On 2006-11-14 at 13:57+0300 "Serge D. Mechveliani" wrote: > Thanks to people who discussed the question of > "who said `fromJust Nothing'" and -xc option. > > My last impression is that instead of using -xc it is better to write > programs in a debug-friendly style. For example, let g x must > return (Just _), but the programmer is not 100% sure that g x is free > of bugs. Then, instead of > f x = h $ fromJust $ g x > one needs too write > > f x = case g x > of > Just y -> h y > _ -> error $ concat > ["Foo.f ", shows x "\n:\nImpossible happened:\n", > "g ", shows x " = Nothing.\n" > ]
wouldn't f x = maybe mistake h (g x) where mistake = error $ ("Foo.f "++). shows x. (":\nThis shouldn't happen:\ng "++). shows x $ " = Nothing.\n" be slightly tidier? Jón -- Jón Fairbairn Jon.Fairbairn at cl.cam.ac.uk _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users