Slightly read-friendlier version of integers_to_ranges method... perhaps?

gistfile1.rb

# receive an array of ints, compact it, order the elements, and group them into ranges


# original: 
def get_ranges_in(values_array)
  return [] if values_array.nil?

  values_array.compact.sort.uniq.inject([]) do |r,x|
     r.empty? || r.last.last.succ != x ? r << (x..x) : r[0..-2] << (r.last.first..x)
  end
end


# expanded: 
def get_ranges_in(values_array)
  return [] if values_array.nil?

  next_upper_value_for = lambda { | range_array | range_array.last.last.succ } 
  current_lower_value_for = lambda { | range_array | range_array.last.first }

  source = values.compact.sort.uniq
  source.inject([]) do |r, x|
    if r.empty? || x != next_upper_value_for[r]
      r << (x..x)
    else
      # replace last element with corrected upper value
      r[0..-2] << (current_lower_value_for[r]..x)
    end
  end
end