Simplifying the structure of the join_stream rule
@@ -187,9 +187,7 @@ standard_stream
;
join_stream
- :left_source=join_source join right_source=join_source right_unidirectional=UNIDIRECTIONAL (ON expression)? (within_time_range per)?
- |left_source=join_source join right_source=join_source (ON expression)? (within_time_range per)?
- |left_source=join_source left_unidirectional=UNIDIRECTIONAL join right_source=join_source (ON expression)? (within_time_range per)?
+ :left_source=join_source (join right_source=join_source (right_unidirectional=UNIDIRECTIONAL)? | left_unidirectional=UNIDIRECTIONAL join right_source=join_source) (ON expression)? (within_time_range per)?
;
join_source
