Question

As an experimental project, I would like to try implementing some DSL on top of JavaScript.
Xtext seems like a great starting point as it has great out of the box Eclipse integration.
I was hoping to start on top of an existing Xtext JavaScript implementation, but could not find one.

It seems others were looking too with not luck. http://www.eclipse.org/forums/index.php/m/756376/

Is Xtext designed for this? What is the major difference between it and Antlr for my purpose?

Answer 1

The question itself is a bit confusing.

Do you want to implement a DSL using JS? (“DSL on top of JavaScript”)
In this case you can find a starting point over here: http://www.mailsend-online.com/blog/a-dsl-in-javascript.html. Also, this article describes several use-cases via CoffeScript which actually compiles into JS.

OR: Do you want to implement a DSL for describing JS files?
It would be a huge work to define a grammar for JavaScript. Sure, you can do it with Xtext, but it’s still huge. Using Xtext, you define your grammar with EBNF notation and then using an MWE workflow, you generate all the necessary artifacts for a basic textual modeling environment: parser, lexer, compiler, the metamodel artifacts, the editor GUI, etc. In the background, Xtext uses ANTLR to parse input files, e.g. the ones edited on the GUI. So if you want to “reuse” an existing grammar, you should check out the grammar list for ANTLR: http://www.antlr.org/grammar/list. (The ECMAScript is what you might be looking for.)