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_use_tree(&mut self, use_tree: UseTree) -> UseTree {
60 noop_fold_use_tree(use_tree, 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_label(&mut self, label: Label) -> Label {
197 noop_fold_label(label, self)
200 fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
201 noop_fold_lifetime(l, self)
204 fn fold_lifetime_def(&mut self, l: LifetimeDef) -> LifetimeDef {
205 noop_fold_lifetime_def(l, self)
208 fn fold_attribute(&mut self, at: Attribute) -> Option<Attribute> {
209 noop_fold_attribute(at, self)
212 fn fold_arg(&mut self, a: Arg) -> Arg {
213 noop_fold_arg(a, self)
216 fn fold_generics(&mut self, generics: Generics) -> Generics {
217 noop_fold_generics(generics, self)
220 fn fold_trait_ref(&mut self, p: TraitRef) -> TraitRef {
221 noop_fold_trait_ref(p, self)
224 fn fold_poly_trait_ref(&mut self, p: PolyTraitRef) -> PolyTraitRef {
225 noop_fold_poly_trait_ref(p, self)
228 fn fold_variant_data(&mut self, vdata: VariantData) -> VariantData {
229 noop_fold_variant_data(vdata, self)
232 fn fold_lifetimes(&mut self, lts: Vec<Lifetime>) -> Vec<Lifetime> {
233 noop_fold_lifetimes(lts, self)
236 fn fold_lifetime_defs(&mut self, lts: Vec<LifetimeDef>) -> Vec<LifetimeDef> {
237 noop_fold_lifetime_defs(lts, self)
240 fn fold_ty_param(&mut self, tp: TyParam) -> TyParam {
241 noop_fold_ty_param(tp, self)
244 fn fold_generic_param(&mut self, param: GenericParam) -> GenericParam {
245 noop_fold_generic_param(param, self)
248 fn fold_generic_params(&mut self, params: Vec<GenericParam>) -> Vec<GenericParam> {
249 noop_fold_generic_params(params, self)
252 fn fold_tt(&mut self, tt: TokenTree) -> TokenTree {
253 noop_fold_tt(tt, self)
256 fn fold_tts(&mut self, tts: TokenStream) -> TokenStream {
257 noop_fold_tts(tts, self)
260 fn fold_token(&mut self, t: token::Token) -> token::Token {
261 noop_fold_token(t, self)
264 fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal {
265 noop_fold_interpolated(nt, self)
268 fn fold_opt_lifetime(&mut self, o_lt: Option<Lifetime>) -> Option<Lifetime> {
269 noop_fold_opt_lifetime(o_lt, self)
272 fn fold_opt_bounds(&mut self, b: Option<TyParamBounds>)
273 -> Option<TyParamBounds> {
274 noop_fold_opt_bounds(b, self)
277 fn fold_bounds(&mut self, b: TyParamBounds)
279 noop_fold_bounds(b, self)
282 fn fold_ty_param_bound(&mut self, tpb: TyParamBound) -> TyParamBound {
283 noop_fold_ty_param_bound(tpb, self)
286 fn fold_mt(&mut self, mt: MutTy) -> MutTy {
287 noop_fold_mt(mt, self)
290 fn fold_field(&mut self, field: Field) -> Field {
291 noop_fold_field(field, self)
294 fn fold_where_clause(&mut self, where_clause: WhereClause)
296 noop_fold_where_clause(where_clause, self)
299 fn fold_where_predicate(&mut self, where_predicate: WherePredicate)
301 noop_fold_where_predicate(where_predicate, self)
304 fn fold_vis(&mut self, vis: Visibility) -> Visibility {
305 noop_fold_vis(vis, self)
308 fn new_id(&mut self, i: NodeId) -> NodeId {
312 fn new_span(&mut self, sp: Span) -> Span {
317 pub fn noop_fold_meta_items<T: Folder>(meta_items: Vec<MetaItem>, fld: &mut T) -> Vec<MetaItem> {
318 meta_items.move_map(|x| fld.fold_meta_item(x))
321 pub fn noop_fold_use_tree<T: Folder>(use_tree: UseTree, fld: &mut T) -> UseTree {
323 span: fld.new_span(use_tree.span),
324 prefix: fld.fold_path(use_tree.prefix),
325 kind: match use_tree.kind {
326 UseTreeKind::Simple(ident) => UseTreeKind::Simple(fld.fold_ident(ident)),
327 UseTreeKind::Glob => UseTreeKind::Glob,
328 UseTreeKind::Nested(items) => UseTreeKind::Nested(items.move_map(|(tree, id)| {
329 (fld.fold_use_tree(tree), fld.new_id(id))
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,
344 fld: &mut T) -> Arm {
346 attrs: fold_attrs(attrs, fld),
347 pats: pats.move_map(|x| fld.fold_pat(x)),
348 guard: guard.map(|x| fld.fold_expr(x)),
349 body: fld.fold_expr(body),
353 pub fn noop_fold_ty_binding<T: Folder>(b: TypeBinding, fld: &mut T) -> TypeBinding {
355 id: fld.new_id(b.id),
356 ident: fld.fold_ident(b.ident),
357 ty: fld.fold_ty(b.ty),
358 span: fld.new_span(b.span),
362 pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> {
363 t.map(|Ty {id, node, span}| Ty {
366 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node,
367 TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)),
368 TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)),
369 TyKind::Rptr(region, mt) => {
370 TyKind::Rptr(fld.fold_opt_lifetime(region), fld.fold_mt(mt))
372 TyKind::BareFn(f) => {
373 TyKind::BareFn(f.map(|BareFnTy {generic_params, unsafety, abi, decl}| BareFnTy {
374 generic_params: fld.fold_generic_params(generic_params),
