Index: pyyaml/trunk/lib/yaml/composer.py
===================================================================
--- pyyaml/trunk/lib/yaml/composer.py	(revision 233)
+++ pyyaml/trunk/lib/yaml/composer.py	(revision 258)
@@ -26,4 +26,25 @@
         if not self.check_event(StreamEndEvent):
             return self.compose_document()
+
+    def get_single_node(self):
+        # Drop the STREAM-START event.
+        self.get_event()
+
+        # Compose a document if the stream is not empty.
+        document = None
+        if not self.check_event(StreamEndEvent):
+            document = self.compose_document()
+
+        # Ensure that the stream contains no more documents.
+        if not self.check_event(StreamEndEvent):
+            event = self.get_event()
+            raise ComposerError("expected a single document in the stream",
+                    document.start_mark, "but found another document",
+                    event.start_mark)
+
+        # Drop the STREAM-END event.
+        self.get_event()
+
+        return document
 
     def compose_document(self):