I've just released a new string escape library. I'm not sure how useful it is and it might be downright stupid. I was messing around with trying to generate JSON documents with SPARQL queries and needed properly escaped strings but that's been mostly rendered unnecessary by the new GraphQL feature. I added functions for json, java, xml, html and xsi just to round it out. Hopefully someone might find some utility in it.
https://github.com/semantalytics-stardog/kibbles-string-escape/releases