Removed CLASS_ELEMENTS from BuildCompilationUnitElementTask and cleaned up comments

pkg/analyzer/lib/task/dart.dart

 // Copyright (c) 2015, 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 analyzer.task.dart;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
 import 'package:analyzer/src/task/dart.dart';
 import 'package:analyzer/task/model.dart';
 
 /**
- * The analysis errors associated with a target.
- *
- * The result is only available for targets representing a Dart compilation unit.
+ * The analysis errors associated with a [Source] representing a compilation
+ * unit.
  */
 final ListResultDescriptor<AnalysisError> DART_ERRORS =
     new ListResultDescriptor<AnalysisError>(
         'DART_ERRORS', AnalysisError.NO_ERRORS);
 
 /**
  * The sources of the libraries that are explicitly imported into a library.
  *
  * The list will be empty if there are no explicit imports, but will not be
  * `null`.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ListResultDescriptor<Source> EXPLICITLY_IMPORTED_LIBRARIES =
     new ListResultDescriptor<Source>(
         'EXPLICITLY_IMPORTED_LIBRARIES', Source.EMPTY_LIST);
 
 /**
  * The sources of the libraries that are exported from a library.
  *
  * The list will be empty if there are no exported libraries, but will not be
  * `null`.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ListResultDescriptor<Source> EXPORTED_LIBRARIES =
     new ListResultDescriptor<Source>('EXPORTED_LIBRARIES', Source.EMPTY_LIST);
 
 /**
  * The sources of the libraries that are implicitly or explicitly imported into
  * a library.
  *
  * The list will minimally contain the source for `dart:core` because it is
  * implicitly imported into every library, and therefore will never be `null`.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ListResultDescriptor<Source> IMPORTED_LIBRARIES =
     new ListResultDescriptor<Source>('IMPORTED_LIBRARIES', Source.EMPTY_LIST);
 
 /**
  * The sources of the parts that are included in a library.
  *
  * The list will be empty if there are no parts, but will not be `null`. The
  * list does *not* include the source for the defining compilation unit.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ListResultDescriptor<Source> INCLUDED_PARTS =
     new ListResultDescriptor<Source>('INCLUDED_PARTS', Source.EMPTY_LIST);
 
 /**
  * A flag specifying whether a library is dependent on code that is only
  * available in a client.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ResultDescriptor<bool> IS_CLIENT =
     new ResultDescriptor<bool>('IS_CLIENT', false);
 
 /**
  * A flag specifying whether a library is launchable.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ResultDescriptor<bool> IS_LAUNCHABLE =
     new ResultDescriptor<bool>('IS_LAUNCHABLE', false);
 
 /**
  * The fully built [LibraryElement] associated with a library.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ResultDescriptor<LibraryElement> LIBRARY_ELEMENT =
     new ResultDescriptor<LibraryElement>('LIBRARY_ELEMENT', null);
 
 /**
  * The compilation unit AST produced while parsing a compilation unit.
  *
  * The AST structure will not have resolution information associated with it.
  *
- * The result is only available for targets representing a Dart compilation unit.
+ * The result is only available for [Source]s representing a compilation unit.
  */
 final ResultDescriptor<CompilationUnit> PARSED_UNIT =
     new ResultDescriptor<CompilationUnit>('PARSED_UNIT', null,
         cachingPolicy: AST_CACHING_POLICY);
 
 /**
- * The resolved [CompilationUnit] associated with a unit.
+ * The resolved [CompilationUnit] associated with a compilation unit.
  *
- * The result is only available for targets representing a unit.
+ * The result is only available for [LibrarySpecificUnit]s.
  */
 final ResultDescriptor<CompilationUnit> RESOLVED_UNIT =
     new ResultDescriptor<CompilationUnit>('RESOLVED_UNIT', null,
         cachingPolicy: AST_CACHING_POLICY);
 
 /**
+ * The kind of a [Source].
+ */
+final ResultDescriptor<SourceKind> SOURCE_KIND =
+    new ResultDescriptor<SourceKind>('SOURCE_KIND', SourceKind.UNKNOWN);
+
+/**
  * The token stream produced while scanning a compilation unit.
  *
  * The value is the first token in the file, or the special end-of-file marker
  * at the end of the stream if the file does not contain any tokens.
  *
- * The result is only available for targets representing a Dart compilation unit.
+ * The result is only available for [Source]s representing a compilation unit.
  */
 final ResultDescriptor<Token> TOKEN_STREAM = new ResultDescriptor<Token>(
     'TOKEN_STREAM', null, cachingPolicy: TOKEN_STREAM_CACHING_POLICY);
 
 /**
  * The sources of the Dart files that a library consists of.
  *
  * The list will include the source of the defining unit and [INCLUDED_PARTS].
  * So, it is never empty or `null`.
  *
- * The result is only available for targets representing a Dart library.
+ * The result is only available for [Source]s representing a library.
  */
 final ListResultDescriptor<Source> UNITS =
     new ListResultDescriptor<Source>('UNITS', Source.EMPTY_LIST);
 
 /**
  * A specific compilation unit in a specific library.
  *
  * This kind of target is associated with information about a compilation unit
  * that differs based on the library that the unit is a part of. For example,
  * the result of resolving a compilation unit depends on the imports, which can
@@ skipping 27 matching lines @@
   @override
   bool operator ==(other) {
     return other is LibrarySpecificUnit &&
         other.library == library &&
         other.unit == unit;
   }
 
   @override
   String toString() => '$unit in $library';
 }