Move LibraryUnitTarget into API.

pkg/analyzer/lib/task/dart.dart

Index: pkg/analyzer/lib/task/dart.dart
diff --git a/pkg/analyzer/lib/task/dart.dart b/pkg/analyzer/lib/task/dart.dart
index 819554965f0341d546e326401f689c42fc7d4585..42191a4aa0637b84e6c0cff5dc87c5d390911a27 100644
--- a/pkg/analyzer/lib/task/dart.dart
+++ b/pkg/analyzer/lib/task/dart.dart
@@ -9,6 +9,7 @@ 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/task/model.dart';
 
 /**
@@ -120,3 +121,28 @@ final ResultDescriptor<Token> TOKEN_STREAM =
  */
 final ListResultDescriptor<Source> UNITS =
     new ListResultDescriptor<Source>('UNITS', Source.EMPTY_ARRAY);
+
+/**
+ * A pair of a library [Source] and a unit [Source] in this library.

[Brian Wilkerson, 2015/04/15 21:41:37]

Perhaps:

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 change if a single part is
included in more than one library.

[scheglov, 2015/04/15 23:27:51]

Done.

+ */
+class LibraryUnitTarget implements AnalysisTarget {

[Brian Wilkerson, 2015/04/15 21:41:37]

I'd prefer a more meaningful name, but I'm having trouble thinking of a good
one. I keep coming up with things like "LibrarySpecificUnit" or
"LibraryQualifiedUnit". "Part" seems too short, and doesn't really fit the
defining compilation unit. Hopefully someone else has a better idea.

[scheglov, 2015/04/15 23:27:51]

Done.

+  final Source library;

[Brian Wilkerson, 2015/04/15 21:41:37]

This needs a comment. Even something as simple as

The defining compilation unit of the library in which the [unit] is analyzed.

[scheglov, 2015/04/15 23:27:51]

Done.

+  final Source unit;

[Brian Wilkerson, 2015/04/15 21:41:37]

This needs a comment.

[scheglov, 2015/04/15 23:27:51]

Done.

+
+  LibraryUnitTarget(this.library, this.unit);

[Brian Wilkerson, 2015/04/15 21:41:37]

This needs a comment.

[scheglov, 2015/04/15 23:27:51]

Done.

+
+  @override
+  int get hashCode {
+    return JenkinsSmiHash.combine(library.hashCode, unit.hashCode);
+  }
+
+  @override
+  Source get source => unit;
+
+  @override
+  bool operator ==(other) {
+    return other is LibraryUnitTarget &&
+        other.library == library &&
+        other.unit == unit;
+  }
+}