CQLParserFunction.java 文件源码

@Override
public Sequence eval(final Sequence[] args, final Sequence contextSequence) throws XPathException {
    final ANTLRInputStream is = new ANTLRInputStream(args[0].getStringValue());

    final CorpusQLLexer lexer = new CorpusQLLexer(is);
    final CommonTokenStream tokens = new CommonTokenStream(lexer);
    final CorpusQLParser parser = new CorpusQLParser(tokens);

    final ParseTree tree = parser.query();

    final MemTreeBuilder builder = new MemTreeBuilder();
    builder.startDocument();

    final CorpusQLXMLVisitor xmlVisitor = new CorpusQLXMLVisitor(builder);
    xmlVisitor.visit(tree);

    builder.endDocument();

    return builder.getDocument();
}