Hello Cafe, I created https://groups.google.com/forum/#!forum/haskell-indexer-users, please join if you use / interested in using haskell-indexer [1]! Quoting Section 4.5.5 of the latest HCAR [2],
Haskell Indexer is a Kythe extension for working with Haskell source code. Kythe is language-agnostic ecosystem for building tools that work with code. An example is code search with cross-reference support: https://cs.chromium.org/. Haskell Indexer makes it possible to use Kythe-based tools with Haskell. With Haskell Indexer it’s possible to list all use-sites of any given function (get reverse-references) and explore the code without any IDE setup. A portion of GHC and Stackage is indexed and available at http://stuff.codereview.me/.
Thank you & happy coding, Robin [1] https://github.com/google/haskell-indexer [2] https://www.haskell.org/communities/11-2017/html/report.html