Examples with Parser org.antlr.v4.runtime.Parser used on opensource projects

Example 96 with Parser

use of org.antlr.v4.runtime.Parser in project antlr4 by antlr.

the class ATNOptimizer method optimizeSets.

private static void optimizeSets(Grammar g, ATN atn) {
    if (g.isParser()) {
        // parser codegen doesn't currently support SetTransition
        return;
    }
    int removedStates = 0;
    List<DecisionState> decisions = atn.decisionToState;
    for (DecisionState decision : decisions) {
        if (decision.ruleIndex >= 0) {
            Rule rule = g.getRule(decision.ruleIndex);
            if (Character.isLowerCase(rule.name.charAt(0))) {
                // parser codegen doesn't currently support SetTransition
                continue;
            }
        }
        IntervalSet setTransitions = new IntervalSet();
        for (int i = 0; i < decision.getNumberOfTransitions(); i++) {
            Transition epsTransition = decision.transition(i);
            if (!(epsTransition instanceof EpsilonTransition)) {
                continue;
            }
            if (epsTransition.target.getNumberOfTransitions() != 1) {
                continue;
            }
            Transition transition = epsTransition.target.transition(0);
            if (!(transition.target instanceof BlockEndState)) {
                continue;
            }
            if (transition instanceof NotSetTransition) {
                // TODO: not yet implemented
                continue;
            }
            if (transition instanceof AtomTransition || transition instanceof RangeTransition || transition instanceof SetTransition) {
                setTransitions.add(i);
            }
        }
        // due to min alt resolution policies, can only collapse sequential alts
        for (int i = setTransitions.getIntervals().size() - 1; i >= 0; i--) {
            Interval interval = setTransitions.getIntervals().get(i);
            if (interval.length() <= 1) {
                continue;
            }
            ATNState blockEndState = decision.transition(interval.a).target.transition(0).target;
            IntervalSet matchSet = new IntervalSet();
            for (int j = interval.a; j <= interval.b; j++) {
                Transition matchTransition = decision.transition(j).target.transition(0);
                if (matchTransition instanceof NotSetTransition) {
                    throw new UnsupportedOperationException("Not yet implemented.");
                }
                IntervalSet set = matchTransition.label();
                List<Interval> intervals = set.getIntervals();
                int n = intervals.size();
                for (int k = 0; k < n; k++) {
                    Interval setInterval = intervals.get(k);
                    int a = setInterval.a;
                    int b = setInterval.b;
                    if (a != -1 && b != -1) {
                        for (int v = a; v <= b; v++) {
                            if (matchSet.contains(v)) {
                                // TODO: Token is missing (i.e. position in source will not be displayed).
                                g.tool.errMgr.grammarError(ErrorType.CHARACTERS_COLLISION_IN_SET, g.fileName, null, CharSupport.getANTLRCharLiteralForChar(v), CharSupport.getIntervalSetEscapedString(matchSet));
                                break;
                            }
                        }
                    }
                }
                matchSet.addAll(set);
            }
            Transition newTransition;
            if (matchSet.getIntervals().size() == 1) {
                if (matchSet.size() == 1) {
                    newTransition = CodePointTransitions.createWithCodePoint(blockEndState, matchSet.getMinElement());
                } else {
                    Interval matchInterval = matchSet.getIntervals().get(0);
                    newTransition = CodePointTransitions.createWithCodePointRange(blockEndState, matchInterval.a, matchInterval.b);
                }
            } else {
                newTransition = new SetTransition(blockEndState, matchSet);
            }
            decision.transition(interval.a).target.setTransition(0, newTransition);
            for (int j = interval.a + 1; j <= interval.b; j++) {
                Transition removed = decision.removeTransition(interval.a + 1);
                atn.removeState(removed.target);
                removedStates++;
            }
        }
    }
//		System.out.println("ATN optimizer removed " + removedStates + " states by collapsing sets.");
}

Example 97 with Parser

use of org.antlr.v4.runtime.Parser in project antlr4 by antlr.

the class TestParserInterpreter method testEmptyInputWithCallsAfter.

@Test
public void testEmptyInputWithCallsAfter() throws Exception {
    LexerGrammar lg = new LexerGrammar("lexer grammar L;\n" + "A : 'a' ;\n");
    Grammar g = new Grammar("parser grammar T;\n" + "s : x y ;\n" + "x : EOF ;\n" + "y : z ;\n" + "z : ;", lg);
    ParseTree t = testInterp(lg, g, "s", "", "(s (x <EOF>) (y z))");
    // s
    assertEquals("0..0", t.getSourceInterval().toString());
    // x
    assertEquals("0..0", t.getChild(0).getSourceInterval().toString());
// unspecified		assertEquals("0..-1", t.getChild(1).getSourceInterval().toString()); // x
}

Example 98 with Parser

use of org.antlr.v4.runtime.Parser in project antlr4 by antlr.

the class TestParserInterpreter method testStarA.

@Test
public void testStarA() throws Exception {
    LexerGrammar lg = new LexerGrammar("lexer grammar L;\n" + "A : 'a' ;\n" + "B : 'b' ;\n" + "C : 'c' ;\n");
    Grammar g = new Grammar("parser grammar T;\n" + "s : A* B ;\n", lg);
    testInterp(lg, g, "s", "b", "(s b)");
    testInterp(lg, g, "s", "ab", "(s a b)");
    testInterp(lg, g, "s", "aaaaaab", "(s a a a a a a b)");
}

Example 99 with Parser

use of org.antlr.v4.runtime.Parser in project antlr4 by antlr.

the class TestParserInterpreter method testLeftRecursiveStartRule.

/**
	 * This is a regression test for antlr/antlr4#461.
	 * https://github.com/antlr/antlr4/issues/461
	 */
@Test
public void testLeftRecursiveStartRule() throws Exception {
    LexerGrammar lg = new LexerGrammar("lexer grammar L;\n" + "A : 'a' ;\n" + "B : 'b' ;\n" + "C : 'c' ;\n" + "PLUS : '+' ;\n" + "MULT : '*' ;\n");
    Grammar g = new Grammar("parser grammar T;\n" + "s : e ;\n" + "e : e MULT e\n" + "  | e PLUS e\n" + "  | A\n" + "  ;\n", lg);
    testInterp(lg, g, "e", "a", "(e a)");
    testInterp(lg, g, "e", "a+a", "(e (e a) + (e a))");
    testInterp(lg, g, "e", "a*a", "(e (e a) * (e a))");
    testInterp(lg, g, "e", "a+a+a", "(e (e (e a) + (e a)) + (e a))");
    testInterp(lg, g, "e", "a*a+a", "(e (e (e a) * (e a)) + (e a))");
    testInterp(lg, g, "e", "a+a*a", "(e (e a) + (e (e a) * (e a)))");
}

Example 100 with Parser

use of org.antlr.v4.runtime.Parser in project antlr4 by antlr.

the class TestParserInterpreter method testA.

@Test
public void testA() throws Exception {
    LexerGrammar lg = new LexerGrammar("lexer grammar L;\n" + "A : 'a' ;\n");
    Grammar g = new Grammar("parser grammar T;\n" + "s : A ;", lg);
    ParseTree t = testInterp(lg, g, "s", "a", "(s a)");
    assertEquals("0..0", t.getSourceInterval().toString());
}