+\begin{code}
+printError :: String -> IO ()
+printError str = hPutStrLn stderr str
+\end{code}
+
+\begin{code}
+type Messages = (Bag WarnMsg, Bag ErrMsg)
+
+errorsFound :: Messages -> Bool
+errorsFound (warns, errs) = not (isEmptyBag errs)
+
+warningsFound :: Messages -> Bool
+warningsFound (warns, errs) = not (isEmptyBag warns)
+
+printErrorsAndWarnings :: PrintUnqualified -> Messages -> IO ()