Introduce OpenWorld.

pkg/compiler/lib/src/compiler.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.compiler_base;
 
 import 'dart:async' show EventSink, Future;
 
 import '../compiler_new.dart' as api;
 import 'cache_strategy.dart' show CacheStrategy;
@@ skipping 59 matching lines @@
 import 'tracer.dart' show Tracer;
 import 'tree/tree.dart' show Node, TypeAnnotation;
 import 'typechecker.dart' show TypeCheckerTask;
 import 'types/types.dart' show GlobalTypeInferenceTask;
 import 'types/masks.dart' show CommonMasks;
 import 'universe/selector.dart' show Selector;
 import 'universe/universe.dart' show ResolutionUniverse, CodegenUniverse;
 import 'universe/use.dart' show StaticUse;
 import 'universe/world_impact.dart' show ImpactStrategy, WorldImpact;
 import 'util/util.dart' show Link, Setlet;
-import 'world.dart' show ClosedWorld, InferenceWorld, World;
+import 'world.dart' show ClosedWorld, InferenceWorld, OpenWorld, WorldImpl;
 
 typedef Backend MakeBackendFuncion(Compiler compiler);
 
 typedef CompilerDiagnosticReporter MakeReporterFunction(
     Compiler compiler, CompilerOptions options);
 
 abstract class Compiler implements LibraryLoaderListener {
   Measurer get measurer;
 
   final IdGenerator idGenerator = new IdGenerator();
-  World _world;
+  WorldImpl _world;
   Types types;
   _CompilerCoreTypes _coreTypes;
   CompilerDiagnosticReporter _reporter;
   _CompilerResolution _resolution;
   ParsingContext _parsingContext;
 
   final CacheStrategy cacheStrategy;
 
   ImpactStrategy impactStrategy = const ImpactStrategy();
 
@@ skipping 116 matching lines @@
       {CompilerOptions options,
       api.CompilerOutput outputProvider,
       this.environment: const _EmptyEnvironment(),
       MakeBackendFuncion makeBackend,
       MakeReporterFunction makeReporter})
       : this.options = options,
         this.cacheStrategy = new CacheStrategy(options.hasIncrementalSupport),
         this.userOutputProvider = outputProvider == null
             ? const NullCompilerOutput()
             : outputProvider {
-    _world = new World(this);
+    _world = new WorldImpl(this);
     if (makeReporter != null) {
       _reporter = makeReporter(this, options);
     } else {
       _reporter = new CompilerDiagnosticReporter(this, options);
     }
     _resolution = new _CompilerResolution(this);
     // TODO(johnniwinther): Initialize core types in [initializeCoreClasses] and
     // make its field final.
     _coreTypes = new _CompilerCoreTypes(_resolution, reporter);
     types = new Types(_resolution);
@@ skipping 58 matching lines @@
     }
 
     _parsingContext =
         new ParsingContext(reporter, options, parser, patchParser, backend);
 
     tasks.addAll(backend.tasks);
   }
 
   /// The world currently being computed by resolution. This forms a basis for
   /// the [inferenceWorld] and later the [closedWorld].
-  World get openWorld => _world;
+  OpenWorld get openWorld => _world;
 
   /// The closed world after resolution but currently refined by inference.
   InferenceWorld get inferenceWorld => _world;
 
   /// The closed world after resolution and inference.
   ClosedWorld get closedWorld => _world;
 
   /// Creates the scanner task.
   ///
   /// Override this to mock the scanner for testing.
@@ skipping 1921 matching lines @@
   _ElementScanner(this.scanner);
   void scanLibrary(LibraryElement library) => scanner.scanLibrary(library);
   void scanUnit(CompilationUnitElement unit) => scanner.scan(unit);
 }
 
 class _EmptyEnvironment implements Environment {
   const _EmptyEnvironment();
 
   String valueOf(String key) => null;
 }