I'm making the same mistake repeatedly. In both my mails there are places where I said (a,b) or (b,a) when I meant (a,a). -- Dan
On Mon, Oct 12, 2009 at 11:09 AM, Dan Piponi <[email protected]> wrote: > Joe, > >> On Mon, Oct 12, 2009 at 11:03 AM, Joe Fredette <[email protected]> wrote: >> I completely forgot about free theorems! Do you have some links to resources >> -- I tried learning about them a while >> ago, but couldn't get a grasp on them... Thanks. > > There is Wadler's paper but I do find it tricky: > http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.38.9875 > > You can play with the generator here: > http://linux.tcs.inf.tu-dresden.de/~voigt/ft/ > The results can look unreadable at first, but I find that if I copy > them onto paper and do all of the remaining substitutions manually > (like I had to do with (a,b) -> (b,a)) you end up with something > readable. If you keep doing this you'll get a good intuition for what > the free theorem for a type will look like. > -- > Dan > _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
