/* This function rerturns the fsm to be equivalent to (fsm1|fsm2)
* XXX : Use with caution. This modifies fsm1, but the return value must be
* stored back in fsm1 for this to be effective.
*
* DO NOT try something like "fsm1 | fsm1", this will ave
*/
FSM * FSM::operator | (FSM& rhs)
{
/* Create a new (empty) start and end FSM */
FSM *startFSM = new FSM();
FSM *endFSM = new FSM();
/* Concatenate one of the two fsm-s with the start and end */
this->concatenate (*endFSM);
startFSM->concatenate (*this);
/* Create a transition to the start state of other fsm */
rhs.concatenate (*endFSM);
/* Create a transition from the end state of other fsm */
startFSM->startState.createTransition ('e', EPSILON, &(rhs.startState));
return startFSM;
}
/* This function returns the fsm that accepts the repetition of strings
* accepted by given fsm.
*/
FSM * FSM::repeat ()
{
/* Create a new (empty) FSM. */
FSM *startFSM = new FSM();
FSM *endFSM = new FSM();
/* Loop back from the accept state of the fsm to the start state */
acceptState->createTransition ('e', EPSILON, &startState);
acceptState->isFinalState = true;
/* Concatenate the endFSM state with fsm */
this->concatenate (*endFSM);
/* Concatenate the startFSM with 'this' fsm */
startFSM->concatenate (*this);
/* Create a epsilon-transition from startFSM to endFSM */
startFSM->startState.createTransition ('e', EPSILON, startFSM->acceptState);
return startFSM;
}
