private void RunTest(ISparqlPath path, IEnumerable<String> expectedOperators)
{
VariablePattern x = new VariablePattern("?x");
VariablePattern y = new VariablePattern("?y");
PathTransformContext context = new PathTransformContext(x, y);
Console.WriteLine("Path: " + path.ToString());
ISparqlAlgebra algebra = path.ToAlgebra(context);
String result = algebra.ToString();
Console.WriteLine("Algebra: " + result);
try
{
GraphPattern gp = algebra.ToGraphPattern();
Console.WriteLine("GraphPattern:");
Console.WriteLine(this._formatter.Format(gp));
Console.WriteLine();
}
catch
{
Console.WriteLine("Algebra not translatable to a GraphPattern");
}
foreach (String op in expectedOperators)
{
if (!result.Contains(op))
{
Console.WriteLine("Expected Operator '" + op + "' missing");
Assert.Fail("Expected Operator '" + op + "' missing");
}
}
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
bool top = context.Top;
//The Object becomes a temporary variable then we transform the LHS of the path
context.Object = context.GetNextTemporaryVariable();
context.Top = false;
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this._lhs, context.Object));
//The Subject is then the Object that results from the LHS transform since the
//Transform may adjust the Object
context.Subject = context.Object;
//We then reset the Object to be the target Object so that if the RHS is the last part
//of the Path then it will complete the path transformation
//If it isn't the last part of the path it will be set to a new temporary variable
context.Top = top;
if (context.Top)
{
context.ResetObject();
}
else
{
context.Object = context.GetNextTemporaryVariable();
}
context.Top = top;
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this._rhs, context.Object));
return context.ToAlgebra();
}
/// <summary>
/// Converts a Path into its Algebra Form.
/// </summary>
/// <param name="context">Path Transformation Context.</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
bool top = context.Top;
// The Object becomes a temporary variable then we transform the LHS of the path
context.Object = context.GetNextTemporaryVariable();
context.Top = false;
context.AddTriplePattern(context.GetTriplePattern(context.Subject, _lhs, context.Object));
// The Subject is then the Object that results from the LHS transform since the
// Transform may adjust the Object
context.Subject = context.Object;
// We then reset the Object to be the target Object so that if the RHS is the last part
// of the Path then it will complete the path transformation
// If it isn't the last part of the path it will be set to a new temporary variable
context.Top = top;
if (context.Top)
{
context.ResetObject();
}
else
{
context.Object = context.GetNextTemporaryVariable();
}
context.Top = top;
context.AddTriplePattern(context.GetTriplePattern(context.Subject, _rhs, context.Object));
return(context.ToAlgebra());
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
if (this._n > 0)
{
// Generate a Triple Pattern for each step in the cardinality
for (int i = 0; i < this._n; i++)
{
context.Object = context.GetNextTemporaryVariable();
if (i < this._n - 1 || !context.Top)
{
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this._path, context.Object));
context.Subject = context.Object;
}
else
{
context.ResetObject();
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this._path, context.Object));
}
}
return(context.ToAlgebra());
}
else
{
return(new ZeroLengthPath(context.Subject, context.Object, this._path));
}
}
/// <summary>
/// Creates a new Path Transform Context from an existing context
/// </summary>
/// <param name="context">Context</param>
public PathTransformContext(PathTransformContext context)
{
this._start = context._start;
this._end = context._end;
this._currSubj = context._currSubj;
this._currObj = context._currObj;
this._nextID = context._nextID;
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
PathTransformContext lhsContext = new PathTransformContext(context);
PathTransformContext rhsContext = new PathTransformContext(context);
ISparqlAlgebra lhs = this._lhs.ToAlgebra(lhsContext);
ISparqlAlgebra rhs = this._rhs.ToAlgebra(rhsContext);
return new Union(lhs, rhs);
}
/// <summary>
/// Creates a new Path Transform Context from an existing context
/// </summary>
/// <param name="context">Context</param>
public PathTransformContext(PathTransformContext context)
{
this._start = context._start;
this._end = context._end;
this._currSubj = context._currSubj;
this._currObj = context._currObj;
this._nextID = context._nextID;
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
PatternItem tempVar = context.GetNextTemporaryVariable();
context.AddTriplePattern(new PropertyPathPattern(context.Subject, new FixedCardinality(this._path, this._n), tempVar));
