Deletes a sequence of characters. The characters that are deleted are
those characters at positions from start_pos up to, but not including
end_pos. If end_pos is negative, then the characters deleted
are those from start_pos to the end of the text.
Note that the positions are specified in characters, not bytes.
Virtual: do_delete_text
Deletes a sequence of characters. The characters that are deleted are those characters at positions from start_pos up to, but not including end_pos. If end_pos is negative, then the characters deleted are those from start_pos to the end of the text. Note that the positions are specified in characters, not bytes. Virtual: do_delete_text