I am working on a merge tool for JavaScript programs, and I need to write a grammar for JavaScript (version >= ES6) in JavaCC format.

For that, I want to use an openly available BNF grammar for ES6, then I would write the grammar in JavaCC format from it.

I was able to find only those (from this Stack Overflow question):

• http://tomcopeland.blogs.com/EcmaScript.html
• http://www.ccs.neu.edu/home/dherman/javascript/

However, these are very old BNFs (and the question on StackOverflow is also very old, from 11 years ago). These grammars work only - and in a limited manner - for versions < ES6.

Do you know about a newer publicly available grammar (BNF, JavaCC file, etc)?

There are parsers available for ES6, such as Esprima, but, since I have to use JavaCC environment, I need the grammar to work on.