Implement named constructors and resolving of redirecting constructors and super-initializers.

frog/leg/typechecker.dart

 // Copyright (c) 2011, 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.
 
 class TypeCheckerTask extends CompilerTask {
   TypeCheckerTask(Compiler compiler) : super(compiler);
   String get name() => "Type checker";
 
   void check(Node tree, TreeElements elements) {
     measure(() {
@@ skipping 492 matching lines @@
 
   Type computeType(Element element) {
     if (element === null) return types.dynamicType;
     return element.computeType(compiler);
   }
 
   Type visitTypeAnnotation(TypeAnnotation node) {
     if (node.typeName === null) return types.dynamicType;
     Identifier identifier = node.typeName.asIdentifier();
     if (identifier === null) {
-      compiler.cancel('library prefix not implemented',
-                      node: node.typeName);
+      fail(node.typeName, 'library prefix not implemented');
     }
     // TODO(ahe): Why wasn't this resolved by the resolver?
     Type type = lookupType(identifier.source, compiler, types);
     if (type === null) {
       // The type name cannot be resolved, but the resolver
       // already gave a warning, so we continue checking.
       return types.dynamicType;
     }
     return type;
   }
@@ skipping 96 matching lines @@
   }
 
   visitCatchBlock(CatchBlock node) {
     compiler.unimplemented('visitCatchBlock', node: node);
   }
 
   visitTypedef(Typedef node) {
     compiler.unimplemented('visitTypedef', node: node);
   }
 }