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Simplify Parser.getExpectedTokens and DefaultErrorStrategy.getErrorRecoverySet

This commit is contained in:
Sam Harwell 2012-11-04 13:29:21 -06:00
parent a70479ad0c
commit d33172dce5
2 changed files with 3 additions and 32 deletions
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16
runtime/Java/src/org/antlr/v4/runtime/DefaultErrorStrategy.java
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@ -34,7 +34,6 @@ import org.antlr.v4.runtime.atn.ATNState;
import org.antlr.v4.runtime.atn.BlockStartState; import org.antlr.v4.runtime.atn.BlockStartState;
import org.antlr.v4.runtime.atn.PlusBlockStartState; import org.antlr.v4.runtime.atn.PlusBlockStartState;
import org.antlr.v4.runtime.atn.PlusLoopbackState; import org.antlr.v4.runtime.atn.PlusLoopbackState;
import org.antlr.v4.runtime.atn.RuleTransition;
import org.antlr.v4.runtime.atn.StarLoopEntryState; import org.antlr.v4.runtime.atn.StarLoopEntryState;
import org.antlr.v4.runtime.atn.StarLoopbackState; import org.antlr.v4.runtime.atn.StarLoopbackState;
import org.antlr.v4.runtime.misc.IntervalSet; import org.antlr.v4.runtime.misc.IntervalSet;
@ -522,19 +521,8 @@ public class DefaultErrorStrategy implements ANTLRErrorStrategy {
*/ */
protected IntervalSet getErrorRecoverySet(Parser recognizer) { protected IntervalSet getErrorRecoverySet(Parser recognizer) {
ATN atn = recognizer.getInterpreter().atn; ATN atn = recognizer.getInterpreter().atn;
RuleContext ctx = recognizer._ctx; ParserRuleContext ctx = recognizer._ctx;
IntervalSet recoverSet = new IntervalSet(); return atn.nextTokens(atn.states.get(ctx.s), ctx);
while ( ctx!=null && ctx.invokingState>=0 ) {
// compute what follows who invoked us
ATNState invokingState = atn.states.get(ctx.invokingState);
RuleTransition rt = (RuleTransition)invokingState.transition(0);
IntervalSet follow = atn.nextTokens(rt.followState);
recoverSet.addAll(follow);
ctx = ctx.parent;
}
recoverSet.remove(Token.EPSILON);
// System.out.println("recover set "+recoverSet.toString(recognizer.getTokenNames()));
return recoverSet;
} }
/** Consume tokens until one matches the given token set */ /** Consume tokens until one matches the given token set */

19
runtime/Java/src/org/antlr/v4/runtime/Parser.java
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@ -547,24 +547,7 @@ public abstract class Parser extends Recognizer<Token, ParserATNSimulator> {
ATN atn = getInterpreter().atn; ATN atn = getInterpreter().atn;
ParserRuleContext ctx = _ctx; ParserRuleContext ctx = _ctx;
ATNState s = atn.states.get(ctx.s); ATNState s = atn.states.get(ctx.s);
IntervalSet following = atn.nextTokens(s); return atn.nextTokens(s, ctx);
// System.out.println("following "+s+"="+following);
if ( !following.contains(Token.EPSILON) ) return following;
IntervalSet expected = new IntervalSet();
expected.addAll(following);
expected.remove(Token.EPSILON);
while ( ctx!=null && ctx.invokingState>=0 && following.contains(Token.EPSILON) ) {
ATNState invokingState = atn.states.get(ctx.invokingState);
RuleTransition rt = (RuleTransition)invokingState.transition(0);
following = atn.nextTokens(rt.followState);
expected.addAll(following);
expected.remove(Token.EPSILON);
ctx = (ParserRuleContext)ctx.parent;
}
if ( following.contains(Token.EPSILON) ) {
expected.add(Token.EOF);
}
return expected;
} }
public IntervalSet getExpectedTokensWithinCurrentRule() { public IntervalSet getExpectedTokensWithinCurrentRule() {