Implement modular compilation

lib/src/js_ast/printer.dart

 // Copyright (c) 2012, 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.
 
 part of js_ast;
 
 
 class JavaScriptPrintingOptions {
   final bool shouldCompressOutput;
   final bool minifyLocalVariables;
@@ skipping 1252 matching lines @@
 
   fromClauseOut(LiteralString from) {
     if (from != null) {
       out(' from');
       spaceOut();
       visit(from);
     }
   }
 
   visitNameSpecifier(NameSpecifier node) {
-    out(node.name);
+    if (node.isStar) {
+      out('*');
+    } else {
+      var importName = node.name.name;
+      out(importName);
+
+      if (node.asName == null) {
+        // If our local was renamed, generate an implicit "as".
+        // This is a convenience feature so imports can be renamed.
+        var localName = localNamer.getName(node.name);
+        if (localName != importName) {
+          out(' as ');
+          out(localName);
+        }
+      }
+    }
     if (node.asName != null) {
       out(' as ');
-      out(node.asName);
+      visitIdentifier(node.asName);
     }
   }
 
   visitModule(Module node) {
     visitAll(node.body);
   }
 
   visitLiteralExpression(LiteralExpression node) {
     String template = node.template;
     List<Expression> inputs = node.inputs;
@@ skipping 395 matching lines @@
     declare(node.name);
     node.function.accept(this);
   }
 
   visitClassExpression(ClassExpression node) {
     declare(node.name);
     if (node.heritage != null) node.heritage.accept(this);
     for (Method element in node.methods) element.accept(this);
   }
 }