com.inxar.syntacs.grammar.regular
Class REOption

java.lang.Object
  |
  +--com.inxar.syntacs.grammar.regular.REOption
All Implemented Interfaces:
Cloneable, Option, RegularExpression

public class REOption
extends Object
implements Option

Standard Option implementation.


Constructor Summary
REOption(REGrammar grammar, RegularExpression internal)
          Constructs the REOption on the given REGrammar and input RegularExpression.
 
Method Summary
 Object clone()
          See the general explanation of clone() given above.
 void follow()
          Triggers the process of computing the follow sets.
 IntSet getFirstSet()
          Returns the IntSet of Intervals which are visible at the logical beginning of the the expression.
 RegularExpression getInternal()
          Returns the RegularExpression which this '?' modifies.
 IntSet getLastSet()
          Returns the IntSet of Intervals which are visible at the logical end of the the expression.
 boolean isNullable()
          Returns true if this RegularExpression either *is* Epsilon or derives it.
 String toString()
           
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

REOption

public REOption(REGrammar grammar,
                RegularExpression internal)
Constructs the REOption on the given REGrammar and input RegularExpression.
Method Detail

toString

public String toString()
Overrides:
toString in class Object

isNullable

public boolean isNullable()
Description copied from interface: RegularExpression
Returns true if this RegularExpression either *is* Epsilon or derives it.
Specified by:
isNullable in interface RegularExpression

getFirstSet

public IntSet getFirstSet()
Description copied from interface: RegularExpression
Returns the IntSet of Intervals which are visible at the logical beginning of the the expression.
Specified by:
getFirstSet in interface RegularExpression

getLastSet

public IntSet getLastSet()
Description copied from interface: RegularExpression
Returns the IntSet of Intervals which are visible at the logical end of the the expression.
Specified by:
getLastSet in interface RegularExpression

follow

public void follow()
Description copied from interface: RegularExpression
Triggers the process of computing the follow sets.
Specified by:
follow in interface RegularExpression

getInternal

public RegularExpression getInternal()
Description copied from interface: Option
Returns the RegularExpression which this '?' modifies.
Specified by:
getInternal in interface Option

clone

public Object clone()
             throws CloneNotSupportedException
Description copied from interface: RegularExpression
See the general explanation of clone() given above.
Specified by:
clone in interface RegularExpression