src/librustc/middle/resolve_lifetime.rs

   1 // Copyright 2012-2013 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.
   4 //
   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.
  10
  11 //! Name resolution for lifetimes.
  12 //!
  13 //! Name resolution for lifetimes follows MUCH simpler rules than the
  14 //! full resolve. For example, lifetime names are never exported or
  15 //! used between functions, and they operate in a purely top-down
  16 //! way. Therefore we break lifetime name resolution into a separate pass.
  17
  18 pub use self::DefRegion::*;
  19 use self::ScopeChain::*;
  20
  21 use session::Session;
  22 use middle::def::{self, DefMap};
  23 use middle::region;
  24 use middle::subst;
  25 use middle::ty;
  26 use std::fmt;
  27 use syntax::ast;
  28 use syntax::codemap::Span;
  29 use syntax::parse::token::special_idents;
  30 use syntax::parse::token;
  31 use syntax::print::pprust::{lifetime_to_string};
  32 use syntax::visit;
  33 use syntax::visit::Visitor;
  34 use util::nodemap::NodeMap;
  35
  36 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
  37 pub enum DefRegion {
  38     DefStaticRegion,
  39     DefEarlyBoundRegion(/* space */ subst::ParamSpace,
  40                         /* index */ u32,
  41                         /* lifetime decl */ ast::NodeId),
  42     DefLateBoundRegion(ty::DebruijnIndex,
  43                        /* lifetime decl */ ast::NodeId),
  44     DefFreeRegion(/* block scope */ region::CodeExtent,
  45                   /* lifetime decl */ ast::NodeId),
  46 }
  47
  48 // maps the id of each lifetime reference to the lifetime decl
  49 // that it corresponds to
  50 pub type NamedRegionMap = NodeMap<DefRegion>;
  51
  52 struct LifetimeContext<'a> {
  53     sess: &'a Session,
  54     named_region_map: &'a mut NamedRegionMap,
  55     scope: Scope<'a>,
  56     def_map: &'a DefMap,
  57 }
  58
  59 enum ScopeChain<'a> {
  60     /// EarlyScope(i, ['a, 'b, ...], s) extends s with early-bound
  61     /// lifetimes, assigning indexes 'a => i, 'b => i+1, ... etc.
  62     EarlyScope(subst::ParamSpace, &'a Vec<ast::LifetimeDef>, Scope<'a>),
  63     /// LateScope(['a, 'b, ...], s) extends s with late-bound
  64     /// lifetimes introduced by the declaration binder_id.
  65     LateScope(&'a Vec<ast::LifetimeDef>, Scope<'a>),
  66     /// lifetimes introduced by items within a code block are scoped
  67     /// to that block.
  68     BlockScope(region::CodeExtent, Scope<'a>),
  69     RootScope
  70 }
  71
  72 type Scope<'a> = &'a ScopeChain<'a>;
  73
  74 static ROOT_SCOPE: ScopeChain<'static> = RootScope;
  75
  76 pub fn krate(sess: &Session, krate: &ast::Crate, def_map: &DefMap) -> NamedRegionMap {
  77     let mut named_region_map = NodeMap();
  78     visit::walk_crate(&mut LifetimeContext {
  79         sess: sess,
  80         named_region_map: &mut named_region_map,
  81         scope: &ROOT_SCOPE,
  82         def_map: def_map,
  83     }, krate);
  84     sess.abort_if_errors();
  85     named_region_map
  86 }
  87
  88 impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
  89     fn visit_item(&mut self, item: &ast::Item) {
  90         // Items always introduce a new root scope
  91         self.with(RootScope, |_, this| {
  92             match item.node {
  93                 ast::ItemFn(..) => {
  94                     // Fn lifetimes get added in visit_fn below:
  95                     visit::walk_item(this, item);
  96                 }
  97                 ast::ItemExternCrate(_) |
  98                 ast::ItemUse(_) |
  99                 ast::ItemMod(..) |
 100                 ast::ItemMac(..) |
 101                 ast::ItemForeignMod(..) |
 102                 ast::ItemStatic(..) |
 103                 ast::ItemConst(..) => {
 104                     // These sorts of items have no lifetime parameters at all.