377 decl: fld.fold_fn_decl(decl)
380 TyKind::Never => node,
381 TyKind::Tup(tys) => TyKind::Tup(tys.move_map(|ty| fld.fold_ty(ty))),
382 TyKind::Paren(ty) => TyKind::Paren(fld.fold_ty(ty)),
383 TyKind::Path(qself, path) => {
384 let qself = qself.map(|QSelf { ty, position }| {
390 TyKind::Path(qself, fld.fold_path(path))
392 TyKind::Array(ty, e) => {
393 TyKind::Array(fld.fold_ty(ty), fld.fold_expr(e))
395 TyKind::Typeof(expr) => {
396 TyKind::Typeof(fld.fold_expr(expr))
398 TyKind::TraitObject(bounds, syntax) => {
399 TyKind::TraitObject(bounds.move_map(|b| fld.fold_ty_param_bound(b)), syntax)
401 TyKind::ImplTrait(bounds) => {
402 TyKind::ImplTrait(bounds.move_map(|b| fld.fold_ty_param_bound(b)))
404 TyKind::Mac(mac) => {
405 TyKind::Mac(fld.fold_mac(mac))
408 span: fld.new_span(span)
412 pub fn noop_fold_foreign_mod<T: Folder>(ForeignMod {abi, items}: ForeignMod,
413 fld: &mut T) -> ForeignMod {
416 items: items.move_map(|x| fld.fold_foreign_item(x)),
420 pub fn noop_fold_global_asm<T: Folder>(ga: P<GlobalAsm>,
421 _: &mut T) -> P<GlobalAsm> {
425 pub fn noop_fold_variant<T: Folder>(v: Variant, fld: &mut T) -> Variant {
428 name: fld.fold_ident(v.node.name),
429 attrs: fold_attrs(v.node.attrs, fld),
430 data: fld.fold_variant_data(v.node.data),
431 disr_expr: v.node.disr_expr.map(|e| fld.fold_expr(e)),
433 span: fld.new_span(v.span),
437 pub fn noop_fold_ident<T: Folder>(i: Ident, _: &mut T) -> Ident {
441 pub fn noop_fold_usize<T: Folder>(i: usize, _: &mut T) -> usize {
445 pub fn noop_fold_path<T: Folder>(Path { segments, span }: Path, fld: &mut T) -> Path {
447 segments: segments.move_map(|PathSegment {identifier, span, parameters}| PathSegment {
448 identifier: fld.fold_ident(identifier),
449 span: fld.new_span(span),
450 parameters: parameters.map(|ps| ps.map(|ps| fld.fold_path_parameters(ps))),
452 span: fld.new_span(span)
456 pub fn noop_fold_path_parameters<T: Folder>(path_parameters: PathParameters, fld: &mut T)
459 match path_parameters {
460 PathParameters::AngleBracketed(data) =>
461 PathParameters::AngleBracketed(fld.fold_angle_bracketed_parameter_data(data)),
462 PathParameters::Parenthesized(data) =>
463 PathParameters::Parenthesized(fld.fold_parenthesized_parameter_data(data)),
467 pub fn noop_fold_angle_bracketed_parameter_data<T: Folder>(data: AngleBracketedParameterData,
469 -> AngleBracketedParameterData
471 let AngleBracketedParameterData { lifetimes, types, bindings, span } = data;
472 AngleBracketedParameterData { lifetimes: fld.fold_lifetimes(lifetimes),
473 types: types.move_map(|ty| fld.fold_ty(ty)),
474 bindings: bindings.move_map(|b| fld.fold_ty_binding(b)),
475 span: fld.new_span(span) }
478 pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesizedParameterData,
480 -> ParenthesizedParameterData
482 let ParenthesizedParameterData { inputs, output, span } = data;
483 ParenthesizedParameterData { inputs: inputs.move_map(|ty| fld.fold_ty(ty)),
484 output: output.map(|ty| fld.fold_ty(ty)),
485 span: fld.new_span(span) }
488 pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
489 l.map(|Local {id, pat, ty, init, span, attrs}| Local {
491 pat: fld.fold_pat(pat),
492 ty: ty.map(|t| fld.fold_ty(t)),
493 init: init.map(|e| fld.fold_expr(e)),
494 span: fld.new_span(span),
495 attrs: fold_attrs(attrs.into(), fld).into(),
499 pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<Attribute> {
503 path: fld.fold_path(attr.path),
504 tokens: fld.fold_tts(attr.tokens),
505 is_sugared_doc: attr.is_sugared_doc,
506 span: fld.new_span(attr.span),
510 pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
513 tts: fld.fold_tts(node.stream()).into(),
514 path: fld.fold_path(node.path),
516 span: fld.new_span(span)
520 pub fn noop_fold_macro_def<T: Folder>(def: MacroDef, fld: &mut T) -> MacroDef {
522 tokens: fld.fold_tts(def.tokens.into()).into(),
527 pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
530 node: match li.node {
531 NestedMetaItemKind::MetaItem(mi) => {
532 NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
534 NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
536 span: fld.new_span(li.span)
540 pub fn noop_fold_meta_item<T: Folder>(mi: MetaItem, fld: &mut T) -> MetaItem {
543 node: match mi.node {
544 MetaItemKind::Word => MetaItemKind::Word,
545 MetaItemKind::List(mis) => {
546 MetaItemKind::List(mis.move_map(|e| fld.fold_meta_list_item(e)))
548 MetaItemKind::NameValue(s) => MetaItemKind::NameValue(s),
550 span: fld.new_span(mi.span)
554 pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg {
557 pat: fld.fold_pat(pat),
562 pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree {
