TuplePull

java.lang.Object
- net.sf.saxon.expr.flwor.TuplePull

Direct Known Subclasses:

CountClausePull, DiagnosticClausePull, ForClausePull, GroupByClausePull, LetClausePull, OrderByClausePull, SingularityPull, TraceClausePull, WhereClausePull, WhileClausePull, WindowClausePull
```
public abstract class TuplePull
extends java.lang.Object
```
Abtract class representing a tuple stream (used to evaluate a FLWOR expression) in pull mode (where the consumer of tuples activates the provider of those tuples)

Constructor Summary

Constructors
Constructor Description

TuplePull()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Close the tuple stream, indicating that although not all tuples have been read, no further tuples are required and resources can be released
`abstract boolean`	`nextTuple(XPathContext context)`	Move on to the next tuple.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - TuplePull
```
public TuplePull()
```
- Method Detail
  - nextTuple
```
public abstract boolean nextTuple(XPathContext context)
                           throws XPathException
```
    Move on to the next tuple. Before returning, this method must set all the variables corresponding to the "returned" tuple in the local stack frame associated with the context object
    
    Parameters:
    
    context - the dynamic evaluation context
    
    Returns:
    
    true if another tuple has been generated; false if the tuple stream is exhausted. If the method returns false, the values of the local variables corresponding to this tuple stream are undefined.
    
    Throws:
    
    XPathException - if any error occurs
  - close
```
public void close()
```
    Close the tuple stream, indicating that although not all tuples have been read, no further tuples are required and resources can be released