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

Class DBIntIndexFunctionSymbolImpl

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.AbstractArgDependentTypedDBFunctionSymbol

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

All Implemented Interfaces:

DBFunctionSymbol, DBFunctionSymbolSerializer, FunctionSymbol, Predicate

public class DBIntIndexFunctionSymbolImpl
extends AbstractArgDependentTypedDBFunctionSymbol

The first sub-term encodes the index of the term to return. Such values correspond to the following sub-terms For instance DB_IDX(1, "roger", "francis", "ernest") returns "francis"

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	DBIntIndexFunctionSymbolImpl(DBTermType dbIntegerType, DBTermType rootDBType, int nbEntries)

Method Summary

Modifier and Type	Method and Description
boolean	canBePostProcessed(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> arguments) 1.
IncrementalEvaluation	evaluateStrictEq(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms, ImmutableTerm otherTerm, TermFactory termFactory, VariableNullability variableNullability) Default implementation, to be overridden to convert more cases Incoming terms are not simplified as they are presumed to be already simplified (so please simplify them before)
protected Stream<? extends ImmutableTerm>	extractPossibleValues(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms)
String	getNativeDBString(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms, Function<ImmutableTerm,String> termConverter, TermFactory termFactory) Encodes it as a SQL case
boolean	isAlwaysInjectiveInTheAbsenceOfNonInjectiveFunctionalTerms() When the function symbol is, in the absence of non-injective functional sub-terms, sometimes but not always injective, please override isInjective(...)
boolean	isPreferringToBePostProcessedOverBeingBlocked() If it is better to be post-processed than being blocked behind an UNION.
protected boolean	mayReturnNullWithoutNullArguments() Returns false when a functional term with this symbol: 1.
ImmutableTerm	simplify(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms, TermFactory termFactory, VariableNullability variableNullability)
protected boolean	tolerateNulls() Should provoke a fatal error when its argument is NULL

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

inferType

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

analyzeInjectivity, buildTermAfterEvaluation, canBeSafelyDecomposedIntoConjunction, decomposeInjectiveTopFunctionalTerm, enableIfElseNullLifting, evaluateIsNotNull, evaluateNullability, evaluateStrictEqWithFunctionalTerm, evaluateStrictEqWithNonNullConstant, getExpectedBaseType, getExpectedBaseTypes, isAggregation, isDeterministic, isInjective, isNullable, proposeProvenanceVariables, 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.FunctionSymbol

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

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

getArity, getName

Constructor Detail

DBIntIndexFunctionSymbolImpl

protected DBIntIndexFunctionSymbolImpl(DBTermType dbIntegerType,
                                       DBTermType rootDBType,
                                       int nbEntries)

Method Detail

tolerateNulls

protected boolean tolerateNulls()

Should provoke a fatal error when its argument is NULL

Specified by:

tolerateNulls in class FunctionSymbolImpl

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

extractPossibleValues

protected Stream<? extends ImmutableTerm> extractPossibleValues(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms)

Specified by:

extractPossibleValues in class AbstractArgDependentTypedDBFunctionSymbol

isPreferringToBePostProcessedOverBeingBlocked

public boolean isPreferringToBePostProcessedOverBeingBlocked()

Description copied from interface: DBFunctionSymbol

If it is better to be post-processed than being blocked behind an UNION. Obviously, non post-processable function symbols must return false.

simplify

public ImmutableTerm simplify(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms,
                              TermFactory termFactory,
                              VariableNullability variableNullability)

Specified by:

simplify in interface FunctionSymbol

Overrides:

simplify in class FunctionSymbolImpl

getNativeDBString

public String getNativeDBString(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms,
                                Function<ImmutableTerm,String> termConverter,
                                TermFactory termFactory)

Encodes it as a SQL case

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(it.unibz.inf.ontop.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).

evaluateStrictEq

public IncrementalEvaluation evaluateStrictEq(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms,
                                              ImmutableTerm otherTerm,
                                              TermFactory termFactory,
                                              VariableNullability variableNullability)

Description copied from class: FunctionSymbolImpl

Default implementation, to be overridden to convert more cases Incoming terms are not simplified as they are presumed to be already simplified (so please simplify them before)

Specified by:

evaluateStrictEq in interface FunctionSymbol

Overrides:

evaluateStrictEq in class FunctionSymbolImpl