Implement prefixes in NewExpression.

dart/frog/leg/resolver.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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
 }
 
 class TreeElementMapping implements TreeElements {
@@ skipping 1424 matching lines @@
 
   visitTypeAnnotation(TypeAnnotation node) {
     // TODO(ahe): Do not ignore type arguments.
     return visit(node.typeName);
   }
 
   visitSend(Send node) {
     Element e = visit(node.receiver);
     if (e === null) return null; // TODO(ahe): Return erroneous element.
 
+    Identifier name = node.selector.asIdentifier();
+    if (name === null) internalError(node.selector, 'unexpected node');
+
     if (e.kind === ElementKind.CLASS) {
       ClassElement cls = e;
       cls.resolve(compiler);
       compiler.resolver.toResolve.add(cls);
       if (cls.isInterface() && (cls.defaultClass === null)) {
         error(node.receiver, MessageKind.CANNOT_INSTANTIATE_INTERFACE,
               [cls.name]);
       }
-      Identifier name = node.selector.asIdentifier();
-      if (name === null) {
-        internalError(node.selector, 'unexpected node');
-      }
       SourceString constructorName =
         Elements.constructConstructorName(cls.name, name.source);
       FunctionElement constructor = cls.lookupConstructor(constructorName);
       if (constructor === null) {
         error(name, MessageKind.CANNOT_FIND_CONSTRUCTOR, [name]);
       }
       e = constructor;
+    } else if (e.kind === ElementKind.PREFIX) {
+      PrefixElement prefix = e;
+      e = prefix.library.lookupLocalMember(name.source);
+      if (e === null) {
+        error(name, MessageKind.CANNOT_RESOLVE, [name]);
+        // TODO(ahe): Return erroneous element.
+      } else if (e.kind !== ElementKind.CLASS) {
+        error(node, MessageKind.NOT_A_TYPE, [name]);
+      }
     } else {
-      internalError(node.resolve, 'unexpected element $e');
+      internalError(node.receiver, 'unexpected element $e');
     }
     return e;
   }
 
   Element visitIdentifier(Identifier node) {
     SourceString name = node.source;
     Element e = resolver.lookup(node, name);
     if (e === null) {
       error(node, MessageKind.CANNOT_RESOLVE, [name]);
       // TODO(ahe): Return erroneous element.
     } else if (e.kind === ElementKind.TYPEDEF) {
       error(node, MessageKind.CANNOT_INSTANTIATE_TYPEDEF, [name]);
-    } else if (e.kind !== ElementKind.CLASS) {
+    } else if (e.kind !== ElementKind.CLASS && e.kind !== ElementKind.PREFIX) {
       error(node, MessageKind.NOT_A_TYPE, [name]);
     }
     return e;
   }
 }
 
 class Scope {
   final Element element;
   final Scope parent;
 
@@ skipping 47 matching lines @@
 class TopScope extends Scope {
   LibraryElement get library() => element;
 
   TopScope(LibraryElement library) : super(null, library);
   Element lookup(SourceString name) => library.find(name);
 
   Element add(Element element) {
     throw "Cannot add an element in the top scope";
   }
 }