This is an example repository for those interested in developing a plug-in to add a language to Rouge. By way of example, this implements my thesis language, Magritte (pdf).
spec/visual/samples/magritteholds the visual spec - this is text intended to stress-test the lexer and catch any weirdnesses or errors.ruby preview.rbwill output the highlighted sample to the terminal. Set the environment variableDEBUG=1to instead output detailed debugging information.rakeorrake specruns the tests.rake serverruns a preview server on port 9292, which hot-reloads the lexer.
You can either use this repository as a starting point (make sure to rename files and constants as relevant, and replace LICENSE), or simply use this as a reference while writing your own. Rouge is extensible simply by subclassing Rouge::RegexLexer, but some of the logic in this repository can be convenient for live-previewing some sample text while developing the lexer.
Additionally, spec/rouge_magritte_spec.rb shows how to best to test relevant properties of a lexer - that it preserves the input, and at least the demo does not contain any error tokens. You are welcome to adapt any of this to your project, with your preferred test framework or testing approach.
Also please read our Lexer Development Guide for a general guide on using the Rouge API to define a lexer.