public override IEnumerable <ISparqlGraphPattern> CreateTriple(ObjectVariants subject, ObjectVariants @object, RdfQuery11Translator q)
{
var subjectNode = IsInverse ? @object : subject;
var objectNode = IsInverse ? subject : @object;
//if (subjectNode is ObjectVariants && objectNode is ObjectVariants)
yield return
(new SparqlMayBeOneTriple(path.CreateTriple((ObjectVariants)subjectNode, objectNode, q),
(ObjectVariants)subjectNode, (ObjectVariants)objectNode, q));
//else
//foreach (var t in path.CreateTriple((ObjectVariants) subjectNode, objectNode, q))
// yield return t;
}
public IEnumerable <SparqlResult> Run(IEnumerable <SparqlResult> variableBindings)
{
var bindings = variableBindings;
Queue <ObjectVariants> newSubjects = new Queue <ObjectVariants>();
ObjectVariants[] fromVariable = null;
ObjectVariants o = null;
ObjectVariants s = null;
switch (NullablePairExt.Get(sVariableNode, oVariableNode))
{
case NP.bothNull:
return(TestSOConnection(Subject, Object) ? bindings : Enumerable.Empty <SparqlResult>());
case NP.leftNull:
newSubjects.Enqueue(Subject);
return(bindings.SelectMany(binding =>
{
o = binding[oVariableNode];
if (o != null)
{
return TestSOConnection(Subject, o)
? Enumerable.Repeat(binding, 1)
: Enumerable.Empty <SparqlResult>();
}
else
{
if (fromVariable == null)
{
fromVariable = GetAllSConnections(Subject).ToArray();
}
return fromVariable.Select(node => binding.Add(node, oVariableNode));
}
}));
case NP.rigthNull:
return(bindings.SelectMany(binding =>
{
s = binding[sVariableNode];
if (s != null)
{
return TestSOConnection(s, Object)
? Enumerable.Repeat(binding, 1)
: Enumerable.Empty <SparqlResult>();
}
else
{
if (fromVariable == null)
{
fromVariable = GetAllOConnections(Object).ToArray();
}
return fromVariable.Select(node => binding.Add(node, sVariableNode));
}
}));
case NP.bothNotNull:
return(bindings.SelectMany(binding =>
{
s = binding[sVariableNode];
o = binding[oVariableNode];
switch (NullablePairExt.Get(s, o))
{
case NP.bothNotNull:
if ((useCache && TestSOConnectionFromCache(s, o)) || (TestSOConnection(s, o)))
{
return Enumerable.Repeat(binding, 1);
}
else
{
return Enumerable.Empty <SparqlResult>();
}
case NP.rigthNull:
return GetAllSConnections(s).Select(node => binding.Add(node, oVariableNode));
break;
case NP.leftNull:
return GetAllOConnections(o).Select(node => binding.Add(node, sVariableNode));
break;
case NP.bothNull:
useCache = true;
bothVariablesChache = predicatePath.CreateTriple(sVariableNode, oVariableNode, q)
.Aggregate(Enumerable.Repeat(new SparqlResult(q), 1),
(enumerable, triple) => triple.Run(enumerable))
.Select(
r =>
new KeyValuePair <ObjectVariants, ObjectVariants>(r[sVariableNode], r[oVariableNode]))
.ToArray();
return bothVariablesCacheBySubject.Keys.SelectMany(GetAllSConnections,
(sbj, node) => binding.Add(sbj, sVariableNode, node, oVariableNode));
default:
throw new ArgumentOutOfRangeException();
}
}));
default:
throw new ArgumentOutOfRangeException();
}
}