## net.sf.saxon.sort
Class GroupAdjacentIterator

    java.lang.Object
      net.sf.saxon.sort.GroupAdjacentIterator

All Implemented Interfaces:
  GroupIterator, LookaheadIterator, SequenceIterator

public class GroupAdjacentIterator
extends java.lang.Object
implements GroupIterator, LookaheadIterator

A GroupAdjacentIterator iterates over a sequence of groups defined by xsl:for-each-group group-adjacent="x". The groups are returned in order of first appearance.

Constructor Summary
`GroupAdjacentIterator(SequenceIterator population, Expression keyExpression, XPathContext baseContext, java.util.Comparator collator)`

Method Summary
`Item` `current()` Get the current value in the sequence (the one returned by the most recent call on next()).
`SequenceIterator` `getAnother()` Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.
`AtomicValue` `getCurrentGroupingKey()` Get the grouping key of the current group
`boolean` `hasNext()` Determine whether there are more items to come.
`SequenceIterator` `iterateCurrentGroup()` Get an iterator over the members of the current group, in population order.
`Item` `next()` Get the next item in the sequence.
`int` `position()` Get the current position.

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

Constructor Detail

### GroupAdjacentIterator

    public GroupAdjacentIterator(SequenceIterator population,
                                 Expression keyExpression,
                                 XPathContext baseContext,
                                 java.util.Comparator collator)
                          throws XPathException

Method Detail

### getCurrentGroupingKey

    public AtomicValue getCurrentGroupingKey()

  Description copied from interface: `GroupIterator`
  Get the grouping key of the current group

  Specified by:
    `getCurrentGroupingKey` in interface `GroupIterator`
  Returns:
    the current grouping key in the case of group-by or group-adjacent, or null in the case of group-starting-with and group-ending-with

### iterateCurrentGroup

    public SequenceIterator iterateCurrentGroup()

  Description copied from interface: `GroupIterator`
  Get an iterator over the members of the current group, in population order. This must always be a clean iterator, that is, an iterator that starts at the first item of the group.

  Specified by:
    `iterateCurrentGroup` in interface `GroupIterator`
  Returns:
    an iterator over all the members of the current group, in population order.

### hasNext

    public boolean hasNext()

  Description copied from interface: `LookaheadIterator`
  Determine whether there are more items to come. Note that this operation is stateless and it is not necessary (or usual) to call it before calling next(). It is used only when there is an explicit need to tell if we are at the last element.

  Specified by:
    `hasNext` in interface `LookaheadIterator`
  Returns:
    true if there are more nodes

### next

    public Item next()
              throws XPathException

  Description copied from interface: `SequenceIterator`
  Get the next item in the sequence.

  Specified by:
    `next` in interface `SequenceIterator`
  Returns:
    the next item, or null if there are no more items.
  Throws:
    `XPathException` - if an error occurs retrieving the next item

### current

    public Item current()

  Description copied from interface: `SequenceIterator`
  Get the current value in the sequence (the one returned by the most recent call on next()). This will be null before the first call of next().

  Specified by:
    `current` in interface `SequenceIterator`
  Returns:
    the current item, the one most recently returned by a call on next(); or null, if next() has not been called, or if the end of the sequence has been reached.

### position

    public int position()

  Description copied from interface: `SequenceIterator`
  Get the current position. This will be zero before the first call on next(), otherwise it will be the number of times that next() has been called.

  Specified by:
    `position` in interface `SequenceIterator`
  Returns:
    the current position, the position of the item returned by the most recent call of next()

### getAnother

    public SequenceIterator getAnother()
                                throws XPathException

  Description copied from interface: `SequenceIterator`
  Get another SequenceIterator that iterates over the same items as the original, but which is repositioned at the start of the sequence.

  Specified by:
    `getAnother` in interface `SequenceIterator`
  Returns:
    a SequenceIterator that iterates over the same items, positioned before the first item
  Throws:
    `XPathException` - if any error occurs