[Haskell-beginners] QuickCheck 2 entering infinite loop

Brent Yorgey byorgey at seas.upenn.edu
Fri Jan 22 11:20:27 EST 2010

On Thu, Jan 21, 2010 at 10:05:20PM +0000, Dominic Mulligan wrote:
> The second property:
>  prop_InjectTypeConFreeVars args =
>    (freeTypeVars . (tyCon "Fun")) args == (concatMap freeTypeVars args)
> Sends quickCheck into an infinite loop of some sort.  It manages to get 
> through 5-6 tests before GHCi is brought to its knees.  Before I go crazy, 
> can anybody explain what I'm doing wrong?

What type is 'args'?  Sounds to me more like a combinatorial explosion
of some sort rather than an actual infinite loop.


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