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Extract method ParserATNSimulator.predicateDFAState

This commit is contained in:
Sam Harwell 2012-11-18 14:15:16 -06:00
parent b214f36044
commit 691532190c
1 changed files with 21 additions and 17 deletions
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38
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
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@ -669,23 +669,7 @@ public class ParserATNSimulator extends ATNSimulator {
}
if ( D.isAcceptState && D.configs.hasSemanticContext ) {
// We need to test all predicates, even in DFA states that
// uniquely predict alternative.
int nalts = decState.getNumberOfTransitions();
// Update DFA so reach becomes accept state with (predicate,alt)
// pairs if preds found for conflicting alts
BitSet altsToCollectPredsFrom = getConflictingAltsOrUniqueAlt(D.configs);
SemanticContext[] altToPred = getPredsForAmbigAlts(altsToCollectPredsFrom, D.configs, nalts);
if ( altToPred!=null ) {
D.predicates = getPredicatePredictions(altsToCollectPredsFrom, altToPred);
D.prediction = ATN.INVALID_ALT_NUMBER; // make sure we use preds
}
else {
// There are preds in configs but they might go away
// when OR'd together like {p}? || NONE == NONE. If neither
// alt has preds, resolve to min alt
D.prediction = altsToCollectPredsFrom.nextSetBit(0);
}
predicateDFAState(D, decState);
if ( D.predicates!=null ) {
int stopIndex = input.index();
@ -720,6 +704,26 @@ public class ParserATNSimulator extends ATNSimulator {
}
}
protected void predicateDFAState(DFAState dfaState, DecisionState decisionState) {
// We need to test all predicates, even in DFA states that
// uniquely predict alternative.
int nalts = decisionState.getNumberOfTransitions();
// Update DFA so reach becomes accept state with (predicate,alt)
// pairs if preds found for conflicting alts
BitSet altsToCollectPredsFrom = getConflictingAltsOrUniqueAlt(dfaState.configs);
SemanticContext[] altToPred = getPredsForAmbigAlts(altsToCollectPredsFrom, dfaState.configs, nalts);
if ( altToPred!=null ) {
dfaState.predicates = getPredicatePredictions(altsToCollectPredsFrom, altToPred);
dfaState.prediction = ATN.INVALID_ALT_NUMBER; // make sure we use preds
}
else {
// There are preds in configs but they might go away
// when OR'd together like {p}? || NONE == NONE. If neither
// alt has preds, resolve to min alt
dfaState.prediction = altsToCollectPredsFrom.nextSetBit(0);
}
}
// comes back with reach.uniqueAlt set to a valid alt
public int execATNWithFullContext(DFA dfa,
DFAState D, // how far we got before failing over