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

Class AbstractCommonDenominatorFunctionSymbol

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.AbstractCommonDenominatorFunctionSymbol

All Implemented Interfaces:

FunctionSymbol, Predicate

Direct Known Subclasses:

CommonDenominatorFunctionSymbolImpl, CommonPropagatedOrSubstitutedNumericTypeFunctionSymbolImpl

public abstract class AbstractCommonDenominatorFunctionSymbol
extends FunctionSymbolImpl

Nested Class Summary

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

FunctionSymbol.FunctionalTermNullability

Constructor Summary

Constructors

Constructor and Description
AbstractCommonDenominatorFunctionSymbol(String functionSymbolName, int arity, MetaRDFTermType metaRDFTermType)

Method Summary

Modifier and Type	Method and Description
protected ImmutableTerm	buildTermAfterEvaluation(com.google.common.collect.ImmutableList<ImmutableTerm> newTerms, TermFactory termFactory, VariableNullability variableNullability) To be overridden by concrete classes Default case: looks for DBIfThen
boolean	canBePostProcessed(com.google.common.collect.ImmutableList<? extends ImmutableTerm> arguments) 1.
protected boolean	enableIfElseNullLifting() Returns false if IfElseNullLifting must be disabled althrough it may have been technically possible.
protected abstract Optional<RDFTermTypeConstant>	evaluateCombination(com.google.common.collect.ImmutableList<RDFTermTypeConstant> constants, Optional<RDFTermTypeConstant> optionalMergedTypeConstant, TermFactory termFactory)
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	mayReturnNullWithoutNullArguments() Returns false when a functional term with this symbol: 1.
protected ImmutableTerm	simplifyUsingMagicNumbers(com.google.common.collect.ImmutableList<ImmutableFunctionalTerm> otherTerms, Optional<RDFTermTypeConstant> optionalMergedTypeConstant, TermFactory termFactory) otherTerms: all use a RDFTermTypeFunctionSymbol.
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.FunctionSymbolImpl

analyzeInjectivity, canBeSafelyDecomposedIntoConjunction, decomposeInjectiveTopFunctionalTerm, 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

equals, getArity, getName, hashCode, toString

Methods inherited from class java.lang.Object

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

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

getArity, getName

Constructor Detail

AbstractCommonDenominatorFunctionSymbol

public AbstractCommonDenominatorFunctionSymbol(String functionSymbolName,
                                               int arity,
                                               MetaRDFTermType metaRDFTermType)

Method Detail

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)

mayReturnNullWithoutNullArguments

protected boolean mayReturnNullWithoutNullArguments()

Description copied from class: FunctionSymbolImpl

Returns false when a functional term with this symbol: 1. never produce NULLs 2. May produce NULLs but it is always due to a NULL argument

Specified by:

mayReturnNullWithoutNullArguments 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

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).

buildTermAfterEvaluation

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

To be overridden by concrete classes Default case: looks for DBIfThen

Overrides:

buildTermAfterEvaluation in class FunctionSymbolImpl

simplifyUsingMagicNumbers

protected ImmutableTerm simplifyUsingMagicNumbers(com.google.common.collect.ImmutableList<ImmutableFunctionalTerm> otherTerms,
                                                  Optional<RDFTermTypeConstant> optionalMergedTypeConstant,
                                                  TermFactory termFactory)

otherTerms: all use a RDFTermTypeFunctionSymbol. Non-empty.

evaluateCombination

protected abstract Optional<RDFTermTypeConstant> evaluateCombination(com.google.common.collect.ImmutableList<RDFTermTypeConstant> constants,
                                                                     Optional<RDFTermTypeConstant> optionalMergedTypeConstant,
                                                                     TermFactory termFactory)

enableIfElseNullLifting

protected boolean enableIfElseNullLifting()

Description copied from class: FunctionSymbolImpl

Returns false if IfElseNullLifting must be disabled althrough it may have been technically possible. False by defaults

Overrides:

enableIfElseNullLifting in class FunctionSymbolImpl