold_method_sig(sig, folder),
977 folder.fold_block(body))
979 ast::ImplItemKind::Type(ty) => ast::ImplItemKind::Type(folder.fold_ty(ty)),
980 ast::ImplItemKind::Macro(mac) => ast::ImplItemKind::Macro(folder.fold_mac(mac))
982 span: folder.new_span(i.span)
986 pub fn noop_fold_mod<T: Folder>(Mod {inner, items}: Mod, folder: &mut T) -> Mod {
988 inner: folder.new_span(inner),
989 items: items.move_flat_map(|x| folder.fold_item(x)),
993 pub fn noop_fold_crate<T: Folder>(Crate {module, attrs, span}: Crate,
994 folder: &mut T) -> Crate {
995 let mut items = folder.fold_item(P(ast::Item {
996 ident: keywords::Invalid.ident(),
998 id: ast::DUMMY_NODE_ID,
999 vis: ast::Visibility::Public,
1001 node: ast::ItemKind::Mod(module),
1004 let (module, attrs, span) = match items.next() {
1006 assert!(items.next().is_none(),
1007 "a crate cannot expand to more than one item");
1008 item.and_then(|ast::Item { attrs, span, node, .. }| {
1010 ast::ItemKind::Mod(m) => (m, attrs, span),
1011 _ => panic!("fold converted a module to not a module"),
1028 // fold one item into possibly many items
1029 pub fn noop_fold_item<T: Folder>(i: P<Item>, folder: &mut T) -> SmallVector<P<Item>> {
1030 SmallVector::one(i.map(|i| folder.fold_item_simple(i)))
1033 // fold one item into exactly one item
1034 pub fn noop_fold_item_simple<T: Folder>(Item {id, ident, attrs, node, vis, span}: Item,
1035 folder: &mut T) -> Item {
1037 id: folder.new_id(id),
1038 vis: folder.fold_vis(vis),
1039 ident: folder.fold_ident(ident),
1040 attrs: fold_attrs(attrs, folder),
1041 node: folder.fold_item_kind(node),
1042 span: folder.new_span(span)
1046 pub fn noop_fold_foreign_item<T: Folder>(ni: ForeignItem, folder: &mut T) -> ForeignItem {
1048 id: folder.new_id(ni.id),
1049 vis: folder.fold_vis(ni.vis),
1050 ident: folder.fold_ident(ni.ident),
1051 attrs: fold_attrs(ni.attrs, folder),
1052 node: match ni.node {
1053 ForeignItemKind::Fn(fdec, generics) => {
1054 ForeignItemKind::Fn(folder.fold_fn_decl(fdec), folder.fold_generics(generics))
1056 ForeignItemKind::Static(t, m) => {
1057 ForeignItemKind::Static(folder.fold_ty(t), m)
1060 span: folder.new_span(ni.span)
1064 pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig {
1066 generics: folder.fold_generics(sig.generics),
1068 unsafety: sig.unsafety,
1069 constness: sig.constness,
1070 decl: folder.fold_fn_decl(sig.decl)
1074 pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
1075 p.map(|Pat {id, node, span}| Pat {
1076 id: folder.new_id(id),
1078 PatKind::Wild => PatKind::Wild,
1079 PatKind::Ident(binding_mode, pth1, sub) => {
1080 PatKind::Ident(binding_mode,
1081 Spanned{span: folder.new_span(pth1.span),
1082 node: folder.fold_ident(pth1.node)},
1083 sub.map(|x| folder.fold_pat(x)))
1085 PatKind::Lit(e) => PatKind::Lit(folder.fold_expr(e)),
1086 PatKind::TupleStruct(pth, pats, ddpos) => {
1087 PatKind::TupleStruct(folder.fold_path(pth),
1088 pats.move_map(|x| folder.fold_pat(x)), ddpos)
1090 PatKind::Path(opt_qself, pth) => {
1091 let opt_qself = opt_qself.map(|qself| {
1092 QSelf { ty: folder.fold_ty(qself.ty), position: qself.position }
1094 PatKind::Path(opt_qself, folder.fold_path(pth))
