Funny you should say that, I was just experimenting with generating one at a time using (StateT StdGen Maybe). If I get stuck (again) I'll check out ListT. Thanks!
Chad On 8/15/07, Paul Johnson <[EMAIL PROTECTED]> wrote: > Chad Scherrer wrote: > > Thanks for your replies. > > > > I actually starting out returning a single element instead. But a > > given lookup might return [], and the only way I could think of to > > handle it in (State StdGen a) would be to fail in the monad. But > > that's not really the effect I want - I'd rather have it ignore that > > element. Another option was to wrap with Maybe, but then since I > > really want a sequence of them anyway, I decided to just wrap in a > > List instead. Is there a way Maybe would work out better? > Ahh. How about using ListT Gen then? That (if I've got it the right > way round) works like the list monad (giving you non-determinism), but > has your random number generator embedded as well. Take a look at "All > About Monads" at http://www.haskell.org/all_about_monads/html/. Each > action in the monad may use a random number and produce zero or more > results. > > Paul. -- Chad Scherrer "Time flies like an arrow; fruit flies like a banana" -- Groucho Marx _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe