org.eclipse.viatra.query.runtime.matchers.backend

Class QueryHintOption<HintValue>

java.lang.Object

org.eclipse.viatra.query.runtime.matchers.backend.QueryHintOption<HintValue>

public class QueryHintOption<HintValue>
extends java.lang.Object

Each instance of this class corresponds to a given hint option. It is recommended to expose options to clients (and query backends) as public static fields.

Since:

1.5

Constructor Summary

Constructors

Constructor and Description
QueryHintOption(java.lang.Class<?> optionNamespace, java.lang.String optionLocalName, HintValue defaultValue) This is the recommended constructor for hint options defined as static fields within an enclosing class.
QueryHintOption(java.lang.String optionQualifiedName, HintValue defaultValue) Instantiates an option object with the given name and default value.

Method Summary

Modifier and Type	Method and Description
HintValue	getDefaultValue() Returns the default value of this hint option, which is to be used by query backends in the case no overriding value is assigned.
java.lang.String	getQualifiedName() Returns the qualified name, a unique string identifier of the option.
HintValue	getValueOrDefault(QueryEvaluationHint hints) Returns the value of this hint option from the given hint collection, or the default value if not defined.
HintValue	getValueOrNull(QueryEvaluationHint hints) Returns the value of this hint option from the given hint collection, or null if not defined.
HintValue	insertOverridingValue(java.util.Map<QueryHintOption,java.lang.Object> hints, HintValue overridingValue) Puts a value of this hint option into an option-to-value map.
boolean	isOverriddenIn(QueryEvaluationHint hints) Returns whether this hint option is defined in the given hint collection.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

QueryHintOption

public QueryHintOption(java.lang.String optionQualifiedName,
                       HintValue defaultValue)

Instantiates an option object with the given name and default value.

QueryHintOption

public QueryHintOption(java.lang.Class<?> optionNamespace,
                       java.lang.String optionLocalName,
                       HintValue defaultValue)

This is the recommended constructor for hint options defined as static fields within an enclosing class. Combines the qualified name of the hint from the (qualified) name of the enclosing class and a local name (unique within that class).

Method Detail

getQualifiedName

public java.lang.String getQualifiedName()

Returns the qualified name, a unique string identifier of the option.

getDefaultValue

public HintValue getDefaultValue()

Returns the default value of this hint option, which is to be used by query backends in the case no overriding value is assigned.

getValueOrDefault

public HintValue getValueOrDefault(QueryEvaluationHint hints)

Returns the value of this hint option from the given hint collection, or the default value if not defined. Intended to be called by backends to find out the definitive value that should be considered.

getValueOrNull

public HintValue getValueOrNull(QueryEvaluationHint hints)

Returns the value of this hint option from the given hint collection, or null if not defined.

isOverriddenIn

public boolean isOverriddenIn(QueryEvaluationHint hints)

Returns whether this hint option is defined in the given hint collection.

insertOverridingValue

public HintValue insertOverridingValue(java.util.Map<QueryHintOption,java.lang.Object> hints,
                                       HintValue overridingValue)

Puts a value of this hint option into an option-to-value map.

This method is offered in lieu of a builder API. Use this method on any number of hint options in order to populate an option-value map. Then instantiate the immutable QueryEvaluationHint using the map.

Returns:

the hint value that was previously present in the map under this hint option, carrying over the semantics of Map.put(Object, Object).

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object