* Yves Parès <yves.pa...@gmail.com> [2012-05-28 11:28:22+0200] > > observe $ flip runStateT 10 $ (put 0 >> mzero) <|> modify (+3) > > ((),13) > > If the only thing you need is backtracking, using LogicT might be a little > overkill, using Maybe in the bottom of you monad stack suits just fine: > > case flip runStateT 10 $ (put 0 >> mzero) <|> modify (+3) of > Just x -> .... > Nothing -> ....
Indeed, I didn't realise that Maybe may be (no pun intended) sufficient here! -- Roman I. Cheplyaka :: http://ro-che.info/ _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe