+
+
+
+-- | Is the given XML file unpickleable? Unpickling will be attempted
+-- using the @unpickler@ argument. If we unilaterally used the
+-- generic 'xpickle' function for our unpickler, a type ambiguity
+-- would result. By taking the unpickler as an argument, we allow
+-- the caller to indirectly specify a concrete type.
+--
+unpickleable :: XmlPickler a => FilePath -> PU a -> IO Bool
+unpickleable filepath unpickler = do
+ xmldoc <- try_unpickle `catch` (\(SomeException _) -> return [])
+ return $ (not . null) xmldoc
+ where
+ try_unpickle = runX $ readDocument parse_opts filepath
+ >>>
+ xunpickleVal unpickler