Well, that's not enough information to answer the question!
Does the man look poor? Or oppressed?
Have I ever done anything to him that would inspire him to attack?
Could we run away?
What does my wife think? What about the kids?
Could I possibly swing the gun like a club and knock the knife out of his hand?
What does the law say about this situation?
Does the gun have appropriate safety built into it?
Why am I carrying a loaded gun anyway, and what kind of message does this send to society and to my children?
Is it possible he'd be happy with just killing me?
Does he definitely want to kill me, or would he be content just to wound me?
If I were to grab his knees and hold on, could my family get away while he was stabbing me?
Should I call 9-1-1?
Why is this street so deserted? We need to raise taxes, have a paint and weed day and make this happier, healthier street that would discourage such behavior.
This is all so confusing! I need to debate this with some friends for few days and try to come to a consensus.