[Haskell-cafe] tuples and Show in GHC

Keean Schupke k.schupke at imperial.ac.uk
Sun Mar 6 19:05:41 EST 2005

Daniel Fischer wrote:

>The Show instances for tuples aren't automatically derived, they are defined 
>in GHC.Show. So somewhere there must be an end, probably the author(s) 
>thought that larger tuples than quintuples aren't used often enough to 
>bother. That's not a principled reason but a practical one, but it's good 
>enough for me.
>If you need them frequently and don't want to define your own instances, 
>BTW, tuples are defined in Data.Tuple up to 62-tuples and Eq and Ord instances 
>are derived up to 15-tuples.
>In Hugs, apparently they are only provided up to quintuples.
Has there been any work done on declaring instances over all tuples? It 
seems the pattern occurs fairly often, and is quite simple to abstract.


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