compiler/rustc_ast_pretty/src/pprust/state/item.rs

   1 use crate::pp::Breaks::Inconsistent;
   2 use crate::pprust::state::delimited::IterDelimited;
   3 use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
   4
   5 use rustc_ast as ast;
   6 use rustc_ast::GenericBound;
   7 use rustc_ast::ModKind;
   8 use rustc_span::symbol::Ident;
   9
  10 fn visibility_qualified(vis: &ast::Visibility, s: &str) -> String {
  11     format!("{}{}", State::to_string(|s| s.print_visibility(vis)), s)
  12 }
  13
  14 impl<'a> State<'a> {
  15     fn print_foreign_mod(&mut self, nmod: &ast::ForeignMod, attrs: &[ast::Attribute]) {
  16         self.print_inner_attributes(attrs);
  17         for item in &nmod.items {
  18             self.print_foreign_item(item);
  19         }
  20     }
  21
  22     pub(crate) fn print_foreign_item(&mut self, item: &ast::ForeignItem) {
  23         let ast::Item { id, span, ident, ref attrs, ref kind, ref vis, tokens: _ } = *item;
  24         self.ann.pre(self, AnnNode::SubItem(id));
  25         self.hardbreak_if_not_bol();
  26         self.maybe_print_comment(span.lo());
  27         self.print_outer_attributes(attrs);
  28         match kind {
  29             ast::ForeignItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
  30                 self.print_fn_full(sig, ident, generics, vis, *defaultness, body.as_deref(), attrs);
  31             }
  32             ast::ForeignItemKind::Static(ty, mutbl, body) => {
  33                 let def = ast::Defaultness::Final;
  34                 self.print_item_const(ident, Some(*mutbl), ty, body.as_deref(), vis, def);
  35             }
  36             ast::ForeignItemKind::TyAlias(box ast::TyAlias {
  37                 defaultness,
  38                 generics,
  39                 where_clauses,
  40                 where_predicates_split,
  41                 bounds,
  42                 ty,
  43             }) => {
  44                 self.print_associated_type(
  45                     ident,
  46                     generics,
  47                     *where_clauses,
  48                     *where_predicates_split,
  49                     bounds,
  50                     ty.as_deref(),
  51                     vis,
  52                     *defaultness,
  53                 );
  54             }
  55             ast::ForeignItemKind::MacCall(m) => {
  56                 self.print_mac(m);
  57                 if m.args.need_semicolon() {
  58                     self.word(";");
  59                 }
  60             }
  61         }
  62         self.ann.post(self, AnnNode::SubItem(id))
  63     }
  64
  65     fn print_item_const(
  66         &mut self,
  67         ident: Ident,
  68         mutbl: Option<ast::Mutability>,
  69         ty: &ast::Ty,
  70         body: Option<&ast::Expr>,
  71         vis: &ast::Visibility,
  72         defaultness: ast::Defaultness,
  73     ) {
  74         self.head("");
  75         self.print_visibility(vis);
  76         self.print_defaultness(defaultness);
  77         let leading = match mutbl {
  78             None => "const",
  79             Some(ast::Mutability::Not) => "static",
  80             Some(ast::Mutability::Mut) => "static mut",
  81         };
  82         self.word_space(leading);
  83         self.print_ident(ident);
  84         self.word_space(":");
  85         self.print_type(ty);
  86         if body.is_some() {
  87             self.space();
  88         }
  89         self.end(); // end the head-ibox
  90         if let Some(body) = body {
  91             self.word_space("=");
  92             self.print_expr(body);
  93         }
  94         self.word(";");
  95         self.end(); // end the outer cbox
  96     }
  97
  98     fn print_associated_type(
  99         &mut self,
 100         ident: Ident,
 101         generics: &ast::Generics,
 102         where_clauses: (ast::TyAliasWhereClause, ast::TyAliasWhereClause),
 103         where_predicates_split: usize,
 104         bounds: &ast::GenericBounds,
 105         ty: Option<&ast::Ty>,
 106         vis: &ast::Visibility,
 107         defaultness: ast::Defaultness,
 108     ) {
 109         let (before_predicates, after_predicates) =
 110             generics.where_clause.predicates.split_at(where_predicates_split);
 111         self.head("");
 112         self.print_visibility(vis);
 113         self.print_defaultness(defaultness);
 114         self.word_space("type");
 115         self.print_ident(ident);
 116         self.print_generic_params(&generics.params);
 117         if !bounds.is_empty() {
 118             self.word_nbsp(":");
 119             self.print_type_bounds(bounds);
 120         }
 121         self.print_where_clause_parts(where_clauses.0.0, before_predicates);
 122         if let Some(ty) = ty {
 123             self.space();
 124             self.word_space("=");
 125             self.print_type(ty);
 126         }
 127         self.print_where_clause_parts(where_clauses.1.0, after_predicates);
 128         self.word(";");
 129         self.end(); // end inner head-block
 130         self.end(); // end outer head-block
 131     }
 132
 133     /// Pretty-prints an item.
