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};
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_lifetime(&mut self, l: Lifetime) -> Lifetime {
193 noop_fold_lifetime(l, self)
196 fn fold_lifetime_def(&mut self, l: LifetimeDef) -> LifetimeDef {
197 noop_fold_lifetime_def(l, self)
200 fn fold_attribute(&mut self, at: Attribute) -> Option<Attribute> {
201 noop_fold_attribute(at, self)
204 fn fold_arg(&mut self, a: Arg) -> Arg {
205 noop_fold_arg(a, self)
208 fn fold_generics(&mut self, generics: Generics) -> Generics {
209 noop_fold_generics(generics, self)
212 fn fold_trait_ref(&mut self, p: TraitRef) -> TraitRef {
213 noop_fold_trait_ref(p, self)
216 fn fold_poly_trait_ref(&mut self, p: PolyTraitRef) -> PolyTraitRef {
217 noop_fold_poly_trait_ref(p, self)
220 fn fold_variant_data(&mut self, vdata: VariantData) -> VariantData {
221 noop_fold_variant_data(vdata, self)
224 fn fold_lifetimes(&mut self, lts: Vec<Lifetime>) -> Vec<Lifetime> {
225 noop_fold_lifetimes(lts, self)
228 fn fold_lifetime_defs(&mut self, lts: Vec<LifetimeDef>) -> Vec<LifetimeDef> {
229 noop_fold_lifetime_defs(lts, self)
232 fn fold_ty_param(&mut self, tp: TyParam) -> TyParam {
233 noop_fold_ty_param(tp, self)
236 fn fold_ty_params(&mut self, tps: Vec<TyParam>) -> Vec<TyParam> {
237 noop_fold_ty_params(tps, self)
240 fn fold_tt(&mut self, tt: TokenTree) -> TokenTree {
241 noop_fold_tt(tt, self)
244 fn fold_tts(&mut self, tts: TokenStream) -> TokenStream {
245 noop_fold_tts(tts, self)
248 fn fold_token(&mut self, t: token::Token) -> token::Token {
249 noop_fold_token(t, self)
252 fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal {
253 noop_fold_interpolated(nt, self)
256 fn fold_opt_lifetime(&mut self, o_lt: Option<Lifetime>) -> Option<Lifetime> {
257 noop_fold_opt_lifetime(o_lt, self)
260 fn fold_opt_bounds(&mut self, b: Option<TyParamBounds>)
261 -> Option<TyParamBounds> {
262 noop_fold_opt_bounds(b, self)
265 fn fold_bounds(&mut self, b: TyParamBounds)
267 noop_fold_bounds(b, self)
270 fn fold_ty_param_bound(&mut self, tpb: TyParamBound) -> TyParamBound {
271 noop_fold_ty_param_bound(tpb, self)
274 fn fold_mt(&mut self, mt: MutTy) -> MutTy {
275 noop_fold_mt(mt, self)
278 fn fold_field(&mut self, field: Field) -> Field {
279 noop_fold_field(field, self)
282 fn fold_where_clause(&mut self, where_clause: WhereClause)
284 noop_fold_where_clause(where_clause, self)
287 fn fold_where_predicate(&mut self, where_predicate: WherePredicate)
289 noop_fold_where_predicate(where_predicate, self)
292 fn fold_vis(&mut self, vis: Visibility) -> Visibility {
293 noop_fold_vis(vis, self)
296 fn new_id(&mut self, i: NodeId) -> NodeId {
300 fn new_span(&mut self, sp: Span) -> Span {
305 pub fn noop_fold_meta_items<T: Folder>(meta_items: Vec<MetaItem>, fld: &mut T) -> Vec<MetaItem> {
306 meta_items.move_map(|x| fld.fold_meta_item(x))
309 pub fn noop_fold_view_path<T: Folder>(view_path: P<ViewPath>, fld: &mut T) -> P<ViewPath> {
310 view_path.map(|Spanned {node, span}| Spanned {
312 ViewPathSimple(ident, path) => {
313 ViewPathSimple(fld.fold_ident(ident), fld.fold_path(path))
315 ViewPathGlob(path) => {
316 ViewPathGlob(fld.fold_path(path))
318 ViewPathList(path, path_list_idents) => {
319 let path = fld.fold_path(path);
320 let path_list_idents = path_list_idents.move_map(|path_list_ident| Spanned {
321 node: PathListItem_ {
322 id: fld.new_id(path_list_ident.node.id),
323 rename: path_list_ident.node.rename.map(|ident| fld.fold_ident(ident)),
324 name: fld.fold_ident(path_list_ident.node.name),
326 span: fld.new_span(path_list_ident.span)
328 ViewPathList(path, path_list_idents)
331 span: fld.new_span(span)
335 pub fn fold_attrs<T: Folder>(attrs: Vec<Attribute>, fld: &mut T) -> Vec<Attribute> {
336 attrs.move_flat_map(|x| fld.fold_attribute(x))
339 pub fn fold_thin_attrs<T: Folder>(attrs: ThinVec<Attribute>, fld: &mut T) -> ThinVec<Attribute> {
340 fold_attrs(attrs.into(), fld).into()
343 pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body}: Arm, fld: &mut T) -> Arm {
345 attrs: fold_attrs(attrs, fld),
346 pats: pats.move_map(|x| fld.fold_pat(x)),
347 guard: guard.map(|x| fld.fold_expr(x)),
348 body: fld.fold_expr(body),
352 pub fn noop_fold_ty_binding<T: Folder>(b: TypeBinding, fld: &mut T) -> TypeBinding {
354 id: fld.new_id(b.id),
355 ident: fld.fold_ident(b.ident),
356 ty: fld.fold_ty(b.ty),
357 span: fld.new_span(b.span),
361 pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> {
362 t.map(|Ty {id, node, span}| Ty {
365 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node,
