Examples with EmptySequence org.exist.xquery.value.EmptySequence used on opensource projects

Example 1 with EmptySequence

use of org.exist.xquery.value.EmptySequence in project exist by eXist-db.

the class Compile method eval.

public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
    // get the query expression
    final String expr = args[0].getStringValue();
    if (expr.trim().isEmpty()) {
        return new EmptySequence();
    }
    context.pushNamespaceContext();
    logger.debug("eval: {}", expr);
    // TODO(pkaminsk2): why replicate XQuery.compile here?
    String error = null;
    ErrorCodes.ErrorCode code = null;
    int line = -1;
    int column = -1;
    final XQueryContext pContext = new XQueryContext(context.getBroker().getBrokerPool());
    if (getArgumentCount() == 2 && args[1].hasOne()) {
        pContext.setModuleLoadPath(args[1].getStringValue());
    }
    final XQueryLexer lexer = new XQueryLexer(pContext, new StringReader(expr));
    final XQueryParser parser = new XQueryParser(lexer);
    // shares the context of the outer expression
    final XQueryTreeParser astParser = new XQueryTreeParser(pContext);
    try {
        parser.xpath();
        if (parser.foundErrors()) {
            logger.debug(parser.getErrorMessage());
            throw new XPathException(this, "error found while executing expression: " + parser.getErrorMessage());
        }
        final AST ast = parser.getAST();
        final PathExpr path = new PathExpr(pContext);
        astParser.xpath(ast, path);
        if (astParser.foundErrors()) {
            throw astParser.getLastException();
        }
        path.analyze(new AnalyzeContextInfo());
    } catch (final RecognitionException | TokenStreamException e) {
        error = e.toString();
    } catch (final XPathException e) {
        line = e.getLine();
        column = e.getColumn();
        code = e.getCode();
        error = e.getDetailMessage();
    } catch (final Exception e) {
        error = e.getMessage();
    } finally {
        context.popNamespaceContext();
        pContext.reset(false);
    }
    if (isCalledAs("compile")) {
        return error == null ? Sequence.EMPTY_SEQUENCE : new StringValue(error);
    } else {
        return response(pContext, error, code, line, column);
    }
}