testrecursivedescentparser.cs

Grammatica is a C# and Java parser generator (compiler compiler). It improves upon simlar tools (lik

    /**
     * Tests an unresolvable token conflict inside a production 
     * alternative.
     */
    public void TestElementTokenConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 0, 1);
        alt.AddToken(T1, 1, -1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        FailPrepareParser(parser);
    }

    /**
     * Tests an unresolvable production conflict inside a production 
     * alternative.
     */
    public void TestElementProductionConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddProduction(P2, 0, 1);
        alt.AddProduction(P3, 1, 1);
        alt.AddToken(T2, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        pattern = new ProductionPattern(P2, "P2");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, 1);
        alt.AddProduction(P2, 0, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        pattern = new ProductionPattern(P3, "P3");
        alt = new ProductionPatternAlternative();
        AddAlternative(pattern, alt);
        alt.AddToken(T1, 1, -1);
        AddPattern(parser, pattern);

        FailPrepareParser(parser);
    }

    /**
     * Tests an unresolvable production conflict in the tail of a
     * production alternative.
     */
    public void TestElementTailConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddProduction(P2, 1, 1);
        alt.AddToken(T2, 0, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        pattern = new ProductionPattern(P2, "P2");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, 1);
        alt.AddToken(T2, 0, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        // TODO: enable this test
        // FailPrepareParser(parser);
    }

    /**
     * Tests a resolvable conflict between two production patterns.
     */
    public void TestResolvableProductionConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddProduction(P2, 1, 1);
        AddAlternative(pattern, alt);
        alt = new ProductionPatternAlternative();
        alt.AddProduction(P3, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        pattern = new ProductionPattern(P2, "P2");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, 1);
        alt.AddToken(T1, 0, 1);
        alt.AddToken(T2, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);
        
        pattern = new ProductionPattern(P3, "P3");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, -1);
        alt.AddToken(T3, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        PrepareParser(parser);
    }

    /**
     * Tests a resolvable conflict between two production 
     * alternatives.
     */
    public void TestResolvableAlternativeConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, 1);
        alt.AddToken(T1, 0, 1);
        alt.AddToken(T2, 1, 1);
        AddAlternative(pattern, alt);
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, -1);
        alt.AddToken(T3, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        PrepareParser(parser);
    }

    /**
     * Tests a resolvable token conflict inside a production 
     * alternative.
     */
    public void TestResolvableElementTokenConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 0, 1);
        alt.AddToken(T1, 1, 1);
        alt.AddToken(T2, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        PrepareParser(parser);
    }

    /**
     * Tests a resolvable production conflict inside a production 
     * alternative.
     */
    public void TestResolvableElementProductionConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddProduction(P2, 0, 1);
        alt.AddToken(T1, 1, -1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        pattern = new ProductionPattern(P2, "P2");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, 1);
        alt.AddToken(T2, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        PrepareParser(parser);
    }

    /**
     * Tests a resolvable production conflict in the tail of a
     * production alternative.
     */
    public void TestResolvableElementTailConflict() {
        Parser parser = CreateParser();

        pattern = new ProductionPattern(P1, "P1");
        alt = new ProductionPatternAlternative();
        alt.AddProduction(P2, 1, 1);
        alt.AddToken(T2, 1, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        pattern = new ProductionPattern(P2, "P2");
        alt = new ProductionPatternAlternative();
        alt.AddToken(T1, 1, 1);
        alt.AddToken(T2, 0, 1);
        AddAlternative(pattern, alt);
        AddPattern(parser, pattern);

        PrepareParser(parser);
    }

    /**
     * Creates a new parser.
     * 
     * @return a new parser
     */
    private Parser CreateParser() {
        return new RecursiveDescentParser(null);
    }

    /**
     * Prepares the parser and reports a test failure if it failed.
     * 
     * @param parser         the parser to prepare
     */
    private void PrepareParser(Parser parser) {
        try {
            parser.Prepare();
        } catch (ParserCreationException e) {
            Fail(e.Message);
        }
    }

    /**
     * Prepares the parser and reports a test failure if it succeeded.
     * 
     * @param parser         the parser to prepare
     */
    private void FailPrepareParser(Parser parser) {
        try {
            parser.Prepare();
            Fail("succeeded in preparing parser");
        } catch (ParserCreationException e) {
            // Failure was expected
        }
    }

    /**
     * Adds a production pattern to a parser and reports a test 
     * failure if it failed.
     * 
     * @param parser         the parser to add a pattern to
     * @param pattern        the production pattern to add
     */
    private void AddPattern(Parser parser, ProductionPattern pattern) {
        try {
            parser.AddPattern(pattern);
        } catch (ParserCreationException e) {
            Fail("couldn't add pattern " + pattern.GetName() + ": " +
                 e.Message);
        }
    }

    /**
     * Adds a production pattern to a parser and reports a test 
     * failure if it succeeded.
     * 
     * @param parser         the parser to add a pattern to
     * @param pattern        the production pattern to add
     */
    private void FailAddPattern(Parser parser, ProductionPattern pattern) {
        try {
            parser.AddPattern(pattern);
            Fail("could add pattern " + pattern.GetName());
        } catch (ParserCreationException e) {
            // Failure was expected
        }
    }

    /**
     * Adds a pattern alternative. This method reports a test failure
     * if an exception was thrown.
     * 
     * @param pattern        the production pattern
     * @param alt            the pattern alternative to add
     */
    private void AddAlternative(ProductionPattern pattern,
                                ProductionPatternAlternative alt) {

        try {
            pattern.AddAlternative(alt);
        } catch (ParserCreationException e) {
            Fail("couldn't add alternative to " + pattern.GetName() + 
                 ": " + e.Message);
        }
    }

    /**
     * Throws a test fail exception.
     *
     * @param message         the test error message
     */
    private void Fail(string message) {
        throw new Exception(message);
    }
}