Examples with GrammarAST org.antlr.v4.tool.ast.GrammarAST used on opensource projects

Example 31 with GrammarAST

use of org.antlr.v4.tool.ast.GrammarAST in project antlr4 by antlr.

the class ParserATNFactory method newState.

public ATNState newState(GrammarAST node) {
    ATNState n = new BasicState();
    n.setRuleIndex(currentRule.index);
    atn.addState(n);
    return n;
}

Example 32 with GrammarAST

use of org.antlr.v4.tool.ast.GrammarAST 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 33 with GrammarAST

use of org.antlr.v4.tool.ast.GrammarAST in project antlr4 by antlr.

the class ParserATNFactory method createATN.

@Override
public ATN createATN() {
    _createATN(g.rules.values());
    assert atn.maxTokenType == g.getMaxTokenType();
    addRuleFollowLinks();
    addEOFTransitionToStartRules();
    ATNOptimizer.optimize(g, atn);
    for (Triple<Rule, ATNState, ATNState> pair : preventEpsilonClosureBlocks) {
        LL1Analyzer analyzer = new LL1Analyzer(atn);
        ATNState blkStart = pair.b;
        ATNState blkStop = pair.c;
        IntervalSet lookahead = analyzer.LOOK(blkStart, blkStop, null);
        if (lookahead.contains(org.antlr.v4.runtime.Token.EPSILON)) {
            ErrorType errorType = pair.a instanceof LeftRecursiveRule ? ErrorType.EPSILON_LR_FOLLOW : ErrorType.EPSILON_CLOSURE;
            g.tool.errMgr.grammarError(errorType, g.fileName, ((GrammarAST) pair.a.ast.getChild(0)).getToken(), pair.a.name);
        }
    }
    optionalCheck: for (Triple<Rule, ATNState, ATNState> pair : preventEpsilonOptionalBlocks) {
        int bypassCount = 0;
        for (int i = 0; i < pair.b.getNumberOfTransitions(); i++) {
            ATNState startState = pair.b.transition(i).target;
            if (startState == pair.c) {
                bypassCount++;
                continue;
            }
            LL1Analyzer analyzer = new LL1Analyzer(atn);
            if (analyzer.LOOK(startState, pair.c, null).contains(org.antlr.v4.runtime.Token.EPSILON)) {
                g.tool.errMgr.grammarError(ErrorType.EPSILON_OPTIONAL, g.fileName, ((GrammarAST) pair.a.ast.getChild(0)).getToken(), pair.a.name);
                continue optionalCheck;
            }
        }
        if (bypassCount != 1) {
            throw new UnsupportedOperationException("Expected optional block with exactly 1 bypass alternative.");
        }
    }
    return atn;
}

Example 34 with GrammarAST

use of org.antlr.v4.tool.ast.GrammarAST in project antlr4 by antlr.

the class ParserATNFactory method _createATN.

protected void _createATN(Collection<Rule> rules) {
    createRuleStartAndStopATNStates();
    GrammarASTAdaptor adaptor = new GrammarASTAdaptor();
    for (Rule r : rules) {
        // find rule's block
        GrammarAST blk = (GrammarAST) r.ast.getFirstChildWithType(ANTLRParser.BLOCK);
        CommonTreeNodeStream nodes = new CommonTreeNodeStream(adaptor, blk);
        ATNBuilder b = new ATNBuilder(nodes, this);
        try {
            setCurrentRuleName(r.name);
            Handle h = b.ruleBlock(null);
            rule(r.ast, r.name, h);
        } catch (RecognitionException re) {
            ErrorManager.fatalInternalError("bad grammar AST structure", re);
        }
    }
}

Example 35 with GrammarAST

use of org.antlr.v4.tool.ast.GrammarAST in project antlr4 by antlr.

the class ParserATNFactory method set.

/** From set build single edge graph {@code o->o-set->o}.  To conform to
     *  what an alt block looks like, must have extra state on left.
	 *  This also handles {@code ~A}, converted to {@code ~{A}} set.
     */
@Override
public Handle set(GrammarAST associatedAST, List<GrammarAST> terminals, boolean invert) {
    ATNState left = newState(associatedAST);
    ATNState right = newState(associatedAST);
    IntervalSet set = new IntervalSet();
    for (GrammarAST t : terminals) {
        int ttype = g.getTokenType(t.getText());
        set.add(ttype);
    }
    if (invert) {
        left.addTransition(new NotSetTransition(right, set));
    } else {
        left.addTransition(new SetTransition(right, set));
    }
    associatedAST.atnState = left;
    return new Handle(left, right);
}