 134     pub(crate) fn print_item(&mut self, item: &ast::Item) {
 135         self.hardbreak_if_not_bol();
 136         self.maybe_print_comment(item.span.lo());
 137         self.print_outer_attributes(&item.attrs);
 138         self.ann.pre(self, AnnNode::Item(item));
 139         match &item.kind {
 140             ast::ItemKind::ExternCrate(orig_name) => {
 141                 self.head(visibility_qualified(&item.vis, "extern crate"));
 142                 if let &Some(orig_name) = orig_name {
 143                     self.print_name(orig_name);
 144                     self.space();
 145                     self.word("as");
 146                     self.space();
 147                 }
 148                 self.print_ident(item.ident);
 149                 self.word(";");
 150                 self.end(); // end inner head-block
 151                 self.end(); // end outer head-block
 152             }
 153             ast::ItemKind::Use(tree) => {
 154                 self.print_visibility(&item.vis);
 155                 self.word_nbsp("use");
 156                 self.print_use_tree(tree);
 157                 self.word(";");
 158             }
 159             ast::ItemKind::Static(ty, mutbl, body) => {
 160                 let def = ast::Defaultness::Final;
 161                 self.print_item_const(
 162                     item.ident,
 163                     Some(*mutbl),
 164                     ty,
 165                     body.as_deref(),
 166                     &item.vis,
 167                     def,
 168                 );
 169             }
 170             ast::ItemKind::Const(def, ty, body) => {
 171                 self.print_item_const(item.ident, None, ty, body.as_deref(), &item.vis, *def);
 172             }
 173             ast::ItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
 174                 self.print_fn_full(
 175                     sig,
 176                     item.ident,
 177                     generics,
 178                     &item.vis,
 179                     *defaultness,
 180                     body.as_deref(),
 181                     &item.attrs,
 182                 );
 183             }
 184             ast::ItemKind::Mod(unsafety, mod_kind) => {
 185                 self.head(Self::to_string(|s| {
 186                     s.print_visibility(&item.vis);
 187                     s.print_unsafety(*unsafety);
 188                     s.word("mod");
 189                 }));
 190                 self.print_ident(item.ident);
 191
 192                 match mod_kind {
 193                     ModKind::Loaded(items, ..) => {
 194                         self.nbsp();
 195                         self.bopen();
 196                         self.print_inner_attributes(&item.attrs);
 197                         for item in items {
 198                             self.print_item(item);
 199                         }
 200                         let empty = item.attrs.is_empty() && items.is_empty();
 201                         self.bclose(item.span, empty);
 202                     }
 203                     ModKind::Unloaded => {
 204                         self.word(";");
 205                         self.end(); // end inner head-block
 206                         self.end(); // end outer head-block
 207                     }
 208                 }
 209             }
 210             ast::ItemKind::ForeignMod(nmod) => {
 211                 self.head(Self::to_string(|s| {
 212                     s.print_unsafety(nmod.unsafety);
 213                     s.word("extern");
 214                 }));
 215                 if let Some(abi) = nmod.abi {
 216                     self.print_token_literal(abi.as_token_lit(), abi.span);
 217                     self.nbsp();
 218                 }
 219                 self.bopen();
 220                 self.print_foreign_mod(nmod, &item.attrs);
 221                 let empty = item.attrs.is_empty() && nmod.items.is_empty();
 222                 self.bclose(item.span, empty);
 223             }
 224             ast::ItemKind::GlobalAsm(asm) => {
 225                 self.head(visibility_qualified(&item.vis, "global_asm!"));
 226                 self.print_inline_asm(asm);
 227                 self.word(";");
 228                 self.end();
 229                 self.end();
 230             }
 231             ast::ItemKind::TyAlias(box ast::TyAlias {
 232                 defaultness,
 233                 generics,
 234                 where_clauses,
 235                 where_predicates_split,
 236                 bounds,
 237                 ty,
 238             }) => {
 239                 self.print_associated_type(
 240                     item.ident,
 241                     generics,
 242                     *where_clauses,
 243                     *where_predicates_split,
 244                     bounds,
 245                     ty.as_deref(),
