com.yahoo.document.select.rule

Interface ExpressionNode

All Known Implementing Classes:

ArithmeticNode, AttributeNode, ComparisonNode, DocumentNode, EmbracedNode, IdNode, LiteralNode, LogicNode, NegationNode, NowNode, SearchColumnNode, VariableNode

public interface ExpressionNode

This is the interface of all expression nodes. It declares the methods requires by all expression nodes to maintain a working document selector language.

Author:

Simon Thoresen

Method Summary

Modifier and Type	Method and Description
void	accept(Visitor visitor) Perform visitation of this node.
Object	evaluate(Context doc) Evaluate the content of this node based on document object, and return that value.
BucketSet	getBucketSet(BucketIdFactory factory) Returns the set of bucket ids covered by this node.
OrderingSpecification	getOrdering(int order) If this document selection implies a specific ordering (using the orderdoc scheme), return that specification.

Method Detail

evaluate

Object evaluate(Context doc)

Evaluate the content of this node based on document object, and return that value.

Parameters:

doc - The document to evaluate over.

Returns:

The value of this.

getBucketSet

BucketSet getBucketSet(BucketIdFactory factory)

Returns the set of bucket ids covered by this node.

Parameters:

factory - The factory used by the current application.

getOrdering

OrderingSpecification getOrdering(int order)

If this document selection implies a specific ordering (using the orderdoc scheme), return that specification.

Parameters:

order - The order in which we are looking to traverse the ordering (ASCENDING or DESCENDING)

accept

void accept(Visitor visitor)

Perform visitation of this node.

Parameters:

visitor - The visitor that wishes to visit the node.