From the chapter Forgiving Ourselves in Bring Home the Dharma by Jack Kornfield:
Forgiveness is not weak or naive. Forgiveness requires courage and clarity; it is not naive.
Forgiveness does not happen quickly… True forgiveness does not paper over what has happened in a superficial way. It is not a misguided effort to suppress or ignore our pain. It cannot be hurried.
Forgiveness does not forget, not does it condone the past. Forgiveness sees wisely. It willingly acknowledges what is unjust, harmful, and wrong.
Forgiveness does not mean that we have to continue to relate to those who have done us harm…. Forgiveness simply means never putting another person out of our heart.
…p. 54
108zenbooks 
That last one is really tricky! I’ve often wondered about that.
Late to the party but I’d like to contribute this….
A student of Sylvia Boorstein (“Tom”) once said to her, “Forgiveness is the price that you have to pay for freedom.”
Puts a different light on forgiveness, at least for me.
Joseph, I agree. It’s taken me lifetimes (it feels like) to even consider the possibility of detaching from the person. I admit it helps to think I can hold them in my heart even if they are not in my physical field of connections.
Barry, I like that! When I am caught in the unforgiving cycle of thoughts and actions, it’s just a generation of suffering.