Class Ask

Represents the Ask step of Query Evaluation.

Inheritance

System.Object

Ask

Implements

IUnaryOperator

ISparqlAlgebra

IVisitable

IProcessable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: VDS.RDF.Query.Algebra

Assembly: dotNetRdf.dll

Syntax

public class Ask : IUnaryOperator, ISparqlAlgebra, IVisitable, IProcessable

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Constructors

Ask(ISparqlAlgebra)

Creates a new ASK.

Declaration

public Ask(ISparqlAlgebra pattern)

Parameters

Type	Name	Description
ISparqlAlgebra	pattern	Inner Pattern.

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Properties

FixedVariables

Gets the enumeration of fixed variables in the algebra i.e. variables that are guaranteed to have a bound value.

Declaration

public IEnumerable<string> FixedVariables { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<T><string>

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

FloatingVariables

Gets the enumeration of floating variables in the algebra i.e. variables that are not guaranteed to have a bound value.

Declaration

public IEnumerable<string> FloatingVariables { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<T><string>

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

InnerAlgebra

Gets the Inner Algebra.

Declaration

public ISparqlAlgebra InnerAlgebra { get; }

Property Value

Type	Description
ISparqlAlgebra

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Variables

Gets the Variables used in the Algebra.

Declaration

public IEnumerable<string> Variables { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<T><string>

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Methods

Accept<T>(ISparqlAlgebraVisitor<T>)

Declaration

public T Accept<T>(ISparqlAlgebraVisitor<T> visitor)

Parameters

Type	Name	Description
ISparqlAlgebraVisitor<T>	visitor

Returns

Type	Description
T

Type Parameters

Name	Description
T

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Accept<TResult, TContext>(ISparqlQueryAlgebraProcessor<TResult, TContext>, TContext)

Declaration

public TResult Accept<TResult, TContext>(ISparqlQueryAlgebraProcessor<TResult, TContext> processor, TContext context)

Parameters

Type	Name	Description
ISparqlQueryAlgebraProcessor<TResult, TContext>	processor
TContext	context

Returns

Type	Description
TResult

Type Parameters

Name	Description
TResult
TContext

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

ToGraphPattern()

Throws an exception since an Ask() cannot be converted to a Graph Pattern.

Declaration

public GraphPattern ToGraphPattern()

Returns

Type	Description
GraphPattern

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Exceptions

Type	Condition
System.NotSupportedException	Thrown since an Ask() cannot be converted to a Graph Pattern.

ToQuery()

Converts the Algebra back to a SPARQL Query.

Declaration

public SparqlQuery ToQuery()

Returns

Type	Description
SparqlQuery

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

ToString()

Gets the String representation of the Ask.

Declaration

public override string ToString()

Returns

Type	Description
string

Overrides

object.ToString()

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Transform(IAlgebraOptimiser)

Transforms the Inner Algebra using the given Optimiser.

Declaration

public ISparqlAlgebra Transform(IAlgebraOptimiser optimiser)

Parameters

Type	Name	Description
IAlgebraOptimiser	optimiser	Optimiser.

Returns

Type	Description
ISparqlAlgebra

Remarks

Used only for ASK queries. Turns the final Multiset into either an IdentityMultiset if the ASK succeeds or a NullMultiset if the ASK fails.

Implements

IUnaryOperator

ISparqlAlgebra

IVisitable

IProcessable

Extension Methods

Extensions.ToSafeString(object)

Extensions.AsEnumerable<T>(T)