public abstract class AbstractTupleCursor extends Object implements TupleCursor
TupleIterator
.
Derived classes need to implement only TupleCursor.forward()
.
Modifier and Type | Field and Description |
---|---|
protected int |
arity |
Constructor and Description |
---|
AbstractTupleCursor(int arity) |
Modifier and Type | Method and Description |
---|---|
void |
currentToArray(Member[] members,
int offset)
Writes the member(s) of the next tuple to a given offset in an array.
|
int |
getArity()
Returns the number of members in each tuple.
|
Member |
member(int column) |
void |
setContext(Evaluator evaluator) |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
current, forward
public void setContext(Evaluator evaluator)
setContext
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 Member member(int column)
member
in interface TupleCursor
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