366 TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)),
367 TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)),
368 TyKind::Rptr(region, mt) => {
369 TyKind::Rptr(fld.fold_opt_lifetime(region), fld.fold_mt(mt))
371 TyKind::BareFn(f) => {
372 TyKind::BareFn(f.map(|BareFnTy {lifetimes, unsafety, abi, decl}| BareFnTy {
373 lifetimes: fld.fold_lifetime_defs(lifetimes),
376 decl: fld.fold_fn_decl(decl)
379 TyKind::Never => node,
380 TyKind::Tup(tys) => TyKind::Tup(tys.move_map(|ty| fld.fold_ty(ty))),
381 TyKind::Paren(ty) => TyKind::Paren(fld.fold_ty(ty)),
382 TyKind::Path(qself, path) => {
383 let qself = qself.map(|QSelf { ty, position }| {
389 TyKind::Path(qself, fld.fold_path(path))
391 TyKind::Array(ty, e) => {
392 TyKind::Array(fld.fold_ty(ty), fld.fold_expr(e))
394 TyKind::Typeof(expr) => {
395 TyKind::Typeof(fld.fold_expr(expr))
397 TyKind::TraitObject(bounds) => {
398 TyKind::TraitObject(bounds.move_map(|b| fld.fold_ty_param_bound(b)))
400 TyKind::ImplTrait(bounds) => {
401 TyKind::ImplTrait(bounds.move_map(|b| fld.fold_ty_param_bound(b)))
403 TyKind::Mac(mac) => {
404 TyKind::Mac(fld.fold_mac(mac))
407 span: fld.new_span(span)
411 pub fn noop_fold_foreign_mod<T: Folder>(ForeignMod {abi, items}: ForeignMod,
412 fld: &mut T) -> ForeignMod {
415 items: items.move_map(|x| fld.fold_foreign_item(x)),
419 pub fn noop_fold_global_asm<T: Folder>(ga: P<GlobalAsm>,
420 _: &mut T) -> P<GlobalAsm> {
424 pub fn noop_fold_variant<T: Folder>(v: Variant, fld: &mut T) -> Variant {
428 attrs: fold_attrs(v.node.attrs, fld),
429 data: fld.fold_variant_data(v.node.data),
430 disr_expr: v.node.disr_expr.map(|e| fld.fold_expr(e)),
432 span: fld.new_span(v.span),
436 pub fn noop_fold_ident<T: Folder>(i: Ident, _: &mut T) -> Ident {
440 pub fn noop_fold_usize<T: Folder>(i: usize, _: &mut T) -> usize {
444 pub fn noop_fold_path<T: Folder>(Path { segments, span }: Path, fld: &mut T) -> Path {
446 segments: segments.move_map(|PathSegment {identifier, span, parameters}| PathSegment {
447 identifier: fld.fold_ident(identifier),
448 span: fld.new_span(span),
449 parameters: parameters.map(|ps| ps.map(|ps| fld.fold_path_parameters(ps))),
451 span: fld.new_span(span)
455 pub fn noop_fold_path_parameters<T: Folder>(path_parameters: PathParameters, fld: &mut T)
458 match path_parameters {
459 PathParameters::AngleBracketed(data) =>
460 PathParameters::AngleBracketed(fld.fold_angle_bracketed_parameter_data(data)),
461 PathParameters::Parenthesized(data) =>
462 PathParameters::Parenthesized(fld.fold_parenthesized_parameter_data(data)),
466 pub fn noop_fold_angle_bracketed_parameter_data<T: Folder>(data: AngleBracketedParameterData,
468 -> AngleBracketedParameterData
470 let AngleBracketedParameterData { lifetimes, types, bindings } = data;
471 AngleBracketedParameterData { lifetimes: fld.fold_lifetimes(lifetimes),
472 types: types.move_map(|ty| fld.fold_ty(ty)),
473 bindings: bindings.move_map(|b| fld.fold_ty_binding(b)) }
476 pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesizedParameterData,
478 -> ParenthesizedParameterData
480 let ParenthesizedParameterData { inputs, output, span } = data;
481 ParenthesizedParameterData { inputs: inputs.move_map(|ty| fld.fold_ty(ty)),
482 output: output.map(|ty| fld.fold_ty(ty)),
483 span: fld.new_span(span) }
486 pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
487 l.map(|Local {id, pat, ty, init, span, attrs}| Local {
489 pat: fld.fold_pat(pat),
490 ty: ty.map(|t| fld.fold_ty(t)),
491 init: init.map(|e| fld.fold_expr(e)),
492 span: fld.new_span(span),
493 attrs: fold_attrs(attrs.into(), fld).into(),
497 pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<Attribute> {
501 path: fld.fold_path(attr.path),
502 tokens: fld.fold_tts(attr.tokens),
503 is_sugared_doc: attr.is_sugared_doc,
504 span: fld.new_span(attr.span),
508 pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
511 tts: fld.fold_tts(node.stream()).into(),
512 path: fld.fold_path(node.path),
514 span: fld.new_span(span)
518 pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
521 node: match li.node {
522 NestedMetaItemKind::MetaItem(mi) => {
523 NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
525 NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
527 span: fld.new_span(li.span)
531 pub fn noop_fold_meta_item<T: Folder>(mi: MetaItem, fld: &mut T) -> MetaItem {
534 node: match mi.node {
535 MetaItemKind::Word => MetaItemKind::Word,
536 MetaItemKind::List(mis) => {
537 MetaItemKind::List(mis.move_map(|e| fld.fold_meta_list_item(e)))
539 MetaItemKind::NameValue(s) => MetaItemKind::NameValue(s),
