class Reline::Unicode

def self.take_range(str, start_col, max_width, encoding = str.encoding)
  chunk = String.new(encoding: encoding)
  total_width = 0
  rest = str.encode(Encoding::UTF_8)
  in_zero_width = false
  rest.scan(WIDTH_SCANNER) do |gc|
    case
    when gc[NON_PRINTING_START_INDEX]
      in_zero_width = true
    when gc[NON_PRINTING_END_INDEX]
      in_zero_width = false
    when gc[CSI_REGEXP_INDEX]
      chunk << gc[CSI_REGEXP_INDEX]
    when gc[OSC_REGEXP_INDEX]
      chunk << gc[OSC_REGEXP_INDEX]
    when gc[GRAPHEME_CLUSTER_INDEX]
      gc = gc[GRAPHEME_CLUSTER_INDEX]
      if in_zero_width
        chunk << gc
      else
        mbchar_width = get_mbchar_width(gc)
        total_width += mbchar_width
        break if (start_col + max_width) < total_width
        chunk << gc if start_col < total_width
      end
    end
  end
  chunk
end