[Template-haskell] TH type not Typeable?

Sean Seefried sseefried at cse.unsw.edu.au
Thu Jun 9 23:02:17 EDT 2005


On 10/06/2005, at 10:07 AM, Abraham Egnor wrote:

> I'd just like to pipe up and say that the lack of Typeable and Data
> instances for the TH types has frustrated me as well.

Me too. But there's a solution. Check out the code that comes with  
the third paper in the "Scrap Your Boilerplate" series. There's a  
module in there called Derive.hs that contains code for deriving  
Typeable and Data instances using Template Haskell.  The cool thing  
is, you can use it *on* Template Haskell's data types too.

In fact, I did this in my PanTHeon project available from my web site  
at:

http://www.cse.unsw.edu.au/~sseefried/pantheon.html

However, this uses an older version of the deriving code. You'd  
probably want to get the latest.

Cheers,

Sean


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