[Haskell-cafe] "desactivate" my Show instance implementations temporarily

Lorenzo Bolla lbolla at gmail.com
Sun Apr 22 11:25:35 CEST 2012

On Sun, Apr 22, 2012 at 11:11:51AM +0200, TP wrote:
> Hello,
> I have a module where I have made several types as instances of the Show 
> typeclass.
> For debugging purpose, I would like to use the default implementation for Show 
> (the one obtained when using "deriving", which shows all the constructors). Is 
> there some option to do that, or have I to comment all the Show instances of 
> my code, and add "Show" in "deriving (...)" for each of my types? If this is 
> the only possibility, is there some script around here to do that 
> automatically?
> Thanks in advance,
> TP

You could use some preprocessor's #if/#else/#endif pragmas.
See here: http://stackoverflow.com/questions/6556778/using-if-else-endif-in-haskell


Lorenzo Bolla
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