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refactoring

This commit is contained in:
Terence Parr 2012-07-31 18:54:00 -07:00
parent abb268416e
commit 3d2cbe087d
1 changed files with 13 additions and 29 deletions
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42
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
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@ -552,7 +552,7 @@ public class ParserATNSimulator<Symbol extends Token> extends ATNSimulator {
PredictionContext predictionCtx = PredictionContext.fromRuleContext(outerContext);
predictionCtx = getCachedContext(predictionCtx);
D.isCtxSensitive = true; // always force DFA to ATN simulate
D.prediction = predictedAlt = fullCtxSet.uniqueAlt; // TODO: why set prediction?
predictedAlt = fullCtxSet.uniqueAlt;
D.prediction = ATN.INVALID_ALT_NUMBER;
D.contextToPredictedAlt.put(predictionCtx, predictedAlt);
addDFAEdge(dfa, previousD, t, D);
@ -590,17 +590,21 @@ public class ParserATNSimulator<Symbol extends Token> extends ATNSimulator {
if ( D.isAcceptState && D.configs.hasSemanticContext ) {
// We need to test all predicates, even in DFA states that
// uniquely predict alternative. We can only get a conflict
// when we're sure that it's an ambiguity not conflict.
// uniquely predict alternative.
int nalts = decState.getNumberOfTransitions();
List<DFAState.PredPrediction> predPredictions =
predicateDFAState(D, D.configs, outerContext, nalts);
// TODO: get rid of side-effects? sets predicted 2x
predicateDFAState(D, D.configs, outerContext, nalts); // alters D
if ( predPredictions!=null ) {
// Update DFA so reach becomes accept state with (predicate,alt)
// pairs if preds found for conflicting alts
IntervalSet conflictingAlts = getConflictingAltsFromConfigSet(D.configs);
SemanticContext[] altToPred = getPredsForAmbigAlts(conflictingAlts, D.configs, nalts);
if ( altToPred!=null ) {
D.predicates = getPredicatePredictions(conflictingAlts, altToPred);
}
D.prediction = ATN.INVALID_ALT_NUMBER; // make sure we use preds
if ( D.predicates!=null ) {
int stopIndex = input.index();
input.seek(startIndex);
IntervalSet alts = evalSemanticContext(predPredictions, outerContext, true);
IntervalSet alts = evalSemanticContext(D.predicates, outerContext, true);
D.prediction = ATN.INVALID_ALT_NUMBER; // indicate we have preds
addDFAEdge(dfa, previousD, t, D);
switch (alts.size()) {
@ -789,26 +793,6 @@ public class ParserATNSimulator<Symbol extends Token> extends ATNSimulator {
return null;
}
/** collect and set D's semantic context */
public List<DFAState.PredPrediction> predicateDFAState(DFAState D,
ATNConfigSet configs,
RuleContext outerContext,
int nalts)
{
IntervalSet conflictingAlts = getConflictingAltsFromConfigSet(configs);
if ( debug ) System.out.println("predicateDFAState "+D);
SemanticContext[] altToPred = getPredsForAmbigAlts(conflictingAlts, configs, nalts);
// altToPred[uniqueAlt] is now our validating predicate (if any)
List<DFAState.PredPrediction> predPredictions = null;
if ( altToPred!=null ) {
// Update DFA so reach becomes accept state with predicate
predPredictions = getPredicatePredictions(conflictingAlts, altToPred);
D.predicates = predPredictions;
D.prediction = ATN.INVALID_ALT_NUMBER; // make sure we use preds
}
return predPredictions;
}
public SemanticContext[] getPredsForAmbigAlts(@NotNull IntervalSet ambigAlts,
@NotNull ATNConfigSet configs,
int nalts)