Return lazily instantiated syntax nodes in the correct order.

lib/treetop/runtime/syntax_node.rb

@@ -25,7 +25,7 @@ def elements
             elements << node
           end
           elements
-        end
+        end.sort
       end
 
       def terminal?
@@ -43,6 +43,10 @@ def text_value
       def empty?
         interval.first == interval.last && interval.exclude_end?
       end
+
+      def <=>(other)
+        self.interval.first <=> other.interval.first
+      end
 
       def extension_modules
         local_extensions =

spec/compiler/character_class_spec.rb

@@ -235,5 +235,13 @@ module ModFoo
       result.elements.size.should == 2
     end
   end
+
+  describe "a character class with a label mixed with other expressions" do
+    testing_expression 'upper:([A-Z]) "b"'
+    it "returns the correct element for the labeled expression" do
+      result = parse('Ab')
+      result.upper.text_value.should == "A"
+    end
+  end
 
 end