Examples with StarLoopEntryState org.antlr.v4.runtime.atn.StarLoopEntryState used on opensource projects

Example 1 with StarLoopEntryState

use of org.antlr.v4.runtime.atn.StarLoopEntryState in project antlr4 by antlr.

the class ParserInterpreter method visitState.

protected void visitState(ATNState p) {
    // System.out.println("visitState "+p.stateNumber);
    int predictedAlt = 1;
    if (p instanceof DecisionState) {
        predictedAlt = visitDecisionState((DecisionState) p);
    }
    Transition transition = p.transition(predictedAlt - 1);
    switch(transition.getSerializationType()) {
        case Transition.EPSILON:
            if (p.getStateType() == ATNState.STAR_LOOP_ENTRY && ((StarLoopEntryState) p).isPrecedenceDecision && !(transition.target instanceof LoopEndState)) {
                // We are at the start of a left recursive rule's (...)* loop
                // and we're not taking the exit branch of loop.
                InterpreterRuleContext localctx = createInterpreterRuleContext(_parentContextStack.peek().a, _parentContextStack.peek().b, _ctx.getRuleIndex());
                pushNewRecursionContext(localctx, atn.ruleToStartState[p.ruleIndex].stateNumber, _ctx.getRuleIndex());
            }
            break;
        case Transition.ATOM:
            match(((AtomTransition) transition).label);
            break;
        case Transition.RANGE:
        case Transition.SET:
        case Transition.NOT_SET:
            if (!transition.matches(_input.LA(1), Token.MIN_USER_TOKEN_TYPE, 65535)) {
                recoverInline();
            }
            matchWildcard();
            break;
        case Transition.WILDCARD:
            matchWildcard();
            break;
        case Transition.RULE:
            RuleStartState ruleStartState = (RuleStartState) transition.target;
            int ruleIndex = ruleStartState.ruleIndex;
            InterpreterRuleContext newctx = createInterpreterRuleContext(_ctx, p.stateNumber, ruleIndex);
            if (ruleStartState.isLeftRecursiveRule) {
                enterRecursionRule(newctx, ruleStartState.stateNumber, ruleIndex, ((RuleTransition) transition).precedence);
            } else {
                enterRule(newctx, transition.target.stateNumber, ruleIndex);
            }
            break;
        case Transition.PREDICATE:
            PredicateTransition predicateTransition = (PredicateTransition) transition;
            if (!sempred(_ctx, predicateTransition.ruleIndex, predicateTransition.predIndex)) {
                throw new FailedPredicateException(this);
            }
            break;
        case Transition.ACTION:
            ActionTransition actionTransition = (ActionTransition) transition;
            action(_ctx, actionTransition.ruleIndex, actionTransition.actionIndex);
            break;
        case Transition.PRECEDENCE:
            if (!precpred(_ctx, ((PrecedencePredicateTransition) transition).precedence)) {
                throw new FailedPredicateException(this, String.format("precpred(_ctx, %d)", ((PrecedencePredicateTransition) transition).precedence));
            }
            break;
        default:
            throw new UnsupportedOperationException("Unrecognized ATN transition type.");
    }
    setState(transition.target.stateNumber);
}

Example 2 with StarLoopEntryState

use of org.antlr.v4.runtime.atn.StarLoopEntryState in project antlr4 by antlr.

the class ParserATNFactory method star.

/**
 * From {@code (blk)*} build {@code ( blk+ )?} with *two* decisions, one for
 * entry and one for choosing alts of {@code blk}.
 *
 * <pre>
 *   |-------------|
 *   v             |
 *   o--[o-blk-o]-&gt;o  o
 *   |                ^
 *   -----------------|
 * </pre>
 *
 * Note that the optional bypass must jump outside the loop as
 * {@code (A|B)*} is not the same thing as {@code (A|B|)+}.
 */
@Override
public Handle star(GrammarAST starAST, Handle elem) {
    StarBlockStartState blkStart = (StarBlockStartState) elem.left;
    BlockEndState blkEnd = (BlockEndState) elem.right;
    preventEpsilonClosureBlocks.add(new Triple<Rule, ATNState, ATNState>(currentRule, blkStart, blkEnd));
    StarLoopEntryState entry = newState(StarLoopEntryState.class, starAST);
    entry.nonGreedy = !((QuantifierAST) starAST).isGreedy();
    atn.defineDecisionState(entry);
    LoopEndState end = newState(LoopEndState.class, starAST);
    StarLoopbackState loop = newState(StarLoopbackState.class, starAST);
    entry.loopBackState = loop;
    end.loopBackState = loop;
    BlockAST blkAST = (BlockAST) starAST.getChild(0);
    if (((QuantifierAST) starAST).isGreedy()) {
        if (expectNonGreedy(blkAST)) {
            g.tool.errMgr.grammarError(ErrorType.EXPECTED_NON_GREEDY_WILDCARD_BLOCK, g.fileName, starAST.getToken(), starAST.getToken().getText());
        }
        // loop enter edge (alt 1)
        epsilon(entry, blkStart);
        // bypass loop edge (alt 2)
        epsilon(entry, end);
    } else {
        // if not greedy, priority to exit branch; make it first
        // bypass loop edge (alt 1)
        epsilon(entry, end);
        // loop enter edge (alt 2)
        epsilon(entry, blkStart);
    }
    // block end hits loop back
    epsilon(blkEnd, loop);
    // loop back to entry/exit decision
    epsilon(loop, entry);
    // decision is to enter/exit; blk is its own decision
    starAST.atnState = entry;
    return new Handle(entry, end);
}

Example 3 with StarLoopEntryState

use of org.antlr.v4.runtime.atn.StarLoopEntryState in project antlr4 by antlr.

the class DOTGenerator method getDOT.

/**
 * Return a String containing a DOT description that, when displayed,
 *  will show the incoming state machine visually.  All nodes reachable
 *  from startState will be included.
 */
public String getDOT(ATNState startState, String[] ruleNames, boolean isLexer) {
    if (startState == null)
        return null;
    // The output DOT graph for visualization
    Set<ATNState> markedStates = new HashSet<ATNState>();
    ST dot = stlib.getInstanceOf("atn");
    dot.add("startState", startState.stateNumber);
    dot.add("rankdir", rankdir);
    List<ATNState> work = new LinkedList<ATNState>();
    work.add(startState);
    while (!work.isEmpty()) {
        ATNState s = work.get(0);
        if (markedStates.contains(s)) {
            work.remove(0);
            continue;
        }
        markedStates.add(s);
        // don't go past end of rule node to the follow states
        if (s instanceof RuleStopState)
            continue;
        // special case: if decision point, then line up the alt start states
        // unless it's an end of block
        // if ( s instanceof BlockStartState ) {
        // ST rankST = stlib.getInstanceOf("decision-rank");
        // DecisionState alt = (DecisionState)s;
        // for (int i=0; i<alt.getNumberOfTransitions(); i++) {
        // ATNState target = alt.transition(i).target;
        // if ( target!=null ) {
        // rankST.add("states", target.stateNumber);
        // }
        // }
        // dot.add("decisionRanks", rankST);
        // }
        // make a DOT edge for each transition
        ST edgeST;
        for (int i = 0; i < s.getNumberOfTransitions(); i++) {
            Transition edge = s.transition(i);
            if (edge instanceof RuleTransition) {
                RuleTransition rr = ((RuleTransition) edge);
                // don't jump to other rules, but display edge to follow node
                edgeST = stlib.getInstanceOf("edge");
                String label = "<" + ruleNames[rr.ruleIndex];
                if (((RuleStartState) rr.target).isLeftRecursiveRule) {
                    label += "[" + rr.precedence + "]";
                }
                label += ">";
                edgeST.add("label", label);
                edgeST.add("src", "s" + s.stateNumber);
                edgeST.add("target", "s" + rr.followState.stateNumber);
                edgeST.add("arrowhead", arrowhead);
                dot.add("edges", edgeST);
                work.add(rr.followState);
                continue;
            }
            if (edge instanceof ActionTransition) {
                edgeST = stlib.getInstanceOf("action-edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
            } else if (edge instanceof AbstractPredicateTransition) {
                edgeST = stlib.getInstanceOf("edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
            } else if (edge.isEpsilon()) {
                edgeST = stlib.getInstanceOf("epsilon-edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
                boolean loopback = false;
                if (edge.target instanceof PlusBlockStartState) {
                    loopback = s.equals(((PlusBlockStartState) edge.target).loopBackState);
                } else if (edge.target instanceof StarLoopEntryState) {
                    loopback = s.equals(((StarLoopEntryState) edge.target).loopBackState);
                }
                edgeST.add("loopback", loopback);
            } else if (edge instanceof AtomTransition) {
                edgeST = stlib.getInstanceOf("edge");
                AtomTransition atom = (AtomTransition) edge;
                String label = String.valueOf(atom.label);
                if (isLexer)
                    label = "'" + getEdgeLabel(new StringBuilder().appendCodePoint(atom.label).toString()) + "'";
                else if (grammar != null)
                    label = grammar.getTokenDisplayName(atom.label);
                edgeST.add("label", getEdgeLabel(label));
            } else if (edge instanceof SetTransition) {
                edgeST = stlib.getInstanceOf("edge");
                SetTransition set = (SetTransition) edge;
                String label = set.label().toString();
                if (isLexer)
                    label = set.label().toString(true);
                else if (grammar != null)
                    label = set.label().toString(grammar.getVocabulary());
                if (edge instanceof NotSetTransition)
                    label = "~" + label;
                edgeST.add("label", getEdgeLabel(label));
            } else if (edge instanceof RangeTransition) {
                edgeST = stlib.getInstanceOf("edge");
                RangeTransition range = (RangeTransition) edge;
                String label = range.label().toString();
                if (isLexer)
                    label = range.toString();
                else if (grammar != null)
                    label = range.label().toString(grammar.getVocabulary());
                edgeST.add("label", getEdgeLabel(label));
            } else {
                edgeST = stlib.getInstanceOf("edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
            }
            edgeST.add("src", "s" + s.stateNumber);
            edgeST.add("target", "s" + edge.target.stateNumber);
            edgeST.add("arrowhead", arrowhead);
            if (s.getNumberOfTransitions() > 1) {
                edgeST.add("transitionIndex", i);
            } else {
                edgeST.add("transitionIndex", false);
            }
            dot.add("edges", edgeST);
            work.add(edge.target);
        }
    }
    // }
    for (ATNState s : markedStates) {
        if (!(s instanceof RuleStopState))
            continue;
        ST st = stlib.getInstanceOf("stopstate");
        st.add("name", "s" + s.stateNumber);
        st.add("label", getStateLabel(s));
        dot.add("states", st);
    }
    for (ATNState s : markedStates) {
        if (s instanceof RuleStopState)
            continue;
        ST st = stlib.getInstanceOf("state");
        st.add("name", "s" + s.stateNumber);
        st.add("label", getStateLabel(s));
        st.add("transitions", s.getTransitions());
        dot.add("states", st);
    }
    return dot.render();
}

