Why can I print a tuple with 5 elements but not with 6 in Haskell?

Question

I tried printing the following tuple

(1,2,3,4,5,6)

which gave me the following error

ERROR - Cannot find "show" function for:
*** Expression : (1,2,3,4,5,6)
*** Of type    : (Integer,Integer,Integer,Integer,Integer,Integer)

But if I try it with the following tuple

(1,2,3,4,5)

everything works like a charm.

My guess is that Haskell only defines Show for tuples up to five elements (since a tuple of with 5 elements is apparently another type than a tuple with 6 elements). But somehow I am to stupid to find proof for that.

So my question is:

Why is this so, and how can I print a tuple with 6 elements (since it seems that I cannot put tuples in the head of an instance definition)?

Edit: I'm using Hugs

Answer 1

Here you go. Include this instance of Show for a 6-tuple

-- Tuples   -- for ref, def'n from the Prelude
{-
instance  (Show a, Show b) => Show (a,b)  where
  showsPrec p (x,y) = showChar '(' . shows x . showChar ',' .
                                   shows y . showChar ')'


instance  (Read a, Read b) => Read (a,b)  where
    readsPrec p       = readParen False
                        (\r -> [((x,y), w) | ("(",s) <- lex r,
                                             (x,t)   <- reads s,
                                             (",",u) <- lex t,
                                             (y,v)   <- reads u,
                                             (")",w) <- lex v ] )
-}
-- Other tuples have similar Read and Show instances

instance  (Show a, Show b, Show c, Show d, Show e, Show f) 
      => Show (a,b,c,d,e,f)  where
  showsPrec p (x1,x2,x3,x4,x5,x6) = showChar '(' . shows x1 . showChar ',' .
                                   shows x2 . showChar ',' . 
                                   shows x3 . showChar ',' .
                                   shows x4 . showChar ',' .
                                   shows x5 . showChar ',' .
                                   shows x6 . showChar ')'