Koen Claessen (Wed, Apr 12, 2006 at 11:06:50AM +0200):
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 QuickCheck.
An increase in the major version number used to show that the new version is incompatible with the old one. Extensions left the major version number unchanged and increase the minor version number. major change : 1.0 -> 2.0 minor change : 1.0 -> 1.1 bugfix change: 1.0.0 -> 1.0.1 So a Cabal package QuickCheck-2.0 should be ok. If you install it, you should expect incompatibilities. Regards, -- Stefan