Fasta builders.

pkg/fasta/lib/src/import.dart

Index: pkg/fasta/lib/src/import.dart
diff --git a/pkg/fasta/lib/src/import.dart b/pkg/fasta/lib/src/import.dart
new file mode 100644
index 0000000000000000000000000000000000000000..0c04bdf215230b4b812335a734b4c25fd2c76470
--- /dev/null
+++ b/pkg/fasta/lib/src/import.dart
@@ -0,0 +1,54 @@
+// 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.import;
+
+import 'builder/builder.dart' show
+    Builder,
+    LibraryBuilder,
+    PrefixBuilder;
+
+import 'combinator.dart' show
+    Combinator;
+
+typedef void AddToScope(String name, Builder member);
+
+class Import {
+  /// The library being imported.
+  final LibraryBuilder imported;
+
+  final String prefix;
+
+  final List<Combinator> combinators;
+
+  Import(this.imported, this.prefix, this.combinators);
+
+  void finalizeImports(LibraryBuilder importer) {
+    AddToScope add;
+    PrefixBuilder prefix;
+    if (this.prefix == null) {
+      add = importer.addToScope;
+    } else {
+      prefix = new PrefixBuilder(this.prefix, <String, Builder>{}, importer);
+      add = (String name, Builder member) {
+        prefix.exports[name] = member;
+      };
+    }
+    imported.exports.forEach((String name, Builder member) {
+      if (combinators != null) {
+        for (Combinator combinator in combinators) {
+          if (combinator.isShow && !combinator.names.contains(name)) return;
+          if (combinator.isHide && combinator.names.contains(name)) return;
+        }
+      }
+      add(name, member);
+    });
+    if (prefix != null) {
+      Builder existing = importer.addBuilder(prefix.name, prefix);
+      if (existing == prefix) {
+        importer.addToScope(prefix.name, prefix);
+      }
+    }
+  }
+}