541 span: fld.new_span(mi.span)
545 pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg {
548 pat: fld.fold_pat(pat),
553 pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree {
555 TokenTree::Token(span, tok) =>
556 TokenTree::Token(fld.new_span(span), fld.fold_token(tok)),
557 TokenTree::Delimited(span, delimed) => TokenTree::Delimited(fld.new_span(span), Delimited {
558 tts: fld.fold_tts(delimed.stream()).into(),
559 delim: delimed.delim,
564 pub fn noop_fold_tts<T: Folder>(tts: TokenStream, fld: &mut T) -> TokenStream {
565 tts.trees().map(|tt| fld.fold_tt(tt)).collect()
568 // apply ident folder if it's an ident, apply other folds to interpolated nodes
569 pub fn noop_fold_token<T: Folder>(t: token::Token, fld: &mut T) -> token::Token {
571 token::Ident(id) => token::Ident(fld.fold_ident(id)),
572 token::Lifetime(id) => token::Lifetime(fld.fold_ident(id)),
573 token::Interpolated(nt) => {
574 let nt = match Rc::try_unwrap(nt) {
576 Err(nt) => (*nt).clone(),
578 token::Interpolated(Rc::new(fld.fold_interpolated(nt)))
580 token::SubstNt(ident) => token::SubstNt(fld.fold_ident(ident)),
585 /// apply folder to elements of interpolated nodes
587 // NB: this can occur only when applying a fold to partially expanded code, where
588 // parsed pieces have gotten implanted ito *other* macro invocations. This is relevant
589 // for macro hygiene, but possibly not elsewhere.
591 // One problem here occurs because the types for fold_item, fold_stmt, etc. allow the
592 // folder to return *multiple* items; this is a problem for the nodes here, because
593 // they insist on having exactly one piece. One solution would be to mangle the fold
594 // trait to include one-to-many and one-to-one versions of these entry points, but that
595 // would probably confuse a lot of people and help very few. Instead, I'm just going
596 // to put in dynamic checks. I think the performance impact of this will be pretty much
597 // nonexistent. The danger is that someone will apply a fold to a partially expanded
598 // node, and will be confused by the fact that their "fold_item" or "fold_stmt" isn't
599 // getting called on NtItem or NtStmt nodes. Hopefully they'll wind up reading this
600 // comment, and doing something appropriate.
602 // BTW, design choice: I considered just changing the type of, e.g., NtItem to contain
603 // multiple items, but decided against it when I looked at parse_item_or_view_item and
604 // tried to figure out what I would do with multiple items there....
605 pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
606 -> token::Nonterminal {
608 token::NtItem(item) =>
609 token::NtItem(fld.fold_item(item)
610 // this is probably okay, because the only folds likely
611 // to peek inside interpolated nodes will be renamings/markings,
612 // which map single items to single items
613 .expect_one("expected fold to produce exactly one item")),
614 token::NtBlock(block) => token::NtBlock(fld.fold_block(block)),
615 token::NtStmt(stmt) =>
616 token::NtStmt(fld.fold_stmt(stmt)
617 // this is probably okay, because the only folds likely
618 // to peek inside interpolated nodes will be renamings/markings,
619 // which map single items to single items
620 .expect_one("expected fold to produce exactly one statement")),
621 token::NtPat(pat) => token::NtPat(fld.fold_pat(pat)),
622 token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)),
623 token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)),
624 token::NtIdent(id) => token::NtIdent(Spanned::<Ident>{node: fld.fold_ident(id.node), ..id}),
625 token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)),
626 token::NtPath(path) => token::NtPath(fld.fold_path(path)),
627 token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)),
628 token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
629 token::NtImplItem(item) =>
630 token::NtImplItem(fld.fold_impl_item(item)
631 .expect_one("expected fold to produce exactly one item")),
632 token::NtTraitItem(item) =>
633 token::NtTraitItem(fld.fold_trait_item(item)
634 .expect_one("expected fold to produce exactly one item")),
635 token::NtGenerics(generics) => token::NtGenerics(fld.fold_generics(generics)),
636 token::NtWhereClause(where_clause) =>
637 token::NtWhereClause(fld.fold_where_clause(where_clause)),
638 token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)),
639 token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)),
643 pub fn noop_fold_fn_decl<T: Folder>(decl: P<FnDecl>, fld: &mut T) -> P<FnDecl> {
644 decl.map(|FnDecl {inputs, output, variadic}| FnDecl {
