Example usage for org.antlr.v4.runtime.misc IntervalSet IntervalSet

Introduction

In this page you can find the example usage for org.antlr.v4.runtime.misc IntervalSet IntervalSet.

Prototype

IntervalSet

Source Link

Usage

From source file:com.sample.JavaErrorStrategy.java

License:BSD License

/**
 * {@inheritDoc}/*www. j a  v a  2  s. c om*/
 *
 * <p>
 * The default implementation resynchronizes the parser by consuming tokens
 * until we find one in the resynchronization set--loosely the set of tokens
 * that can follow the current rule.
 * </p>
 */
@Override
public void recover(Parser recognizer, RecognitionException e) {
    // System.out.println("recover in "+recognizer.getRuleInvocationStack()+
    // " index="+recognizer.getInputStream().index()+
    // ", lastErrorIndex="+
    // lastErrorIndex+
    // ", states="+lastErrorStates);
    if (lastErrorIndex == recognizer.getInputStream().index() && lastErrorStates != null
            && lastErrorStates.contains(recognizer.getState())) {
        // uh oh, another error at same token index and previously-visited
        // state in ATN; must be a case where LT(1) is in the recovery
        // token set so nothing got consumed. Consume a single token
        // at least to prevent an infinite loop; this is a failsafe.
        // System.err.println("seen error condition before index="+
        // lastErrorIndex+", states="+lastErrorStates);
        // System.err.println("FAILSAFE consumes "+recognizer.getTokenNames()[recognizer.getInputStream().LA(1)]);
        recognizer.consume();
    }
    lastErrorIndex = recognizer.getInputStream().index();
    if (lastErrorStates == null)
        lastErrorStates = new IntervalSet();
    lastErrorStates.add(recognizer.getState());
}

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From source file:com.sample.JavaErrorStrategy.java

License:BSD License

@NotNull
protected IntervalSet getErrorRecoverySet(@NotNull Parser recognizer) {
    ATN atn = recognizer.getInterpreter().atn;
    RuleContext ctx = recognizer.getContext();
    IntervalSet recoverSet = new IntervalSet();
    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);//w ww . j  a v  a  2  s.  c o m
        ctx = ctx.parent;
    }
    recoverSet.remove(Token.EPSILON);
    // System.out.println("recover set "+recoverSet.toString(recognizer.getTokenNames()));
    return recoverSet;
}

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