Package org.eclipse.rdf4j.query.algebra.evaluation.util

Class QueryEvaluationUtility

java.lang.Object

org.eclipse.rdf4j.query.algebra.evaluation.util.QueryEvaluationUtility

@InternalUseOnly
public class QueryEvaluationUtility
extends Object

This class will take over for QueryEvaluationUtil. Currently marked as InternalUseOnly because there may still be changes to how this class works.

Author:

Arjohn Kampman, Håvard M. Ottestad

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	QueryEvaluationUtility.Result

Constructor Summary

Constructors

Constructor	Description
QueryEvaluationUtility()

Method Summary

Modifier and Type	Method	Description
static QueryEvaluationUtility.Result	compare(Value leftVal, Value rightVal, Compare.CompareOp operator)
static QueryEvaluationUtility.Result	compare(Value leftVal, Value rightVal, Compare.CompareOp operator, boolean strict)
static org.eclipse.rdf4j.query.algebra.evaluation.util.QueryEvaluationUtility.Order	compareLiterals(Literal leftLit, Literal rightLit, boolean strict)
static QueryEvaluationUtility.Result	compareLiterals(Literal leftLit, Literal rightLit, Compare.CompareOp operator)	Compares the supplied Literal arguments using the supplied operator, using strict (minimally-conforming) SPARQL 1.1 operator behavior.
static QueryEvaluationUtility.Result	compareLiterals(Literal leftLit, Literal rightLit, Compare.CompareOp operator, boolean strict)	Compares the supplied Literal arguments using the supplied operator.
static boolean	compatibleArguments(Literal arg1, Literal arg2)	Checks whether the supplied two literal arguments are 'argument compatible' according to the SPARQL definition.
static QueryEvaluationUtility.Result	getEffectiveBooleanValue(Value value)	Determines the effective boolean value (EBV) of the supplied value as defined in the SPARQL specification: The EBV of any literal whose type is CoreDatatype.XSD:boolean or numeric is false if the lexical form is not valid for that datatype (e.g.
static boolean	isPlainLiteral(Literal l)
static boolean	isPlainLiteral(Value v)	Checks whether the supplied value is a "plain literal".
static boolean	isSimpleLiteral(boolean isLang, CoreDatatype datatype)	Checks whether the supplied literal is a "simple literal".
static boolean	isSimpleLiteral(Literal l)	Checks whether the supplied literal is a "simple literal".
static boolean	isSimpleLiteral(Value v)	Checks whether the supplied value is a "simple literal".
static boolean	isStringLiteral(Literal l)	Checks whether the supplied literal is a "string literal".
static boolean	isStringLiteral(Value v)	Checks whether the supplied literal is a "string literal".

Methods inherited from class java.lang.Object

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

Constructor Details

QueryEvaluationUtility

public QueryEvaluationUtility()

Method Details

getEffectiveBooleanValue

public static QueryEvaluationUtility.Result getEffectiveBooleanValue(Value value)

Determines the effective boolean value (EBV) of the supplied value as defined in the SPARQL specification:

• The EBV of any literal whose type is CoreDatatype.XSD:boolean or numeric is false if the lexical form is not valid for that datatype (e.g. "abc"^^xsd:integer).
• If the argument is a typed literal with a datatype of CoreDatatype.XSD:boolean, the EBV is the value of that argument.
• If the argument is a plain literal or a typed literal with a datatype of CoreDatatype.XSD:string, the EBV is false if the operand value has zero length; otherwise the EBV is true.
• If the argument is a numeric type or a typed literal with a datatype derived from a numeric type, the EBV is false if the operand value is NaN or is numerically equal to zero; otherwise the EBV is true.
• All other arguments, including unbound arguments, produce a type error.

Parameters:

value - Some value.

Returns:

The EBV of value.

compare

public static QueryEvaluationUtility.Result compare(Value leftVal,
 Value rightVal,
 Compare.CompareOp operator)

compare

public static QueryEvaluationUtility.Result compare(Value leftVal,
 Value rightVal,
 Compare.CompareOp operator,
 boolean strict)

compareLiterals

public static QueryEvaluationUtility.Result compareLiterals(Literal leftLit,
 Literal rightLit,
 Compare.CompareOp operator)

Compares the supplied Literal arguments using the supplied operator, using strict (minimally-conforming) SPARQL 1.1 operator behavior.

Parameters:

leftLit - the left literal argument of the comparison.

rightLit - the right literal argument of the comparison.

operator - the comparison operator to use.

Returns:

true if execution of the supplied operator on the supplied arguments succeeds, false otherwise.

compareLiterals

public static org.eclipse.rdf4j.query.algebra.evaluation.util.QueryEvaluationUtility.Order compareLiterals(Literal leftLit,
 Literal rightLit,
 boolean strict)

compareLiterals

public static QueryEvaluationUtility.Result compareLiterals(Literal leftLit,
 Literal rightLit,
 Compare.CompareOp operator,
 boolean strict)

Compares the supplied Literal arguments using the supplied operator.

Parameters:

leftLit - the left literal argument of the comparison.

rightLit - the right literal argument of the comparison.

operator - the comparison operator to use.

strict - boolean indicating whether comparison should use strict (minimally-conforming) SPARQL 1.1 operator behavior, or extended behavior.

Returns:

true if execution of the supplied operator on the supplied arguments succeeds, false otherwise.

isPlainLiteral

public static boolean isPlainLiteral(Value v)

Checks whether the supplied value is a "plain literal". A "plain literal" is a literal with no datatype and optionally a language tag.

See Also:

• RDF Literal Documentation

isPlainLiteral

public static boolean isPlainLiteral(Literal l)

isSimpleLiteral

public static boolean isSimpleLiteral(Value v)

Checks whether the supplied value is a "simple literal". A "simple literal" is a literal with no language tag nor datatype.

See Also:

• SPARQL Simple Literal Documentation

isSimpleLiteral

public static boolean isSimpleLiteral(Literal l)

Checks whether the supplied literal is a "simple literal". A "simple literal" is a literal with no language tag and the datatype CoreDatatype.XSD.STRING.

See Also:

• SPARQL Simple Literal Documentation

isSimpleLiteral

public static boolean isSimpleLiteral(boolean isLang,
 CoreDatatype datatype)

Checks whether the supplied literal is a "simple literal". A "simple literal" is a literal with no language tag and the datatype CoreDatatype.XSD.STRING.

See Also:

• SPARQL Simple Literal Documentation

isStringLiteral

public static boolean isStringLiteral(Value v)

Checks whether the supplied literal is a "string literal". A "string literal" is either a simple literal, a plain literal with language tag, or a literal with datatype CoreDatatype.XSD:string.

See Also:

• SPARQL Functions on Strings Documentation

compatibleArguments

public static boolean compatibleArguments(Literal arg1,
 Literal arg2)

Checks whether the supplied two literal arguments are 'argument compatible' according to the SPARQL definition.

Parameters:

arg1 - the first argument

arg2 - the second argument

Returns:

true iff the two supplied arguments are argument compatible, false otherwise

See Also:

• SPARQL Argument Compatibility Rules

isStringLiteral

public static boolean isStringLiteral(Literal l)

Checks whether the supplied literal is a "string literal". A "string literal" is either a simple literal, a plain literal with language tag, or a literal with datatype CoreDatatype.XSD:string.

See Also:

• SPARQL Functions on Strings Documentation