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was not computing lookahead correctly in _LOOK. It assumed all epsilons were predicates.

This commit is contained in:
Terence Parr 2012-03-19 17:50:51 -07:00
parent ea7037dd2d
commit 2232ea5101
1 changed files with 28 additions and 23 deletions
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51
runtime/Java/src/org/antlr/v4/runtime/atn/LL1Analyzer.java
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@ -114,29 +114,34 @@ public class LL1Analyzer {
int n = s.getNumberOfTransitions();
for (int i=0; i<n; i++) {
Transition t = s.transition(i);
if ( t.getClass() == RuleTransition.class ) {
RuleContext newContext =
new RuleContext(ctx, s.stateNumber);
_LOOK(t.target, newContext, look, lookBusy, seeThruPreds);
}
else if ( t.isEpsilon() && seeThruPreds ) {
_LOOK(t.target, ctx, look, lookBusy, seeThruPreds);
}
else if ( t.getClass() == WildcardTransition.class ) {
look.addAll( IntervalSet.of(Token.MIN_USER_TOKEN_TYPE, atn.maxTokenType) );
}
else {
Transition t = s.transition(i);
if ( t.getClass() == RuleTransition.class ) {
RuleContext newContext =
new RuleContext(ctx, s.stateNumber);
_LOOK(t.target, newContext, look, lookBusy, seeThruPreds);
}
else if ( t instanceof PredicateTransition ) {
if ( seeThruPreds ) {
_LOOK(t.target, ctx, look, lookBusy, seeThruPreds);
}
}
else if ( t.isEpsilon() ) {
_LOOK(t.target, ctx, look, lookBusy, seeThruPreds);
}
else if ( t.getClass() == WildcardTransition.class ) {
look.addAll( IntervalSet.of(Token.MIN_USER_TOKEN_TYPE, atn.maxTokenType) );
}
else {
// System.out.println("adding "+ t);
IntervalSet set = t.label();
if (set != null) {
if (t instanceof NotSetTransition) {
set = set.complement(IntervalSet.of(Token.MIN_USER_TOKEN_TYPE, atn.maxTokenType));
}
look.addAll(set);
}
}
}
}
IntervalSet set = t.label();
if (set != null) {
if (t instanceof NotSetTransition) {
set = set.complement(IntervalSet.of(Token.MIN_USER_TOKEN_TYPE, atn.maxTokenType));
}
look.addAll(set);
}
}
}
}
}