filterSigNames :: (name -> Bool) -> Sig name -> Maybe (Sig name)
filterSigNames p orig@(SpecSig n _ _)          = ifTrueJust (p $ unLoc n) orig
filterSigNames :: (name -> Bool) -> Sig name -> Maybe (Sig name)
filterSigNames p orig@(SpecSig n _ _)          = ifTrueJust (p $ unLoc n) orig
filterSigNames p orig@(SpecSig n _ _)          = ifTrueJust (p $ unLoc n) orig