## com.icl.saxon.expr
Class FilterEnumerator

    java.lang.Object
      |
      +--com.icl.saxon.expr.FilterEnumerator

All Implemented Interfaces:
  NodeEnumeration

public class FilterEnumerator
extends java.lang.Object
implements NodeEnumeration

A FilterEnumerator filters an input NodeEnumeration using a filter expression. The complication is that on request, it must determine the value of the last() position, which requires a lookahead.

Constructor Summary
`FilterEnumerator(NodeEnumeration base, Expression filter, Context context, boolean finishAfterReject)` Constructor

Method Summary
`boolean` `hasMoreElements()` Test whether there are any more nodes available in the enumeration
`boolean` `isPeer()` Determine whether the nodes are guaranteed to be peers
`boolean` `isReverseSorted()` Determine whether the nodes returned by this enumeration are known to be in reverse document order.
`boolean` `isSorted()` Determine whether the nodes are guaranteed to be in document order
`NodeInfo` `nextElement()` Get the next node if there is one

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

Constructor Detail

### FilterEnumerator

    public FilterEnumerator(NodeEnumeration base,
                            Expression filter,
                            Context context,
                            boolean finishAfterReject)
                     throws XPathException

  Constructor

Parameters:
  `base` - A node-set expression denoting the absolute or relative set of nodes from which the navigation path should start.
  `filter` - The expression defining the filter predicate
  `context` - The context in which the expression is being evaluated

Method Detail

### hasMoreElements

    public boolean hasMoreElements()

  Test whether there are any more nodes available in the enumeration

  Specified by:
    `hasMoreElements` in interface `NodeEnumeration`
  Returns:
    true if there are more nodes

### nextElement

    public NodeInfo nextElement()
                         throws XPathException

  Get the next node if there is one

  Specified by:
    `nextElement` in interface `NodeEnumeration`
  Returns:
    the next NodeInfo
    `XPathException`

### isSorted

    public boolean isSorted()

  Determine whether the nodes are guaranteed to be in document order

  Specified by:
    `isSorted` in interface `NodeEnumeration`
  Returns:
    true if the nodes are guaranteed to be in document order.

### isReverseSorted

    public boolean isReverseSorted()

  Description copied from interface: `NodeEnumeration`
  Determine whether the nodes returned by this enumeration are known to be in reverse document order.

  Specified by:
    `isReverseSorted` in interface `NodeEnumeration`
  Returns:
    true if the nodes are guaranteed to be in document order.

### isPeer

    public boolean isPeer()

  Determine whether the nodes are guaranteed to be peers

  Specified by:
    `isPeer` in interface `NodeEnumeration`