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

Class ObjectStringTemplateFunctionSymbolImpl

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.ObjectStringTemplateFunctionSymbolImpl

All Implemented Interfaces:

DBFunctionSymbol, DBFunctionSymbolSerializer, ObjectStringTemplateFunctionSymbol, FunctionSymbol, Predicate

Direct Known Subclasses:

BnodeStringTemplateFunctionSymbolImpl, IRIStringTemplateFunctionSymbolImpl

public abstract class ObjectStringTemplateFunctionSymbolImpl
extends FunctionSymbolImpl
implements ObjectStringTemplateFunctionSymbol

Nested Class Summary

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

FunctionSymbol.FunctionalTermNullability

Field Summary

Fields

Modifier and Type	Field and Description
protected static String	PLACE_HOLDER
protected static com.google.common.collect.ImmutableList<Character>	SOME_SAFE_SEPARATORS TODO: enrich this list (incomplete)

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ObjectStringTemplateFunctionSymbolImpl(String template, int arity, TypeFactory typeFactory)

Method Summary

Modifier and Type	Method and Description
protected boolean	areCompatible(String otherTemplate) Is guaranteed not to return false negative.
protected ImmutableTerm	buildTermAfterEvaluation(com.google.common.collect.ImmutableList<ImmutableTerm> newTerms, TermFactory termFactory, VariableNullability variableNullability) By default, just build a new functional term.
boolean	canBePostProcessed(com.google.common.collect.ImmutableList<? extends ImmutableTerm> arguments) 1.
protected IncrementalEvaluation	evaluateStrictEqWithFunctionalTerm(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms, ImmutableFunctionalTerm otherTerm, TermFactory termFactory, VariableNullability variableNullability) Default implementation, can be overridden
protected IncrementalEvaluation	evaluateStrictEqWithNonNullConstant(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms, NonNullConstant otherTerm, TermFactory termFactory, VariableNullability variableNullability) Default implementation, does nothing, can be overridden
protected static com.google.common.collect.ImmutableList<String>	extractIntermediateStrings(String template) Strings between the place holders
protected static Pattern	extractPattern(String template, boolean surroundWithParentheses)
String	getNativeDBString(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms, Function<ImmutableTerm,String> termConverter, TermFactory termFactory) Returns a String in the native query language.
String	getTemplate()
protected com.google.common.collect.ImmutableList<DBConstant>	getTemplateConstants(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	isInjective(int arity, String template) Must not produce false positive
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.
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, enableIfElseNullLifting, evaluateIsNotNull, evaluateNullability, evaluateStrictEq, 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

Field Detail

SOME_SAFE_SEPARATORS

protected static final com.google.common.collect.ImmutableList<Character> SOME_SAFE_SEPARATORS

TODO: enrich this list (incomplete)

PLACE_HOLDER

protected static final String PLACE_HOLDER

See Also:

Constant Field Values

Constructor Detail

ObjectStringTemplateFunctionSymbolImpl

protected ObjectStringTemplateFunctionSymbolImpl(String template,
                                                 int arity,
                                                 TypeFactory typeFactory)

Method Detail

isInjective

protected boolean isInjective(int arity,
                              String template)

Must not produce false positive

extractIntermediateStrings

protected static com.google.common.collect.ImmutableList<String> extractIntermediateStrings(String template)

Strings between the place holders

getTemplate

public String getTemplate()

Specified by:

getTemplate in interface ObjectStringTemplateFunctionSymbol

inferType

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

Specified by:

inferType in interface FunctionSymbol

buildTermAfterEvaluation

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

Description copied from class: FunctionSymbolImpl

By default, just build a new functional term. NB: If the function symbol does not tolerate NULL values, no need to handle them here.

Overrides:

buildTermAfterEvaluation in class FunctionSymbolImpl

getTemplateConstants

protected com.google.common.collect.ImmutableList<DBConstant> getTemplateConstants(TermFactory termFactory)

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

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).

Specified by:

canBePostProcessed in interface FunctionSymbol

getNativeDBString

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

Description copied from interface: DBFunctionSymbolSerializer

Returns a String in the native query language.

Specified by:

getNativeDBString in interface DBFunctionSymbolSerializer

evaluateStrictEqWithFunctionalTerm

protected IncrementalEvaluation evaluateStrictEqWithFunctionalTerm(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms,
                                                                   ImmutableFunctionalTerm otherTerm,
                                                                   TermFactory termFactory,
                                                                   VariableNullability variableNullability)

Description copied from class: FunctionSymbolImpl

Default implementation, can be overridden

Overrides:

evaluateStrictEqWithFunctionalTerm in class FunctionSymbolImpl

areCompatible

protected boolean areCompatible(String otherTemplate)

Is guaranteed not to return false negative.

extractPattern

protected static Pattern extractPattern(String template,
                                        boolean surroundWithParentheses)

evaluateStrictEqWithNonNullConstant

protected IncrementalEvaluation evaluateStrictEqWithNonNullConstant(com.google.common.collect.ImmutableList<? extends ImmutableTerm> terms,
                                                                    NonNullConstant otherTerm,
                                                                    TermFactory termFactory,
                                                                    VariableNullability variableNullability)

Description copied from class: FunctionSymbolImpl

Default implementation, does nothing, can be overridden

Overrides:

evaluateStrictEqWithNonNullConstant in class FunctionSymbolImpl

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.

Specified by:

isPreferringToBePostProcessedOverBeingBlocked in interface DBFunctionSymbol