Option to ignore certain directory

[denibertovic]

Is there an option in the config file that I can turn on for the formatter to ignore an entire directory and/or project?

My use case is with using vim-stylish-haskell to run the formatter on each buffer save. That works out for all of my projects except a huge legacy one that I would want to avoid reformatting.

[ivan-m]

I'd like this as well, working on projects with others were the formatting differs wildly; as such except for greenfield projects I'd like to disable it in some projects.