Running properties that do not draw any random values only once

[Simon Hengel]

> I have had this request before, but decided then that it was not
> really worth spending much time on, because if there are no arguments,
> the result of the property will only be evaluated once anyway, because
> of laziness.

Yes, you are right.  As long as you do not use any IO, it seems to be
only "cosmetic".

It still makes a difference if you do IO (say testing some Database
adaption code, that needs to create a database connection).  And Nick's
changes give me enough flexibility to experiment with.

Cheers,
Simon