645 inputs: inputs.move_map(|x| fld.fold_arg(x)),
646 output: match output {
647 FunctionRetTy::Ty(ty) => FunctionRetTy::Ty(fld.fold_ty(ty)),
648 FunctionRetTy::Default(span) => FunctionRetTy::Default(fld.new_span(span)),
654 pub fn noop_fold_ty_param_bound<T>(tpb: TyParamBound, fld: &mut T)
658 TraitTyParamBound(ty, modifier) => TraitTyParamBound(fld.fold_poly_trait_ref(ty), modifier),
659 RegionTyParamBound(lifetime) => RegionTyParamBound(fld.fold_lifetime(lifetime)),
663 pub fn noop_fold_ty_param<T: Folder>(tp: TyParam, fld: &mut T) -> TyParam {
664 let TyParam {attrs, id, ident, bounds, default, span} = tp;
665 let attrs: Vec<_> = attrs.into();
667 attrs: attrs.into_iter()
668 .flat_map(|x| fld.fold_attribute(x).into_iter())
672 ident: fld.fold_ident(ident),
673 bounds: fld.fold_bounds(bounds),
674 default: default.map(|x| fld.fold_ty(x)),
675 span: fld.new_span(span),
679 pub fn noop_fold_ty_params<T: Folder>(tps: Vec<TyParam>, fld: &mut T) -> Vec<TyParam> {
680 tps.move_map(|tp| fld.fold_ty_param(tp))
683 pub fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
685 id: fld.new_id(l.id),
687 span: fld.new_span(l.span)
691 pub fn noop_fold_lifetime_def<T: Folder>(l: LifetimeDef, fld: &mut T)
693 let attrs: Vec<_> = l.attrs.into();
695 attrs: attrs.into_iter()
696 .flat_map(|x| fld.fold_attribute(x).into_iter())
699 lifetime: fld.fold_lifetime(l.lifetime),
700 bounds: fld.fold_lifetimes(l.bounds),
704 pub fn noop_fold_lifetimes<T: Folder>(lts: Vec<Lifetime>, fld: &mut T) -> Vec<Lifetime> {
705 lts.move_map(|l| fld.fold_lifetime(l))
708 pub fn noop_fold_lifetime_defs<T: Folder>(lts: Vec<LifetimeDef>, fld: &mut T)
709 -> Vec<LifetimeDef> {
710 lts.move_map(|l| fld.fold_lifetime_def(l))
713 pub fn noop_fold_opt_lifetime<T: Folder>(o_lt: Option<Lifetime>, fld: &mut T)
714 -> Option<Lifetime> {
715 o_lt.map(|lt| fld.fold_lifetime(lt))
718 pub fn noop_fold_generics<T: Folder>(Generics {ty_params, lifetimes, where_clause, span}: Generics,
719 fld: &mut T) -> Generics {
721 ty_params: fld.fold_ty_params(ty_params),
722 lifetimes: fld.fold_lifetime_defs(lifetimes),
723 where_clause: fld.fold_where_clause(where_clause),
724 span: fld.new_span(span),
728 pub fn noop_fold_where_clause<T: Folder>(
729 WhereClause {id, predicates}: WhereClause,
734 predicates: predicates.move_map(|predicate| {
735 fld.fold_where_predicate(predicate)
740 pub fn noop_fold_where_predicate<T: Folder>(
741 pred: WherePredicate,
745 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{bound_lifetimes,
749 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
750 bound_lifetimes: fld.fold_lifetime_defs(bound_lifetimes),
751 bounded_ty: fld.fold_ty(bounded_ty),
752 bounds: bounds.move_map(|x| fld.fold_ty_param_bound(x)),
753 span: fld.new_span(span)
756 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime,
759 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
760 span: fld.new_span(span),
761 lifetime: fld.fold_lifetime(lifetime),
762 bounds: bounds.move_map(|bound| fld.fold_lifetime(bound))
765 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
769 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{
771 lhs_ty: fld.fold_ty(lhs_ty),
772 rhs_ty: fld.fold_ty(rhs_ty),
773 span: fld.new_span(span)
779 pub fn noop_fold_variant_data<T: Folder>(vdata: VariantData, fld: &mut T) -> VariantData {
781 ast::VariantData::Struct(fields, id) => {
782 ast::VariantData::Struct(fields.move_map(|f| fld.fold_struct_field(f)),
785 ast::VariantData::Tuple(fields, id) => {
786 ast::VariantData::Tuple(fields.move_map(|f| fld.fold_struct_field(f)),
789 ast::VariantData::Unit(id) => ast::VariantData::Unit(fld.new_id(id))
793 pub fn noop_fold_trait_ref<T: Folder>(p: TraitRef, fld: &mut T) -> TraitRef {
794 let id = fld.new_id(p.ref_id);
800 path: fld.fold_path(path),
805 pub fn noop_fold_poly_trait_ref<T: Folder>(p: PolyTraitRef, fld: &mut T) -> PolyTraitRef {
807 bound_lifetimes: fld.fold_lifetime_defs(p.bound_lifetimes),
808 trait_ref: fld.fold_trait_ref(p.trait_ref),
809 span: fld.new_span(p.span),
813 pub fn noop_fold_struct_field<T: Folder>(f: StructField, fld: &mut T) -> StructField {
815 span: fld.new_span(f.span),
816 id: fld.new_id(f.id),
817 ident: f.ident.map(|ident| fld.fold_ident(ident)),
818 vis: fld.fold_vis(f.vis),
819 ty: fld.fold_ty(f.ty),
820 attrs: fold_attrs(f.attrs, fld),
824 pub fn noop_fold_field<T: Folder>(f: Field, folder: &mut T) -> Field {
826 ident: respan(f.ident.span, folder.fold_ident(f.ident.node)),
827 expr: folder.fold_expr(f.expr),
828 span: folder.new_span(f.span),
