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

Class QueryEvaluationUtil

  • public class QueryEvaluationUtil
extends Object
    Author:
    Arjohn Kampman

    • Constructor Detail

      • QueryEvaluationUtil

        public QueryEvaluationUtil()

    • Method Detail

      • getEffectiveBooleanValue

        public static boolean getEffectiveBooleanValue​(Value value)
                                        throws ValueExprEvaluationException
        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.
        Throws:
        ValueExprEvaluationException - In case the application of the EBV algorithm results in a type error.

      • compareLiterals

        public static boolean compareLiterals​(Literal leftLit,
                                      Literal rightLit,
                                      Compare.CompareOp operator)
                               throws ValueExprEvaluationException
        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.
        Throws:
        ValueExprEvaluationException - if a type error occurred.

      • compareLiterals

        public static boolean compareLiterals​(Literal leftLit,
                                      Literal rightLit,
                                      Compare.CompareOp operator,
                                      boolean strict)
                               throws ValueExprEvaluationException
        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.
        Throws:
        ValueExprEvaluationException - if a type error occurred.

      • 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

      • 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