^this post hits the nail on the head: punishment done out of anger is not the same as discipline done to teach or enforce. the difference between discipline and abuse is not just what method you use, but the reason behind it and how you carry it out. non-violent methods can become abusive or damaging just as easily as corporal punishments.

i don't believe a parent should ever do anything to their child out of anger. if you feel that you can't act objectively in the moment after your child has broken a rule, step away and come back to it later. discipline should always be about teaching and enforcing, not about gratuitously unloading your feelings onto your child or lashing out to hurt them.