829 is_shorthand: f.is_shorthand,
830 attrs: fold_thin_attrs(f.attrs, folder),
834 pub fn noop_fold_mt<T: Folder>(MutTy {ty, mutbl}: MutTy, folder: &mut T) -> MutTy {
836 ty: folder.fold_ty(ty),
841 pub fn noop_fold_opt_bounds<T: Folder>(b: Option<TyParamBounds>, folder: &mut T)
842 -> Option<TyParamBounds> {
843 b.map(|bounds| folder.fold_bounds(bounds))
846 fn noop_fold_bounds<T: Folder>(bounds: TyParamBounds, folder: &mut T)
848 bounds.move_map(|bound| folder.fold_ty_param_bound(bound))
851 pub fn noop_fold_block<T: Folder>(b: P<Block>, folder: &mut T) -> P<Block> {
852 b.map(|Block {id, stmts, rules, span}| Block {
853 id: folder.new_id(id),
854 stmts: stmts.move_flat_map(|s| folder.fold_stmt(s).into_iter()),
856 span: folder.new_span(span),
860 pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
862 ItemKind::ExternCrate(string) => ItemKind::ExternCrate(string),
863 ItemKind::Use(view_path) => {
864 ItemKind::Use(folder.fold_view_path(view_path))
866 ItemKind::Static(t, m, e) => {
867 ItemKind::Static(folder.fold_ty(t), m, folder.fold_expr(e))
869 ItemKind::Const(t, e) => {
870 ItemKind::Const(folder.fold_ty(t), folder.fold_expr(e))
872 ItemKind::Fn(decl, unsafety, constness, abi, generics, body) => {
873 let generics = folder.fold_generics(generics);
874 let decl = folder.fold_fn_decl(decl);
875 let body = folder.fold_block(body);
876 ItemKind::Fn(decl, unsafety, constness, abi, generics, body)
878 ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)),
879 ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)),
880 ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)),
881 ItemKind::Ty(t, generics) => {
882 ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics))
884 ItemKind::Enum(enum_definition, generics) => {
885 let generics = folder.fold_generics(generics);
886 let variants = enum_definition.variants.move_map(|x| folder.fold_variant(x));
887 ItemKind::Enum(ast::EnumDef { variants: variants }, generics)
889 ItemKind::Struct(struct_def, generics) => {
890 let generics = folder.fold_generics(generics);
891 ItemKind::Struct(folder.fold_variant_data(struct_def), generics)
893 ItemKind::Union(struct_def, generics) => {
894 let generics = folder.fold_generics(generics);
895 ItemKind::Union(folder.fold_variant_data(struct_def), generics)
897 ItemKind::DefaultImpl(unsafety, ref trait_ref) => {
898 ItemKind::DefaultImpl(unsafety, folder.fold_trait_ref((*trait_ref).clone()))
900 ItemKind::Impl(unsafety,
906 impl_items) => ItemKind::Impl(
910 folder.fold_generics(generics),
911 ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref.clone())),
913 impl_items.move_flat_map(|item| folder.fold_impl_item(item)),
915 ItemKind::Trait(unsafety, generics, bounds, items) => ItemKind::Trait(
917 folder.fold_generics(generics),
918 folder.fold_bounds(bounds),
919 items.move_flat_map(|item| folder.fold_trait_item(item)),
921 ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)),
922 ItemKind::MacroDef(tts) => ItemKind::MacroDef(folder.fold_tts(tts.into()).into()),
926 pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T)
927 -> SmallVector<TraitItem> {
928 SmallVector::one(TraitItem {
929 id: folder.new_id(i.id),
930 ident: folder.fold_ident(i.ident),
931 attrs: fold_attrs(i.attrs, folder),
933 TraitItemKind::Const(ty, default) => {
934 TraitItemKind::Const(folder.fold_ty(ty),
935 default.map(|x| folder.fold_expr(x)))
937 TraitItemKind::Method(sig, body) => {
938 TraitItemKind::Method(noop_fold_method_sig(sig, folder),
939 body.map(|x| folder.fold_block(x)))
941 TraitItemKind::Type(bounds, default) => {
942 TraitItemKind::Type(folder.fold_bounds(bounds),
943 default.map(|x| folder.fold_ty(x)))
945 ast::TraitItemKind::Macro(mac) => {
946 TraitItemKind::Macro(folder.fold_mac(mac))
949 span: folder.new_span(i.span)
953 pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T)
954 -> SmallVector<ImplItem> {
955 SmallVector::one(ImplItem {
956 id: folder.new_id(i.id),
957 vis: folder.fold_vis(i.vis),
958 ident: folder.fold_ident(i.ident),
959 attrs: fold_attrs(i.attrs, folder),
960 defaultness: i.defaultness,
962 ast::ImplItemKind::Const(ty, expr) => {
963 ast::ImplItemKind::Const(folder.fold_ty(ty), folder.fold_expr(expr))
965 ast::ImplItemKind::Method(sig, body) => {
966 ast::ImplItemKind::Method(noop_fold_method_sig(sig, folder),
967 folder.fold_block(body))
969 ast::ImplItemKind::Type(ty) => ast::ImplItemKind::Type(folder.fold_ty(ty)),
970 ast::ImplItemKind::Macro(mac) => ast::ImplItemKind::Macro(folder.fold_mac(mac))
972 span: folder.new_span(i.span)
