Data and Typeable instances for GenericPackageDescription
duncan.coutts at googlemail.com
Wed Jun 16 19:21:14 EDT 2010
On Tue, 2010-06-15 at 20:43 +0200, JP Moresmau wrote:
> Hello, I was wondering if there are instances for Typeable and Data
> available somewhere for GenericPackageDescription. Automatic deriving
> fails, probably, if I read the docs right, because some types in there
> have more than 7 parameters. It would help me to use the cabal file
> parsing functions and convert the result automatically to JSON for use
> in Eclipse through Scion. Of course if there isn't I suppose I can
> write my own instances and maybe share them with who ever is
I'm happy to accept patches.
One thing to keep in mind is that the Cabal library must be compilable
with hugs and nhc98 as well as ghc. I think that means we cannot use
deriving Typeable or Data since, as far as I know, neither of those
compilers supports that language extension.
Note that the ModuleName constructor is not exported on purpose. Do Data
instances make sense for abstract types?
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