incremental improvement to top level code completion results

pkg/analysis_services/lib/src/completion/top_level_computer.dart

 // Copyright (c) 2014, 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 services.completion.computer.toplevel;
 
 import 'dart:async';
 
 import 'package:analysis_services/completion/completion_computer.dart';
 import 'package:analysis_services/completion/completion_suggestion.dart';
 import 'package:analysis_services/search/search_engine.dart';
+import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 
 /**
- * A computer for `completion.getSuggestions` request results.
+ * A computer for calculating class and top level variable
+ * `completion.getSuggestions` request results
  */
 class TopLevelComputer extends CompletionComputer {
   final SearchEngine searchEngine;
+  final CompilationUnit unit;
 
-  TopLevelComputer(this.searchEngine);
+  TopLevelComputer(this.searchEngine, this.unit);
 
   /**
    * Computes [CompletionSuggestion]s for the specified position in the source.
    */
   Future<List<CompletionSuggestion>> compute() {
     var future = searchEngine.searchTopLevelDeclarations('');
     return future.then((List<SearchMatch> matches) {
-      return matches.map((SearchMatch match) {
-        Element element = match.element;
-        String completion = element.displayName;
-        return new CompletionSuggestion(
-            CompletionSuggestionKind.fromElementKind(element.kind),
-            CompletionRelevance.DEFAULT,
-            completion,
-            completion.length,
-            0,
-            element.isDeprecated,
-            false // isPotential
-            );
-      }).toList();
+
+      // Compute the set of visible libraries to determine relevance
+      var visibleLibraries = new Set<LibraryElement>();
+      visibleLibraries.add(unit.element.library);
+      visibleLibraries.addAll(unit.element.library.importedLibraries);

[Paul Berry, 2014/08/06 18:50:41]

Do we need to do extra work to filter out names beginning with '_' from imported
libraries?  E.g.

foo.dart:
import 'bar.dart';
class A {}
class _B {}
main() {
  ^
}

bar.dart:
class C {}
class _D {}

Completing at the position marked "^" should show "A", "_B", and "C" as options,
but not "_D".

(It's ok by me if you want to address this in a future CL).

[danrubel, 2014/08/06 19:44:38]

Good point. https://codereview.chromium.org/445083003/

+
+      // Compute the set of possible classes and top level variables
+      var suggestions = new List<CompletionSuggestion>();
+      matches.forEach((SearchMatch match) {
+        if (match.kind == MatchKind.DECLARATION) {
+          Element element = match.element;
+          String completion = element.displayName;
+          suggestions.add(
+              new CompletionSuggestion(
+                  CompletionSuggestionKind.fromElementKind(element.kind),
+                  visibleLibraries.contains(element.library) ?
+                      CompletionRelevance.DEFAULT :
+                      CompletionRelevance.LOW,
+                  completion,
+                  completion.length,
+                  0,
+                  element.isDeprecated,
+                  false // isPotential
+          ));
+        }
+      });
+      return suggestions;
     });
   }
+
 }