I was wandering around a class I wrote five years ago...

FiveYeardiff.rb

# 5 years ago.....
    if first.nil?
      first_non_nil = compact.first
      each_with_index{|val, i|
        break if val
        self[i] = first_non_nil
      }
    end
 
    # Forwardfill
    if last.nil?
      last_non_nil = compact.last
      reverse!.each_with_index{|val, i|
        break if val
        self[i] = last_non_nil
      }
      reverse!
    end
 
# Re-factoring today...
 
self[0] = find_all {|x| !x.nil?}.first if first.nil?
self[(size - 1)] = find_all {|x| !x.nil?}.last if last.nil?