Package org.eclipse.rdf4j.federated.algebra

## Class NTuple

- java.lang.Object
- - org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode
  - - org.eclipse.rdf4j.federated.algebra.NTuple

- All Implemented Interfaces:
    `Serializable`, `Cloneable`, `QueryRef`, `GraphPatternGroupable`, `QueryModelNode`, `TupleExpr`, `VariableScopeChange`
  Direct Known Subclasses:
    `EmptyNJoin`, `EmptyNUnion`, `NJoin`, `NUnion`

      public abstract class NTuple
      extends AbstractQueryModelNode
      implements TupleExpr, QueryRef

  Base class for any nary-tuple expression
  Author:
    Andreas Schwarte
  See Also:
    `NJoin`, `NUnion`, Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected List<TupleExpr>` | `args` |
    `protected QueryInfo` | `queryInfo` |

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `NTuple​(List<TupleExpr> args, QueryInfo queryInfo)` | Construct an nary-tuple.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `NTuple` | `clone()` | Returns a (deep) clone of this query model node.
    `TupleExpr` | `getArg​(int i)` |
    `List<TupleExpr>` | `getArgs()` |
    `Set<String>` | `getAssuredBindingNames()` | Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.
    `Set<String>` | `getBindingNames()` | Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.
    `int` | `getNumberOfArguments()` |
    `QueryInfo` | `getQueryInfo()` | Retrieve the attached query information of the tuple expression
    `void` | `replaceChildNode​(QueryModelNode current, QueryModelNode replacement)` | Default implementation of `QueryModelNode.replaceChildNode(QueryModelNode, QueryModelNode)` that throws an `IllegalArgumentException` indicating that current is not a child node of this node.
    `<X extends Exception> void` | `visit​(QueryModelVisitor<X> visitor)` | Visits this node.
    `<X extends Exception> void` | `visitChildren​(QueryModelVisitor<X> visitor)` | Dummy implementation of `QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>)` that does nothing.

    - ### Methods inherited from class org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

      `getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, isGraphPatternGroup, isVariableScopeChange, nullEquals, replaceNodeInList, replaceWith, setCostEstimate, setGraphPatternGroup, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, setVariableScopeChange, toString`

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

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

    - ### Methods inherited from interface org.eclipse.rdf4j.query.algebra.QueryModelNode

      `equals, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, replaceWith, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, toString`

- - ### Field Detail

    - #### args

          protected final List<TupleExpr> args

    - #### queryInfo

          protected final QueryInfo queryInfo

  - ### Constructor Detail

    - #### NTuple

          public NTuple​(List<TupleExpr> args,
                        QueryInfo queryInfo)

      Construct an nary-tuple. Note that the parentNode of all arguments is set to this instance.
      Parameters:
        `args` -

  - ### Method Detail

    - #### getArg

          public TupleExpr getArg​(int i)

    - #### getArgs

          public List<TupleExpr> getArgs()

    - #### getNumberOfArguments

          public int getNumberOfArguments()

    - #### visitChildren

          public <X extends Exception> void visitChildren​(QueryModelVisitor<X> visitor)
                                                   throws X extends Exception

      Description copied from class: `AbstractQueryModelNode`
      Dummy implementation of `QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>)` that does nothing. Subclasses should override this method when they have child nodes.
      Specified by:
        `visitChildren` in interface `QueryModelNode`
      Overrides:
        `visitChildren` in class `AbstractQueryModelNode`
      Throws:
        `X extends Exception`

    - #### clone

          public NTuple clone()

      Description copied from interface: `QueryModelNode`
      Returns a (deep) clone of this query model node. This method recursively clones the entire node tree, starting from this nodes.
      Specified by:
        `clone` in interface `QueryModelNode`
      Specified by:
        `clone` in interface `TupleExpr`
      Overrides:
        `clone` in class `AbstractQueryModelNode`
      Returns:
        A deep clone of this query model node.

    - #### getAssuredBindingNames

          public Set<String> getAssuredBindingNames()

      Description copied from interface: `TupleExpr`
      Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.
      Specified by:
        `getAssuredBindingNames` in interface `TupleExpr`
      Returns:
        A set of binding names.

    - #### getBindingNames

          public Set<String> getBindingNames()

      Description copied from interface: `TupleExpr`
      Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.
      Specified by:
        `getBindingNames` in interface `TupleExpr`
      Returns:
        A set of binding names.

    - #### replaceChildNode

          public void replaceChildNode​(QueryModelNode current,
                                       QueryModelNode replacement)

      Description copied from class: `AbstractQueryModelNode`
      Default implementation of `QueryModelNode.replaceChildNode(QueryModelNode, QueryModelNode)` that throws an `IllegalArgumentException` indicating that current is not a child node of this node.
      Specified by:
        `replaceChildNode` in interface `QueryModelNode`
      Overrides:
        `replaceChildNode` in class `AbstractQueryModelNode`
      Parameters:
        `current` - The current child node.
        `replacement` - The new child node.

    - #### visit

          public <X extends Exception> void visit​(QueryModelVisitor<X> visitor)
                                           throws X extends Exception

      Description copied from interface: `QueryModelNode`
      Visits this node. The node reports itself to the visitor with the proper runtime type.
      Specified by:
        `visit` in interface `QueryModelNode`
      Throws:
        `X extends Exception`

    - #### getQueryInfo

          public QueryInfo getQueryInfo()

      Description copied from interface: `QueryRef`
      Retrieve the attached query information of the tuple expression
      Specified by:
        `getQueryInfo` in interface `QueryRef`
      Returns:
        the `QueryInfo`