public class LuaSourceParser extends AbstractSourceParser {

	/**
	 * AST cache, allow to keep previous AST in mind when syntax errors occurs
	 */
	private static ModuleDeclaration _cache = null;

	/**
	 * Provide DLTK compliant AST
	 * 
	 * @return {@link ModuleDeclaration}, in case of syntax errors, the previous
	 *         valid AST is given
	 * @see org.eclipse.dltk.ast.parser.ISourceParser#parse(char[], char[],
	 *      org.eclipse.dltk.compiler.problem.IProblemReporter)
	 */
	@Override
	public ModuleDeclaration parse(char[] fileName, char[] source,
			IProblemReporter reporter) {

		// Analyze code
		NodeFactory factory = new NodeFactory(new String(source));

		/*
		 * Keep older version of AST in case of syntax errors, when cache is
		 * defined.
		 */
		if ((_cache == null) || !factory.errorDetected()) {
			_cache = factory.getRoot();
		}

		// Transfers problems if there is any
		if (factory.errorDetected()) {
			IProblem problem = buildProblem(fileName, factory.analyser());
			reporter.reportProblem(problem);
		}
		return _cache;
	}

	public IProblem buildProblem(char[] fileName, LuaParseErrorAnalyzer analyzer) {
		int col = analyzer.syntaxErrorColumn();
		int offset = analyzer.syntaxErrorOffset();
		int line = analyzer.syntaxErrorLine();
		int id = 1;
		int severity = ProblemSeverities.Error;
		String[] args = {};
		String error = analyzer.getErrorString();
		String file = new String(fileName);

		IProblem problem = new DefaultProblem(file, error, id, args, severity,
				offset, offset, line, col);
		return problem;
	}

}

if (reporter != null) {
			reporter.reportProblem(buildProblem());
		}
...	
	private IProblem buildProblem() {
		int offset = 0;
		int line = 0; // 1st line
		int severity = ProblemSeverities.Error;
		String[] args = null;
		String message = "EXAMPLE ERROR";
		int id = 0;
		return new DefaultProblem(message, id, args, severity, offset, offset, line);
	}