org.vedantatree.expressionoasis.grammar.rules

Class ProductionRule

java.lang.Object

org.vedantatree.expressionoasis.grammar.rules.ProductionRule

All Implemented Interfaces:

IProductionRule

public class ProductionRule
extends Object
implements IProductionRule

This class provides the production rule based on regular expression. It uses the regular expression to define a production rule.

Version:

1.0 Modified to compile and reuse approachable and allowed regular expressions in order to improve performance., 1.1

Author:

Parmod Kamboj, Mohit Gupta, Kris Marwood

Constructor Summary

Constructors

Constructor and Description
ProductionRule(String name, String regularExpression) Constructs the ProductionRule
ProductionRule(String name, String approachableRegex, String allowedRegex) Constructs the ProductionRule

Method Summary

Modifier and Type	Method and Description
String	getName() Returns the name of production rule.
boolean	isAllowed(String token) Checks whether the token is allowed or not.
boolean	isApproaching(String pattern) Checks whether the given token is approachable using any of the pattern or not.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ProductionRule

public ProductionRule(String name,
                      String regularExpression)

Constructs the ProductionRule

Parameters:

name - name of the production rule

regularExpression - regular expression, will be used as approachable and allowed regular expression

Throws:

IllegalArgumentException - if the parameters are not valid

ProductionRule

public ProductionRule(String name,
                      String approachableRegex,
                      String allowedRegex)

Constructs the ProductionRule

Parameters:

name - name of the production rule

approachableRegex - Regular Expression for checking the approachable token

allowedRegex - Expression for checking the approachable token

Throws:

IllegalArgumentException - if the parameters are not valid

Method Detail

getName

public String getName()

Description copied from interface: IProductionRule

Returns the name of production rule.

Specified by:

getName in interface IProductionRule

Returns:

the name of production rule

See Also:

IProductionRule.getName()

isApproaching

public boolean isApproaching(String pattern)

Description copied from interface: IProductionRule

Checks whether the given token is approachable using any of the pattern or not. Given token can be partially or fully constructed token during parsing process. Parser/DefaultXMLGrammar generally calls this method to check whether the current token can be combined with next character of expression to form some meaningful token or not. If not, then it utilize the existing collected characters as one token, otherwise it keep collecting characters.

Specified by:

isApproaching in interface IProductionRule

Returns:

true if the token pattern is approachable false otherwise.

See Also:

IProductionRule.isApproaching(java.lang.String)

isAllowed

public boolean isAllowed(String token)

Description copied from interface: IProductionRule

Checks whether the token is allowed or not. A token is fully constructed token. DefaultXMLGrammar/Parser generally calls this method to check whether the current token is a valid token as per the production rules or not.

Specified by:

isAllowed in interface IProductionRule

Parameters:

token - the token which is to be checked for its validity

Returns:

true if the token is allowed false otherwise.

See Also:

IProductionRule.isAllowed(java.lang.String)