976 pub fn noop_fold_mod<T: Folder>(Mod {inner, items}: Mod, folder: &mut T) -> Mod {
978 inner: folder.new_span(inner),
979 items: items.move_flat_map(|x| folder.fold_item(x)),
983 pub fn noop_fold_crate<T: Folder>(Crate {module, attrs, span}: Crate,
984 folder: &mut T) -> Crate {
985 let mut items = folder.fold_item(P(ast::Item {
986 ident: keywords::Invalid.ident(),
988 id: ast::DUMMY_NODE_ID,
989 vis: ast::Visibility::Public,
991 node: ast::ItemKind::Mod(module),
994 let (module, attrs, span) = match items.next() {
996 assert!(items.next().is_none(),
997 "a crate cannot expand to more than one item");
998 item.and_then(|ast::Item { attrs, span, node, .. }| {
1000 ast::ItemKind::Mod(m) => (m, attrs, span),
1001 _ => panic!("fold converted a module to not a module"),
1018 // fold one item into possibly many items
1019 pub fn noop_fold_item<T: Folder>(i: P<Item>, folder: &mut T) -> SmallVector<P<Item>> {
1020 SmallVector::one(i.map(|i| folder.fold_item_simple(i)))
1023 // fold one item into exactly one item
1024 pub fn noop_fold_item_simple<T: Folder>(Item {id, ident, attrs, node, vis, span}: Item,
1025 folder: &mut T) -> Item {
1027 id: folder.new_id(id),
1028 vis: folder.fold_vis(vis),
1029 ident: folder.fold_ident(ident),
1030 attrs: fold_attrs(attrs, folder),
1031 node: folder.fold_item_kind(node),
1032 span: folder.new_span(span)
1036 pub fn noop_fold_foreign_item<T: Folder>(ni: ForeignItem, folder: &mut T) -> ForeignItem {
1038 id: folder.new_id(ni.id),
1039 vis: folder.fold_vis(ni.vis),
1040 ident: folder.fold_ident(ni.ident),
1041 attrs: fold_attrs(ni.attrs, folder),
1042 node: match ni.node {
1043 ForeignItemKind::Fn(fdec, generics) => {
1044 ForeignItemKind::Fn(folder.fold_fn_decl(fdec), folder.fold_generics(generics))
1046 ForeignItemKind::Static(t, m) => {
1047 ForeignItemKind::Static(folder.fold_ty(t), m)
1050 span: folder.new_span(ni.span)
1054 pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig {
1056 generics: folder.fold_generics(sig.generics),
1058 unsafety: sig.unsafety,
1059 constness: sig.constness,
1060 decl: folder.fold_fn_decl(sig.decl)
1064 pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
1065 p.map(|Pat {id, node, span}| Pat {
1066 id: folder.new_id(id),
1068 PatKind::Wild => PatKind::Wild,
1069 PatKind::Ident(binding_mode, pth1, sub) => {
1070 PatKind::Ident(binding_mode,
1071 Spanned{span: folder.new_span(pth1.span),
1072 node: folder.fold_ident(pth1.node)},
1073 sub.map(|x| folder.fold_pat(x)))
1075 PatKind::Lit(e) => PatKind::Lit(folder.fold_expr(e)),
1076 PatKind::TupleStruct(pth, pats, ddpos) => {
1077 PatKind::TupleStruct(folder.fold_path(pth),
1078 pats.move_map(|x| folder.fold_pat(x)), ddpos)
1080 PatKind::Path(opt_qself, pth) => {
1081 let opt_qself = opt_qself.map(|qself| {
1082 QSelf { ty: folder.fold_ty(qself.ty), position: qself.position }
1084 PatKind::Path(opt_qself, folder.fold_path(pth))
1086 PatKind::Struct(pth, fields, etc) => {
1087 let pth = folder.fold_path(pth);
1088 let fs = fields.move_map(|f| {
1089 Spanned { span: folder.new_span(f.span),
1090 node: ast::FieldPat {
1091 ident: folder.fold_ident(f.node.ident),
1092 pat: folder.fold_pat(f.node.pat),
1093 is_shorthand: f.node.is_shorthand,
1094 attrs: fold_attrs(f.node.attrs.into(), folder).into()
1097 PatKind::Struct(pth, fs, etc)
1099 PatKind::Tuple(elts, ddpos) => {
1100 PatKind::Tuple(elts.move_map(|x| folder.fold_pat(x)), ddpos)
1102 PatKind::Box(inner) => PatKind::Box(folder.fold_pat(inner)),
1103 PatKind::Ref(inner, mutbl) => PatKind::Ref(folder.fold_pat(inner), mutbl),
1104 PatKind::Range(e1, e2, end) => {
1105 PatKind::Range(folder.fold_expr(e1),
1106 folder.fold_expr(e2),
1107 folder.fold_range_end(end))
1109 PatKind::Slice(before, slice, after) => {
1110 PatKind::Slice(before.move_map(|x| folder.fold_pat(x)),
1111 slice.map(|x| folder.fold_pat(x)),
1112 after.move_map(|x| folder.fold_pat(x)))
1114 PatKind::Mac(mac) => PatKind::Mac(folder.fold_mac(mac))
1116 span: folder.new_span(span)
1120 pub fn noop_fold_range_end<T: Folder>(end: RangeEnd, _folder: &mut T) -> RangeEnd {
1124 pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mut T) -> Expr {
1127 ExprKind::Box(e) => {
1128 ExprKind::Box(folder.fold_expr(e))
1130 ExprKind::InPlace(p, e) => {
1131 ExprKind::InPlace(folder.fold_expr(p), folder.fold_expr(e))
1133 ExprKind::Array(exprs) => {
1134 ExprKind::Array(folder.fold_exprs(exprs))
1136 ExprKind::Repeat(expr, count) => {
1137 ExprKind::Repeat(folder.fold_expr(expr), folder.fold_expr(count))
1139 ExprKind::Tup(exprs) => ExprKind::Tup(folder.fold_exprs(exprs)),