 246                     &item.vis,
 247                     *defaultness,
 248                 );
 249             }
 250             ast::ItemKind::Enum(enum_definition, params) => {
 251                 self.print_enum_def(enum_definition, params, item.ident, item.span, &item.vis);
 252             }
 253             ast::ItemKind::Struct(struct_def, generics) => {
 254                 self.head(visibility_qualified(&item.vis, "struct"));
 255                 self.print_struct(struct_def, generics, item.ident, item.span, true);
 256             }
 257             ast::ItemKind::Union(struct_def, generics) => {
 258                 self.head(visibility_qualified(&item.vis, "union"));
 259                 self.print_struct(struct_def, generics, item.ident, item.span, true);
 260             }
 261             ast::ItemKind::Impl(box ast::Impl {
 262                 unsafety,
 263                 polarity,
 264                 defaultness,
 265                 constness,
 266                 generics,
 267                 of_trait,
 268                 self_ty,
 269                 items,
 270             }) => {
 271                 self.head("");
 272                 self.print_visibility(&item.vis);
 273                 self.print_defaultness(*defaultness);
 274                 self.print_unsafety(*unsafety);
 275                 self.word("impl");
 276
 277                 if generics.params.is_empty() {
 278                     self.nbsp();
 279                 } else {
 280                     self.print_generic_params(&generics.params);
 281                     self.space();
 282                 }
 283
 284                 self.print_constness(*constness);
 285
 286                 if let ast::ImplPolarity::Negative(_) = polarity {
 287                     self.word("!");
 288                 }
 289
 290                 if let Some(t) = of_trait {
 291                     self.print_trait_ref(t);
 292                     self.space();
 293                     self.word_space("for");
 294                 }
 295
 296                 self.print_type(self_ty);
 297                 self.print_where_clause(&generics.where_clause);
 298
 299                 self.space();
 300                 self.bopen();
 301                 self.print_inner_attributes(&item.attrs);
 302                 for impl_item in items {
 303                     self.print_assoc_item(impl_item);
 304                 }
 305                 let empty = item.attrs.is_empty() && items.is_empty();
 306                 self.bclose(item.span, empty);
 307             }
 308             ast::ItemKind::Trait(box ast::Trait {
 309                 is_auto,
 310                 unsafety,
 311                 generics,
 312                 bounds,
 313                 items,
 314                 ..
 315             }) => {
 316                 self.head("");
 317                 self.print_visibility(&item.vis);
 318                 self.print_unsafety(*unsafety);
 319                 self.print_is_auto(*is_auto);
 320                 self.word_nbsp("trait");
 321                 self.print_ident(item.ident);
 322                 self.print_generic_params(&generics.params);
 323                 let mut real_bounds = Vec::with_capacity(bounds.len());
 324                 for b in bounds.iter() {
 325                     if let GenericBound::Trait(ptr, ast::TraitBoundModifier::Maybe) = b {
 326                         self.space();
 327                         self.word_space("for ?");
 328                         self.print_trait_ref(&ptr.trait_ref);
 329                     } else {
 330                         real_bounds.push(b.clone());
 331                     }
 332                 }
 333                 if !real_bounds.is_empty() {
 334                     self.word_nbsp(":");
 335                     self.print_type_bounds(&real_bounds);
 336                 }
 337                 self.print_where_clause(&generics.where_clause);
 338                 self.word(" ");
 339                 self.bopen();
 340                 self.print_inner_attributes(&item.attrs);
 341                 for trait_item in items {
 342                     self.print_assoc_item(trait_item);
 343                 }
 344                 let empty = item.attrs.is_empty() && items.is_empty();
 345                 self.bclose(item.span, empty);
 346             }
 347             ast::ItemKind::TraitAlias(generics, bounds) => {
 348                 self.head(visibility_qualified(&item.vis, "trait"));
 349                 self.print_ident(item.ident);
 350                 self.print_generic_params(&generics.params);
 351                 self.nbsp();
 352                 if !bounds.is_empty() {
 353                     self.word_nbsp("=");
 354                     self.print_type_bounds(&bounds);
 355                 }
 356                 self.print_where_clause(&generics.where_clause);
 357                 self.word(";");
