Split a Ruby array into regularly-sized chunks

to_rows.rb

class Array
  def to_rows(column_length, padding = true)
    i = 0
    array = []
    while i < self.size
      chunk = self[i..(i + column_length - 1)]
      chunk << [] while chunk.size < column_length if padding
      
      array << chunk
      
      i += column_length
    end
    array
  end
end