 105                     visit::walk_item(this, item);
 106                 }
 107                 ast::ItemTy(_, ref generics) |
 108                 ast::ItemEnum(_, ref generics) |
 109                 ast::ItemStruct(_, ref generics) |
 110                 ast::ItemTrait(_, ref generics, _, _) |
 111                 ast::ItemImpl(_, _, ref generics, _, _, _) => {
 112                     // These kinds of items have only early bound lifetime parameters.
 113                     let lifetimes = &generics.lifetimes;
 114                     let early_scope = EarlyScope(subst::TypeSpace, lifetimes, &ROOT_SCOPE);
 115                     this.with(early_scope, |old_scope, this| {
 116                         this.check_lifetime_defs(old_scope, lifetimes);
 117                         visit::walk_item(this, item);
 118                     });
 119                 }
 120             }
 121         });
 122     }
 123
 124     fn visit_fn(&mut self, fk: visit::FnKind<'v>, fd: &'v ast::FnDecl,
 125                 b: &'v ast::Block, s: Span, _: ast::NodeId) {
 126         match fk {
 127             visit::FkItemFn(_, generics, _, _) |
 128             visit::FkMethod(_, generics, _) => {
 129                 self.visit_early_late(subst::FnSpace, generics, |this| {
 130                     visit::walk_fn(this, fk, fd, b, s)
 131                 })
 132             }
 133             visit::FkFnBlock(..) => {
 134                 visit::walk_fn(self, fk, fd, b, s)
 135             }
 136         }
 137     }
 138
 139     fn visit_ty(&mut self, ty: &ast::Ty) {
 140         match ty.node {
 141             ast::TyBareFn(ref c) => {
 142                 visit::walk_lifetime_decls_helper(self, &c.lifetimes);
 143                 self.with(LateScope(&c.lifetimes, self.scope), |old_scope, this| {
 144                     // a bare fn has no bounds, so everything
 145                     // contained within is scoped within its binder.
 146                     this.check_lifetime_defs(old_scope, &c.lifetimes);
 147                     visit::walk_ty(this, ty);
 148                 });
 149             }
 150             ast::TyPath(ref path, id) => {
 151                 // if this path references a trait, then this will resolve to
 152                 // a trait ref, which introduces a binding scope.
 153                 match self.def_map.borrow().get(&id) {
 154                     Some(&def::DefTrait(..)) => {
 155                         self.with(LateScope(&Vec::new(), self.scope), |_, this| {
 156                             this.visit_path(path, id);
 157                         });
 158                     }
 159                     _ => {
 160                         visit::walk_ty(self, ty);
 161                     }
 162                 }
 163             }
 164             _ => {
 165                 visit::walk_ty(self, ty)
 166             }
 167         }
 168     }
 169
 170     fn visit_ty_method(&mut self, m: &ast::TypeMethod) {
 171         self.visit_early_late(
 172             subst::FnSpace, &m.generics,
 173             |this| visit::walk_ty_method(this, m))
 174     }
 175
 176     fn visit_block(&mut self, b: &ast::Block) {
 177         self.with(BlockScope(region::CodeExtent::from_node_id(b.id), self.scope),
 178                   |_, this| visit::walk_block(this, b));
 179     }
 180
 181     fn visit_lifetime_ref(&mut self, lifetime_ref: &ast::Lifetime) {
 182         if lifetime_ref.name == special_idents::static_lifetime.name {
 183             self.insert_lifetime(lifetime_ref, DefStaticRegion);
 184             return;
 185         }
 186         self.resolve_lifetime_ref(lifetime_ref);
 187     }
 188
 189     fn visit_generics(&mut self, generics: &ast::Generics) {
 190         for ty_param in &*generics.ty_params {
 191             visit::walk_ty_param_bounds_helper(self, &ty_param.bounds);
 192             match ty_param.default {
 193                 Some(ref ty) => self.visit_ty(&**ty),
 194                 None => {}
 195             }
 196         }
 197         for predicate in &generics.where_clause.predicates {
 198             match predicate {
 199                 &ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{ ref bounded_ty,
 200                                                                                ref bounds,
 201                                                                                .. }) => {
 202                     self.visit_ty(&**bounded_ty);
 203                     visit::walk_ty_param_bounds_helper(self, bounds);
 204                 }
 205                 &ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{ref lifetime,
 206                                                                                 ref bounds,