 358                 self.end(); // end inner head-block
 359                 self.end(); // end outer head-block
 360             }
 361             ast::ItemKind::MacCall(mac) => {
 362                 self.print_mac(mac);
 363                 if mac.args.need_semicolon() {
 364                     self.word(";");
 365                 }
 366             }
 367             ast::ItemKind::MacroDef(macro_def) => {
 368                 self.print_mac_def(macro_def, &item.ident, item.span, |state| {
 369                     state.print_visibility(&item.vis)
 370                 });
 371             }
 372         }
 373         self.ann.post(self, AnnNode::Item(item))
 374     }
 375
 376     fn print_enum_def(
 377         &mut self,
 378         enum_definition: &ast::EnumDef,
 379         generics: &ast::Generics,
 380         ident: Ident,
 381         span: rustc_span::Span,
 382         visibility: &ast::Visibility,
 383     ) {
 384         self.head(visibility_qualified(visibility, "enum"));
 385         self.print_ident(ident);
 386         self.print_generic_params(&generics.params);
 387         self.print_where_clause(&generics.where_clause);
 388         self.space();
 389         self.print_variants(&enum_definition.variants, span)
 390     }
 391
 392     fn print_variants(&mut self, variants: &[ast::Variant], span: rustc_span::Span) {
 393         self.bopen();
 394         for v in variants {
 395             self.space_if_not_bol();
 396             self.maybe_print_comment(v.span.lo());
 397             self.print_outer_attributes(&v.attrs);
 398             self.ibox(0);
 399             self.print_variant(v);
 400             self.word(",");
 401             self.end();
 402             self.maybe_print_trailing_comment(v.span, None);
 403         }
 404         let empty = variants.is_empty();
 405         self.bclose(span, empty)
 406     }
 407
 408     pub(crate) fn print_visibility(&mut self, vis: &ast::Visibility) {
 409         match &vis.kind {
 410             ast::VisibilityKind::Public => self.word_nbsp("pub"),
 411             ast::VisibilityKind::Restricted { path, shorthand, .. } => {
 412                 let path = Self::to_string(|s| s.print_path(path, false, 0));
 413                 if *shorthand && (path == "crate" || path == "self" || path == "super") {
 414                     self.word_nbsp(format!("pub({})", path))
 415                 } else {
 416                     self.word_nbsp(format!("pub(in {})", path))
 417                 }
 418             }
 419             ast::VisibilityKind::Inherited => {}
 420         }
 421     }
 422
 423     fn print_defaultness(&mut self, defaultness: ast::Defaultness) {
 424         if let ast::Defaultness::Default(_) = defaultness {
 425             self.word_nbsp("default");
 426         }
 427     }
 428
 429     fn print_record_struct_body(&mut self, fields: &[ast::FieldDef], span: rustc_span::Span) {
 430         self.nbsp();
 431         self.bopen();
 432
 433         let empty = fields.is_empty();
 434         if !empty {
 435             self.hardbreak_if_not_bol();
 436
 437             for field in fields {
 438                 self.hardbreak_if_not_bol();
 439                 self.maybe_print_comment(field.span.lo());
 440                 self.print_outer_attributes(&field.attrs);
 441                 self.print_visibility(&field.vis);
 442                 self.print_ident(field.ident.unwrap());
 443                 self.word_nbsp(":");
 444                 self.print_type(&field.ty);
 445                 self.word(",");
 446             }
 447         }
 448
 449         self.bclose(span, empty);
 450     }
 451
 452     fn print_struct(
 453         &mut self,
 454         struct_def: &ast::VariantData,
 455         generics: &ast::Generics,
 456         ident: Ident,
 457         span: rustc_span::Span,
 458         print_finalizer: bool,
 459     ) {
 460         self.print_ident(ident);
 461         self.print_generic_params(&generics.params);
 462         match &struct_def {
 463             ast::VariantData::Tuple(..) | ast::VariantData::Unit(..) => {
 464                 if let ast::VariantData::Tuple(..) = struct_def {
 465                     self.popen();
 466                     self.commasep(Inconsistent, struct_def.fields(), |s, field| {
 467                         s.maybe_print_comment(field.span.lo());
 468                         s.print_outer_attributes(&field.attrs);
 469                         s.print_visibility(&field.vis);
 470                         s.print_type(&field.ty)
 471                     });
 472                     self.pclose();
 473                 }
 474                 self.print_where_clause(&generics.where_clause);
 475                 if print_finalizer {
 476                     self.word(";");
 477                 }
 478                 self.end();
 479                 self.end(); // Close the outer-box.
