RFC: changes to -i flag for finding source files

[Simon Marlow]

On 25/04/2014 17:57, Roman Cheplyaka wrote:
> * Edward Kmett <ekmett at gmail.com> [2014-04-25 11:22:46-0400]
>> +1 from me. I have a lot of projects that suffer with 4 levels of vacuous
>> subdirectories just for this.
>>
>> In theory cabal could support this on older GHC versions by copying all of the
>> files to a working dir in dist with the expected layout on older GHCs.
>>
>> That would enable this to get much greater penetration more quickly.
>
> I'd really not want that people start putting ghc-options: -isrc=...
> into their cabal files. That'd make them irrecoverably ghc-specific, as no other
> tool will know how to process the files unless it reads ghc-options.

No, the idea would be to use hs-source-dirs like this:

   hs-source-dirs: A.B.C=src

Cabal just passes this in a -i option to GHC, so it almost Just Works, 
except that Cabal needs to preprocess some source files so it needs to 
find them, and also sdist needs to find source files.

Cheers,
Simon

> I'm +1 on adding support for this to cabal. Then the mechanism cabal uses to
> achieve this is just that — an implementation detail. And this new -i syntax can
> become one of such mechanisms.
>
> But cabal support should really come first, so that people aren't tempted by
> ghc-specific solutions.
>
> Roman
>