Examples with Rule org.antlr.v4.tool.Rule used on opensource projects

Example 16 with Rule

use of org.antlr.v4.tool.Rule in project antlr4 by antlr.

the class LeftRecursiveRule method getPrimaryAlts.

/** Return an array that maps predicted alt from primary decision
	 *  to original alt of rule. For following rule, return [0, 2, 4]
	 *
		e : e '*' e
		  | INT
		  | e '+' e
		  | ID
		  ;

	 *  That maps predicted alt 1 to original alt 2 and predicted 2 to alt 4.
	 *
	 *  @since 4.5.1
	 */
public int[] getPrimaryAlts() {
    if (recPrimaryAlts.size() == 0)
        return null;
    int[] alts = new int[recPrimaryAlts.size() + 1];
    for (int i = 0; i < recPrimaryAlts.size(); i++) {
        // recPrimaryAlts is a List not Map like recOpAlts
        LeftRecursiveRuleAltInfo altInfo = recPrimaryAlts.get(i);
        alts[i + 1] = altInfo.altNum;
    }
    return alts;
}

Example 17 with Rule

use of org.antlr.v4.tool.Rule in project antlr4 by antlr.

the class Rule method getAltLabels.

/**
	 * Get {@code #} labels. The keys of the map are the labels applied to outer
	 * alternatives of a lexer rule, and the values are collections of pairs
	 * (alternative number and {@link AltAST}) identifying the alternatives with
	 * this label. Unlabeled alternatives are not included in the result.
	 */
public Map<String, List<Pair<Integer, AltAST>>> getAltLabels() {
    Map<String, List<Pair<Integer, AltAST>>> labels = new LinkedHashMap<String, List<Pair<Integer, AltAST>>>();
    for (int i = 1; i <= numberOfAlts; i++) {
        GrammarAST altLabel = alt[i].ast.altLabel;
        if (altLabel != null) {
            List<Pair<Integer, AltAST>> list = labels.get(altLabel.getText());
            if (list == null) {
                list = new ArrayList<Pair<Integer, AltAST>>();
                labels.put(altLabel.getText(), list);
            }
            list.add(new Pair<Integer, AltAST>(i, alt[i].ast));
        }
    }
    if (labels.isEmpty())
        return null;
    return labels;
}

Example 18 with Rule

use of org.antlr.v4.tool.Rule in project antlr4 by antlr.

the class BaseJavaTest method checkRuleDFA.

List<ANTLRMessage> checkRuleDFA(String gtext, String ruleName, String expecting) throws Exception {
    ErrorQueue equeue = new ErrorQueue();
    Grammar g = new Grammar(gtext, equeue);
    ATN atn = createATN(g, false);
    ATNState s = atn.ruleToStartState[g.getRule(ruleName).index];
    if (s == null) {
        System.err.println("no such rule: " + ruleName);
        return null;
    }
    ATNState t = s.transition(0).target;
    if (!(t instanceof DecisionState)) {
        System.out.println(ruleName + " has no decision");
        return null;
    }
    DecisionState blk = (DecisionState) t;
    checkRuleDFA(g, blk, expecting);
    return equeue.all;
}

Example 19 with Rule

use of org.antlr.v4.tool.Rule in project antlr4 by antlr.

the class BaseCppTest method checkRuleDFA.

List<ANTLRMessage> checkRuleDFA(String gtext, String ruleName, String expecting) throws Exception {
    ErrorQueue equeue = new ErrorQueue();
    Grammar g = new Grammar(gtext, equeue);
    ATN atn = createATN(g, false);
    ATNState s = atn.ruleToStartState[g.getRule(ruleName).index];
    if (s == null) {
        System.err.println("no such rule: " + ruleName);
        return null;
    }
    ATNState t = s.transition(0).target;
    if (!(t instanceof DecisionState)) {
        System.out.println(ruleName + " has no decision");
        return null;
    }
    DecisionState blk = (DecisionState) t;
    checkRuleDFA(g, blk, expecting);
    return equeue.all;
}

Example 20 with Rule

use of org.antlr.v4.tool.Rule in project antlr4 by antlr.

the class TestATNParserPrediction method testAltsForLRRuleComputation.

@Test
public void testAltsForLRRuleComputation() throws Exception {
    Grammar g = new Grammar("grammar T;\n" + "e : e '*' e\n" + "  | INT\n" + "  | e '+' e\n" + "  | ID\n" + "  ;\n" + "ID : [a-z]+ ;\n" + "INT : [0-9]+ ;\n" + "WS : [ \\r\\t\\n]+ ;");
    Rule e = g.getRule("e");
    assertTrue(e instanceof LeftRecursiveRule);
    LeftRecursiveRule lr = (LeftRecursiveRule) e;
    assertEquals("[0, 2, 4]", Arrays.toString(lr.getPrimaryAlts()));
    assertEquals("[0, 1, 3]", Arrays.toString(lr.getRecursiveOpAlts()));
}