 480             }
 481             ast::VariantData::Struct(fields, ..) => {
 482                 self.print_where_clause(&generics.where_clause);
 483                 self.print_record_struct_body(fields, span);
 484             }
 485         }
 486     }
 487
 488     pub(crate) fn print_variant(&mut self, v: &ast::Variant) {
 489         self.head("");
 490         self.print_visibility(&v.vis);
 491         let generics = ast::Generics::default();
 492         self.print_struct(&v.data, &generics, v.ident, v.span, false);
 493         if let Some(d) = &v.disr_expr {
 494             self.space();
 495             self.word_space("=");
 496             self.print_expr(&d.value)
 497         }
 498     }
 499
 500     pub(crate) fn print_assoc_item(&mut self, item: &ast::AssocItem) {
 501         let ast::Item { id, span, ident, ref attrs, ref kind, ref vis, tokens: _ } = *item;
 502         self.ann.pre(self, AnnNode::SubItem(id));
 503         self.hardbreak_if_not_bol();
 504         self.maybe_print_comment(span.lo());
 505         self.print_outer_attributes(attrs);
 506         match kind {
 507             ast::AssocItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
 508                 self.print_fn_full(sig, ident, generics, vis, *defaultness, body.as_deref(), attrs);
 509             }
 510             ast::AssocItemKind::Const(def, ty, body) => {
 511                 self.print_item_const(ident, None, ty, body.as_deref(), vis, *def);
 512             }
 513             ast::AssocItemKind::Type(box ast::TyAlias {
 514                 defaultness,
 515                 generics,
 516                 where_clauses,
 517                 where_predicates_split,
 518                 bounds,
 519                 ty,
 520             }) => {
 521                 self.print_associated_type(
 522                     ident,
 523                     generics,
 524                     *where_clauses,
 525                     *where_predicates_split,
 526                     bounds,
 527                     ty.as_deref(),
 528                     vis,
 529                     *defaultness,
 530                 );
 531             }
 532             ast::AssocItemKind::MacCall(m) => {
 533                 self.print_mac(m);
 534                 if m.args.need_semicolon() {
 535                     self.word(";");
 536                 }
 537             }
 538         }
 539         self.ann.post(self, AnnNode::SubItem(id))
 540     }
 541
 542     fn print_fn_full(
 543         &mut self,
 544         sig: &ast::FnSig,
 545         name: Ident,
 546         generics: &ast::Generics,
 547         vis: &ast::Visibility,
 548         defaultness: ast::Defaultness,
 549         body: Option<&ast::Block>,
 550         attrs: &[ast::Attribute],
 551     ) {
 552         if body.is_some() {
 553             self.head("");
 554         }
 555         self.print_visibility(vis);
 556         self.print_defaultness(defaultness);
 557         self.print_fn(&sig.decl, sig.header, Some(name), generics);
 558         if let Some(body) = body {
 559             self.nbsp();
 560             self.print_block_with_attrs(body, attrs);
 561         } else {
 562             self.word(";");
 563         }
 564     }
 565
 566     pub(crate) fn print_fn(
 567         &mut self,
 568         decl: &ast::FnDecl,
 569         header: ast::FnHeader,
 570         name: Option<Ident>,
 571         generics: &ast::Generics,
 572     ) {
 573         self.print_fn_header_info(header);
 574         if let Some(name) = name {
 575             self.nbsp();
 576             self.print_ident(name);
 577         }
 578         self.print_generic_params(&generics.params);
 579         self.print_fn_params_and_ret(decl, false);
 580         self.print_where_clause(&generics.where_clause)
 581     }
 582
 583     pub(crate) fn print_fn_params_and_ret(&mut self, decl: &ast::FnDecl, is_closure: bool) {
 584         let (open, close) = if is_closure { ("|", "|") } else { ("(", ")") };
 585         self.word(open);
 586         self.commasep(Inconsistent, &decl.inputs, |s, param| s.print_param(param, is_closure));
 587         self.word(close);
 588         self.print_fn_ret_ty(&decl.output)
 589     }
 590
 591     fn print_where_clause(&mut self, where_clause: &ast::WhereClause) {