context.AddTriplePattern(new PropertyPathPattern(tempVar, new ZeroOrMore(this._path), context.Object));
return(context.ToAlgebra());
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
PathTransformContext lhsContext = new PathTransformContext(context);
PathTransformContext rhsContext = new PathTransformContext(context);
ISparqlAlgebra lhs = new ZeroLengthPath(lhsContext.Subject, lhsContext.Object, this._path);
ISparqlAlgebra rhs = this._path.ToAlgebra(rhsContext);
return(new Distinct(new Union(lhs, rhs)));
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
PathTransformContext lhsContext = new PathTransformContext(context);
PathTransformContext rhsContext = new PathTransformContext(context);
ISparqlAlgebra lhs = this._lhs.ToAlgebra(lhsContext);
ISparqlAlgebra rhs = this._rhs.ToAlgebra(rhsContext);
return(new Union(lhs, rhs));
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
//Swap the Subject and Object over
PatternItem tempObj = context.Object;
PatternItem tempSubj = context.Subject;
PatternItem tempEnd = context.End;
context.Object = tempSubj;
context.Subject = tempObj;
context.End = tempSubj;
//Then transform the path
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this._path, context.Object));
//Then swap the Subject and Object back
context.Subject = tempSubj;
context.Object = tempObj;
context.End = tempEnd;
return context.ToAlgebra();
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
ISparqlAlgebra complex = null;
int i = this._n;
while (i <= this._m)
{
PathTransformContext tempContext = new PathTransformContext(context);
tempContext.AddTriplePattern(new PropertyPathPattern(context.Subject, new FixedCardinality(this._path, i), context.Object));
if (complex == null)
{
complex = tempContext.ToAlgebra();
}
else
{
complex = new Union(complex, tempContext.ToAlgebra());
}
i++;
}
return(complex);
}
/// <summary>
/// Converts a Path into its Algebra Form.
/// </summary>
/// <param name="context">Path Transformation Context.</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
// Swap the Subject and Object over
PatternItem tempObj = context.Object;
PatternItem tempSubj = context.Subject;
PatternItem tempEnd = context.End;
context.Object = tempSubj;
context.Subject = tempObj;
context.End = tempSubj;
// Then transform the path
context.AddTriplePattern(context.GetTriplePattern(context.Subject, _path, context.Object));
// Then swap the Subject and Object back
context.Subject = tempSubj;
context.Object = tempObj;
context.End = tempEnd;
return(context.ToAlgebra());
}
/// <summary>
/// Converts a Path into its Algebra Form.
/// </summary>
/// <param name="context">Path Transformation Context.</param>
/// <returns></returns>
public ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
if (_properties.Count > 0 && _inverseProperties.Count == 0)
{
return(new NegatedPropertySet(context.Subject, context.Object, _properties));
}
else if (_properties.Count == 0 && _inverseProperties.Count > 0)
{
return(new NegatedPropertySet(context.Object, context.Subject, _inverseProperties, true));
}
else
{
PathTransformContext lhsContext = new PathTransformContext(context);
PathTransformContext rhsContext = new PathTransformContext(context);
lhsContext.AddTriplePattern(new PropertyPathPattern(lhsContext.Subject, new NegatedSet(_properties, Enumerable.Empty <Property>()), lhsContext.Object));
rhsContext.AddTriplePattern(new PropertyPathPattern(rhsContext.Subject, new NegatedSet(Enumerable.Empty <Property>(), _inverseProperties), rhsContext.Object));
ISparqlAlgebra lhs = lhsContext.ToAlgebra();
ISparqlAlgebra rhs = rhsContext.ToAlgebra();
return(new Union(lhs, rhs));
}
}
private ISparqlAlgebra GetAlgebra(ISparqlPath path, INode start, INode end)
{
PatternItem x, y;
if (start == null)
{
x = new VariablePattern("?x");
}
else
{
x = new NodeMatchPattern(start);
}
if (end == null)
{
y = new VariablePattern("?y");
}
else
{
y = new NodeMatchPattern(end);
}
PathTransformContext context = new PathTransformContext(x, y);
return path.ToAlgebra(context);
}
/// <summary>
/// Evaluates the Path in the given context
/// </summary>
/// <param name="context">Evaluation Context</param>
/// <returns></returns>
public override BaseMultiset Evaluate(SparqlEvaluationContext context)
{
//Try and generate an Algebra expression
//Make sure we don't generate clashing temporary variable IDs over the life of the
//Evaluation
PathTransformContext transformContext = new PathTransformContext(this.PathStart, this.PathEnd);
if (context["PathTransformID"] != null)
{
transformContext.NextID = (int)context["PathTransformID"];
}
ISparqlAlgebra algebra = this.Path.ToAlgebra(transformContext);
context["PathTransformID"] = transformContext.NextID;
//Now we can evaluate the resulting algebra
//Note: We may need to preserve Blank Node variables across evaluations
