@param idx Index
@param tid Target ID
@param beg Start of region
@param end End of region
@param readrec Callback to read a record from the input file
@return An iterator on success; NULL on failure
The iterator struct returned by a successful call should be freed
via hts_itr_destroy() when it is no longer needed.
@param idx Index @param tid Target ID @param beg Start of region @param end End of region @param readrec Callback to read a record from the input file @return An iterator on success; NULL on failure
The iterator struct returned by a successful call should be freed via hts_itr_destroy() when it is no longer needed.