com.hazelcast.jet.function

Class DistributedFunctions

java.lang.Object

com.hazelcast.jet.function.DistributedFunctions

public final class DistributedFunctions
extends Object

Factory methods for several common distributed functions.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CONSTANT_KEY The string key returned by constantKey().

Method Summary

Modifier and Type	Method and Description
static <T> DistributedPredicate<T>	alwaysFalse() Return sa predicate that always evaluates to false.
static <T> DistributedPredicate<T>	alwaysTrue() Returns a predicate that always evaluates to true.
static <T> DistributedFunction<T,String>	constantKey() Returns a function that always evaluates to the CONSTANT_KEY.
static <K,V> DistributedFunction<Map.Entry<K,V>,K>	entryKey() Returns a function that extracts the key of a Map.Entry.
static <K,V> DistributedFunction<Map.Entry<K,V>,V>	entryValue() Returns a function that extracts the value of a Map.Entry.
static <T> DistributedConsumer<T>	noopConsumer() Returns a consumer that does nothing with the argument.
static <T> DistributedFunction<T,T>	wholeItem() Synonym for DistributedFunction.identity(), to be used as a projection function (e.g., key extractor).

Methods inherited from class java.lang.Object

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

Field Detail

CONSTANT_KEY

public static final String CONSTANT_KEY

The string key returned by constantKey().

See Also:

Constant Field Values

Method Detail

wholeItem

@Nonnull
public static <T> DistributedFunction<T,T> wholeItem()

Synonym for DistributedFunction.identity(), to be used as a projection function (e.g., key extractor).

entryKey

@Nonnull
public static <K,V> DistributedFunction<Map.Entry<K,V>,K> entryKey()

Returns a function that extracts the key of a Map.Entry.

Type Parameters:

K - type of entry's key

entryValue

@Nonnull
public static <K,V> DistributedFunction<Map.Entry<K,V>,V> entryValue()

Returns a function that extracts the value of a Map.Entry.

Type Parameters:

V - type of entry's value

constantKey

@Nonnull
public static <T> DistributedFunction<T,String> constantKey()

Returns a function that always evaluates to the CONSTANT_KEY. This is useful as a key extractor in group-by operations where no classification by key is desired.

noopConsumer

@Nonnull
public static <T> DistributedConsumer<T> noopConsumer()

Returns a consumer that does nothing with the argument.

alwaysTrue

@Nonnull
public static <T> DistributedPredicate<T> alwaysTrue()

Returns a predicate that always evaluates to true.

alwaysFalse

@Nonnull
public static <T> DistributedPredicate<T> alwaysFalse()

Return sa predicate that always evaluates to false.