protected class AbstractTupleList.AbstractTupleListIterator extends Object implements TupleIterator
TupleIterator
for
ArrayTupleList
.
Based upon AbstractList.Itr, but with concurrent modification checking
removed.Modifier | Constructor and Description |
---|---|
protected |
AbstractTupleListIterator() |
Modifier and Type | Method and Description |
---|---|
List<Member> |
current()
Returns the tuple that this cursor is positioned on.
|
void |
currentToArray(Member[] members,
int offset)
Writes the member(s) of the next tuple to a given offset in an array.
|
boolean |
forward()
Moves the iterator forward one position.
|
int |
getArity()
Returns the number of members in each tuple.
|
boolean |
hasNext() |
Member |
member(int column) |
List<Member> |
next() |
void |
remove() |
void |
setContext(Evaluator evaluator) |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
forEachRemaining
public boolean forward()
TupleCursor
Returns false only when end of data has been reached.
Similar to calling the Iterator
methods
Iterator.hasNext()
followed by
Iterator.next()
but
does not construct an object, and is therefore cheaper.
If you want to use an Iterator, see TupleIterator
.
forward
in interface TupleCursor
public List<Member> current()
TupleCursor
This method never returns null, and may safely be called multiple times (or not all) for each position in the iteration.
Invalid to call this method when the cursor is has not been
positioned, for example, if TupleCursor.forward()
has not been called or
if the most recent call to forward
returned false
.
current
in interface TupleCursor
public void currentToArray(Member[] members, int offset)
TupleCursor
This method saves the overhead of a memory allocation when the
resulting tuple will be written immediately to an array. The effect of
currentToArray(members, 0)
is the same as calling
current().toArray(members)
.
Before calling this method, you must position the iterator at a valid position. Typically you would call hasNext followed by next; or forward.
currentToArray
in interface TupleCursor
members
- Membersoffset
- Offset in the array to write topublic int getArity()
TupleCursor
getArity
in interface TupleCursor
public void setContext(Evaluator evaluator)
setContext
in interface TupleCursor
public Member member(int column)
member
in interface TupleCursor
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