it.unibz.inf.ontop.model.term.functionsymbol.impl

Class SameTermSPARQLFunctionSymbolImpl

java.lang.Object

it.unibz.inf.ontop.model.term.impl.PredicateImpl

it.unibz.inf.ontop.model.term.functionsymbol.impl.FunctionSymbolImpl

it.unibz.inf.ontop.model.term.functionsymbol.impl.SPARQLLikeFunctionSymbolImpl

it.unibz.inf.ontop.model.term.functionsymbol.impl.SPARQLFunctionSymbolImpl

it.unibz.inf.ontop.model.term.functionsymbol.impl.SameTermSPARQLFunctionSymbolImpl

All Implemented Interfaces:

FunctionSymbol, Predicate, SPARQLFunctionSymbol

public class SameTermSPARQLFunctionSymbolImpl
extends SPARQLFunctionSymbolImpl

SPARQL's strict equality function symbol

Nested Class Summary

Nested classes/interfaces inherited from interface it.unibz.inf.ontop.model.term.functionsymbol.FunctionSymbol

FunctionSymbol.FunctionalTermNullability

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SameTermSPARQLFunctionSymbolImpl(RDFTermType rdfRootType, RDFDatatype xsdBooleanType)

Method Summary

Modifier and Type	Method and Description
protected ImmutableTerm	buildTermAfterEvaluation(com.google.common.collect.ImmutableList<ImmutableTerm> newTerms, TermFactory termFactory, VariableNullability variableNullability) Always simplifies itself
boolean	canBePostProcessed(com.google.common.collect.ImmutableList<? extends ImmutableTerm> arguments) 1.
Optional<TermTypeInference>	inferType(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms)
boolean	isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms() When the function symbol is, in the absence of non-injective functional sub-terms, sometimes but not always injective, please override isInjective(...)
protected boolean	tolerateNulls() Returns true if is not guaranteed to return NULL when one argument is NULL.

Methods inherited from class it.unibz.inf.ontop.model.term.functionsymbol.impl.SPARQLFunctionSymbolImpl

getIRI, getOfficialName

Methods inherited from class it.unibz.inf.ontop.model.term.functionsymbol.impl.SPARQLLikeFunctionSymbolImpl

extractLexicalTerm, extractRDFTermTypeTerm, isRDFFunctionalTerm, mayReturnNullWithoutNullArguments

Methods inherited from class it.unibz.inf.ontop.model.term.functionsymbol.impl.FunctionSymbolImpl

analyzeInjectivity, canBeSafelyDecomposedIntoConjunction, decomposeInjectiveTopFunctionalTerm, enableIfElseNullLifting, evaluateIsNotNull, evaluateNullability, evaluateStrictEq, evaluateStrictEqWithFunctionalTerm, evaluateStrictEqWithNonNullConstant, getExpectedBaseType, getExpectedBaseTypes, isAggregation, isDeterministic, isInjective, isNullable, proposeProvenanceVariables, simplify, simplifyAsGuaranteedToBeNonNull, transformIntoRegularArguments, tryToLiftMagicNumbers

Methods inherited from class it.unibz.inf.ontop.model.term.impl.PredicateImpl

clone, equals, getArity, getName, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unibz.inf.ontop.model.term.functionsymbol.FunctionSymbol

analyzeInjectivity, evaluateIsNotNull, evaluateNullability, evaluateStrictEq, getExpectedBaseType, isAggregation, isDeterministic, isNullable, proposeProvenanceVariables, simplify, simplifyAsGuaranteedToBeNonNull

Methods inherited from interface it.unibz.inf.ontop.model.term.functionsymbol.Predicate

getArity, getName

Constructor Detail

SameTermSPARQLFunctionSymbolImpl

protected SameTermSPARQLFunctionSymbolImpl(@Nonnull
                                           RDFTermType rdfRootType,
                                           RDFDatatype xsdBooleanType)

Method Detail

buildTermAfterEvaluation

protected ImmutableTerm buildTermAfterEvaluation(com.google.common.collect.ImmutableList<ImmutableTerm> newTerms,
                                                 TermFactory termFactory,
                                                 VariableNullability variableNullability)

Always simplifies itself

Overrides:

buildTermAfterEvaluation in class FunctionSymbolImpl

tolerateNulls

protected boolean tolerateNulls()

Description copied from class: FunctionSymbolImpl

Returns true if is not guaranteed to return NULL when one argument is NULL. Can be the case for some function symbols that are rejecting certain cases and therefore refuse to simplify themselves, e.g. RDF(NULL,IRI) is invalid and therefore cannot be simplified.

Specified by:

tolerateNulls in class FunctionSymbolImpl

isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms

public boolean isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms()

Description copied from class: FunctionSymbolImpl

When the function symbol is, in the absence of non-injective functional sub-terms, sometimes but not always injective, please override isInjective(...)

Specified by:

isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms in class FunctionSymbolImpl

inferType

public Optional<TermTypeInference> inferType(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms)

canBePostProcessed

public boolean canBePostProcessed(com.google.common.collect.ImmutableList<? extends ImmutableTerm> arguments)

Description copied from interface: FunctionSymbol

1. When a functional term simplifies itself in a BOTTOM-UP manner: Returns true if is guaranteed to "simplify itself" as a Constant when receiving Constants as arguments (outside the optimization phase) . 2. When a functional term simplifies itself in a TOP-DOWN manner (e.g. IF-THEN-ELSE functional terms): The permission for post-processing may depend on the ability of sub-functional terms to be post-processed or safely evaluated by the DB engine. (Recall that top-down evaluation allows some arguments not to be evaluated when their pre-conditions are not met. This is particularly valuable for preventing fatal errors).