Package org.rumbledb.runtime.functions.sequences.general

Class HeadFunctionIterator

java.lang.Object

org.rumbledb.runtime.plan.RuntimePlan<Item>

org.rumbledb.runtime.plan.ItemRuntimePlan

org.rumbledb.runtime.AbstractAtMostOneItemRuntimePlan

org.rumbledb.runtime.functions.sequences.general.HeadFunctionIterator

All Implemented Interfaces:

Serializable, AtMostOneLocalRuntimePlan<Item>, LocalRuntimePlan<Item>

public class HeadFunctionIterator
extends AbstractAtMostOneItemRuntimePlan

See Also:

• Serialized Form

Field Summary

Fields inherited from class org.rumbledb.runtime.plan.RuntimePlan

staticContext

Constructor Summary

Constructors

Constructor	Description
HeadFunctionIterator(List<ItemRuntimePlan> parameters, RuntimeStaticContext staticContext)

Method Summary

Modifier and Type	Method	Description
Item	evaluateAtMostOne(DynamicContext dynamicContext)	Evaluates the plan without allocating a cursor.

Methods inherited from class org.rumbledb.runtime.AbstractAtMostOneItemRuntimePlan

createNativeCursor

Methods inherited from class org.rumbledb.runtime.plan.ItemRuntimePlan

getChild, getChildren, getStaticType, getVariableDependencies, isSparkJobNeeded, print

Methods inherited from class org.rumbledb.runtime.plan.RuntimePlan

getConfiguration, getCursor, getDataFrame, getMetadata, getRDD, getRuntimeStaticContext, materialize, materializeAtMost, materializeAtMostOne, materializeExactlyOne, materializeFirstOrNull

Methods inherited from class java.lang.Object

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

Constructor Details

HeadFunctionIterator

public HeadFunctionIterator(List<ItemRuntimePlan> parameters,
 RuntimeStaticContext staticContext)

Method Details

evaluateAtMostOne

public Item evaluateAtMostOne(DynamicContext dynamicContext)

Description copied from interface: AtMostOneLocalRuntimePlan

Evaluates the plan without allocating a cursor.

Specified by:

evaluateAtMostOne in interface AtMostOneLocalRuntimePlan<Item>

Specified by:

evaluateAtMostOne in class AbstractAtMostOneItemRuntimePlan

Parameters:

dynamicContext - the dynamic context for the evaluation

Returns:

the value, or null for the empty sequence