1096 PatKind::Struct(pth, fields, etc) => {
1097 let pth = folder.fold_path(pth);
1098 let fs = fields.move_map(|f| {
1099 Spanned { span: folder.new_span(f.span),
1100 node: ast::FieldPat {
1101 ident: folder.fold_ident(f.node.ident),
1102 pat: folder.fold_pat(f.node.pat),
1103 is_shorthand: f.node.is_shorthand,
1104 attrs: fold_attrs(f.node.attrs.into(), folder).into()
1107 PatKind::Struct(pth, fs, etc)
1109 PatKind::Tuple(elts, ddpos) => {
1110 PatKind::Tuple(elts.move_map(|x| folder.fold_pat(x)), ddpos)
1112 PatKind::Box(inner) => PatKind::Box(folder.fold_pat(inner)),
1113 PatKind::Ref(inner, mutbl) => PatKind::Ref(folder.fold_pat(inner), mutbl),
1114 PatKind::Range(e1, e2, end) => {
1115 PatKind::Range(folder.fold_expr(e1),
1116 folder.fold_expr(e2),
1117 folder.fold_range_end(end))
1119 PatKind::Slice(before, slice, after) => {
1120 PatKind::Slice(before.move_map(|x| folder.fold_pat(x)),
1121 slice.map(|x| folder.fold_pat(x)),
1122 after.move_map(|x| folder.fold_pat(x)))
1124 PatKind::Mac(mac) => PatKind::Mac(folder.fold_mac(mac))
1126 span: folder.new_span(span)
1130 pub fn noop_fold_range_end<T: Folder>(end: RangeEnd, _folder: &mut T) -> RangeEnd {
1134 pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mut T) -> Expr {
1137 ExprKind::Box(e) => {
1138 ExprKind::Box(folder.fold_expr(e))
1140 ExprKind::InPlace(p, e) => {
1141 ExprKind::InPlace(folder.fold_expr(p), folder.fold_expr(e))
1143 ExprKind::Array(exprs) => {
1144 ExprKind::Array(folder.fold_exprs(exprs))
1146 ExprKind::Repeat(expr, count) => {
1147 ExprKind::Repeat(folder.fold_expr(expr), folder.fold_expr(count))
1149 ExprKind::Tup(exprs) => ExprKind::Tup(folder.fold_exprs(exprs)),
1150 ExprKind::Call(f, args) => {
1151 ExprKind::Call(folder.fold_expr(f),
1152 folder.fold_exprs(args))
1154 ExprKind::MethodCall(i, tps, args) => {
1155 ExprKind::MethodCall(
1156 respan(folder.new_span(i.span), folder.fold_ident(i.node)),
1157 tps.move_map(|x| folder.fold_ty(x)),
1158 folder.fold_exprs(args))
1160 ExprKind::Binary(binop, lhs, rhs) => {
1161 ExprKind::Binary(binop,
1162 folder.fold_expr(lhs),
1163 folder.fold_expr(rhs))
1165 ExprKind::Unary(binop, ohs) => {
1166 ExprKind::Unary(binop, folder.fold_expr(ohs))
1168 ExprKind::Lit(l) => ExprKind::Lit(l),
1169 ExprKind::Cast(expr, ty) => {
1170 ExprKind::Cast(folder.fold_expr(expr), folder.fold_ty(ty))
1172 ExprKind::Type(expr, ty) => {
1173 ExprKind::Type(folder.fold_expr(expr), folder.fold_ty(ty))
1175 ExprKind::AddrOf(m, ohs) => ExprKind::AddrOf(m, folder.fold_expr(ohs)),
1176 ExprKind::If(cond, tr, fl) => {
1177 ExprKind::If(folder.fold_expr(cond),
1178 folder.fold_block(tr),
1179 fl.map(|x| folder.fold_expr(x)))
1181 ExprKind::IfLet(pat, expr, tr, fl) => {
1182 ExprKind::IfLet(folder.fold_pat(pat),
1183 folder.fold_expr(expr),
1184 folder.fold_block(tr),
1185 fl.map(|x| folder.fold_expr(x)))
1187 ExprKind::While(cond, body, opt_ident) => {
1188 ExprKind::While(folder.fold_expr(cond),
1189 folder.fold_block(body),
1190 opt_ident.map(|label| respan(folder.new_span(label.span),
1191 folder.fold_ident(label.node))))
1193 ExprKind::WhileLet(pat, expr, body, opt_ident) => {