 592         self.print_where_clause_parts(where_clause.has_where_token, &where_clause.predicates);
 593     }
 594
 595     pub(crate) fn print_where_clause_parts(
 596         &mut self,
 597         has_where_token: bool,
 598         predicates: &[ast::WherePredicate],
 599     ) {
 600         if predicates.is_empty() && !has_where_token {
 601             return;
 602         }
 603
 604         self.space();
 605         self.word_space("where");
 606
 607         for (i, predicate) in predicates.iter().enumerate() {
 608             if i != 0 {
 609                 self.word_space(",");
 610             }
 611
 612             self.print_where_predicate(predicate);
 613         }
 614     }
 615
 616     pub fn print_where_predicate(&mut self, predicate: &ast::WherePredicate) {
 617         match predicate {
 618             ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
 619                 bound_generic_params,
 620                 bounded_ty,
 621                 bounds,
 622                 ..
 623             }) => {
 624                 self.print_formal_generic_params(bound_generic_params);
 625                 self.print_type(bounded_ty);
 626                 self.word(":");
 627                 if !bounds.is_empty() {
 628                     self.nbsp();
 629                     self.print_type_bounds(bounds);
 630                 }
 631             }
 632             ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
 633                 lifetime,
 634                 bounds,
 635                 ..
 636             }) => {
 637                 self.print_lifetime(*lifetime);
 638                 self.word(":");
 639                 if !bounds.is_empty() {
 640                     self.nbsp();
 641                     self.print_lifetime_bounds(bounds);
 642                 }
 643             }
 644             ast::WherePredicate::EqPredicate(ast::WhereEqPredicate { lhs_ty, rhs_ty, .. }) => {
 645                 self.print_type(lhs_ty);
 646                 self.space();
 647                 self.word_space("=");
 648                 self.print_type(rhs_ty);
 649             }
 650         }
 651     }
 652
 653     fn print_use_tree(&mut self, tree: &ast::UseTree) {
 654         match &tree.kind {
 655             ast::UseTreeKind::Simple(rename) => {
 656                 self.print_path(&tree.prefix, false, 0);
 657                 if let &Some(rename) = rename {
 658                     self.nbsp();
 659                     self.word_nbsp("as");
 660                     self.print_ident(rename);
 661                 }
 662             }
 663             ast::UseTreeKind::Glob => {
 664                 if !tree.prefix.segments.is_empty() {
 665                     self.print_path(&tree.prefix, false, 0);
 666                     self.word("::");
 667                 }
 668                 self.word("*");
 669             }
 670             ast::UseTreeKind::Nested(items) => {
 671                 if !tree.prefix.segments.is_empty() {
 672                     self.print_path(&tree.prefix, false, 0);
 673                     self.word("::");
 674                 }
 675                 if items.is_empty() {
 676                     self.word("{}");
 677                 } else if items.len() == 1 {
 678                     self.print_use_tree(&items[0].0);
 679                 } else {
 680                     self.cbox(INDENT_UNIT);
 681                     self.word("{");
 682                     self.zerobreak();
 683                     self.ibox(0);
 684                     for use_tree in items.iter().delimited() {
 685                         self.print_use_tree(&use_tree.0);
 686                         if !use_tree.is_last {
 687                             self.word(",");
 688                             if let ast::UseTreeKind::Nested(_) = use_tree.0.kind {
 689                                 self.hardbreak();
 690                             } else {
 691                                 self.space();
 692                             }
 693                         }
 694                     }
 695                     self.end();
 696                     self.trailing_comma();
 697                     self.offset(-INDENT_UNIT);
 698                     self.word("}");
 699                     self.end();
 700                 }
 701             }
 702         }
 703     }
 704 }