public abstract class AggregatorNode extends GroupingExpression
GroupingExpression
. Because it operates on a list of data, it
can not be used as a document-level expression (i.e. level 0, see GroupingExpression.resolveLevel(int)
). The
contained expression is evaluated at the level of the aggregator minus 1.Modifier and Type | Field and Description |
---|---|
private GroupingExpression |
exp |
Modifier | Constructor and Description |
---|---|
protected |
AggregatorNode(String image) |
protected |
AggregatorNode(String image,
GroupingExpression exp) |
Modifier and Type | Method and Description |
---|---|
GroupingExpression |
getExpression()
Returns the expression that this node aggregates on.
|
void |
resolveLevel(int level)
Resolves the conceptual level of this expression.
|
void |
visit(ExpressionVisitor visitor)
Recursively calls
ExpressionVisitor.visitExpression(GroupingExpression) for this expression and all of
its argument expressions. |
asImage, asString, getLevel, setLabel
getLabel, toString
private final GroupingExpression exp
protected AggregatorNode(String image)
protected AggregatorNode(String image, GroupingExpression exp)
public GroupingExpression getExpression()
public void resolveLevel(int level)
GroupingExpression
resolveLevel
in class GroupingExpression
level
- The level of the input data.public void visit(ExpressionVisitor visitor)
GroupingExpression
ExpressionVisitor.visitExpression(GroupingExpression)
for this expression and all of
its argument expressions.visit
in class GroupingExpression
visitor
- The visitor to call.Copyright © 2018. All rights reserved.