564 TokenTree::Token(span, tok) =>
565 TokenTree::Token(fld.new_span(span), fld.fold_token(tok)),
566 TokenTree::Delimited(span, delimed) => TokenTree::Delimited(fld.new_span(span), Delimited {
567 tts: fld.fold_tts(delimed.stream()).into(),
568 delim: delimed.delim,
573 pub fn noop_fold_tts<T: Folder>(tts: TokenStream, fld: &mut T) -> TokenStream {
574 tts.map(|tt| fld.fold_tt(tt))
577 // apply ident folder if it's an ident, apply other folds to interpolated nodes
578 pub fn noop_fold_token<T: Folder>(t: token::Token, fld: &mut T) -> token::Token {
580 token::Ident(id) => token::Ident(fld.fold_ident(id)),
581 token::Lifetime(id) => token::Lifetime(fld.fold_ident(id)),
582 token::Interpolated(nt) => {
583 let nt = match Rc::try_unwrap(nt) {
585 Err(nt) => (*nt).clone(),
587 Token::interpolated(fld.fold_interpolated(nt.0))
593 /// apply folder to elements of interpolated nodes
595 // NB: this can occur only when applying a fold to partially expanded code, where
596 // parsed pieces have gotten implanted ito *other* macro invocations. This is relevant
597 // for macro hygiene, but possibly not elsewhere.
599 // One problem here occurs because the types for fold_item, fold_stmt, etc. allow the
600 // folder to return *multiple* items; this is a problem for the nodes here, because
601 // they insist on having exactly one piece. One solution would be to mangle the fold
602 // trait to include one-to-many and one-to-one versions of these entry points, but that
603 // would probably confuse a lot of people and help very few. Instead, I'm just going
604 // to put in dynamic checks. I think the performance impact of this will be pretty much
605 // nonexistent. The danger is that someone will apply a fold to a partially expanded
606 // node, and will be confused by the fact that their "fold_item" or "fold_stmt" isn't
607 // getting called on NtItem or NtStmt nodes. Hopefully they'll wind up reading this
608 // comment, and doing something appropriate.
610 // BTW, design choice: I considered just changing the type of, e.g., NtItem to contain
611 // multiple items, but decided against it when I looked at parse_item_or_view_item and
612 // tried to figure out what I would do with multiple items there....
613 pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
614 -> token::Nonterminal {
616 token::NtItem(item) =>
617 token::NtItem(fld.fold_item(item)
618 // this is probably okay, because the only folds likely
619 // to peek inside interpolated nodes will be renamings/markings,
620 // which map single items to single items
621 .expect_one("expected fold to produce exactly one item")),
622 token::NtBlock(block) => token::NtBlock(fld.fold_block(block)),
623 token::NtStmt(stmt) =>
624 token::NtStmt(fld.fold_stmt(stmt)
625 // this is probably okay, because the only folds likely
626 // to peek inside interpolated nodes will be renamings/markings,
627 // which map single items to single items
628 .expect_one("expected fold to produce exactly one statement")),
629 token::NtPat(pat) => token::NtPat(fld.fold_pat(pat)),
630 token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)),
631 token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)),
632 token::NtIdent(id) => token::NtIdent(Spanned::<Ident>{node: fld.fold_ident(id.node), ..id}),
633 token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)),
634 token::NtPath(path) => token::NtPath(fld.fold_path(path)),
635 token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)),
636 token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
637 token::NtImplItem(item) =>
638 token::NtImplItem(fld.fold_impl_item(item)
639 .expect_one("expected fold to produce exactly one item")),
640 token::NtTraitItem(item) =>
641 token::NtTraitItem(fld.fold_trait_item(item)
642 .expect_one("expected fold to produce exactly one item")),
643 token::NtGenerics(generics) => token::NtGenerics(fld.fold_generics(generics)),
644 token::NtWhereClause(where_clause) =>
645 token::NtWhereClause(fld.fold_where_clause(where_clause)),
646 token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)),
647 token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)),
648 token::NtLifetime(lifetime) => token::NtLifetime(fld.fold_lifetime(lifetime)),
652 pub fn noop_fold_fn_decl<T: Folder>(decl: P<FnDecl>, fld: &mut T) -> P<FnDecl> {
653 decl.map(|FnDecl {inputs, output, variadic}| FnDecl {
654 inputs: inputs.move_map(|x| fld.fold_arg(x)),
655 output: match output {
656 FunctionRetTy::Ty(ty) => FunctionRetTy::Ty(fld.fold_ty(ty)),
657 FunctionRetTy::Default(span) => FunctionRetTy::Default(fld.new_span(span)),
