testrecursivedescentparser.java

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

        addPattern(parser, pattern);

        failPrepareParser(parser);
    }

    /**
     * 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.getMessage());
        }
    }

    /**
     * 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();
        } 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.getMessage());
        }
    }

    /**
     * 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.getMessage());
        }
    }
}