org.gridgain.grid.lang
Class GridReducer3<E1,E2,E3,R>

java.lang.Object
  org.gridgain.grid.lang.GridMetadataAwareAdapter
      org.gridgain.grid.lang.GridLambdaAdapter
          org.gridgain.grid.lang.GridOutClosure<R>
              org.gridgain.grid.lang.GridReducer3<E1,E2,E3,R>

Type Parameters:

E1 - Type of the first free variable, i.e. the element the closure is called on.

E2 - Type of the second free variable, i.e. the element the closure is called on.

E3 - Type of the third free variable, i.e. the element the closure is called on.

R - Type of the closure's return value.

All Implemented Interfaces:

Serializable, Cloneable, Callable<R>, GridJob, GridMetadataAware, GridPeerDeployAware, GridLambda

Direct Known Subclasses:

GridReducer3X, R3

public abstract class GridReducer3<E1,E2,E3,R>
extends GridOutClosure<R>

Defines generic for-all or reduce type of closure. Unlike for-each type of closure that returns optional value on each execution of the closure - the reducer returns a single value for one or more collected values.

Closures are a first-class functions that are defined with (or closed over) their free variables that are bound to the closure scope at execution. Since Java 6 doesn't provide a language construct for first-class function the closures are implemented as abstract classes.

Thread Safety

Note that this interface does not impose or assume any specific thread-safety by its implementations. Each implementation can elect what type of thread-safety it provides, if any.

Wiki & Forum:

Wiki
Forum

See Also:

Serialized Form

Constructor Summary

GridReducer3()

Method Summary

abstract boolean	collect(E1 e1, E2 e2, E3 e3) Collects given values.
GridOutClosure<R>	curry(GridTuple3<E1,E2,E3>... t) Curries this closure with given tuple values.

Methods inherited from class org.gridgain.grid.lang.GridOutClosure

andThen, andThen, apply, call, cancel, execute, uncurry, uncurry2, uncurry3

Methods inherited from class org.gridgain.grid.lang.GridLambdaAdapter

classLoader, deployClass, peerDeployLike, withMeta

Methods inherited from class org.gridgain.grid.lang.GridMetadataAwareAdapter

addMeta, addMetaIfAbsent, addMetaIfAbsent, allMeta, clone, copyMeta, copyMeta, hasMeta, hasMeta, meta, putMetaIfAbsent, putMetaIfAbsent, readExternalMeta, removeMeta, removeMeta, replaceMeta, writeExternalMeta

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.gridgain.grid.GridMetadataAware

addMeta, addMetaIfAbsent, addMetaIfAbsent, allMeta, copyMeta, copyMeta, hasMeta, hasMeta, meta, putMetaIfAbsent, putMetaIfAbsent, removeMeta, removeMeta, replaceMeta

Constructor Detail

GridReducer3

public GridReducer3()

Method Detail

collect

public abstract boolean collect(E1 e1,
                                E2 e2,
                                E3 e3)

Collects given values. All values will be reduced by GridOutClosure.apply() method.

Parameters:

e1 - First bound free variable, i.e. the element the closure is called on.

e2 - Second bound free variable, i.e. the element the closure is called on.

e3 - Third bound free variable, i.e. the element the closure is called on.

Returns:

true to continue collecting, false to instruct caller to stop collecting and call GridOutClosure.apply() method.

curry

public GridOutClosure<R> curry(GridTuple3<E1,E2,E3>... t)

Curries this closure with given tuple values. When result closure is called it will be executed with given values.

Parameters:

t - Tuples each with three values.

Returns:

Curried or partially applied closure with given values.