get_occurrence_position
Description:
[ Version ( since = "3.10" ) ]
public int get_occurrence_position (TextIter match_start, TextIter match_end)
  public int get_occurrence_position (TextIter match_start, TextIter match_end)
Gets the position of a search occurrence.
 If the buffer is not already fully scanned, the position may be unknown, and -1 is returned. If 0 is returned, it means that this part of the
      buffer has already been scanned, and that match_start and match_end don't delimit an occurrence.
Parameters:
| this | |
| match_start | the start of the occurrence. | 
| match_end | the end of the occurrence. | 
Returns:
| the position of the search occurrence. The first occurrence has the position 1 (not 0). Returns 0 if  |