 207                                                                                 .. }) => {
 208
 209                     self.visit_lifetime_ref(lifetime);
 210                     for bound in bounds {
 211                         self.visit_lifetime_ref(bound);
 212                     }
 213                 }
 214                 &ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{ id,
 215                                                                          ref path,
 216                                                                          ref ty,
 217                                                                          .. }) => {
 218                     self.visit_path(path, id);
 219                     self.visit_ty(&**ty);
 220                 }
 221             }
 222         }
 223     }
 224
 225     fn visit_poly_trait_ref(&mut self, trait_ref:
 226                             &ast::PolyTraitRef,
 227                             _modifier: &ast::TraitBoundModifier) {
 228         debug!("visit_poly_trait_ref trait_ref={:?}", trait_ref);
 229
 230         self.with(LateScope(&trait_ref.bound_lifetimes, self.scope), |old_scope, this| {
 231             this.check_lifetime_defs(old_scope, &trait_ref.bound_lifetimes);
 232             for lifetime in &trait_ref.bound_lifetimes {
 233                 this.visit_lifetime_def(lifetime);
 234             }
 235             this.visit_trait_ref(&trait_ref.trait_ref)
 236         })
 237     }
 238
 239     fn visit_trait_ref(&mut self, trait_ref: &ast::TraitRef) {
 240         self.visit_path(&trait_ref.path, trait_ref.ref_id);
 241     }
 242 }
 243
 244 impl<'a> LifetimeContext<'a> {
 245     fn with<F>(&mut self, wrap_scope: ScopeChain, f: F) where
 246         F: FnOnce(Scope, &mut LifetimeContext),
 247     {
 248         let LifetimeContext {sess, ref mut named_region_map, ..} = *self;
 249         let mut this = LifetimeContext {
 250             sess: sess,
 251             named_region_map: *named_region_map,
 252             scope: &wrap_scope,
 253             def_map: self.def_map,
 254         };
 255         debug!("entering scope {:?}", this.scope);
 256         f(self.scope, &mut this);
 257         debug!("exiting scope {:?}", this.scope);
 258     }
 259
 260     /// Visits self by adding a scope and handling recursive walk over the contents with `walk`.
 261     ///
 262     /// Handles visiting fns and methods. These are a bit complicated because we must distinguish
 263     /// early- vs late-bound lifetime parameters. We do this by checking which lifetimes appear
 264     /// within type bounds; those are early bound lifetimes, and the rest are late bound.
 265     ///
 266     /// For example:
 267     ///
 268     ///    fn foo<'a,'b,'c,T:Trait<'b>>(...)
 269     ///
 270     /// Here `'a` and `'c` are late bound but `'b` is early bound. Note that early- and late-bound
 271     /// lifetimes may be interspersed together.
 272     ///
 273     /// If early bound lifetimes are present, we separate them into their own list (and likewise
 274     /// for late bound). They will be numbered sequentially, starting from the lowest index that is
 275     /// already in scope (for a fn item, that will be 0, but for a method it might not be). Late
 276     /// bound lifetimes are resolved by name and associated with a binder id (`binder_id`), so the
 277     /// ordering is not important there.
 278     fn visit_early_late<F>(&mut self,
 279                            early_space: subst::ParamSpace,
 280                            generics: &ast::Generics,
 281                            walk: F) where
 282         F: FnOnce(&mut LifetimeContext),
 283     {
 284         let referenced_idents = early_bound_lifetime_names(generics);
 285
 286         debug!("visit_early_late: referenced_idents={:?}",
 287                referenced_idents);
 288
 289         let (early, late): (Vec<_>, _) = generics.lifetimes.iter().cloned().partition(
 290             |l| referenced_idents.iter().any(|&i| i == l.lifetime.name));
 291
 292         self.with(EarlyScope(early_space, &early, self.scope), move |old_scope, this| {
 293             this.with(LateScope(&late, this.scope), move |_, this| {
 294                 this.check_lifetime_defs(old_scope, &generics.lifetimes);
 295                 walk(this);
 296             });
 297         });
 298     }
 299
 300     fn resolve_lifetime_ref(&mut self, lifetime_ref: &ast::Lifetime) {
 301         // Walk up the scope chain, tracking the number of fn scopes
 302         // that we pass through, until we find a lifetime with the
 303         // given name or we run out of scopes. If we encounter a code
 304         // block, then the lifetime is not bound but free, so switch
 305         // over to `resolve_free_lifetime_ref()` to complete the
 306         // search.