Example 4 with StarLoopEntryState

use of org.antlr.v4.runtime.atn.StarLoopEntryState in project antlr4 by tunnelvisionlabs.

the class GrammarParserInterpreter method findOuterMostDecisionStates.

/**
 * identify the ATN states where we need to set the outer alt number.
 *  For regular rules, that's the block at the target to rule start state.
 *  For left-recursive rules, we track the primary block, which looks just
 *  like a regular rule's outer block, and the star loop block (always
 *  there even if 1 alt).
 */
public BitSet findOuterMostDecisionStates() {
    BitSet track = new BitSet(atn.states.size());
    int numberOfDecisions = atn.getNumberOfDecisions();
    for (int i = 0; i < numberOfDecisions; i++) {
        DecisionState decisionState = atn.getDecisionState(i);
        RuleStartState startState = atn.ruleToStartState[decisionState.ruleIndex];
        // Look for StarLoopEntryState that is in any left recursive rule
        if (decisionState instanceof StarLoopEntryState) {
            StarLoopEntryState loopEntry = (StarLoopEntryState) decisionState;
            if (loopEntry.precedenceRuleDecision) {
                // Recursive alts always result in a (...)* in the transformed
                // left recursive rule and that always has a BasicBlockStartState
                // even if just 1 recursive alt exists.
                ATNState blockStart = loopEntry.transition(0).target;
                // track the StarBlockStartState associated with the recursive alternatives
                track.set(blockStart.stateNumber);
            }
        } else if (startState.transition(0).target == decisionState) {
            // always track outermost block for any rule if it exists
            track.set(decisionState.stateNumber);
        }
    }
    return track;
}

Example 5 with StarLoopEntryState

use of org.antlr.v4.runtime.atn.StarLoopEntryState in project antlr4 by tunnelvisionlabs.

the class DOTGenerator method getDOT.

