monq.jfa.actions

Class If

java.lang.Object

monq.jfa.AbstractFaAction

monq.jfa.actions.If

All Implemented Interfaces:

java.io.Serializable, FaAction

public class If
extends AbstractFaAction

run one or another FaAction depending on the outcome of asking a Verifier. A typical use case normally employs a Verifier and a Hold:

 Hold hold = new Hold();
 Count c = new Count("yada");
 Nfa nfa = new Nfa("start", new Run(hold, c.reset()))
               .or("cute pattern", c)
               .or("end", new If(c.ge(2), hold.ship(), hold.drop());
 

In the example, a Count object is used to count the occurrences of the string "cute pattern". The counter is reset on seeing "start". When seeing "end", If calls the Verifier returned by c.ge(2) which will return true or false depending on whether more than 1 pattern was seen. Then it calls one of the actions hold.ship() or hold.drop() accordingly.

Author:

© 2004 Harald Kirsch

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
If(Verifier v, FaAction thendo, FaAction elsedo)

Method Summary

Modifier and Type	Method and Description
void	invoke(java.lang.StringBuilder yytext, int start, DfaRun r) is called by methods of DfaRun in case of a match.

Methods inherited from class monq.jfa.AbstractFaAction

mergeWith, setPriority

Methods inherited from class java.lang.Object

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

Constructor Detail

If

public If(Verifier v,
          FaAction thendo,
          FaAction elsedo)

Method Detail

invoke

public void invoke(java.lang.StringBuilder yytext,
                   int start,
                   DfaRun r)
            throws CallbackException

Description copied from interface: FaAction

is called by methods of DfaRun in case of a match. Parameter yytext contains the matching text from position start onwards. The callback may change the whole of yytext, but the under most circumstances, only the matching text should be changed. Parameter runner is the DfaRun object which called this function. Of interest are its fields DfaRun.clientData and DfaRun.collect.

Throws:

CallbackException