 307         let mut late_depth = 0;
 308         let mut scope = self.scope;
 309         loop {
 310             match *scope {
 311                 BlockScope(blk_scope, s) => {
 312                     return self.resolve_free_lifetime_ref(blk_scope, lifetime_ref, s);
 313                 }
 314
 315                 RootScope => {
 316                     break;
 317                 }
 318
 319                 EarlyScope(space, lifetimes, s) => {
 320                     match search_lifetimes(lifetimes, lifetime_ref) {
 321                         Some((index, lifetime_def)) => {
 322                             let decl_id = lifetime_def.id;
 323                             let def = DefEarlyBoundRegion(space, index, decl_id);
 324                             self.insert_lifetime(lifetime_ref, def);
 325                             return;
 326                         }
 327                         None => {
 328                             scope = s;
 329                         }
 330                     }
 331                 }
 332
 333                 LateScope(lifetimes, s) => {
 334                     match search_lifetimes(lifetimes, lifetime_ref) {
 335                         Some((_index, lifetime_def)) => {
 336                             let decl_id = lifetime_def.id;
 337                             let debruijn = ty::DebruijnIndex::new(late_depth + 1);
 338                             let def = DefLateBoundRegion(debruijn, decl_id);
 339                             self.insert_lifetime(lifetime_ref, def);
 340                             return;
 341                         }
 342
 343                         None => {
 344                             late_depth += 1;
 345                             scope = s;
 346                         }
 347                     }
 348                 }
 349             }
 350         }
 351
 352         self.unresolved_lifetime_ref(lifetime_ref);
 353     }
 354
 355     fn resolve_free_lifetime_ref(&mut self,
 356                                  scope_data: region::CodeExtent,
 357                                  lifetime_ref: &ast::Lifetime,
 358                                  scope: Scope) {
 359         // Walk up the scope chain, tracking the outermost free scope,
 360         // until we encounter a scope that contains the named lifetime
 361         // or we run out of scopes.
 362         let mut scope_data = scope_data;
 363         let mut scope = scope;
 364         let mut search_result = None;
 365         loop {
 366             match *scope {
 367                 BlockScope(blk_scope_data, s) => {
 368                     scope_data = blk_scope_data;
 369                     scope = s;
 370                 }
 371
 372                 RootScope => {
 373                     break;
 374                 }
 375
 376                 EarlyScope(_, lifetimes, s) |
 377                 LateScope(lifetimes, s) => {
 378                     search_result = search_lifetimes(lifetimes, lifetime_ref);
 379                     if search_result.is_some() {
 380                         break;
 381                     }
 382                     scope = s;
 383                 }
 384             }
 385         }
 386
 387         match search_result {
 388             Some((_depth, lifetime)) => {
 389                 let def = DefFreeRegion(scope_data, lifetime.id);
 390                 self.insert_lifetime(lifetime_ref, def);
 391             }
 392
 393             None => {
 394                 self.unresolved_lifetime_ref(lifetime_ref);
 395             }
 396         }
 397
 398     }
 399
 400     fn unresolved_lifetime_ref(&self, lifetime_ref: &ast::Lifetime) {
 401         span_err!(self.sess, lifetime_ref.span, E0261,
 402             "use of undeclared lifetime name `{}`",
 403                     token::get_name(lifetime_ref.name));
 404     }
 405
 406     fn check_lifetime_defs(&mut self, old_scope: Scope, lifetimes: &Vec<ast::LifetimeDef>) {
 407         for i in 0..lifetimes.len() {
 408             let lifetime_i = &lifetimes[i];
 409
 410             let special_idents = [special_idents::static_lifetime];
 411             for lifetime in lifetimes {
 412                 if special_idents.iter().any(|&i| i.name == lifetime.lifetime.name) {
 413                     span_err!(self.sess, lifetime.lifetime.span, E0262,
 414                         "illegal lifetime parameter name: `{}`",
 415                                 token::get_name(lifetime.lifetime.name));
 416                 }
 417             }
 418
 419             // It is a hard error to shadow a lifetime within the same scope.
