XQueryX is a recommendation for an XML notation of XQuery. It is directly inspired by the XQuery EBNF grammar but with convenient differences for following evaluation. XQueryX is used in homemade XSLTForms XPath parser but this parser has its own limitations.

XQuery is text, XQueryX is XML: is it a good idea to use Invisible XML to generate XQueryX from XQuery?

Invisible XML grammars are context free and are always detecting ambiguities which can be problematic for performance for big inputs.

Different topics are to be considered:

• Ambiguities in XQuery EBNF grammar
• Ambiguities in XQueryX XML schema
• Whitespace troubles
• Limitations of a context free parser for a programming language
• Proposed extensions for Invisible XML engines
• Postprocessing on resulting XML nodes

Grammix is an Invisible XML Javascript implementation which has been extended for XQueryX generation.

The proposed extended Invisible XML grammar for XQueryX allows to parse XQuery 3.1 sources. It supports all XQuery 3.1 features with minimal restrictions for whitespaces. Its conformance has been evaluated against XQuery 3.1 Test Suite.