If you have nested type, then it usually makes sense to have Show defined for the inside types, too, but it's not a requirement. Technically, only when you call 'show' for something in the data type you are defining Show for, *then* you need a Show instance defined for that inside-type.
On Fri, May 20, 2011 at 12:15 AM, Andrew Coppin <andrewcop...@btinternet.com > wrote: > On 19/05/2011 10:11 PM, Artyom Kazak wrote: > >> And I can declare an instance for (x, y) which does NOT implies (Show x): >> >> instance Show (x, y) where >> show _ = "I'm tuple! Hooray!" >> > > Ah. So it's a feature. > > Fortunately I refactored the program where this came up, so it's no longer > an issue. I just wanted to see whether or not it was a bug. > > PS. Wouldn't such an instance require FlexibleContexts or something? > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > -- Markus Läll
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