 420             for j in i + 1..lifetimes.len() {
 421                 let lifetime_j = &lifetimes[j];
 422
 423                 if lifetime_i.lifetime.name == lifetime_j.lifetime.name {
 424                     span_err!(self.sess, lifetime_j.lifetime.span, E0263,
 425                         "lifetime name `{}` declared twice in \
 426                                 the same scope",
 427                                 token::get_name(lifetime_j.lifetime.name));
 428                 }
 429             }
 430
 431             // It is a soft error to shadow a lifetime within a parent scope.
 432             self.check_lifetime_def_for_shadowing(old_scope, &lifetime_i.lifetime);
 433
 434             for bound in &lifetime_i.bounds {
 435                 self.resolve_lifetime_ref(bound);
 436             }
 437         }
 438     }
 439
 440     fn check_lifetime_def_for_shadowing(&self,
 441                                         mut old_scope: Scope,
 442                                         lifetime: &ast::Lifetime)
 443     {
 444         loop {
 445             match *old_scope {
 446                 BlockScope(_, s) => {
 447                     old_scope = s;
 448                 }
 449
 450                 RootScope => {
 451                     return;
 452                 }
 453
 454                 EarlyScope(_, lifetimes, s) |
 455                 LateScope(lifetimes, s) => {
 456                     if let Some((_, lifetime_def)) = search_lifetimes(lifetimes, lifetime) {
 457                         self.sess.span_warn(
 458                             lifetime.span,
 459                             &format!("lifetime name `{}` shadows another \
 460                                      lifetime name that is already in scope",
 461                                      token::get_name(lifetime.name)));
 462                         self.sess.span_note(
 463                             lifetime_def.span,
 464                             &format!("shadowed lifetime `{}` declared here",
 465                                      token::get_name(lifetime.name)));
 466                         self.sess.span_note(
 467                             lifetime.span,
 468                             "shadowed lifetimes are deprecated \
 469                              and will become a hard error before 1.0");
 470                         return;
 471                     }
 472
 473                     old_scope = s;
 474                 }
 475             }
 476         }
 477     }
 478
 479     fn insert_lifetime(&mut self,
 480                        lifetime_ref: &ast::Lifetime,
 481                        def: DefRegion) {
 482         if lifetime_ref.id == ast::DUMMY_NODE_ID {
 483             self.sess.span_bug(lifetime_ref.span,
 484                                "lifetime reference not renumbered, \
 485                                probably a bug in syntax::fold");
 486         }
 487
 488         debug!("lifetime_ref={:?} id={:?} resolved to {:?}",
 489                 lifetime_to_string(lifetime_ref),
 490                 lifetime_ref.id,
 491                 def);
 492         self.named_region_map.insert(lifetime_ref.id, def);
 493     }
 494 }
 495
 496 fn search_lifetimes<'a>(lifetimes: &'a Vec<ast::LifetimeDef>,
 497                     lifetime_ref: &ast::Lifetime)
 498                     -> Option<(u32, &'a ast::Lifetime)> {
 499     for (i, lifetime_decl) in lifetimes.iter().enumerate() {
 500         if lifetime_decl.lifetime.name == lifetime_ref.name {
 501             return Some((i as u32, &lifetime_decl.lifetime));
 502         }
 503     }
 504     return None;
 505 }
 506
 507 ///////////////////////////////////////////////////////////////////////////
 508
 509 pub fn early_bound_lifetimes<'a>(generics: &'a ast::Generics) -> Vec<ast::LifetimeDef> {
 510     let referenced_idents = early_bound_lifetime_names(generics);
 511     if referenced_idents.is_empty() {
 512         return Vec::new();
 513     }
 514
 515     generics.lifetimes.iter()
 516         .filter(|l| referenced_idents.iter().any(|&i| i == l.lifetime.name))
 517         .map(|l| (*l).clone())
 518         .collect()
 519 }
 520
 521 /// Given a set of generic declarations, returns a list of names containing all early bound
 522 /// lifetime names for those generics. (In fact, this list may also contain other names.)
