[Haskell-cafe] template haskell for typeclass synonyms

Christopher Done chrisdone at googlemail.com
Mon Nov 1 13:09:29 EDT 2010


On 1 November 2010 17:53, Paolino <paolo.veronelli at gmail.com> wrote:
> 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.


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