SequenceIterator<T>
, LookaheadIterator<T>
, UnfailingIterator<T>
public abstract class IteratorIterator<T extends Item> extends java.lang.Object implements LookaheadIterator<T>, UnfailingIterator<T>
GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD
Constructor | Description |
---|---|
IteratorIterator(java.util.Iterator<T> base) |
Create a SequenceIterator over a given iterator
|
Modifier and Type | Method | Description |
---|---|---|
void |
close() |
Close the iterator.
|
T |
current() |
Get the current value in the sequence (the one returned by the
most recent call on next()).
|
abstract UnfailingIterator<T> |
getAnother() |
Get another SequenceIterator that iterates over the same items as the original,
but which is repositioned at the start of the sequence.
|
int |
getProperties() |
Get properties of this iterator, as a bit-significant integer.
|
boolean |
hasNext() |
Determine whether there are more items to come.
|
T |
next() |
Get the next item in the sequence.
|
int |
position() |
Get the current position.
|
public IteratorIterator(java.util.Iterator<T> base)
base
- the base Iteratorpublic boolean hasNext()
LookaheadIterator
SequenceIterator.LOOKAHEAD
hasNext
in interface LookaheadIterator<T extends Item>
public T next()
SequenceIterator
next
in interface SequenceIterator<T extends Item>
next
in interface UnfailingIterator<T extends Item>
public T current()
SequenceIterator
current
in interface SequenceIterator<T extends Item>
current
in interface UnfailingIterator<T extends Item>
public int position()
SequenceIterator
This method does not change the state of the iterator.
position
in interface SequenceIterator<T extends Item>
position
in interface UnfailingIterator<T extends Item>
public void close()
SequenceIterator
(Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)
close
in interface SequenceIterator<T extends Item>
public abstract UnfailingIterator<T> getAnother()
SequenceIterator
This method allows access to all the items in the sequence without disturbing the current position of the iterator. Internally, its main use is in evaluating the last() function.
This method does not change the state of the iterator.
getAnother
in interface SequenceIterator<T extends Item>
getAnother
in interface UnfailingIterator<T extends Item>
public int getProperties()
getProperties
in interface SequenceIterator<T extends Item>
SequenceIterator.GROUNDED
, SequenceIterator.LAST_POSITION_FINDER
,
and SequenceIterator.LOOKAHEAD
. It is always
acceptable to return the value zero, indicating that there are no known special properties.
It is acceptable for the properties of the iterator to change depending on its state.