import DarcsUtils ( bug )
#define impossible (bug $ "Impossible case at "++__FILE__++":"++show (__LINE__ :: Int)++" compiled "++__TIME__++" "++__DATE__)

#define fromJust (\m_fromJust_funny_name -> case m_fromJust_funny_name of {Nothing -> bug ("fromJust error at "++__FILE__++":"++show (__LINE__ :: Int)++" compiled "++__TIME__++" "++__DATE__); Just x -> x})