codex

This tool download and cache the source code of packages in your local hackage, it can then use this cache to generate tags files aggregating the sources of all the dependencies of your cabal/stack projects. You basically do `codex update` in your project directory and you'll get a file (codex.tags by default, or TAGS when using emacs format) that you can use in your favorite text editor. Usage overview can be found in the README.