com.tinkerpop.pipes

Interface Pipe<S,E>

All Superinterfaces:

Iterable<E>, Iterator<E>

All Known Subinterfaces:

FilterPipe<S>, SideEffectPipe<S,T>, SideEffectPipe.GreedySideEffectPipe<S,T>, SideEffectPipe.LazySideEffectPipe<S,T>, TransformPipe<S,E>

All Known Implementing Classes:

AbstractMetaPipe, AbstractPipe, AggregatePipe, AndFilterPipe, AsPipe, BackFilterPipe, BothEdgesPipe, BothPipe, BothVerticesPipe, CollectionFilterPipe, CopySplitPipe, CountPipe, CyclicPathFilterPipe, DuplicateFilterPipe, EdgesVerticesPipe, ExceptFilterPipe, ExhaustMergePipe, ExpandablePipe, FairMergePipe, FilterFunctionPipe, FunctionPipe, FutureFilterPipe, GatherFunctionPipe, GatherPipe, GraphQueryPipe, GroupByPipe, GroupByReducePipe, GroupCountFunctionPipe, GroupCountPipe, HasCountPipe, HasNextPipe, IdEdgePipe, IdentityPipe, IdFilterPipe, IdPipe, IdVertexPipe, IfThenElsePipe, IndexElementsPipe, InEdgesPipe, InPipe, IntervalFilterPipe, InVertexPipe, LabelFilterPipe, LabelPipe, LinkPipe, LoopPipe, MemoizePipe, ObjectFilterPipe, OptionalPipe, OrderMapPipe, OrderPipe, OrFilterPipe, OutEdgesPipe, OutPipe, OutVertexPipe, PathPipe, Pipeline, PipesPipeline, PropertyFilterPipe, PropertyMapPipe, PropertyPipe, QueryPipe, RandomFilterPipe, RangeFilterPipe, RetainFilterPipe, ScatterPipe, SelectPipe, ShufflePipe, SideEffectCapPipe, SideEffectFunctionPipe, StartPipe, StorePipe, TablePipe, ToStringPipe, TransformFunctionPipe, TreePipe, VertexQueryPipe, VerticesEdgesPipe, VerticesVerticesPipe

public interface Pipe<S,E>
extends Iterator<E>, Iterable<E>

The generic interface for any Pipe implementation. A Pipe takes/consumes objects of type S and returns/emits objects of type E. S refers to starts and the E refers to ends.

Author:

Marko A. Rodriguez (http://markorodriguez.com), Darrick Wiebe (darrick@innatesoftware.com)

Field Summary

Fields

Modifier and Type	Field and Description
static String	NO_PATH_MESSAGE

Method Summary

Methods

Modifier and Type	Method and Description
void	enablePath(boolean enable) Calculating paths can be an expensive operation for some pipes.
List	getCurrentPath() Returns the transformation path to arrive at the current object of the pipe.
void	reset() A pipe may maintain state.
void	setStarts(Iterable<S> starts) Set an iterable of S objects to the head (start) of the pipe.
void	setStarts(Iterator<S> starts) Set an iterator of S objects to the head (start) of the pipe.

Methods inherited from interface java.util.Iterator

hasNext, next, remove

Methods inherited from interface java.lang.Iterable

iterator

Field Detail

NO_PATH_MESSAGE

static final String NO_PATH_MESSAGE

See Also:

Constant Field Values

Method Detail

setStarts

void setStarts(Iterator<S> starts)

Set an iterator of S objects to the head (start) of the pipe.

Parameters:

starts - the iterator of incoming objects

setStarts

void setStarts(Iterable<S> starts)

Set an iterable of S objects to the head (start) of the pipe.

Parameters:

starts - the iterable of incoming objects

getCurrentPath

List getCurrentPath()

Returns the transformation path to arrive at the current object of the pipe.

Returns:

a List of all of the objects traversed for the current iterator position of the pipe.

enablePath

void enablePath(boolean enable)

Calculating paths can be an expensive operation for some pipes. This method is used to activate or deactivate the calculation of paths. The default state of a newly constructed pipe should have its path calculations disabled. An implementation of this method should be recursive whereby the starts (if a Pipe) should have this method called on it.

Parameters:

enable - enable path calculations

reset

void reset()

A pipe may maintain state. Reset is used to remove state. The general use case for reset() is to reuse a pipe in another computation without having to create a new Pipe object. An implementation of this method should be recursive whereby the starts (if a Pipe) should have this method called on it.