Re: [Haskell-cafe] Generating Haskell with associated types (and kind annotations)

Hi Neil, Thanks for the suggestion! I'd seen the package before, but I couldn't figure out a good way to integrate it into my codegen situation. I guess I should write the "skeleton" of the code I want to generate, get HSE to parse it, and then replace the parts I want to change of the AST with what I need? Is there a nicer way (TH-like?) to get the modified AST into GHC than prettyprinting the AST again and asking GHC to compile the output file? Thank you, Dan On Fri, May 8, 2009 at 11:49 AM, Neil Mitchell wrote:

Hi Dan,

...

I was wondering whether anyone had any suggestions on a good way to generate repetitive code with associated types and kind annotations.

haskell-src-exts is the answer: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/haskell-src-exts

From the project description:

"Haskell-Source with Extensions (HSE, haskell-src-exts) is an extension of the standard haskell-src package, and handles most common syntactic extensions to Haskell, including: ... Indexed type families (including associated types)"

I've used the project extensively in HLint (http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hlint) and it works fantastically.

Thanks

Neil

On Fri, May 8, 2009 at 4:24 PM, Daniel Peebles wrote:

...

Hi all,

I'd like to use TH but as far as I understand, it doesn't support this yet (I think associated types are in HEAD but not kinds), so for now I've been using ruby with string interpolation, which feels rather ugly. It means that I have to edit the ruby script and regenerate the file in question each time I make a change, which doesn't fit in very nicely with cabal (or my patience) and so on. Ideally, I'd have something that I can write mostly like real Haskell (with "holes" to substitute values into), that can be integrated nicely into the cabal build system without using custom external preprocessors or anything like that.

Any ideas?

Thanks, Dan _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe