[Haskell] Re: QuickCheck revival and Cabal

Koen Claessen koen at chalmers.se
Wed Apr 12 05:06:50 EDT 2006

>> There is currently an old QuickCheck version in the standard hierarchy
>> in Test.QuickCheck. As the new QuickCheck is incompatible with the old
>> one, I do not want to override that place. Rather, I would like to
>> create my own little space in the hierarchy where the new version can
>> sit and develop.

> If you intend the new version as a replacement for the old, then it 
> should be called Test.QuickCheck, and the package should identify itself 
> as a newer version (2.0, or whatever).  It's possible to have multiple 
> versions of a package simultaneously installed (at least with GHC). 
> Currently it isn't possible to use them both in the same program, but we 
> intend to allow that in the future.

The new QuickCheck is not a replacement for the old. For one, it is 
incompatible (in some trivial ways, but still). I don't want peoples 
programs or other libraries to break just because they rely on the old 

> Frederik mentioned "mounting", a concept which is also known as 
> "grafting", which would allow you the user to move modules around in the 
> hierarchy, and it would free the package author from deciding once and 
> for all what absolute module names to use.  This is the direction we 
> plan to go in for GHC, I'm not sure when it will happen though.


So, I'll just decide an arbitrary name/place and then later migrate to 
this new thing.


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