If you're doing something like agent based modeling, FP is great since you get snapshots of your simulation "for free". And whats the difference between e.g.

If you're doing something like agent based modeling, FP is great since you get snapshots of your simulation "for free". And whats the difference between e.g. agents[0].location.x += 5; versus (update-in agents [0 location x] + 5)