//which we usually don't do BUT because of the way we translate only part of the path
//into an algebra at a time and may need to do further nested translate calls we do
//need to do this here
BaseMultiset initialInput = context.InputMultiset;
bool trimMode = context.TrimTemporaryVariables;
try
{
context.TrimTemporaryVariables = false;
BaseMultiset result = context.Evaluate(algebra);//algebra.Evaluate(context);
//Also note that we don't trim temporary variables here even if we've set the setting back
//to enabled since a Trim will be done at the end of whatever BGP we are being evaluated in
//Once we have our results can join then into our input
context.OutputMultiset = initialInput.Join(result);
}
finally
{
context.TrimTemporaryVariables = trimMode;
}
return context.OutputMultiset;
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
context.AddTriplePattern(new PropertyPathPattern(context.Subject, new NToM(this._path, 0, this._n), context.Object));
return context.ToAlgebra();
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
ISparqlAlgebra complex = null;
int i = this._n;
while (i <= this._m)
{
PathTransformContext tempContext = new PathTransformContext(context);
tempContext.AddTriplePattern(new PropertyPathPattern(context.Subject, new FixedCardinality(this._path, i), context.Object));
if (complex == null)
{
complex = tempContext.ToAlgebra();
}
else
{
complex = new Union(complex, tempContext.ToAlgebra());
}
i++;
}
return complex;
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
return new OneOrMorePath(context.Subject, context.Object, this._path);
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
PatternItem tempVar = context.GetNextTemporaryVariable();
context.AddTriplePattern(new PropertyPathPattern(context.Subject, new FixedCardinality(this._path, this._n), tempVar));
context.AddTriplePattern(new PropertyPathPattern(tempVar, new ZeroOrMore(this._path), context.Object));
return context.ToAlgebra();
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
if (this._n > 0)
{
//Generate a Triple Pattern for each step in the cardinality
for (int i = 0; i < this._n; i++)
{
context.Object = context.GetNextTemporaryVariable();
if (i < this._n - 1 || !context.Top)
{
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this._path, context.Object));
context.Subject = context.Object;
}
else
{
context.ResetObject();
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this._path, context.Object));
}
}
return context.ToAlgebra();
}
else
{
return new ZeroLengthPath(context.Subject, context.Object, this._path);
}
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
PathTransformContext lhsContext = new PathTransformContext(context);
PathTransformContext rhsContext = new PathTransformContext(context);
ISparqlAlgebra lhs = new ZeroLengthPath(lhsContext.Subject, lhsContext.Object, this._path);
ISparqlAlgebra rhs = this._path.ToAlgebra(context);
return new Union(lhs, rhs);
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
context.AddTriplePattern(context.GetTriplePattern(context.Subject, this, context.Object));
return context.ToAlgebra();
}
/// <summary> /// Converts a Path into its Algebra Form /// </summary> /// <param name="context">Path Transformation Context</param> /// <returns></returns> public abstract ISparqlAlgebra ToAlgebra(PathTransformContext context);
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
if (this._properties.Count > 0 && this._inverseProperties.Count == 0)
{
return new NegatedPropertySet(context.Subject, context.Object, this._properties);
}
else if (this._properties.Count == 0 && this._inverseProperties.Count > 0)
{
return new NegatedPropertySet(context.Object, context.Subject, this._inverseProperties, true);
}
else
{
PathTransformContext lhsContext = new PathTransformContext(context);
PathTransformContext rhsContext = new PathTransformContext(context);
lhsContext.AddTriplePattern(new PropertyPathPattern(lhsContext.Subject, new NegatedSet(this._properties, Enumerable.Empty<Property>()), lhsContext.Object));
rhsContext.AddTriplePattern(new PropertyPathPattern(rhsContext.Subject, new NegatedSet(Enumerable.Empty<Property>(), this._inverseProperties), rhsContext.Object));
ISparqlAlgebra lhs = lhsContext.ToAlgebra();
ISparqlAlgebra rhs = rhsContext.ToAlgebra();
return new Union(lhs, rhs);
}
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
context.AddTriplePattern(new PropertyPathPattern(context.Subject, new NToM(this._path, 0, this._n), context.Object));
return(context.ToAlgebra());
}
/// <summary>
/// Converts a Path into its Algebra Form
/// </summary>
/// <param name="context">Path Transformation Context</param>
/// <returns></returns>
public override ISparqlAlgebra ToAlgebra(PathTransformContext context)
{
return(new OneOrMorePath(context.Subject, context.Object, this._path));
}
