public void addRuleFollowLinks() {
for (ATNState p : atn.states) {
if (p != null
&& p.getClass() == ATNState.class
&& p.getNumberOfTransitions() == 1
&& p.transition(0) instanceof RuleTransition) {
RuleTransition rt = (RuleTransition) p.transition(0);
addFollowLink(rt.ruleIndex, rt.followState);
}
}
}
@Override
public void visitState(ATNState p) {
if (p.getClass() == ATNState.class && p.getNumberOfTransitions() == 1) {
ATNState q = p.transition(0).target;
if (p.transition(0) instanceof RuleTransition) {
q = ((RuleTransition) p.transition(0)).followState;
}
if (q.getClass() == ATNState.class) {
// we have p-x->q for x in {rule, action, pred, token, ...}
// if edge out of q is single epsilon to block end
// we can strip epsilon p-x->q-eps->r
Transition trans = q.transition(0);
if (q.getNumberOfTransitions() == 1
&& trans.isEpsilon()
&& !(trans instanceof ActionTransition)) {
ATNState r = trans.target;
if (r instanceof BlockEndState
|| r instanceof PlusLoopbackState
|| r instanceof StarLoopbackState) {
// skip over q
if (p.transition(0) instanceof RuleTransition) {
((RuleTransition) p.transition(0)).followState = r;
} else {
p.transition(0).target = r;
}
atn.removeState(q);
}
}
}
}
}