def coordinate(location)
      ## Returns array of numerical equiv coordinates (e.g. "AA11" -> [20,11])
      error = "\n\nSomething wrong during coordinate-mapping.\nAre you sure you passed an alphanumeric string\n to the coordinate() method?\n"
      split_index = -1
      location.each_char do |character|
        if letter?(character)
          split_index += 1
        end
      end
      row = location[0..split_index]
      column = location[split_index + 1..-1]
      fail ArgumentError, error unless row.length > 0 && column.length > 0
      ## Now convert alphanumeric row to jedec equiv' with to_row() method
      # and return coordinates.
      coordinates = [to_row(row), column.to_i - 1]
    end
def coordinate(location)
      ## Returns array of numerical equiv coordinates (e.g. "AA11" -> [20,11])
      error = "\n\nSomething wrong during coordinate-mapping.\nAre you sure you passed an alphanumeric string\n to the coordinate() method?\n"
      split_index = -1
      location.each_char do |character|
        if letter?(character)
          split_index += 1
        end
      end
      row = location[0..split_index]
      column = location[split_index + 1..-1]
      fail ArgumentError, error unless row.length > 0 && column.length > 0
      ## Now convert alphanumeric row to jedec equiv' with to_row() method
      # and return coordinates.
      coordinates = [to_row(row), column.to_i - 1]
    end
############# String/Coordinate Manipulation