Embed data files

[Avi-D-coder]

closes:#699

Embeds data files so the hlint executable is self contained.
This allows for easy packaging with stack and cabal.
And enables hlint to be used as a library without shipping data files.

From #620 (comment)

ndmitchell would you reconsider the TH approach?

It's not just nicer for using hlint as a library it's nicer when using the executable too. I'm on a 256G laptop and I delete ~/.stack when ever it gets past 10G. I install hlint using stack install, so when I delete ~/.stack hlint has to be rebuilt, just to get 3 data files.

Here's a commit using file-embed. The TH is relegated to one file. The executable actually gets slightly smaller 48117184 to 48020968 (GHC 8.8).

[Avi-D-coder]

TemplateHaskell is confined to src/EmbedData.hs. If it causes a problem on a particular platform, an alternative module could be conditionally compiled with the old readFile $ cmdDataDir </> "default.yaml" method.

[ndmitchell]

Thanks for the PR! Given what you've said, and the obvious benefits, it does seem like this is the right way to go to simplify everything. Let's address the remarks in the PR and then I'll merge.

[ndmitchell]

That's way nicer. Thanks a lot!

[Avi-D-coder]

@ndmitchell Could you push a release to hackage so hie can use this?

[ndmitchell]

Sorry @Avi-D-coder - I've been on holiday. Should have this done by this evening.

[Avi-D-coder]

Great thanks