made UNION faster by not preventing duplicates

pchampin · pchampin · commit 58d6369a1279 · 2017-05-14T16:03:04.000+02:00
diff --git a/rdflib/plugins/sparql/evaluate.py b/rdflib/plugins/sparql/evaluate.py
@@ -112,13 +112,10 @@ def evalJoin(ctx, join):
 
 
 def evalUnion(ctx, union):
-    res = set()
     for x in evalPart(ctx, union.p1):
-        res.add(x)
         yield x
     for x in evalPart(ctx, union.p2):
-        if x not in res:
-            yield x
+        yield x
 
 
 def evalMinus(ctx, minus):
