[darcs-users] Delta Debugging

[David Roundy]

On Mon, May 24, 2004 at 10:23:44AM -0400, Andrew Pimlott wrote:
> > I imagine implementing something like
> > 
> > latest_working_version :: FilePath -> (IO ()) -> (IO Bool) -> IO PatchSet
> > 
> > where the first argument is the location of a repository (a PatchSet could
> > be given instead, but we might want to throw away and reread the patches to
> > save memory), the second argument is an initialization function, and the
> > third is the actual test.
> 
> I think the initialization function should be IO Bool--that tells you
> whether (eg) your compile succeeded, mostly solving the problem of
> distinguishing between the target bug and compile errors.

I think you're misinterpreting the meaning of my two IO args.  The
initialization wouldn't be run for each test--it would only be run once on
a "known-good" version.  It is for things like autoconf and configure that
you don't want to keep rerunning (since they're slow).  Of course, it would
still be useful to have it return a Bool, since then you wouldn't need to
require that the user specify a known-good version.

I think Kenn's suggestion that the test itself return IO (Maybe Bool)
sounds like the best way to deal with distinguishing between compile errors
and "the real bug".

> Also, hopefully this is obvious, but the third argument should be
> user-specifiable, because you often want to run a small test case, not
> the entire test suite.

Yes, of course.
-- 
David Roundy
http://www.abridgegame.org