DeleteLines

Deletes lines from the beginning of the selection to the end, or the current line if there is no selection.

-- Deletes the lines spanned by the selection or delete current line if no selection.
function delete_lines()
  buffer:begin_undo_action()
  if buffer.selection_empty then
    buffer:line_delete()
  else
    local start_line = buffer:line_from_position(buffer.selection_start)
    local end_line = buffer:line_from_position(buffer.selection_end)
    local start_pos = buffer:position_from_line(start_line)
    local end_pos = buffer:position_from_line(end_line + 1)
    buffer:delete_range(start_pos, end_pos - start_pos)
  end
  buffer:end_undo_action()
end