jashkenas/coffee-script — pull request #2696 by jwalton (2013-02-06 15:32:25+00:00)
Title: Add source-location-awareness to coffee-script compiler.

This change makes it so that the coffee-script compiler keeps track of where tokens came from in the original .coffee source, and passes this data along to Jison, which will imbed it in the AST. This can serve as the foundation for source-maps in CoffeeScript.