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