Verify type annotations on public APIs (#24).

lib/src/ast.dart

Index: lib/src/ast.dart
diff --git a/lib/src/ast.dart b/lib/src/ast.dart
index 5bd3bdf9392224cbc0b1f79b8d2529964896b288..6556d5608929572a5407bb51bcf1d700c33e6641 100644
--- a/lib/src/ast.dart
+++ b/lib/src/ast.dart
@@ -24,6 +24,7 @@ import 'package:analyzer/src/generated/ast.dart'
         FieldDeclaration,
         FunctionDeclaration,
         FunctionTypeAlias,
+        Identifier,
         MethodDeclaration,
         ReturnStatement,
         SimpleIdentifier,
@@ -243,6 +244,10 @@ AstNode _getNodeToAnnotate(Declaration node) {
   return null;
 }
 
+/// Check if the given identifier has a private name.
+bool isPrivate(SimpleIdentifier identifier) =>
+    identifier != null ? Identifier.isPrivateName(identifier.name) : false;
+
 /// An [Element] processor function type.
 /// If `true` is returned, children of [element] will be visited.
 typedef bool ElementProcessor(Element element);