Fixed some BIND scoping issues

Made Extend eval only forget vars not bound outside. Made Extend only collect vars not in "expr" This fixes #580
RDFLib · Jan 18, 2017 · c1b29ae · c1b29ae
1 parent 87414fd
commit c1b29ae
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Showing 9 changed files with 99 additions and 12 deletions.
diff --git a/rdflib/plugins/sparql/algebra.py b/rdflib/plugins/sparql/algebra.py
@@ -435,16 +435,21 @@ def _addVars(x, children):
     if isinstance(x, Variable):
         return set([x])
     elif isinstance(x, CompValue):
-        x["_vars"] = set(reduce(operator.or_, children, set()))
-        if x.name == "Bind":
-            return set([x.var])
-        elif x.name == 'SubSelect':
-            if x.projection:
-                s = set(v.var or v.evar for v in x.projection)
-            else:
-                s = set()
+        if x.name == "Extend":
+            # vars only used in the expr for a bind should not be included
+            x["_vars"] = reduce(operator.or_, [ child for child,part in zip(children,x) if part!='expr' ], set())
+
+            return set([x.var]) # perhaps this should expose all vars here too?
+        else:
+            x["_vars"] = set(reduce(operator.or_, children, set()))
+
+            if x.name == 'SubSelect':
+                if x.projection:
+                    s = set(v.var or v.evar for v in x.projection)
+                else:
+                    s = set()
 
-            return s
+                return s
     return reduce(operator.or_, children, set())
 
 

diff --git a/rdflib/plugins/sparql/evaluate.py b/rdflib/plugins/sparql/evaluate.py
@@ -74,7 +74,7 @@ def evalExtend(ctx, extend):
 
     for c in evalPart(ctx, extend.p):
         try:
-            e = _eval(extend.expr, c.forget(ctx))
+            e = _eval(extend.expr, c.forget(ctx, _except=extend._vars))
             if isinstance(e, SPARQLError):
                 raise e
 

diff --git a/rdflib/plugins/sparql/sparql.py b/rdflib/plugins/sparql/sparql.py
@@ -191,13 +191,14 @@ def _prologue(self):
     bnodes = property(_bnodes)
     now = property(_now)
 
-    def forget(self, before):
+    def forget(self, before, _except=None):
         """
         return a frozen dict only of bindings made in self
         since before
         """
+        if not _except : _except = []
 
-        return FrozenBindings(self.ctx, (x for x in self.iteritems() if before[x[0]] is None))
+        return FrozenBindings(self.ctx, (x for x in self.iteritems() if x[0] in _except or before[x[0]] is None))
 
     def remember(self, these):
         """

diff --git a/test/DAWG/rdflib/bindscope.rq b/test/DAWG/rdflib/bindscope.rq
@@ -0,0 +1,6 @@
+PREFIX s: <http://schema.org/>
+
+SELECT ?s ?o ?x WHERE {
+  ?x s:knows ?o .
+  { ?x a s:Person. BIND(?x as ?s) }
+}
diff --git a/test/DAWG/rdflib/bindscope.srx b/test/DAWG/rdflib/bindscope.srx
@@ -0,0 +1,22 @@
+<?xml version="1.0"?>
+<sparql xmlns="http://www.w3.org/2005/sparql-results#">
+  <head>
+	<variable name="s"/>
+	<variable name="o"/>
+	<variable name="x"/>
+  </head>
+  <results>
+    <result>
+      <binding name="s">
+        <uri>http://example.org/jane</uri>
+      </binding>
+      <binding name="o">
+        <uri>http://example.org/john</uri>
+      </binding>
+      <binding name="x">
+        <uri>http://example.org/jane</uri>
+      </binding>
+
+    </result>
+  </results>
+</sparql>
diff --git a/test/DAWG/rdflib/bindscope.ttl b/test/DAWG/rdflib/bindscope.ttl
@@ -0,0 +1,6 @@
+@prefix s: <http://schema.org/> .
+@prefix x: <http://example.org/> .
+
+x:john a s:Person ; s:name "John" .
+x:jane a s:Person ; s:name "Jane" ; s:knows x:john.
+x:ecorp a s:Organization ; s:name "Evil Corp" ; s:employee x:jane .
diff --git a/test/DAWG/rdflib/bindscope2.rq b/test/DAWG/rdflib/bindscope2.rq
@@ -0,0 +1,9 @@
+PREFIX s: <http://schema.org/>
+PREFIX x: <http://example.org/>
+
+SELECT ?s ?p ?o ?x
+WHERE {
+  ?x a s:Person .
+  { ?x ?p ?o . BIND (?x as ?s) } UNION
+  { ?s ?p ?x . BIND (?x as ?o) }
+}
diff --git a/test/DAWG/rdflib/bindscope2.tsv b/test/DAWG/rdflib/bindscope2.tsv
@@ -0,0 +1,8 @@
+?s	?p	?o	?x
+<http://example.org/john>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://schema.org/Person>	<http://example.org/john>
+<http://example.org/john>	<http://schema.org/name>	"John"	<http://example.org/john>
+<http://example.org/jane>	<http://schema.org/knows>	<http://example.org/john>	<http://example.org/john>
+<http://example.org/jane>	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://schema.org/Person>	<http://example.org/jane>
+<http://example.org/jane>	<http://schema.org/name>	"Jane"	<http://example.org/jane>
+<http://example.org/jane>	<http://schema.org/knows>	<http://example.org/john>	<http://example.org/jane>
+<http://example.org/ecorp>	<http://schema.org/employee>	<http://example.org/jane>	<http://example.org/jane>
diff --git a/test/DAWG/rdflib/manifest.ttl b/test/DAWG/rdflib/manifest.ttl
@@ -16,6 +16,8 @@
     :whitespacedot
     :minusfilter
     :notexistsfilter
+    :bindscope
+    :bindscope2
 	) .
 
 
@@ -81,3 +83,31 @@ From https://github.com/RDFLib/rdflib/issues/615, contributed by https://github.
            qt:data <minusfilter.ttl> ] ;
     mf:result  <notexistsfilter.srx>
     .
+
+
+:bindscope rdf:type mf:QueryEvaluationTest ;
+    mf:name "Scope of bind in groups";
+    rdfs:comment """
+    From https://github.com/RDFLib/rdflib/issues/580, contributed by https://github.com/pchampin
+""";
+    dawgt:approval dawgt:Approved ;
+    dawgt:approvedBy <http://gromgull.net/me> ;
+    mf:action
+         [ qt:query  <bindscope.rq> ;
+           qt:data <bindscope.ttl> ] ;
+    mf:result  <bindscope.srx>
+    .
+
+
+:bindscope2 rdf:type mf:QueryEvaluationTest ;
+    mf:name "Scope of bind in groups2";
+    rdfs:comment """
+    From https://github.com/RDFLib/rdflib/issues/580, contributed by https://github.com/pchampin
+""";
+    dawgt:approval dawgt:Approved ;
+    dawgt:approvedBy <http://gromgull.net/me> ;
+    mf:action
+         [ qt:query  <bindscope2.rq> ;
+           qt:data <bindscope.ttl> ] ;
+    mf:result  <bindscope2.tsv>
+    .