Use Map(s) for top-level declarations.

pkg/analyzer/lib/src/dart/analysis/file_state.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/error/listener.dart';
@@ skipping 83 matching lines @@
 
   List<FileState> _importedFiles;
   List<FileState> _exportedFiles;
   List<FileState> _partedFiles;
   List<NameFilter> _exportFilters;
 
   Set<FileState> _directReferencedFiles = new Set<FileState>();
   Set<FileState> _transitiveFiles;
   String _transitiveSignature;
 
-  List<TopLevelDeclaration> _topLevelDeclarations;
-  List<TopLevelDeclaration> _exportedTopLevelDeclarations;
+  Map<String, TopLevelDeclaration> _topLevelDeclarations;
+  Map<String, TopLevelDeclaration> _exportedTopLevelDeclarations;
 
   FileState._(this._fsState, this.path, this.uri, this.source);
 
   /**
    * The unlinked API signature of the file.
    */
   List<int> get apiSignature => _apiSignature;
 
   /**
    * The content of the file.
@@ skipping 10 matching lines @@
    * parted.
    */
   Set<FileState> get directReferencedFiles => _directReferencedFiles;
 
   /**
    * The list of files this file exports.
    */
   List<FileState> get exportedFiles => _exportedFiles;
 
   /**
    * Return [TopLevelDeclaration]s exported from the this library file.

[Paul Berry, 2016/12/02 16:34:42]

Can you update this comment to explain that the keys to the map are the
declaration names?

    */
-  List<TopLevelDeclaration> get exportedTopLevelDeclarations {
+  Map<String, TopLevelDeclaration> get exportedTopLevelDeclarations {
     if (_exportedTopLevelDeclarations == null) {
-      _exportedTopLevelDeclarations = <TopLevelDeclaration>[];
+      _exportedTopLevelDeclarations = <String, TopLevelDeclaration>{};
 
       Set<FileState> seenLibraries = new Set<FileState>();
 
       /**
        * Compute [TopLevelDeclaration]s exported from the [library].
        */
-      List<TopLevelDeclaration> computeExported(FileState library) {
+      Map<String, TopLevelDeclaration> computeExported(FileState library) {
         var declarations = <String, TopLevelDeclaration>{};
         if (seenLibraries.add(library)) {
           // Append the library declarations.
-          for (TopLevelDeclaration t in library.topLevelDeclarations) {
-            declarations[t.name] = t;
-          }
+          declarations.addAll(library.topLevelDeclarations);
           for (FileState part in library.partedFiles) {
-            for (TopLevelDeclaration t in part.topLevelDeclarations) {
-              declarations[t.name] = t;
-            }
+            declarations.addAll(part.topLevelDeclarations);
           }
 
           // Append the exported declarations.
           for (int i = 0; i < library._exportedFiles.length; i++) {
-            List<TopLevelDeclaration> exported =
+            Map<String, TopLevelDeclaration> exported =
                 computeExported(library._exportedFiles[i]);
-            for (TopLevelDeclaration t in exported) {
+            exported.forEach((String name, TopLevelDeclaration t) {
               if (!declarations.containsKey(t.name) &&

[Brian Wilkerson, 2016/12/02 16:32:17]

Somewhat off topic, but if we append the exported declarations before the
library declarations, then we don't need to test whether the name is already
defined.

                   library._exportFilters[i].accepts(t.name)) {
                 declarations[t.name] = t;
               }
-            }
+            });
           }
 
           // We're done with this library.
           seenLibraries.remove(library);
         }
 
-        return declarations.values.toList();
+        return declarations;
       }
 
       _exportedTopLevelDeclarations = computeExported(this);
     }
     return _exportedTopLevelDeclarations;
   }
 
   @override
   int get hashCode => uri.hashCode;
 
@@ skipping 30 matching lines @@
    * The list of files this library file references as parts.
    */
   List<FileState> get partedFiles => _partedFiles;
 
   /**
    * The external names referenced by the file.
    */
   Set<String> get referencedNames => _referencedNames;
 
   /**
    * Return public top-level declarations declared in the file.

[Paul Berry, 2016/12/02 16:34:42]

Ditto

    */
-  List<TopLevelDeclaration> get topLevelDeclarations {
+  Map<String, TopLevelDeclaration> get topLevelDeclarations {
     if (_topLevelDeclarations == null) {
-      _topLevelDeclarations = <TopLevelDeclaration>[];
+      _topLevelDeclarations = <String, TopLevelDeclaration>{};
 
       void addDeclaration(TopLevelDeclarationKind kind, String name) {
         if (!name.startsWith('_')) {
-          _topLevelDeclarations.add(new TopLevelDeclaration(kind, name));
+          _topLevelDeclarations[name] = new TopLevelDeclaration(kind, name);
         }
       }
 
       // Add types.
       for (UnlinkedClass type in unlinked.classes) {
         addDeclaration(TopLevelDeclarationKind.type, type.name);
       }
       for (UnlinkedEnum type in unlinked.enums) {
         addDeclaration(TopLevelDeclarationKind.type, type.name);
       }
@@ skipping 423 matching lines @@
         .where((f) => f._transitiveFiles == null)
         .toSet();
   }
 
   Set<FileState> get filesWithoutTransitiveSignature {
     return state._uriToFile.values
         .where((f) => f._transitiveSignature == null)
         .toSet();
   }
 }