1194 ExprKind::WhileLet(folder.fold_pat(pat),
1195 folder.fold_expr(expr),
1196 folder.fold_block(body),
1197 opt_ident.map(|label| respan(folder.new_span(label.span),
1198 folder.fold_ident(label.node))))
1200 ExprKind::ForLoop(pat, iter, body, opt_ident) => {
1201 ExprKind::ForLoop(folder.fold_pat(pat),
1202 folder.fold_expr(iter),
1203 folder.fold_block(body),
1204 opt_ident.map(|label| respan(folder.new_span(label.span),
1205 folder.fold_ident(label.node))))
1207 ExprKind::Loop(body, opt_ident) => {
1208 ExprKind::Loop(folder.fold_block(body),
1209 opt_ident.map(|label| respan(folder.new_span(label.span),
1210 folder.fold_ident(label.node))))
1212 ExprKind::Match(expr, arms) => {
1213 ExprKind::Match(folder.fold_expr(expr),
1214 arms.move_map(|x| folder.fold_arm(x)))
1216 ExprKind::Closure(capture_clause, decl, body, span) => {
1217 ExprKind::Closure(capture_clause,
1218 folder.fold_fn_decl(decl),
1219 folder.fold_expr(body),
1220 folder.new_span(span))
1222 ExprKind::Block(blk) => ExprKind::Block(folder.fold_block(blk)),
1223 ExprKind::Assign(el, er) => {
1224 ExprKind::Assign(folder.fold_expr(el), folder.fold_expr(er))
1226 ExprKind::AssignOp(op, el, er) => {
1227 ExprKind::AssignOp(op,
1228 folder.fold_expr(el),
1229 folder.fold_expr(er))
1231 ExprKind::Field(el, ident) => {
1232 ExprKind::Field(folder.fold_expr(el),
1233 respan(folder.new_span(ident.span),
1234 folder.fold_ident(ident.node)))
1236 ExprKind::TupField(el, ident) => {
1237 ExprKind::TupField(folder.fold_expr(el),
1238 respan(folder.new_span(ident.span),
1239 folder.fold_usize(ident.node)))
1241 ExprKind::Index(el, er) => {
1242 ExprKind::Index(folder.fold_expr(el), folder.fold_expr(er))
1244 ExprKind::Range(e1, e2, lim) => {
1245 ExprKind::Range(e1.map(|x| folder.fold_expr(x)),
1246 e2.map(|x| folder.fold_expr(x)),
1249 ExprKind::Path(qself, path) => {
1250 let qself = qself.map(|QSelf { ty, position }| {
1252 ty: folder.fold_ty(ty),
1256 ExprKind::Path(qself, folder.fold_path(path))
1258 ExprKind::Break(opt_ident, opt_expr) => {
1259 ExprKind::Break(opt_ident.map(|label| respan(folder.new_span(label.span),
1260 folder.fold_ident(label.node))),
1261 opt_expr.map(|e| folder.fold_expr(e)))
1263 ExprKind::Continue(opt_ident) => ExprKind::Continue(opt_ident.map(|label|
1264 respan(folder.new_span(label.span),
1265 folder.fold_ident(label.node)))
1267 ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
1268 ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
1270 inputs: asm.inputs.move_map(|(c, input)| {
1271 (c, folder.fold_expr(input))
1273 outputs: asm.outputs.move_map(|out| {
1275 constraint: out.constraint,
1276 expr: folder.fold_expr(out.expr),
1278 is_indirect: out.is_indirect,
1284 ExprKind::Mac(mac) => ExprKind::Mac(folder.fold_mac(mac)),
1285 ExprKind::Struct(path, fields, maybe_expr) => {
1286 ExprKind::Struct(folder.fold_path(path),
1287 fields.move_map(|x| folder.fold_field(x)),
1288 maybe_expr.map(|x| folder.fold_expr(x)))
1290 ExprKind::Paren(ex) => {
1291 let sub_expr = folder.fold_expr(ex);
1293 // Nodes that are equal modulo `Paren` sugar no-ops should have the same ids.
