WhileClausePull

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

```
public class WhileClausePull
extends TuplePull
```
This class represents the tuple stream delivered as the output of a while clause in a FLWOR expression: that is, it returns all the tuples in its input stream that satisfy a specified predicate, until it finds one that doesn't. It does not change the values of any variables in the tuple stream.

Constructor Summary

Constructors
Constructor Description

WhileClausePull(TuplePull base, BooleanEvaluator predicate)

Method Summary

All Methods Instance 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
`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
  - WhileClausePull
```
public WhileClausePull(TuplePull base,
                       BooleanEvaluator predicate)
```
- Method Detail
  - nextTuple
```
public 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
    
    Specified by:
    
    nextTuple in class TuplePull
    
    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
    
    Overrides:
    
    close in class TuplePull