Fasta infrastructure.

pkg/fasta/lib/src/target_implementation.dart

Index: pkg/fasta/lib/src/target_implementation.dart
diff --git a/pkg/fasta/lib/src/target_implementation.dart b/pkg/fasta/lib/src/target_implementation.dart
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+// 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.
+
+library fasta.target_implementation;
+
+import 'builder/builder.dart' show
+    ClassBuilder,
+    LibraryBuilder;
+
+import 'target.dart' show
+    Target;
+
+import 'ticker.dart' show
+    Ticker;
+
+import 'translate_uri.dart' show
+    TranslateUri;
+
+/// Provides the implementation details used by a loader for a target.
+abstract class TargetImplementation extends Target {
+  final TranslateUri uriTranslator;
+
+  TargetImplementation(Ticker ticker, this.uriTranslator)
+      : super(ticker);
+
+  /// Creates a [LibraryBuilder] corresponding to [uri], if one doesn't exist
+  /// already.
+  LibraryBuilder createLibraryBuilder(Uri uri);
+
+  /// Add the classes extended or implemented directly by [cls] to [set].
+  void addDirectSupertype(ClassBuilder cls, Set<ClassBuilder> set);
+
+  /// Returns all classes that will be included in the resulting program.
+  List<ClassBuilder> collectAllClasses();
+
+  /// The class [cls] is involved in a cyclic definition. This method should
+  /// ensure that the cycle is broken, for example, by removing superclass and
+  /// implemented interfaces.
+  void breakCycle(ClassBuilder cls);
+
+  Uri translateUri(Uri uri) => uriTranslator.translate(uri);
+}