{-
************************************************************************
*                                                                      *
        Checking an instance against conflicts with an instance env
*                                                                      *
************************************************************************

Check whether a single family instance conflicts with those in two instance
environments (one for the EPS and one for the HPT).
-}

checkForConflicts :: FamInstEnvs -> FamInst -> TcM Bool
checkForConflicts inst_envs fam_inst
  = do { let conflicts = lookupFamInstEnvConflicts inst_envs fam_inst
             no_conflicts = null conflicts
       ; traceTc "checkForConflicts" $
         vcat [ ppr (map fim_instance conflicts)
              , ppr fam_inst
              -- , ppr inst_envs
         ]
       ; unless no_conflicts $ conflictInstErr fam_inst conflicts
       ; return no_conflicts }
checkForConflicts :: FamInstEnvs -> FamInst -> TcM Bool
checkForConflicts inst_envs fam_inst
  = do { let conflicts = lookupFamInstEnvConflicts inst_envs fam_inst
             no_conflicts = null conflicts
       ; traceTc "checkForConflicts" $
         vcat [ ppr (map fim_instance conflicts)
              , ppr fam_inst
              -- , ppr inst_envs
         ]
       ; unless no_conflicts $ conflictInstErr fam_inst conflicts
       ; return no_conflicts }
checkForConflicts inst_envs fam_inst
  = do { let conflicts = lookupFamInstEnvConflicts inst_envs fam_inst
             no_conflicts = null conflicts
       ; traceTc "checkForConflicts" $
         vcat [ ppr (map fim_instance conflicts)
              , ppr fam_inst
              -- , ppr inst_envs
         ]
       ; unless no_conflicts $ conflictInstErr fam_inst conflicts
       ; return no_conflicts }