663 pub fn noop_fold_ty_param_bound<T>(tpb: TyParamBound, fld: &mut T)
667 TraitTyParamBound(ty, modifier) => TraitTyParamBound(fld.fold_poly_trait_ref(ty), modifier),
668 RegionTyParamBound(lifetime) => RegionTyParamBound(fld.fold_lifetime(lifetime)),
672 pub fn noop_fold_ty_param<T: Folder>(tp: TyParam, fld: &mut T) -> TyParam {
673 let TyParam {attrs, id, ident, bounds, default, span} = tp;
674 let attrs: Vec<_> = attrs.into();
676 attrs: attrs.into_iter()
677 .flat_map(|x| fld.fold_attribute(x).into_iter())
681 ident: fld.fold_ident(ident),
682 bounds: fld.fold_bounds(bounds),
683 default: default.map(|x| fld.fold_ty(x)),
684 span: fld.new_span(span),
688 pub fn noop_fold_generic_param<T: Folder>(param: GenericParam, fld: &mut T) -> GenericParam {
690 GenericParam::Lifetime(l) => GenericParam::Lifetime(fld.fold_lifetime_def(l)),
691 GenericParam::Type(t) => GenericParam::Type(fld.fold_ty_param(t)),
695 pub fn noop_fold_generic_params<T: Folder>(
696 params: Vec<GenericParam>,
698 ) -> Vec<GenericParam> {
699 params.move_map(|p| fld.fold_generic_param(p))
702 pub fn noop_fold_label<T: Folder>(label: Label, fld: &mut T) -> Label {
704 ident: fld.fold_ident(label.ident),
705 span: fld.new_span(label.span),
709 pub fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
711 id: fld.new_id(l.id),
712 ident: fld.fold_ident(l.ident),
713 span: fld.new_span(l.span)
717 pub fn noop_fold_lifetime_def<T: Folder>(l: LifetimeDef, fld: &mut T)
719 let attrs: Vec<_> = l.attrs.into();
721 attrs: attrs.into_iter()
722 .flat_map(|x| fld.fold_attribute(x).into_iter())
725 lifetime: fld.fold_lifetime(l.lifetime),
726 bounds: fld.fold_lifetimes(l.bounds),
730 pub fn noop_fold_lifetimes<T: Folder>(lts: Vec<Lifetime>, fld: &mut T) -> Vec<Lifetime> {
731 lts.move_map(|l| fld.fold_lifetime(l))
734 pub fn noop_fold_lifetime_defs<T: Folder>(lts: Vec<LifetimeDef>, fld: &mut T)
735 -> Vec<LifetimeDef> {
736 lts.move_map(|l| fld.fold_lifetime_def(l))
739 pub fn noop_fold_opt_lifetime<T: Folder>(o_lt: Option<Lifetime>, fld: &mut T)
740 -> Option<Lifetime> {
741 o_lt.map(|lt| fld.fold_lifetime(lt))
744 pub fn noop_fold_generics<T: Folder>(Generics { params, where_clause, span }: Generics,
745 fld: &mut T) -> Generics {
747 params: fld.fold_generic_params(params),
748 where_clause: fld.fold_where_clause(where_clause),
749 span: fld.new_span(span),
753 pub fn noop_fold_where_clause<T: Folder>(
754 WhereClause {id, predicates, span}: WhereClause,
759 predicates: predicates.move_map(|predicate| {
760 fld.fold_where_predicate(predicate)
766 pub fn noop_fold_where_predicate<T: Folder>(
767 pred: WherePredicate,
771 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{bound_generic_params,
775 ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
776 bound_generic_params: fld.fold_generic_params(bound_generic_params),
777 bounded_ty: fld.fold_ty(bounded_ty),
778 bounds: bounds.move_map(|x| fld.fold_ty_param_bound(x)),
779 span: fld.new_span(span)
782 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime,
785 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
786 span: fld.new_span(span),
787 lifetime: fld.fold_lifetime(lifetime),
788 bounds: bounds.move_map(|bound| fld.fold_lifetime(bound))
791 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
795 ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{
797 lhs_ty: fld.fold_ty(lhs_ty),
798 rhs_ty: fld.fold_ty(rhs_ty),
799 span: fld.new_span(span)
805 pub fn noop_fold_variant_data<T: Folder>(vdata: VariantData, fld: &mut T) -> VariantData {
807 ast::VariantData::Struct(fields, id) => {
808 ast::VariantData::Struct(fields.move_map(|f| fld.fold_struct_field(f)),
811 ast::VariantData::Tuple(fields, id) => {
812 ast::VariantData::Tuple(fields.move_map(|f| fld.fold_struct_field(f)),
815 ast::VariantData::Unit(id) => ast::VariantData::Unit(fld.new_id(id))
819 pub fn noop_fold_trait_ref<T: Folder>(p: TraitRef, fld: &mut T) -> TraitRef {
820 let id = fld.new_id(p.ref_id);
826 path: fld.fold_path(path),
831 pub fn noop_fold_poly_trait_ref<T: Folder>(p: PolyTraitRef, fld: &mut T) -> PolyTraitRef {
833 bound_generic_params: fld.fold_generic_params(p.bound_generic_params),
834 trait_ref: fld.fold_trait_ref(p.trait_ref),
835 span: fld.new_span(p.span),
839 pub fn noop_fold_struct_field<T: Folder>(f: StructField, fld: &mut T) -> StructField {
841 span: fld.new_span(f.span),
842 id: fld.new_id(f.id),
843 ident: f.ident.map(|ident| fld.fold_ident(ident)),
844 vis: fld.fold_vis(f.vis),
845 ty: fld.fold_ty(f.ty),
846 attrs: fold_attrs(f.attrs, fld),
850 pub fn noop_fold_field<T: Folder>(f: Field, folder: &mut T) -> Field {
