Implement search for PrefixElement.

pkg/analyzer/lib/src/dart/analysis/search.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:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/visitor.dart';
@@ skipping 42 matching lines @@
     } else if (kind == ElementKind.FUNCTION || kind == ElementKind.METHOD) {
       if (element.enclosingElement is ExecutableElement) {
         return _searchReferences_Local(element, (n) => n is Block);
       }
       return _searchReferences_Function(element);
     } else if (kind == ElementKind.LABEL ||
         kind == ElementKind.LOCAL_VARIABLE) {
       return _searchReferences_Local(element, (n) => n is Block);
     } else if (kind == ElementKind.PARAMETER) {
       return _searchReferences_Parameter(element);
+    } else if (kind == ElementKind.PREFIX) {
+      return _searchReferences_Prefix(element);
     } else if (kind == ElementKind.TYPE_PARAMETER) {
       return _searchReferences_Local(
           element, (n) => n.parent is CompilationUnit);
     }
     // TODO(scheglov) support other kinds
     return const <SearchResult>[];
   }
 
   Future<Null> _addResults(List<SearchResult> results, Element element,
       Map<IndexRelationKind, SearchResultKind> relationToResultKind) async {
@@ skipping 116 matching lines @@
   Future<List<SearchResult>> _searchReferences_Parameter(
       ParameterElement parameter) async {
     List<SearchResult> results = <SearchResult>[];
     results.addAll(await _searchReferences(parameter));
     results.addAll(await _searchReferences_Local(parameter, (AstNode node) {
       AstNode parent = node.parent;
       return parent is ClassDeclaration || parent is CompilationUnit;
     }));
     return results;
   }
+
+  Future<List<SearchResult>> _searchReferences_Prefix(
+      PrefixElement element) async {
+    List<SearchResult> results = <SearchResult>[];
+    LibraryElement libraryElement = element.library;
+    for (CompilationUnitElement unitElement in libraryElement.units) {
+      String unitPath = unitElement.source.fullName;
+      AnalysisResult unitAnalysisResult = await _driver.getResult(unitPath);
+      _LocalReferencesVisitor visitor =
+          new _LocalReferencesVisitor(element, unitElement);
+      unitAnalysisResult.unit.accept(visitor);
+      results.addAll(visitor.results);
+    }
+    return results;
+  }
 }
 
 /**
  * A single search result.
  */
 class SearchResult {
   /**
    * The element that is used at this result.
    */
   final Element element;
@@ skipping 306 matching lines @@
   }
 
   void _addResult(AstNode node, SearchResultKind kind) {
     bool isQualified = node.parent is Label;
     Element enclosingElement =
         _getEnclosingElement(enclosingUnitElement, node.offset);
     results.add(new SearchResult._(element, enclosingElement, kind, node.offset,
         node.length, true, isQualified));
   }
 }