Short version: here is the poll
I noticed recently that Foo.Bar.hs is supported by GHC. I had always assumed it wasn't because people always use directories.
I've never liked having separate directories for each level of hierarchy. It's easier to just list a list of files and script (e.g. even copying a file X.hs to Y.hs is a bummer). When opening them on GitHub you have to click through to get a complete picture of a project.
Other languages do and don't do this. Lispers, for example, don't.
How do other Haskellers feel about it? Would it mess with anybody's tooling or mojo if I switched to that style in my packages?
For one I know that Stack (my own implementation), actually assumes hierarchical filenames. So I'd have to patch that to implement this. E.g.
> Unable to find a known candidate for the Cabal entry "HIndent.Types", but did find: HIndent.Types.hs. If you are using a custom preprocessor for this module with its own file extension, consider adding the file(s) to your .cabal under extra-source-files.
I suppose the real question is, as a language standard and a community preference, should this be considered a bug? Should people be free to use X.Y.hs or X/Y.hs styles?
Ciao!