/**
 * Return a String containing a DOT description that, when displayed,
 *  will show the incoming state machine visually.  All nodes reachable
 *  from startState will be included.
 */
public String getDOT(ATNState startState, String[] ruleNames, boolean isLexer) {
    if (startState == null)
        return null;
    // The output DOT graph for visualization
    Set<ATNState> markedStates = new HashSet<ATNState>();
    ST dot = stlib.getInstanceOf("atn");
    dot.add("startState", startState.stateNumber);
    dot.add("rankdir", rankdir);
    List<ATNState> work = new LinkedList<ATNState>();
    work.add(startState);
    while (!work.isEmpty()) {
        ATNState s = work.get(0);
        if (markedStates.contains(s)) {
            work.remove(0);
            continue;
        }
        markedStates.add(s);
        // don't go past end of rule node to the follow states
        if (s instanceof RuleStopState)
            continue;
        // special case: if decision point, then line up the alt start states
        // unless it's an end of block
        // if ( s instanceof BlockStartState ) {
        // ST rankST = stlib.getInstanceOf("decision-rank");
        // DecisionState alt = (DecisionState)s;
        // for (int i=0; i<alt.getNumberOfTransitions(); i++) {
        // ATNState target = alt.transition(i).target;
        // if ( target!=null ) {
        // rankST.add("states", target.stateNumber);
        // }
        // }
        // dot.add("decisionRanks", rankST);
        // }
        // make a DOT edge for each transition
        ST edgeST;
        for (int i = 0; i < s.getNumberOfTransitions(); i++) {
            Transition edge = s.transition(i);
            if (edge instanceof RuleTransition) {
                RuleTransition rr = ((RuleTransition) edge);
                // don't jump to other rules, but display edge to follow node
                edgeST = stlib.getInstanceOf("edge");
                String label = "<" + ruleNames[rr.ruleIndex];
                if (((RuleStartState) rr.target).isPrecedenceRule) {
                    label += "[" + rr.precedence + "]";
                }
                label += ">";
                edgeST.add("label", label);
                edgeST.add("src", "s" + s.stateNumber);
                edgeST.add("target", "s" + rr.followState.stateNumber);
                edgeST.add("arrowhead", arrowhead);
                dot.add("edges", edgeST);
                work.add(rr.followState);
                continue;
            }
            if (edge instanceof ActionTransition) {
                edgeST = stlib.getInstanceOf("action-edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
            } else if (edge instanceof AbstractPredicateTransition) {
                edgeST = stlib.getInstanceOf("edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
            } else if (edge.isEpsilon()) {
                edgeST = stlib.getInstanceOf("epsilon-edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
                boolean loopback = false;
                if (edge.target instanceof PlusBlockStartState) {
                    loopback = s.equals(((PlusBlockStartState) edge.target).loopBackState);
                } else if (edge.target instanceof StarLoopEntryState) {
                    loopback = s.equals(((StarLoopEntryState) edge.target).loopBackState);
                }
                edgeST.add("loopback", loopback);
            } else if (edge instanceof AtomTransition) {
                edgeST = stlib.getInstanceOf("edge");
                AtomTransition atom = (AtomTransition) edge;
                String label = String.valueOf(atom.label);
                if (isLexer)
                    label = "'" + getEdgeLabel(new StringBuilder().appendCodePoint(atom.label).toString()) + "'";
                else if (grammar != null)
                    label = grammar.getTokenDisplayName(atom.label);
                edgeST.add("label", getEdgeLabel(label));
            } else if (edge instanceof SetTransition) {
                edgeST = stlib.getInstanceOf("edge");
                SetTransition set = (SetTransition) edge;
                String label = set.label().toString();
                if (isLexer)
                    label = set.label().toString(true);
                else if (grammar != null)
                    label = set.label().toString(grammar.getVocabulary());
                if (edge instanceof NotSetTransition)
                    label = "~" + label;
                edgeST.add("label", getEdgeLabel(label));
            } else if (edge instanceof RangeTransition) {
                edgeST = stlib.getInstanceOf("edge");
                RangeTransition range = (RangeTransition) edge;
                String label = range.label().toString();
                if (isLexer)
                    label = range.toString();
                else if (grammar != null)
                    label = range.label().toString(grammar.getVocabulary());
                edgeST.add("label", getEdgeLabel(label));
            } else {
                edgeST = stlib.getInstanceOf("edge");
                edgeST.add("label", getEdgeLabel(edge.toString()));
            }
            edgeST.add("src", "s" + s.stateNumber);
            edgeST.add("target", "s" + edge.target.stateNumber);
            edgeST.add("arrowhead", arrowhead);
            if (s.getNumberOfTransitions() > 1) {
                edgeST.add("transitionIndex", i);
            } else {
                edgeST.add("transitionIndex", false);
            }
            dot.add("edges", edgeST);
            work.add(edge.target);
        }
    }
    // }
    for (ATNState s : markedStates) {
        if (!(s instanceof RuleStopState))
            continue;
        ST st = stlib.getInstanceOf("stopstate");
        st.add("name", "s" + s.stateNumber);
        st.add("label", getStateLabel(s));
        dot.add("states", st);
    }
    for (ATNState s : markedStates) {
        if (s instanceof RuleStopState)
            continue;
        ST st = stlib.getInstanceOf("state");
        st.add("name", "s" + s.stateNumber);
        st.add("label", getStateLabel(s));
        st.add("transitions", s.getTransitions());
        dot.add("states", st);
    }
    return dot.render();
}