Re: [Haskell-cafe] template haskell for typeclass synonyms

I think I've got something nice in the end. http://hpaste.org/41042/classsynonymhs example: class ( ParteDi (Servizio a) s , Read a , Eq a , Show a , Integer `ParteDi` s ) => SClass s a $(classSynonym ''SClass) ghci ":i SClass" command is printing some strange type variables but it compiles paolino 2010/11/1 Gábor Lehel

On Mon, Nov 1, 2010 at 6:09 PM, Christopher Done wrote:

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On 1 November 2010 17:53, Paolino wrote:

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I'd like to have a template haskell function that take some constraints and a class name and write an empty class from those and relative empty instance to simulate typeclass synonyms.

As I've never written TH and couldn't find a easily adaptable code around, I ask here for the code, or some hints on how to arrive there.

I took Justin Bailey's haskelldb-th library as a TH example to work from and rewrote one TH function to try my hand at it, it's quite easy to follow with a simple example:

http://hpaste.org/paste/41035/demo

Maybe this is enough example to get you going. The rest you can find syntax parts from the TH Haddock documentation.

A useful FYI: the API docs are (almost) completely devoid of comments, but if you click to see the source, it does have some additional information in comments there, just not Haddock-formatted.

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