852 ident: respan(f.ident.span, folder.fold_ident(f.ident.node)),
853 expr: folder.fold_expr(f.expr),
854 span: folder.new_span(f.span),
855 is_shorthand: f.is_shorthand,
856 attrs: fold_thin_attrs(f.attrs, folder),
860 pub fn noop_fold_mt<T: Folder>(MutTy {ty, mutbl}: MutTy, folder: &mut T) -> MutTy {
862 ty: folder.fold_ty(ty),
867 pub fn noop_fold_opt_bounds<T: Folder>(b: Option<TyParamBounds>, folder: &mut T)
868 -> Option<TyParamBounds> {
869 b.map(|bounds| folder.fold_bounds(bounds))
872 fn noop_fold_bounds<T: Folder>(bounds: TyParamBounds, folder: &mut T)
874 bounds.move_map(|bound| folder.fold_ty_param_bound(bound))
877 pub fn noop_fold_block<T: Folder>(b: P<Block>, folder: &mut T) -> P<Block> {
878 b.map(|Block {id, stmts, rules, span, recovered}| Block {
879 id: folder.new_id(id),
880 stmts: stmts.move_flat_map(|s| folder.fold_stmt(s).into_iter()),
882 span: folder.new_span(span),
887 pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
889 ItemKind::ExternCrate(string) => ItemKind::ExternCrate(string),
890 ItemKind::Use(use_tree) => {
891 ItemKind::Use(use_tree.map(|tree| folder.fold_use_tree(tree)))
893 ItemKind::Static(t, m, e) => {
894 ItemKind::Static(folder.fold_ty(t), m, folder.fold_expr(e))
896 ItemKind::Const(t, e) => {
897 ItemKind::Const(folder.fold_ty(t), folder.fold_expr(e))
899 ItemKind::Fn(decl, unsafety, constness, abi, generics, body) => {
900 let generics = folder.fold_generics(generics);
901 let decl = folder.fold_fn_decl(decl);
902 let body = folder.fold_block(body);
903 ItemKind::Fn(decl, unsafety, constness, abi, generics, body)
905 ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)),
906 ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)),
907 ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)),
908 ItemKind::Ty(t, generics) => {
909 ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics))
911 ItemKind::Enum(enum_definition, generics) => {
912 let generics = folder.fold_generics(generics);
913 let variants = enum_definition.variants.move_map(|x| folder.fold_variant(x));
914 ItemKind::Enum(ast::EnumDef { variants: variants }, generics)
916 ItemKind::Struct(struct_def, generics) => {
917 let generics = folder.fold_generics(generics);
918 ItemKind::Struct(folder.fold_variant_data(struct_def), generics)
920 ItemKind::Union(struct_def, generics) => {
921 let generics = folder.fold_generics(generics);
922 ItemKind::Union(folder.fold_variant_data(struct_def), generics)
924 ItemKind::Impl(unsafety,
930 impl_items) => ItemKind::Impl(
934 folder.fold_generics(generics),
935 ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref.clone())),
937 impl_items.move_flat_map(|item| folder.fold_impl_item(item)),
939 ItemKind::Trait(is_auto, unsafety, generics, bounds, items) => ItemKind::Trait(
942 folder.fold_generics(generics),
943 folder.fold_bounds(bounds),
944 items.move_flat_map(|item| folder.fold_trait_item(item)),
946 ItemKind::TraitAlias(generics, bounds) => ItemKind::TraitAlias(
947 folder.fold_generics(generics),
948 folder.fold_bounds(bounds)),
949 ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)),
950 ItemKind::MacroDef(def) => ItemKind::MacroDef(folder.fold_macro_def(def)),
954 pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T)
955 -> SmallVector<TraitItem> {
956 SmallVector::one(TraitItem {
957 id: folder.new_id(i.id),
958 ident: folder.fold_ident(i.ident),
959 attrs: fold_attrs(i.attrs, folder),
960 generics: folder.fold_generics(i.generics),
962 TraitItemKind::Const(ty, default) => {
963 TraitItemKind::Const(folder.fold_ty(ty),
964 default.map(|x| folder.fold_expr(x)))
966 TraitItemKind::Method(sig, body) => {
967 TraitItemKind::Method(noop_fold_method_sig(sig, folder),
968 body.map(|x| folder.fold_block(x)))
970 TraitItemKind::Type(bounds, default) => {
971 TraitItemKind::Type(folder.fold_bounds(bounds),
972 default.map(|x| folder.fold_ty(x)))
974 ast::TraitItemKind::Macro(mac) => {
975 TraitItemKind::Macro(folder.fold_mac(mac))
978 span: folder.new_span(i.span),
983 pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T)
984 -> SmallVector<ImplItem> {
985 SmallVector::one(ImplItem {
986 id: folder.new_id(i.id),
987 vis: folder.fold_vis(i.vis),
988 ident: folder.fold_ident(i.ident),
989 attrs: fold_attrs(i.attrs, folder),
990 generics: folder.fold_generics(i.generics),
991 defaultness: i.defaultness,
993 ast::ImplItemKind::Const(ty, expr) => {
994 ast::ImplItemKind::Const(folder.fold_ty(ty), folder.fold_expr(expr))
996 ast::ImplItemKind::Method(sig, body) => {
997 ast::ImplItemKind::Method(noop_fold_method_sig(sig, folder),
998 folder.fold_block(body))
1000 ast::ImplItemKind::Type(ty) => ast::ImplItemKind::Type(folder.fold_ty(ty)),
1001 ast::ImplItemKind::Macro(mac) => ast::ImplItemKind::Macro(folder.fold_mac(mac))
1003 span: folder.new_span(i.span),
1008 pub fn noop_fold_mod<T: Folder>(Mod {inner, items}: Mod, folder: &mut T) -> Mod {
1010 inner: folder.new_span(inner),
1011 items: items.move_flat_map(|x| folder.fold_item(x)),
1015 pub fn noop_fold_crate<T: Folder>(Crate {module, attrs, span}: Crate,
1016 folder: &mut T) -> Crate {
1017 let mut items = folder.fold_item(P(ast::Item {
1018 ident: keywords::Invalid.ident(),
1020 id: ast::DUMMY_NODE_ID,
1021 vis: ast::Visibility::Public,
1023 node: ast::ItemKind::Mod(module),
1027 let (module, attrs, span) = match items.next() {
1029 assert!(items.next().is_none(),
1030 "a crate cannot expand to more than one item");
1031 item.and_then(|ast::Item { attrs, span, node, .. }| {
1033 ast::ItemKind::Mod(m) => (m, attrs, span),
1034 _ => panic!("fold converted a module to not a module"),
1051 // fold one item into possibly many items
1052 pub fn noop_fold_item<T: Folder>(i: P<Item>, folder: &mut T) -> SmallVector<P<Item>> {
1053 SmallVector::one(i.map(|i| folder.fold_item_simple(i)))
1056 // fold one item into exactly one item
1057 pub fn noop_fold_item_simple<T: Folder>(Item {id, ident, attrs, node, vis, span, tokens}: Item,
1058 folder: &mut T) -> Item {
1060 id: folder.new_id(id),
1061 vis: folder.fold_vis(vis),
1062 ident: folder.fold_ident(ident),
1063 attrs: fold_attrs(attrs, folder),
1064 node: folder.fold_item_kind(node),
1065 span: folder.new_span(span),
1067 // FIXME: if this is replaced with a call to `folder.fold_tts` it causes
1068 // an ICE during resolve... odd!
1073 pub fn noop_fold_foreign_item<T: Folder>(ni: ForeignItem, folder: &mut T) -> ForeignItem {
1075 id: folder.new_id(ni.id),
1076 vis: folder.fold_vis(ni.vis),
1077 ident: folder.fold_ident(ni.ident),
1078 attrs: fold_attrs(ni.attrs, folder),
1079 node: match ni.node {
1080 ForeignItemKind::Fn(fdec, generics) => {
1081 ForeignItemKind::Fn(folder.fold_fn_decl(fdec), folder.fold_generics(generics))
1083 ForeignItemKind::Static(t, m) => {
1084 ForeignItemKind::Static(folder.fold_ty(t), m)
1086 ForeignItemKind::Ty => ForeignItemKind::Ty,
1088 span: folder.new_span(ni.span)
1092 pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig {
1095 unsafety: sig.unsafety,
1096 constness: sig.constness,
1097 decl: folder.fold_fn_decl(sig.decl)
1101 pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
1102 p.map(|Pat {id, node, span}| Pat {
1103 id: folder.new_id(id),
1105 PatKind::Wild => PatKind::Wild,
1106 PatKind::Ident(binding_mode, pth1, sub) => {
1107 PatKind::Ident(binding_mode,
1108 Spanned{span: folder.new_span(pth1.span),
1109 node: folder.fold_ident(pth1.node)},
1110 sub.map(|x| folder.fold_pat(x)))
1112 PatKind::Lit(e) => PatKind::Lit(folder.fold_expr(e)),
1113 PatKind::TupleStruct(pth, pats, ddpos) => {
1114 PatKind::TupleStruct(folder.fold_path(pth),
1115 pats.move_map(|x| folder.fold_pat(x)), ddpos)
1117 PatKind::Path(opt_qself, pth) => {
1118 let opt_qself = opt_qself.map(|qself| {
1119 QSelf { ty: folder.fold_ty(qself.ty), position: qself.position }
1121 PatKind::Path(opt_qself, folder.fold_path(pth))
1123 PatKind::Struct(pth, fields, etc) => {
1124 let pth = folder.fold_path(pth);
1125 let fs = fields.move_map(|f| {
1126 Spanned { span: folder.new_span(f.span),
1127 node: ast::FieldPat {
1128 ident: folder.fold_ident(f.node.ident),
1129 pat: folder.fold_pat(f.node.pat),
1130 is_shorthand: f.node.is_shorthand,
1131 attrs: fold_attrs(f.node.attrs.into(), folder).into()
1134 PatKind::Struct(pth, fs, etc)
1136 PatKind::Tuple(elts, ddpos) => {
1137 PatKind::Tuple(elts.move_map(|x| folder.fold_pat(x)), ddpos)
1139 PatKind::Box(inner) => PatKind::Box(folder.fold_pat(inner)),
1140 PatKind::Ref(inner, mutbl) => PatKind::Ref(folder.fold_pat(inner), mutbl),
1141 PatKind::Range(e1, e2, end) => {
1142 PatKind::Range(folder.fold_expr(e1),
1143 folder.fold_expr(e2),
1144 folder.fold_range_end(end))
1146 PatKind::Slice(before, slice, after) => {
1147 PatKind::Slice(before.move_map(|x| folder.fold_pat(x)),
1148 slice.map(|x| folder.fold_pat(x)),
1149 after.move_map(|x| folder.fold_pat(x)))
1151 PatKind::Mac(mac) => PatKind::Mac(folder.fold_mac(mac))
1153 span: folder.new_span(span)
1157 pub fn noop_fold_range_end<T: Folder>(end: RangeEnd, _folder: &mut T) -> RangeEnd {
1161 pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mut T) -> Expr {
1164 ExprKind::Box(e) => {
1165 ExprKind::Box(folder.fold_expr(e))
1167 ExprKind::InPlace(p, e) => {
1168 ExprKind::InPlace(folder.fold_expr(p), folder.fold_expr(e))
1170 ExprKind::Array(exprs) => {
1171 ExprKind::Array(folder.fold_exprs(exprs))
1173 ExprKind::Repeat(expr, count) => {
1174 ExprKind::Repeat(folder.fold_expr(expr), folder.fold_expr(count))
1176 ExprKind::Tup(exprs) => ExprKind::Tup(folder.fold_exprs(exprs)),
1177 ExprKind::Call(f, args) => {
1178 ExprKind::Call(folder.fold_expr(f),
1179 folder.fold_exprs(args))
1181 ExprKind::MethodCall(seg, args) => {
1182 ExprKind::MethodCall(
1184 identifier: folder.fold_ident(seg.identifier),
1185 span: folder.new_span(seg.span),
1186 parameters: seg.parameters.map(|ps| {
1187 ps.map(|ps| folder.fold_path_parameters(ps))
1190 folder.fold_exprs(args))
1192 ExprKind::Binary(binop, lhs, rhs) => {
1193 ExprKind::Binary(binop,
1194 folder.fold_expr(lhs),
1195 folder.fold_expr(rhs))
1197 ExprKind::Unary(binop, ohs) => {
1198 ExprKind::Unary(binop, folder.fold_expr(ohs))
1200 ExprKind::Lit(l) => ExprKind::Lit(l),
1201 ExprKind::Cast(expr, ty) => {
1202 ExprKind::Cast(folder.fold_expr(expr), folder.fold_ty(ty))
1204 ExprKind::Type(expr, ty) => {
1205 ExprKind::Type(folder.fold_expr(expr), folder.fold_ty(ty))
1207 ExprKind::AddrOf(m, ohs) => ExprKind::AddrOf(m, folder.fold_expr(ohs)),
1208 ExprKind::If(cond, tr, fl) => {
1209 ExprKind::If(folder.fold_expr(cond),
1210 folder.fold_block(tr),
1211 fl.map(|x| folder.fold_expr(x)))
1213 ExprKind::IfLet(pat, expr, tr, fl) => {
1214 ExprKind::IfLet(folder.fold_pat(pat),
1215 folder.fold_expr(expr),
1216 folder.fold_block(tr),
1217 fl.map(|x| folder.fold_expr(x)))
1219 ExprKind::While(cond, body, opt_label) => {
1220 ExprKind::While(folder.fold_expr(cond),
1221 folder.fold_block(body),
1222 opt_label.map(|label| folder.fold_label(label)))
1224 ExprKind::WhileLet(pat, expr, body, opt_label) => {
1225 ExprKind::WhileLet(folder.fold_pat(pat),
1226 folder.fold_expr(expr),
1227 folder.fold_block(body),
1228 opt_label.map(|label| folder.fold_label(label)))
1230 ExprKind::ForLoop(pat, iter, body, opt_label) => {
1231 ExprKind::ForLoop(folder.fold_pat(pat),
1232 folder.fold_expr(iter),
1233 folder.fold_block(body),
1234 opt_label.map(|label| folder.fold_label(label)))
1236 ExprKind::Loop(body, opt_label) => {
1237 ExprKind::Loop(folder.fold_block(body),
1238 opt_label.map(|label| folder.fold_label(label)))
1240 ExprKind::Match(expr, arms) => {
1241 ExprKind::Match(folder.fold_expr(expr),
1242 arms.move_map(|x| folder.fold_arm(x)))
1244 ExprKind::Closure(capture_clause, movability, decl, body, span) => {
1245 ExprKind::Closure(capture_clause,
1247 folder.fold_fn_decl(decl),
1248 folder.fold_expr(body),
1249 folder.new_span(span))
1251 ExprKind::Block(blk) => ExprKind::Block(folder.fold_block(blk)),
1252 ExprKind::Assign(el, er) => {
1253 ExprKind::Assign(folder.fold_expr(el), folder.fold_expr(er))
1255 ExprKind::AssignOp(op, el, er) => {
1256 ExprKind::AssignOp(op,
1257 folder.fold_expr(el),
1258 folder.fold_expr(er))
1260 ExprKind::Field(el, ident) => {
1261 ExprKind::Field(folder.fold_expr(el),
1262 respan(folder.new_span(ident.span),
1263 folder.fold_ident(ident.node)))
1265 ExprKind::TupField(el, ident) => {
1266 ExprKind::TupField(folder.fold_expr(el),
1267 respan(folder.new_span(ident.span),
1268 folder.fold_usize(ident.node)))
1270 ExprKind::Index(el, er) => {
1271 ExprKind::Index(folder.fold_expr(el), folder.fold_expr(er))
1273 ExprKind::Range(e1, e2, lim) => {
1274 ExprKind::Range(e1.map(|x| folder.fold_expr(x)),
1275 e2.map(|x| folder.fold_expr(x)),
1278 ExprKind::Path(qself, path) => {
1279 let qself = qself.map(|QSelf { ty, position }| {
1281 ty: folder.fold_ty(ty),
1285 ExprKind::Path(qself, folder.fold_path(path))
1287 ExprKind::Break(opt_label, opt_expr) => {
1288 ExprKind::Break(opt_label.map(|label| folder.fold_label(label)),
1289 opt_expr.map(|e| folder.fold_expr(e)))
1291 ExprKind::Continue(opt_label) => {
1292 ExprKind::Continue(opt_label.map(|label| folder.fold_label(label)))
1294 ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
1295 ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
1297 inputs: asm.inputs.move_map(|(c, input)| {
1298 (c, folder.fold_expr(input))
1300 outputs: asm.outputs.move_map(|out| {
1302 constraint: out.constraint,
1303 expr: folder.fold_expr(out.expr),
1305 is_indirect: out.is_indirect,
1311 ExprKind::Mac(mac) => ExprKind::Mac(folder.fold_mac(mac)),
1312 ExprKind::Struct(path, fields, maybe_expr) => {
1313 ExprKind::Struct(folder.fold_path(path),
1314 fields.move_map(|x| folder.fold_field(x)),
1315 maybe_expr.map(|x| folder.fold_expr(x)))
1317 ExprKind::Paren(ex) => {
1318 let sub_expr = folder.fold_expr(ex);
1320 // Nodes that are equal modulo `Paren` sugar no-ops should have the same ids.
