code: def unix_line_discard(event):
      
      buff = event.current_buffer
  
      if buff.document.cursor_position_col == 0 and buff.document.cursor_position > 0:
          buff.delete_before_cursor(count=1)
      else:
          deleted = buff.delete_before_cursor(count=-buff.document.get_start_of_line_position())
          event.cli.clipboard.set_text(deleted)
docs: Kill backward from the cursor to the beginning of the current line.