1140 ExprKind::Call(f, args) => {
1141 ExprKind::Call(folder.fold_expr(f),
1142 folder.fold_exprs(args))
1144 ExprKind::MethodCall(i, tps, args) => {
1145 ExprKind::MethodCall(
1146 respan(folder.new_span(i.span), folder.fold_ident(i.node)),
1147 tps.move_map(|x| folder.fold_ty(x)),
1148 folder.fold_exprs(args))
1150 ExprKind::Binary(binop, lhs, rhs) => {
1151 ExprKind::Binary(binop,
1152 folder.fold_expr(lhs),
1153 folder.fold_expr(rhs))
1155 ExprKind::Unary(binop, ohs) => {
1156 ExprKind::Unary(binop, folder.fold_expr(ohs))
1158 ExprKind::Lit(l) => ExprKind::Lit(l),
1159 ExprKind::Cast(expr, ty) => {
1160 ExprKind::Cast(folder.fold_expr(expr), folder.fold_ty(ty))
1162 ExprKind::Type(expr, ty) => {
1163 ExprKind::Type(folder.fold_expr(expr), folder.fold_ty(ty))
1165 ExprKind::AddrOf(m, ohs) => ExprKind::AddrOf(m, folder.fold_expr(ohs)),
1166 ExprKind::If(cond, tr, fl) => {
1167 ExprKind::If(folder.fold_expr(cond),
1168 folder.fold_block(tr),
1169 fl.map(|x| folder.fold_expr(x)))
1171 ExprKind::IfLet(pat, expr, tr, fl) => {
1172 ExprKind::IfLet(folder.fold_pat(pat),
1173 folder.fold_expr(expr),
1174 folder.fold_block(tr),
1175 fl.map(|x| folder.fold_expr(x)))
1177 ExprKind::While(cond, body, opt_ident) => {
1178 ExprKind::While(folder.fold_expr(cond),
1179 folder.fold_block(body),
1180 opt_ident.map(|label| respan(folder.new_span(label.span),
1181 folder.fold_ident(label.node))))
1183 ExprKind::WhileLet(pat, expr, body, opt_ident) => {
1184 ExprKind::WhileLet(folder.fold_pat(pat),
1185 folder.fold_expr(expr),
1186 folder.fold_block(body),
1187 opt_ident.map(|label| respan(folder.new_span(label.span),
1188 folder.fold_ident(label.node))))
1190 ExprKind::ForLoop(pat, iter, body, opt_ident) => {
1191 ExprKind::ForLoop(folder.fold_pat(pat),
1192 folder.fold_expr(iter),
1193 folder.fold_block(body),
1194 opt_ident.map(|label| respan(folder.new_span(label.span),
1195 folder.fold_ident(label.node))))
1197 ExprKind::Loop(body, opt_ident) => {
1198 ExprKind::Loop(folder.fold_block(body),
1199 opt_ident.map(|label| respan(folder.new_span(label.span),
1200 folder.fold_ident(label.node))))
1202 ExprKind::Match(expr, arms) => {
1203 ExprKind::Match(folder.fold_expr(expr),
1204 arms.move_map(|x| folder.fold_arm(x)))
1206 ExprKind::Closure(capture_clause, decl, body, span) => {
1207 ExprKind::Closure(capture_clause,
1208 folder.fold_fn_decl(decl),
1209 folder.fold_expr(body),
1210 folder.new_span(span))
1212 ExprKind::Block(blk) => ExprKind::Block(folder.fold_block(blk)),
1213 ExprKind::Assign(el, er) => {
1214 ExprKind::Assign(folder.fold_expr(el), folder.fold_expr(er))
1216 ExprKind::AssignOp(op, el, er) => {
1217 ExprKind::AssignOp(op,
1218 folder.fold_expr(el),
1219 folder.fold_expr(er))
1221 ExprKind::Field(el, ident) => {
1222 ExprKind::Field(folder.fold_expr(el),
1223 respan(folder.new_span(ident.span),
1224 folder.fold_ident(ident.node)))
1226 ExprKind::TupField(el, ident) => {
1227 ExprKind::TupField(folder.fold_expr(el),
1228 respan(folder.new_span(ident.span),
1229 folder.fold_usize(ident.node)))
1231 ExprKind::Index(el, er) => {
1232 ExprKind::Index(folder.fold_expr(el), folder.fold_expr(er))
1234 ExprKind::Range(e1, e2, lim) => {
1235 ExprKind::Range(e1.map(|x| folder.fold_expr(x)),
1236 e2.map(|x| folder.fold_expr(x)),
1239 ExprKind::Path(qself, path) => {
1240 let qself = qself.map(|QSelf { ty, position }| {
1242 ty: folder.fold_ty(ty),
1246 ExprKind::Path(qself, folder.fold_path(path))
1248 ExprKind::Break(opt_ident, opt_expr) => {
1249 ExprKind::Break(opt_ident.map(|label| respan(folder.new_span(label.span),
1250 folder.fold_ident(label.node))),
1251 opt_expr.map(|e| folder.fold_expr(e)))
1253 ExprKind::Continue(opt_ident) => ExprKind::Continue(opt_ident.map(|label|
1254 respan(folder.new_span(label.span),
1255 folder.fold_ident(label.node)))
1257 ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
1258 ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
1260 inputs: asm.inputs.move_map(|(c, input)| {
1261 (c, folder.fold_expr(input))
1263 outputs: asm.outputs.move_map(|out| {
1265 constraint: out.constraint,
1266 expr: folder.fold_expr(out.expr),
1268 is_indirect: out.is_indirect,
1274 ExprKind::Mac(mac) => ExprKind::Mac(folder.fold_mac(mac)),
1275 ExprKind::Struct(path, fields, maybe_expr) => {
1276 ExprKind::Struct(folder.fold_path(path),
1277 fields.move_map(|x| folder.fold_field(x)),
1278 maybe_expr.map(|x| folder.fold_expr(x)))
1280 ExprKind::Paren(ex) => {
1281 let sub_expr = folder.fold_expr(ex);
1283 // Nodes that are equal modulo `Paren` sugar no-ops should have the same ids.
