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

Class NullToleratingDBConcatFunctionSymbol

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.db.impl.AbstractTypedDBFunctionSymbol

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

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

All Implemented Interfaces:

DBConcatFunctionSymbol, DBFunctionSymbol, DBFunctionSymbolSerializer, FunctionSymbol, Predicate

public class NullToleratingDBConcatFunctionSymbol
extends AbstractDBConcatFunctionSymbol

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	NullToleratingDBConcatFunctionSymbol(String nameInDialect, int arity, DBTermType dbStringType, DBTermType rootDBTermType, boolean isOperator)

Method Summary

Modifier and Type	Method and Description
boolean	canBePostProcessed(com.google.common.collect.ImmutableList<? extends ImmutableTerm> arguments) 1.
IncrementalEvaluation	evaluateIsNotNull(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms, TermFactory termFactory, VariableNullability variableNullability) Never returns NULL
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.db.impl.AbstractDBConcatFunctionSymbol

analyzeInjectivity, getNativeDBString

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

getTargetType, inferType, isPreferringToBePostProcessedOverBeingBlocked, mayReturnNullWithoutNullArguments

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

buildTermAfterEvaluation, canBeSafelyDecomposedIntoConjunction, decomposeInjectiveTopFunctionalTerm, enableIfElseNullLifting, 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.db.DBFunctionSymbol

isPreferringToBePostProcessedOverBeingBlocked

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

evaluateNullability, evaluateStrictEq, getExpectedBaseType, inferType, isAggregation, isDeterministic, isNullable, proposeProvenanceVariables, simplify, simplifyAsGuaranteedToBeNonNull

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

getArity, getName

Constructor Detail

NullToleratingDBConcatFunctionSymbol

protected NullToleratingDBConcatFunctionSymbol(String nameInDialect,
                                               int arity,
                                               DBTermType dbStringType,
                                               DBTermType rootDBTermType,
                                               boolean isOperator)

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

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).

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.

Overrides:

tolerateNulls in class AbstractTypedDBFunctionSymbol

evaluateIsNotNull

public IncrementalEvaluation evaluateIsNotNull(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms,
                                               TermFactory termFactory,
                                               VariableNullability variableNullability)

Never returns NULL

Specified by:

evaluateIsNotNull in interface FunctionSymbol

Overrides:

evaluateIsNotNull in class FunctionSymbolImpl