de_dup_adjacents.rb

# Remove adjacent duplicates in an array.
#
# @param [Array] a_list the array to de-dup
# @return [Array] the processed list of items
# @note Created to help display a user's log entries.
def de_dup(a_list)
  a_list.reduce([]) do |new_list, elem|
    new_list + (new_list.last.eql?(elem) ? [] : [elem])
  end
end