1285 node: ExprKind::Paren(sub_expr),
1286 span: folder.new_span(span),
1287 attrs: fold_attrs(attrs.into(), folder).into(),
1290 ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)),
1291 ExprKind::Catch(body) => ExprKind::Catch(folder.fold_block(body)),
1293 id: folder.new_id(id),
1294 span: folder.new_span(span),
1295 attrs: fold_attrs(attrs.into(), folder).into(),
1299 pub fn noop_fold_opt_expr<T: Folder>(e: P<Expr>, folder: &mut T) -> Option<P<Expr>> {
1300 Some(folder.fold_expr(e))
1303 pub fn noop_fold_exprs<T: Folder>(es: Vec<P<Expr>>, folder: &mut T) -> Vec<P<Expr>> {
1304 es.move_flat_map(|e| folder.fold_opt_expr(e))
1307 pub fn noop_fold_stmt<T: Folder>(Stmt {node, span, id}: Stmt, folder: &mut T) -> SmallVector<Stmt> {
1308 let id = folder.new_id(id);
1309 let span = folder.new_span(span);
1310 noop_fold_stmt_kind(node, folder).into_iter().map(|node| {
1311 Stmt { id: id, node: node, span: span }
1315 pub fn noop_fold_stmt_kind<T: Folder>(node: StmtKind, folder: &mut T) -> SmallVector<StmtKind> {
1317 StmtKind::Local(local) => SmallVector::one(StmtKind::Local(folder.fold_local(local))),
1318 StmtKind::Item(item) => folder.fold_item(item).into_iter().map(StmtKind::Item).collect(),
1319 StmtKind::Expr(expr) => {
1320 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Expr).collect()
1322 StmtKind::Semi(expr) => {
1323 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Semi).collect()
1325 StmtKind::Mac(mac) => SmallVector::one(StmtKind::Mac(mac.map(|(mac, semi, attrs)| {
1326 (folder.fold_mac(mac), semi, fold_attrs(attrs.into(), folder).into())
1331 pub fn noop_fold_vis<T: Folder>(vis: Visibility, folder: &mut T) -> Visibility {
1333 Visibility::Restricted { path, id } => Visibility::Restricted {
1334 path: path.map(|path| folder.fold_path(path)),
1335 id: folder.new_id(id)
1344 use ast::{self, Ident};
1345 use util::parser_testing::{string_to_crate, matches_codepattern};
1350 // this version doesn't care about getting comments or docstrings in.
1351 fn fake_print_crate(s: &mut pprust::State,
1352 krate: &ast::Crate) -> io::Result<()> {
1353 s.print_mod(&krate.module, &krate.attrs)
1356 // change every identifier to "zz"
1357 struct ToZzIdentFolder;
1359 impl Folder for ToZzIdentFolder {
1360 fn fold_ident(&mut self, _: ast::Ident) -> ast::Ident {
1361 Ident::from_str("zz")
1363 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1364 fold::noop_fold_mac(mac, self)
1368 // maybe add to expand.rs...
1369 macro_rules! assert_pred {
1370 ($pred:expr, $predname:expr, $a:expr , $b:expr) => (
1372 let pred_val = $pred;
1375 if !(pred_val(&a_val, &b_val)) {
1376 panic!("expected args satisfying {}, got {} and {}",
1377 $predname, a_val, b_val);
1383 // make sure idents get transformed everywhere
1384 #[test] fn ident_transformation () {
1385 let mut zz_fold = ToZzIdentFolder;
1386 let ast = string_to_crate(
1387 "#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string());
1388 let folded_crate = zz_fold.fold_crate(ast);
1390 matches_codepattern,
1391 "matches_codepattern",
1392 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1393 "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
1396 // even inside macro defs....
1397 #[test] fn ident_transformation_in_defs () {
1398 let mut zz_fold = ToZzIdentFolder;
1399 let ast = string_to_crate(
1400 "macro_rules! a {(b $c:expr $(d $e:token)f+ => \
1401 (g $(d $d $e)+))} ".to_string());
1402 let folded_crate = zz_fold.fold_crate(ast);
1404 matches_codepattern,
1405 "matches_codepattern",
1406 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1407 "macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string());