Does Rascal have language support for parsing and transforming Javascript?

Question

I'm trying to make modifications to javascript files (in fact multiple prog. languages, but javascript will do for the moment), in an automated manner.

I came across Rascal as a meta-programming language. I'm just wondering if it already has support for parsing and transforming Javascript, the way it has for Java (through lang::Java)?

Where should I be looking, to start making simple AST transforms like adding a statement, before a return, etc?

Answer 1

No not out-of-the-box. We have some rudimentary start of a javascript grammar somewhere (the SDF2 grammar which can be transformed to Rascal), but I am guessing it would take some serious work to make it ready for simple AST transforms.

Answer 2

We have pretty good Javascript (ES5) grammar in the standard library in lang::javascript::saner::Syntax. (See here: https://github.com/cwi-swat/rascal/blob/master/src/org/rascalmpl/library/lang/javascript/saner/Syntax.rsc)

This grammar has two limitations:

• Semi-colons are required.
• No support for comma expressions.