SharedAppendEvaluator

java.lang.Object
- net.sf.saxon.expr.elab.SharedAppendEvaluator

All Implemented Interfaces:

SequenceEvaluator
```
public class SharedAppendEvaluator
extends java.lang.Object
implements SequenceEvaluator
```
Evaluator for expressions that are evaluated in "shared append" mode. This mode is used when the optimizer establishes that a sequence is being built incrementally, typically via a sequence of recursive function calls. The sequence itself is implemented as a ZenoSequence to make incremental append (at either end) efficient, without copying the entirety of the existing sequence.

Constructor Summary

Constructors
Constructor Description

SharedAppendEvaluator(Block expr)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Sequence`	`evaluate(XPathContext context)`	Evaluate a construct to produce a value (which might be a lazily evaluated Sequence)

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

- Constructor Detail
  - SharedAppendEvaluator
```
public SharedAppendEvaluator(Block expr)
```
- Method Detail
  - evaluate
```
public Sequence evaluate(XPathContext context)
                  throws XPathException
```
    Evaluate a construct to produce a value (which might be a lazily evaluated Sequence)
    
    Specified by:
    
    evaluate in interface SequenceEvaluator
    
    Parameters:
    
    context - the evaluation context
    
    Returns:
    
    a Sequence (not necessarily grounded)
    
    Throws:
    
    XPathException - if a dynamic error occurs during the evaluation.