A minimal test case that shows the problem I am encountered parsing quoted strings with regex expressions in Parboiled.

MinimalTest.java

import static org.junit.Assert.*;
import static org.parboiled.support.ParseTreeUtils.printNodeTree;

import org.junit.Test;
import org.parboiled.BaseParser;
import org.parboiled.Parboiled;
import org.parboiled.Rule;
import org.parboiled.annotations.BuildParseTree;
import org.parboiled.buffers.IndentDedentInputBuffer;
import org.parboiled.errors.ErrorUtils;
import org.parboiled.matchers.CharMatcher;
import org.parboiled.parserunners.ReportingParseRunner;
import org.parboiled.support.ParsingResult;

public class MinimalTest {

    MyDSLParser parser = Parboiled.createParser(MyDSLParser.class);

    void parse(Rule rule, String input) {
        ParsingResult<?> result = new ReportingParseRunner(rule)
                .run(new IndentDedentInputBuffer(input.toCharArray(), 2, ";",
                        true, true));
        if (!result.parseErrors.isEmpty()) {
            System.out.println(ErrorUtils.printParseError(result.parseErrors
                    .get(0)));
        } else {
            System.out.println("NodeTree: " + printNodeTree(result) + '\n');
        }

        assertTrue(result.parseErrors.isEmpty());
    }

    // this fails
    @Test
    public void testQuotedString() {
        parse(parser.quotedString(), "\";\"");
    }

}

@BuildParseTree
class MyDSLParser extends BaseParser<Object> {

    Rule quotedString() {
        return Sequence(
                quote(),
                stringValue(),
                quote());
    }

    public Rule stringValue() {
        return Sequence(
                ZeroOrMore(
                    FirstOf(
                        semicolon(),
                        escapedQuote(),
                        Sequence(TestNot(quote()), ANY))),
                push(match()));
    }

    public Rule semicolon() {
        return new CharMatcher(';');
    }

    public Rule escapedQuote() {
        return Sequence(escape(), quote());
    }

    public Rule quote() {
        return new CharMatcher('"');
    }

    public Rule escape() {
        return String("\\");
    }
}