1322 node: ExprKind::Paren(sub_expr),
1323 span: folder.new_span(span),
1324 attrs: fold_attrs(attrs.into(), folder).into(),
1327 ExprKind::Yield(ex) => ExprKind::Yield(ex.map(|x| folder.fold_expr(x))),
1328 ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)),
1329 ExprKind::Catch(body) => ExprKind::Catch(folder.fold_block(body)),
1331 id: folder.new_id(id),
1332 span: folder.new_span(span),
1333 attrs: fold_attrs(attrs.into(), folder).into(),
1337 pub fn noop_fold_opt_expr<T: Folder>(e: P<Expr>, folder: &mut T) -> Option<P<Expr>> {
1338 Some(folder.fold_expr(e))
1341 pub fn noop_fold_exprs<T: Folder>(es: Vec<P<Expr>>, folder: &mut T) -> Vec<P<Expr>> {
1342 es.move_flat_map(|e| folder.fold_opt_expr(e))
1345 pub fn noop_fold_stmt<T: Folder>(Stmt {node, span, id}: Stmt, folder: &mut T) -> SmallVector<Stmt> {
1346 let id = folder.new_id(id);
1347 let span = folder.new_span(span);
1348 noop_fold_stmt_kind(node, folder).into_iter().map(|node| {
1349 Stmt { id: id, node: node, span: span }
1353 pub fn noop_fold_stmt_kind<T: Folder>(node: StmtKind, folder: &mut T) -> SmallVector<StmtKind> {
1355 StmtKind::Local(local) => SmallVector::one(StmtKind::Local(folder.fold_local(local))),
1356 StmtKind::Item(item) => folder.fold_item(item).into_iter().map(StmtKind::Item).collect(),
1357 StmtKind::Expr(expr) => {
1358 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Expr).collect()
1360 StmtKind::Semi(expr) => {
1361 folder.fold_opt_expr(expr).into_iter().map(StmtKind::Semi).collect()
1363 StmtKind::Mac(mac) => SmallVector::one(StmtKind::Mac(mac.map(|(mac, semi, attrs)| {
1364 (folder.fold_mac(mac), semi, fold_attrs(attrs.into(), folder).into())
1369 pub fn noop_fold_vis<T: Folder>(vis: Visibility, folder: &mut T) -> Visibility {
1371 Visibility::Restricted { path, id } => Visibility::Restricted {
1372 path: path.map(|path| folder.fold_path(path)),
1373 id: folder.new_id(id)
1382 use ast::{self, Ident};
1383 use util::parser_testing::{string_to_crate, matches_codepattern};
1388 // this version doesn't care about getting comments or docstrings in.
1389 fn fake_print_crate(s: &mut pprust::State,
1390 krate: &ast::Crate) -> io::Result<()> {
1391 s.print_mod(&krate.module, &krate.attrs)
1394 // change every identifier to "zz"
1395 struct ToZzIdentFolder;
1397 impl Folder for ToZzIdentFolder {
1398 fn fold_ident(&mut self, _: ast::Ident) -> ast::Ident {
1399 Ident::from_str("zz")
1401 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1402 fold::noop_fold_mac(mac, self)
1406 // maybe add to expand.rs...
1407 macro_rules! assert_pred {
1408 ($pred:expr, $predname:expr, $a:expr , $b:expr) => (
1410 let pred_val = $pred;
1413 if !(pred_val(&a_val, &b_val)) {
1414 panic!("expected args satisfying {}, got {} and {}",
1415 $predname, a_val, b_val);
1421 // make sure idents get transformed everywhere
1422 #[test] fn ident_transformation () {
1423 let mut zz_fold = ToZzIdentFolder;
1424 let ast = string_to_crate(
1425 "#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string());
1426 let folded_crate = zz_fold.fold_crate(ast);
1428 matches_codepattern,
1429 "matches_codepattern",
1430 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1431 "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
1434 // even inside macro defs....
1435 #[test] fn ident_transformation_in_defs () {
1436 let mut zz_fold = ToZzIdentFolder;
1437 let ast = string_to_crate(
1438 "macro_rules! a {(b $c:expr $(d $e:token)f+ => \
1439 (g $(d $d $e)+))} ".to_string());
1440 let folded_crate = zz_fold.fold_crate(ast);
1442 matches_codepattern,
1443 "matches_codepattern",
1444 pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
1445 "macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string());