com.yahoo.prelude.semantics.rule

Class ProductionRule

java.lang.Object

com.yahoo.prelude.semantics.rule.ProductionRule

Direct Known Subclasses:

AddingProductionRule, ReplacingProductionRule, RuleBase.IncludeDirective

public abstract class ProductionRule
extends Object

A query rewriting rule.

Author:

bratseth

Field Summary

Fields

Modifier and Type	Field and Description
private Condition	condition What must be true for this rule to be true
private Set<String>	matchReferences The set of match name Strings which the production part of this rule references
private ProductionList	production What is produced when this rule is true

Constructor Summary

Constructors

Constructor and Description
ProductionRule()

Method Summary

Modifier and Type	Method and Description
private boolean	conditionIsEllipsAndOtherNameSpacesOnly(Condition condition)
Condition	getCondition()
ProductionList	getProduction()
protected abstract String	getSymbol() Returns the symbol of this production rule.
boolean	isLoop() Returns true if it is known that this rule matches its own output.
void	makeReferences(RuleBase rules)
boolean	matches(RuleEvaluation e) Returns whether this rule matches the given query
Set<String>	matchReferences() Returns the set of context names the production of this rule references
void	produce(RuleEvaluation e) Carries out the production of this rule
void	setCondition(Condition condition) Sets what must be true for this rule to be true
void	setProduction(ProductionList production) Sets what is produced when this rule is true
String	toString() Returns the canonical string representation of this rule.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

condition

private Condition condition

What must be true for this rule to be true

production

private ProductionList production

What is produced when this rule is true

matchReferences

private Set<String> matchReferences

The set of match name Strings which the production part of this rule references

Constructor Detail

ProductionRule

public ProductionRule()

Method Detail

setCondition

public void setCondition(Condition condition)

Sets what must be true for this rule to be true

getCondition

public Condition getCondition()

setProduction

public void setProduction(ProductionList production)

Sets what is produced when this rule is true

getProduction

public ProductionList getProduction()

matches

public boolean matches(RuleEvaluation e)

Returns whether this rule matches the given query

matchReferences

public Set<String> matchReferences()

Returns the set of context names the production of this rule references

Returns:

an unmodifiable Set of condition context name Strings

makeReferences

public void makeReferences(RuleBase rules)

produce

public void produce(RuleEvaluation e)

Carries out the production of this rule

toString

public String toString()

Returns the canonical string representation of this rule. This string representation can always be reparsed to produce an identical rule to this one.

Overrides:

toString in class Object

getSymbol

protected abstract String getSymbol()

Returns the symbol of this production rule. All rules are on the form condition symbol production.

isLoop

public boolean isLoop()

Returns true if it is known that this rule matches its own output. If it does, it will only be evaluated once, to avoid infinite loops. This default implementation returns false;

conditionIsEllipsAndOtherNameSpacesOnly

private boolean conditionIsEllipsAndOtherNameSpacesOnly(Condition condition)