Your implication is backwards. ==> is read "implies" So your way has "do blah with positive integers" implies "x > 0 && y > 0". That's backwards.
Try prop_something x y = x > 0 && y > 0 ==> ... do blah with positive integers - Clark On Tue, Nov 13, 2012 at 4:52 PM, <[email protected]> wrote: > Thanks, will try them both. With regards to the implication I assume > it's just regarded as one property test ? > > To get two values greater than zero I have something like > > prop_something x y = .......do blah with positive integers > ==> x > 0 && y > 0 > > But my test fails as it appears to be injecting a negative number and > the test fails. But the implication does not cause the failed test to be > ignored. > > Must be missing something ??? > > Thanks > > On Mon, Nov 12, 2012, at 10:00 PM, Iustin Pop wrote: > > On Mon, Nov 12, 2012 at 10:14:30PM +0100, Simon Hengel wrote: > > > On Mon, Nov 12, 2012 at 07:21:06PM +0000, [email protected] wrote: > > > > Hi, > > > > > > > > Trying to find some good docs on QuickCheck, if anyone has one ? > > > > > > > > Been scanning what I can find, but a question. > > > > > > > > What would be the best way to generate two different/distinct > integers ? > > > > > > I would use Quickcheck's implication operator here: > > > > > > quickCheck $ \x y -> x /= (y :: Int) ==> ... > > > > That's good, but it only eliminates test cases after they have been > > generated. A slightly better (IMHO) version is to generate "correct" > > values in the first place: > > > > prop_Test :: Property > > prop_Test = > > forAll (arbitrary::Gen Int) $ \x -> > > forAll (arbitrary `suchThat` (/= x)) $ \y -> > > … > > > > regards, > > iustin > > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe >
_______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
