If I defined a Ruby method in IRB, how do I edit that method without retyping everything?

Say I am running IRB and I type this into the console:

def full_name(first, last)   puts "Your full name is: #{first, '', last}"end

Say, that I wanted to edit that to include the parameter middle, how would I just bring back up that same method and edit the parameter list and edit the puts statement without having to retype the entire method?

P.S. I know that this example is simple and I could easily just retype the method, but I have much larger methods I am experimenting with and I am using this simple one for brevity.

Thanks.