Package org.aksw.jena_sparql_api.algebra.expr.transform

Class ExprTransformVirtualBnodeUris

java.lang.Object

org.apache.jena.sparql.expr.ExprTransformCopy

org.aksw.jena_sparql_api.algebra.expr.transform.ExprTransformVirtualBnodeUris

All Implemented Interfaces:

org.apache.jena.sparql.expr.ExprTransform

public class ExprTransformVirtualBnodeUris
extends org.apache.jena.sparql.expr.ExprTransformCopy

Decode "blanknode URIs" - i.e. URIs that represent blank nodes, such as bnode://{blank-node-label} This means ?x = <bnode://foobar> becomes encode(?x) = decode(<bnode://foobar>) encode(?x) = 'foobar' Issue: How to deal with queries that test for blank nodes? In principle, this rewrite virtually eleminates them, so maybe the most reasonable approach is to simply rewrite isBlank to true. in fact, the standard bnode function would also have to yield bnode uris instead bnodeLabel(?x) := if ?x is a blank node, return its label as an xsd:string, type error otherwise Auxiliary functions (defined in terms of the aforementioned and SPARQL standard functions) typeError() := abs("") encodeBnodeUri(xsd:string ?x) := URI(CONCAT('bnode://', ?x)) create an URI from a blank node label isBnodeUri(uri) := isURI(?x) && STRSTARTS(STR(?x), 'bnode://') true if uri represents a bnode decodeBnodeUri(uri ?x) := IF(isBnodeURI(?x), STRAFTER(STR(?x), 'bnode://'), typeError()), extract the blank node label from a URI forceBnodeUri(?x) -> IF(isBlank(?x), encodeBnodeURI(bnodeLabel(?x)), ?x) Transformations: - Given ?x = const if(isBnodeURI(const)) { emit bnodeLabel(?x) = decodeBnodeURI(uri) }

Author:

raven

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ExprTransformVirtualBnodeUris.BnodeRewriteMode
static class	ExprTransformVirtualBnodeUris.ExprTransformConstantFoldWithIris

Field Summary

Fields

Modifier and Type	Field	Description
static final String	bidOfFnIri
static final String	decodeBnodeIriFnIri
static final String	forceBnodeIriFnIri
static final String	isBnodeIriFnIri
protected Map<String,org.apache.jena.sparql.function.user.UserDefinedFunctionDefinition>	macros
static final String	ns
protected Map<String,Boolean>	propertyFunctions
protected ExprTransformVirtualBnodeUris.BnodeRewriteMode	rewriteMode

Fields inherited from class org.apache.jena.sparql.expr.ExprTransformCopy

COPY_ALWAYS, COPY_ONLY_ON_CHANGE

Constructor Summary

Constructors

Constructor	Description
ExprTransformVirtualBnodeUris(Map<String,org.apache.jena.sparql.function.user.UserDefinedFunctionDefinition> macros, Map<String,Boolean> propertyFunctions, ExprTransformVirtualBnodeUris.BnodeRewriteMode rewriteMode)

Method Summary

Modifier and Type	Method	Description
static org.apache.jena.graph.Node	bnodeToIri(org.apache.jena.graph.Node node)
static <T extends org.apache.jena.sparql.expr.ExprFunction2> T	copy(T func, org.apache.jena.sparql.expr.Expr a, org.apache.jena.sparql.expr.Expr b, boolean swapped)
static ExprTransformVirtualBnodeUris	createTransformFromUdfModel(org.apache.jena.rdf.model.Model model, Collection<String> activeProfiles, ExprTransformVirtualBnodeUris.BnodeRewriteMode rewriteMode)
org.apache.jena.sparql.expr.NodeValue	decodeBnodeIriFn(org.apache.jena.sparql.expr.NodeValue in)
org.apache.jena.sparql.algebra.Op	forceBnodeUris(org.apache.jena.sparql.algebra.Op op)
boolean	isBnodeIri(org.apache.jena.sparql.expr.NodeValue in)
static void	main(String[] args)
org.apache.jena.query.Query	rewrite(org.apache.jena.query.Query query)
org.apache.jena.sparql.expr.Expr	transform(org.apache.jena.sparql.expr.ExprFunction2 func, org.apache.jena.sparql.expr.Expr a, org.apache.jena.sparql.expr.Expr b)
org.apache.jena.sparql.expr.Expr	transform(org.apache.jena.sparql.expr.ExprFunctionN func, org.apache.jena.sparql.expr.ExprList args)
org.apache.jena.sparql.expr.ExprFunction2	trySubst(org.apache.jena.sparql.expr.ExprFunction2 func, org.apache.jena.sparql.expr.Expr lhs, org.apache.jena.sparql.expr.Expr b, boolean swapped)

Methods inherited from class org.apache.jena.sparql.expr.ExprTransformCopy

transform, transform, transform, transform, transform, transform, transform, transform

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.jena.sparql.expr.ExprTransform

transform

Field Details

ns

public static final String ns

See Also:

• Constant Field Values

bidOfFnIri

public static final String bidOfFnIri

See Also:

• Constant Field Values

decodeBnodeIriFnIri

public static final String decodeBnodeIriFnIri

See Also:

• Constant Field Values

isBnodeIriFnIri

public static final String isBnodeIriFnIri

See Also:

• Constant Field Values

forceBnodeIriFnIri

public static final String forceBnodeIriFnIri

See Also:

• Constant Field Values

macros

protected Map<String,org.apache.jena.sparql.function.user.UserDefinedFunctionDefinition> macros

propertyFunctions

protected Map<String,Boolean> propertyFunctions

rewriteMode

protected ExprTransformVirtualBnodeUris.BnodeRewriteMode rewriteMode

Constructor Details

ExprTransformVirtualBnodeUris

public ExprTransformVirtualBnodeUris(Map<String,org.apache.jena.sparql.function.user.UserDefinedFunctionDefinition> macros,
 Map<String,Boolean> propertyFunctions,
 ExprTransformVirtualBnodeUris.BnodeRewriteMode rewriteMode)

Method Details

transform

public org.apache.jena.sparql.expr.Expr transform(org.apache.jena.sparql.expr.ExprFunctionN func,
 org.apache.jena.sparql.expr.ExprList args)

Specified by:

transform in interface org.apache.jena.sparql.expr.ExprTransform

Overrides:

transform in class org.apache.jena.sparql.expr.ExprTransformCopy

transform

public org.apache.jena.sparql.expr.Expr transform(org.apache.jena.sparql.expr.ExprFunction2 func,
 org.apache.jena.sparql.expr.Expr a,
 org.apache.jena.sparql.expr.Expr b)

Specified by:

transform in interface org.apache.jena.sparql.expr.ExprTransform

Overrides:

transform in class org.apache.jena.sparql.expr.ExprTransformCopy

copy

public static <T extends org.apache.jena.sparql.expr.ExprFunction2>
T copy(T func,
 org.apache.jena.sparql.expr.Expr a,
 org.apache.jena.sparql.expr.Expr b,
 boolean swapped)

bnodeToIri

public static org.apache.jena.graph.Node bnodeToIri(org.apache.jena.graph.Node node)

isBnodeIri

public boolean isBnodeIri(org.apache.jena.sparql.expr.NodeValue in)

decodeBnodeIriFn

public org.apache.jena.sparql.expr.NodeValue decodeBnodeIriFn(org.apache.jena.sparql.expr.NodeValue in)

trySubst

public org.apache.jena.sparql.expr.ExprFunction2 trySubst(org.apache.jena.sparql.expr.ExprFunction2 func,
 org.apache.jena.sparql.expr.Expr lhs,
 org.apache.jena.sparql.expr.Expr b,
 boolean swapped)

rewrite

public org.apache.jena.query.Query rewrite(org.apache.jena.query.Query query)

createTransformFromUdfModel

public static ExprTransformVirtualBnodeUris createTransformFromUdfModel(org.apache.jena.rdf.model.Model model,
 Collection<String> activeProfiles,
 ExprTransformVirtualBnodeUris.BnodeRewriteMode rewriteMode)

forceBnodeUris

public org.apache.jena.sparql.algebra.Op forceBnodeUris(org.apache.jena.sparql.algebra.Op op)

main

public static void main(String[] args)