org.apache.tinkerpop.gremlin.process.traversal.step.map

## Class CoalesceStep<S,E>

- java.lang.Object
- - org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep<S,E>
  - - org.apache.tinkerpop.gremlin.process.traversal.step.map.FlatMapStep<S,E>
    - - org.apache.tinkerpop.gremlin.process.traversal.step.map.CoalesceStep<S,E>

- All Implemented Interfaces:
    Serializable, AutoCloseable, Cloneable, Iterator<Traverser.Admin<E>>, Step<S,E>, TraversalParent

      public final class CoalesceStep<S,E>
      extends FlatMapStep<S,E>
      implements TraversalParent

  Author:
    Daniel Kuppitz (http://gremlin.guru)
  See Also:
    Serialized Form

- - ### Field Summary

    - ### Fields inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

      `id, labels, nextEnd, nextStep, previousStep, starts, traversal, traverserStepIdAndLabelsSetByChild`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `CoalesceStep(Traversal.Admin traversal, Traversal.Admin<S,E>... coalesceTraversals)`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `CoalesceStep<S,E>` | `clone()` Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication.
    `protected Iterator<E>` | `flatMap(Traverser.Admin<S> traverser)`
    `List<Traversal.Admin<S,E>>` | `getLocalChildren()`
    `Set<TraverserRequirement>` | `getRequirements()` Provide the necessary `TraverserRequirement` that must be met by the traverser in order for the step to function properly.
    `int` | `hashCode()`
    `void` | `setTraversal(Traversal.Admin<?,?> parentTraversal)` Set the `Traversal` that this step is contained within.
    `String` | `toString()`

    - ### Methods inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.map.FlatMapStep

      `closeIterator, processNextStart, reset`

    - ### Methods inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

      `addLabel, addStart, addStarts, equals, getId, getLabels, getNextStep, getPreviousStep, getTraversal, hasNext, next, removeLabel, setId, setNextStep, setPreviousStep`

    - ### Methods inherited from class java.lang.Object

      `finalize, getClass, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.TraversalParent

      `addGlobalChild, addLocalChild, asStep, close, getGlobalChildren, getSelfAndChildRequirements, integrateChild, removeGlobalChild, removeLocalChild`

    - ### Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.Step

      `equals`

    - ### Methods inherited from interface java.util.Iterator

      `forEachRemaining, remove`

- - ### Constructor Detail

    - #### CoalesceStep

          @SafeVarargs
          public CoalesceStep(Traversal.Admin traversal,
                                           Traversal.Admin<S,E>... coalesceTraversals)

  - ### Method Detail

    - #### flatMap

          protected Iterator<E> flatMap(Traverser.Admin<S> traverser)

      Specified by:
        `flatMap` in class `FlatMapStep<S,E>`

    - #### getRequirements

          public Set<TraverserRequirement> getRequirements()

      Description copied from interface: `Step`
      Provide the necessary `TraverserRequirement` that must be met by the traverser in order for the step to function properly. The provided default implements returns an empty set.
      Specified by:
        `getRequirements` in interface `Step<S,E>`
      Returns:
        the set of requirements

    - #### getLocalChildren

          public List<Traversal.Admin<S,E>> getLocalChildren()

      Specified by:
        `getLocalChildren` in interface `TraversalParent`

    - #### clone

          public CoalesceStep<S,E> clone()

      Description copied from interface: `Step`
      Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication. When cloning a step, it is important that the steps, the cloned step is equivalent to the state of the step when reset() is called. Moreover, the previous and next steps should be set to `EmptyStep`.
      Specified by:
        `clone` in interface `Step<S,E>`
      Overrides:
        `clone` in class `AbstractStep<S,E>`
      Returns:
        The cloned step

    - #### setTraversal

          public void setTraversal(Traversal.Admin<?,?> parentTraversal)

      Description copied from interface: `Step`
      Set the `Traversal` that this step is contained within.
      Specified by:
        `setTraversal` in interface `Step<S,E>`
      Overrides:
        `setTraversal` in class `AbstractStep<S,E>`
      Parameters:
        `parentTraversal` - the new traversal for this step

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `AbstractStep<S,E>`

    - #### hashCode

          public int hashCode()

      Overrides:
        `hashCode` in class `AbstractStep<S,E>`

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