 523 fn early_bound_lifetime_names(generics: &ast::Generics) -> Vec<ast::Name> {
 524     // Create two lists, dividing the lifetimes into early/late bound.
 525     // Initially, all of them are considered late, but we will move
 526     // things from late into early as we go if we find references to
 527     // them.
 528     let mut early_bound = Vec::new();
 529     let mut late_bound = generics.lifetimes.iter()
 530                                            .map(|l| l.lifetime.name)
 531                                            .collect();
 532
 533     // Any lifetime that appears in a type bound is early.
 534     {
 535         let mut collector =
 536             FreeLifetimeCollector { early_bound: &mut early_bound,
 537                                     late_bound: &mut late_bound };
 538         for ty_param in &*generics.ty_params {
 539             visit::walk_ty_param_bounds_helper(&mut collector, &ty_param.bounds);
 540         }
 541         for predicate in &generics.where_clause.predicates {
 542             match predicate {
 543                 &ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{ref bounds,
 544                                                                               ref bounded_ty,
 545                                                                               ..}) => {
 546                     collector.visit_ty(&**bounded_ty);
 547                     visit::walk_ty_param_bounds_helper(&mut collector, bounds);
 548                 }
 549                 &ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{ref lifetime,
 550                                                                                 ref bounds,
 551                                                                                 ..}) => {
 552                     collector.visit_lifetime_ref(lifetime);
 553
 554                     for bound in bounds {
 555                         collector.visit_lifetime_ref(bound);
 556                     }
 557                 }
 558                 &ast::WherePredicate::EqPredicate(_) => unimplemented!()
 559             }
 560         }
 561     }
 562
 563     // Any lifetime that either has a bound or is referenced by a
 564     // bound is early.
 565     for lifetime_def in &generics.lifetimes {
 566         if !lifetime_def.bounds.is_empty() {
 567             shuffle(&mut early_bound, &mut late_bound,
 568                     lifetime_def.lifetime.name);
 569             for bound in &lifetime_def.bounds {
 570                 shuffle(&mut early_bound, &mut late_bound,
 571                         bound.name);
 572             }
 573         }
 574     }
 575     return early_bound;
 576
 577     struct FreeLifetimeCollector<'a> {
 578         early_bound: &'a mut Vec<ast::Name>,
 579         late_bound: &'a mut Vec<ast::Name>,
 580     }
 581
 582     impl<'a, 'v> Visitor<'v> for FreeLifetimeCollector<'a> {
 583         fn visit_lifetime_ref(&mut self, lifetime_ref: &ast::Lifetime) {
 584             shuffle(self.early_bound, self.late_bound,
 585                     lifetime_ref.name);
 586         }
 587     }
 588
 589     fn shuffle(early_bound: &mut Vec<ast::Name>,
 590                late_bound: &mut Vec<ast::Name>,
 591                name: ast::Name) {
 592         match late_bound.iter().position(|n| *n == name) {
 593             Some(index) => {
 594                 late_bound.swap_remove(index);
 595                 early_bound.push(name);
 596             }
 597             None => { }
 598         }
 599     }
 600 }
 601
 602 impl<'a> fmt::Debug for ScopeChain<'a> {
 603     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 604         match *self {
 605             EarlyScope(space, defs, _) => write!(fmt, "EarlyScope({:?}, {:?})", space, defs),
 606             LateScope(defs, _) => write!(fmt, "LateScope({:?})", defs),
 607             BlockScope(id, _) => write!(fmt, "BlockScope({:?})", id),
 608             RootScope => write!(fmt, "RootScope"),
 609         }
 610     }
 611 }