[Haskell-cafe] QuickCheck - Extracting data values from tests

Martin Sjögren msjogren at gmail.com
Fri Sep 3 02:35:26 EDT 2004

On Fri, 3 Sep 2004 01:35:45 +0100, Jorge Adriano Aires
<jadrian at mat.uc.pt> wrote:
> Not sure which part is not clear... I'll just try to explain each of them.
> Lets say I'm implementing a generators for Graphs.
> > > Also, even when I'm implementing a generator, I want to see how it is
> > > working.
> I want to check if the generated Graphs are like I intended them to be.
> > > Running a verboseCheck on some dummy property helps, but I may
> verboseCheck by default prints all the data.
> I can run it on a dummy function that always returns True to see what kind of
> data I'm getting.
> > > want to analyse the data, or some parts of it better
> May want to print the 'actual graphs' on the screen (ASCII art, or maybe using
> some function that calls Gnuplot). Then I may want to check in more detail
> the info in contained in some of the nodes. Then I may decide to run some
> functions on it.
> > > many data structures I have alternative "show" functions that take
> > > parameters as arguments.
> Like I just said, I may want to "show" the graph in many ways.
> But there are more possibilities.
> Why limitate the usefulness of QuickCheck? Suppose I just implemented
> generators for a few kinds of terms and formulas to test some properties. Now
> I want to benchmark a couple of different unification functions... I'd expect
> to be able to use my generator for that. Unless I'm missing something, I
> cannot. Am I right?

The generate function is exported:

generate :: Int -> StdGen -> Gen a -> a


More information about the Haskell-Cafe mailing list