1295 node: ExprKind::Paren(sub_expr),
1296 span: folder.new_span(span),
1297 attrs: fold_attrs(attrs.into(), folder).into(),
1300 ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)),
1301 ExprKind::Catch(body) => ExprKind::Catch(folder.fold_block(body)),
1303 id: folder.new_id(id),
1304 span: folder.new_span(span),
1305 attrs: fold_attrs(attrs.into(), folder).into(),
1309 pub fn noop_fold_opt_expr<T: Folder>(e: P<Expr>, folder: &mut T) -> Option<P<Expr>> {
1310 Some(folder.fold_expr(e))
1313 pub fn noop_fold_exprs<T: Folder>(es: Vec<P<Expr>>, folder: &mut T) -> Vec<P<Expr>> {
1314 es.move_flat_map(|e| folder.fold_opt_expr(e))
1317 pub fn noop_fold_stmt<T: Folder>(Stmt {node, span, id}: Stmt, folder: &mut T) -> SmallVector<Stmt> {
1318 let id = folder.new_id(id);
1319 let span = folder.new_span(span);
1320 noop_fold_stmt_kind(node, folder).into_iter().map(|node| {
1321 Stmt { id: id, node: node, span: span }
1325 pub fn noop_fold_stmt_kind<T: Folder>(node: StmtKind, folder: &mut T) -> SmallVector<StmtKind> {
1327 StmtKind::Local(local) => SmallVector::one(StmtKind::Local(folder.fold_local(local))),
1328 StmtKind::Item(item) => folder.fold_item(item).into_iter().map(StmtKind::Item).collect(),
1329 StmtKind::Expr(expr) => {
1330 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Expr).collect()
1332 StmtKind::Semi(expr) => {
1333 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Semi).collect()
1335 StmtKind::Mac(mac) => SmallVector::one(StmtKind::Mac(mac.map(|(mac, semi, attrs)| {
1336 (folder.fold_mac(mac), semi, fold_attrs(attrs.into(), folder).into())
1341 pub fn noop_fold_vis<T: Folder>(vis: Visibility, folder: &mut T) -> Visibility {
1343 Visibility::Restricted { path, id } => Visibility::Restricted {
1344 path: path.map(|path| folder.fold_path(path)),
1345 id: folder.new_id(id)
1354 use ast::{self, Ident};
1355 use util::parser_testing::{string_to_crate, matches_codepattern};
1360 // this version doesn't care about getting comments or docstrings in.
1361 fn fake_print_crate(s: &mut pprust::State,
1362 krate: &ast::Crate) -> io::Result<()> {
1363 s.print_mod(&krate.module, &krate.attrs)
1366 // change every identifier to "zz"
1367 struct ToZzIdentFolder;
1369 impl Folder for ToZzIdentFolder {
1370 fn fold_ident(&mut self, _: ast::Ident) -> ast::Ident {
1371 Ident::from_str("zz")
1373 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1374 fold::noop_fold_mac(mac, self)
1378 // maybe add to expand.rs...
1379 macro_rules! assert_pred {
1380 ($pred:expr, $predname:expr, $a:expr , $b:expr) => (
1382 let pred_val = $pred;
1385 if !(pred_val(&a_val, &b_val)) {
1386 panic!("expected args satisfying {}, got {} and {}",
1387 $predname, a_val, b_val);
1393 // make sure idents get transformed everywhere
1394 #[test] fn ident_transformation () {
1395 let mut zz_fold = ToZzIdentFolder;
1396 let ast = string_to_crate(
1397 "#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string());
1398 let folded_crate = zz_fold.fold_crate(ast);
1400 matches_codepattern,
1401 "matches_codepattern",
1402 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1403 "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
1406 // even inside macro defs....
1407 #[test] fn ident_transformation_in_defs () {
1408 let mut zz_fold = ToZzIdentFolder;
1409 let ast = string_to_crate(
1410 "macro_rules! a {(b $c:expr $(d $e:token)f+ => \
1411 (g $(d $d $e)+))} ".to_string());
1412 let folded_crate = zz_fold.fold_crate(ast);
1414 matches_codepattern,
1415 "matches_codepattern",
1416 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1417 "macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string());